No major differences in perinatal and maternal outcomes between uninterrupted embryo culture in time-lapse system and conventional embryo culture.

STUDY QUESTION: Is embryo culture in a closed time-lapse system associated with any differences in perinatal and maternal outcomes in comparison to conventional culture and spontaneous conception? SUMMARY ANSWER: There were no significant differences between time-lapse and conventional embryo culture in preterm birth (PTB, <37 weeks), low birth weight (LBW, >2500 g) and hypertensive disorders of pregnancy for singleton deliveries, the primary outcomes of this study. WHAT IS KNOWN ALREADY: Evidence from prospective trials evaluating the safety of time-lapse incubation for clinical use show similar embryo development rates, implantation rates, and ongoing pregnancy and live birth rates when compared to conventional incubation. Few studies have investigated if uninterrupted culture can alter risks of adverse perinatal outcomes presently associated with IVF when compared to conventional culture and spontaneous conceptions. STUDY DESIGN, SIZE, DURATION: This study is a Swedish population-based retrospective registry study, including 7379 singleton deliveries after fresh embryo transfer between 2013 and 2018 from selected IVF clinics. Perinatal outcomes of singletons born from time-lapse-cultured embryos were compared to singletons from embryos cultured in conventional incubators and 71 300 singletons from spontaneous conceptions. Main perinatal outcomes included PTB and LBW. Main maternal outcomes included hypertensive disorders of pregnancy (pregnancy hypertension and preeclampsia). PARTICIPANTS/MATERIALS, SETTING, METHODS: From nine IVF clinics, 2683 singletons born after fresh embryo transfer in a time-lapse system were compared to 4696 singletons born after culture in a conventional incubator and 71 300 singletons born after spontaneous conception matched for year of birth, parity, and maternal age. Patient and treatment characteristics from IVF deliveries were cross-linked with the Swedish Medical Birth Register, Register of Birth Defects, National Patient Register and Statistics Sweden. Children born after sperm and oocyte donation cycles and after Preimplantation Genetic testing cycles were excluded. Odds ratio (OR) and adjusted OR were calculated, adjusting for relevant confounders. MAIN RESULTS AND THE ROLE OF CHANCE: In the adjusted analyses, no significant differences were found for risk of PTB (adjusted OR 1.11, 95% CI 0.87-1.41) and LBW (adjusted OR 0.86, 95% CI 0.66-1.14) or hypertensive disorders of pregnancy; preeclampsia and hypertension (adjusted OR 0.99, 95% CI 0.67-1.45 and adjusted OR 0.98, 95% CI 0.62-1.53, respectively) between time-lapse and conventional incubation systems. A significantly increased risk of PTB (adjusted OR 1.31, 95% CI 1.08-1.60) and LBW (adjusted OR 1.36, 95% CI 1.08-1.72) was found for singletons born after time-lapse incubation compared to singletons born after spontaneous conceptions. In addition, a lower risk for pregnancy hypertension (adjusted OR 0.72 95% CI 0.53-0.99) but no significant difference for preeclampsia (adjusted OR 0.87, 95% CI 0.68-1.12) was found compared to spontaneous conceptions. Subgroup analyses showed that some risks were related to the day of embryo transfer, with more adverse outcomes after blastocyst transfer in comparison to cleavage stage transfer. LIMITATIONS, REASONS FOR CAUTION: This study is retrospective in design and different clinical strategies may have been used to select specific patient groups for time-lapse versus conventional incubation. The number of patients is limited and larger datasets are required to obtain more precise estimates and adjust for possible effect of additional embryo culture variables. WIDER IMPLICATIONS OF THE FINDINGS: Embryo culture in time-lapse systems is not associated with major differences in perinatal and maternal outcomes, compared to conventional embryo culture, suggesting that this technology is an acceptable alternative for embryo incubation. STUDY FUNDING/COMPETING INTEREST(S): The study was financed by a research grant from Gedeon Richter. There are no conflicts of interest for all authors to declare. TRIAL REGISTRATION NUMBER: N/A.

Puberty disorders among ART-conceived singletons: a Nordic register study from the CoNARTaS group.

STUDY QUESTION: Do ART-conceived children have an increased risk for puberty disorders? SUMMARY ANSWER: Both ART-conceived boys and girls had a higher risk of puberty disorders; early puberty was more common among girls and late puberty among boys. WHAT IS KNOWN ALREADY: Some physiological differences in growth and metabolism have been reported for ART-conceived children compared to non-ART-conceived children. Knowledge on pubertal development and disorders in ART-conceived children is limited. STUDY DESIGN, SIZE, DURATION: A register-based cohort study was carried out including data from 1985 to 2015. The Committee of Nordic Assisted Reproductive Technology and Safety (CoNARTaS) study population consists of all live and stillborn children, as well as their mothers, registered in the Medical Birth Registers during the study period in Denmark, Sweden, Finland and Norway. PARTICIPANTS/MATERIALS, SETTING, METHODS: A total of 122 321 ART-conceived singletons and 6 576 410 non-ART singletons born in Denmark (1994-2014), Finland (1990-2014), Norway (2002-2015) and Sweden (1985-2015) were included. Puberty disorders were defined using International Classification of Diseases and Related Health Problems (ICD)-9/ICD-10 codes and classified in the following groups: late puberty (6268/E30.0), early puberty (2591 and 2958/E30.1 and E30.8) and unspecified disorders (V212 and V579/E30.9 and Z00.3 as well as Z51.80 for Finland). The results in Cox regression were adjusted for maternal age, parity, smoking, gestational diabetes, chronic hypertension, hypertensive disorders during pregnancy and country, and further for either gestational age, birthweight, small for gestational age or large for gestational age. MAIN RESULTS AND THE ROLE OF CHANCE: There were 37 869 children with diagnoses related to puberty disorders, and 603 of them were born after ART. ART-conceived children had higher risks for early (adjusted hazard ratio (aHR) 1.45, 95% CI: 1.29-1.64) and late puberty (aHR 1.47, 95% CI: 1.21-1.77). Girls had more diagnoses related to early puberty (aHR 1.46, 95% CI: 1.29-1.66) and boys with late puberty (aHR 1.55, 95% CI: 1.24-1.95). LIMITATIONS, REASONS FOR CAUTION: Using reported puberty disorders with ICD codes in health care registers might vary, which may affect the numbers of cases found in the registers. Register data may give an underestimation both among ART and non-ART-conceived children, especially among non-ART children, who may not be as carefully followed as ART-conceived children. Adjustment for causes and duration of infertility, mothers' own puberty characteristics and BMI, as well as children's BMI, was not possible because data were not available or data were missing for the early years. It was also not possible to compare ART to non-ART siblings or to study the pubertal disorders by cause of subfertility owing to a small number of discordant sibling pairs and a large proportion of missing data on cause of subfertility. WIDER IMPLICATIONS OF THE FINDINGS: This large, register-based study suggests that ART-conceived children have a higher risk for puberty disorders. However, the mechanisms of infertility and pubertal onset are complex, and ART is a rapidly advancing field with various treatment options. Studying the pubertal disorders of ART-conceived offspring is a continuing challenge. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the Nordic Trial Alliance: a pilot project jointly funded by the Nordic Council of Ministers and NordForsk (71450), the Central Norway Regional Health Authorities (46045000), the Nordic Federation of Obstetrics and Gynaecology (NF13041, NF15058, NF16026 and NF17043), the Interreg Öresund-Kattegat-Skagerrak European Regional Development Fund (ReproUnion project), the Research Council of Norway's Centre of Excellence funding scheme (262700), the Swedish state under the agreement between the Swedish government and the county councils, the ALF-agreement (ALFGBG-70940) and FLUX Consortium 'Family Formation in Flux-Causes, Consequences and Possible Futures', funded by the Strategic Research Council, Academy of Finland (DEMOGRAPHY 345130). The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript. The authors have no conflicts of interest to disclose. TRIAL REGISTRATION NUMBER: N/A.

High birth weight and large-for-gestational-age in singletons born after frozen compared to fresh embryo transfer, by gestational week: a Nordic register study from the CoNARTaS group.

STUDY QUESTION: When do the differences in birth weights become apparent between singletons born after frozen embryo transfer (FET) and fresh embryo transfer (fresh ET)? SUMMARY ANSWER: Mean birth weights after FET become significantly higher starting from gestational week (GW) 33 among boys and from GW 34 among girls. WHAT IS KNOWN ALREADY: In recent years, there has been a steep rise in recorded FET treatments, enabling widespread use of elective single embryo transfer, thus reducing the risks associated with multiple gestations. However, singletons born after FET are heavier and there is a higher risk of large-for-gestational-age (LGA) (birth weight > 90 percentiles) compared to fresh ET. In contrast, risk of small-for-gestational-age (SGA, birth weight < 10 percentiles) is lower in singletons born after FET compared to fresh ET. The reasons, timing and consequences of these differences remain largely unclear. There is limited evidence about whether this difference in growth develops before the last trimester of pregnancy. STUDY DESIGN, SIZE, DURATION: This retrospective Nordic register-based cohort study compared singletons born after FET (n = 17 500) to singletons born after fresh ET (n = 69 510) and natural conception (NC, n = 3 311 588). All live born singletons born between the years 2000 and 2015 in Denmark, Norway and Sweden at gestational age ≥22 weeks were included from the population-based Committee of Nordic ART and Safety (CoNARTaS) study population. PARTICIPANTS/MATERIALS, SETTING, METHODS: Children born after FET were compared to those born after fresh ET and NC for mean birth weight and proportion of LGA and SGA for each GW at birth. Chi-square test and tests for relative proportions were used to compare categorical variables and Student's t-test was used to compare continuous variables. Adjusted odds ratios (aORs) for LGA and SGA were calculated using logistic regressions, adjusting for year of birth, maternal age, parity, BMI, chronic hypertension, diabetes, smoking and offspring sex. MAIN RESULTS AND THE ROLE OF CHANCE: Mean birth weights were significantly higher after FET compared to fresh ET starting from GW 33 (range from 75 g to 228 g by week) for boys and starting from GW 34 (range from 90 g to 236 g by week) for girls. Boys born after FET had a significantly higher proportion of LGA (11.0-15.1%) at birth between GW 36 and 42, compared to those born after fresh ET (7.1-9.4%) (range from P < 0.001 to P = 0.048 by week). For girls born after FET, the difference was seen between GW 37 and 42 (10.6-13.4%) compared to those born after fresh ET (6.6-8.0%) (range from P < 0.001 to P = 0.009 by week).The proportion of SGA was significantly lower among boys born after FET (7.6-8.7%) compared to fresh ET (11.9-13.6%) between GW 36 and 42 (range from P < 0.001 to P = 0.016 by week). For girls born after FET, the difference was seen between GW 38 and 42 (7.0-9.3%) compared to those born after fresh ET (13.0-14.6%) (P < 0.001). The proportion of LGA (12.3-15.1%) was significantly higher for boys born after FET between GW 38 and 41 (P < 0.001) and for girls born after FET (12.6-13.4%) between GW 37 and 40 (range from P < 0.001 to P = 0.018 by week), compared to naturally conceived boys (9.7-9.9%) and girls (9.0-10.0%). All singletons born after FET had a higher risk of LGA compared to singletons born after fresh ET (aOR 1.87, 95% CI 1.76-1.98) and singletons born after NC (aOR 1.28, 95% CI 1.22-1.35). LIMITATIONS, REASONS FOR CAUTION: There may be residual confounding factors that we were not able to control for, most importantly the causes of preterm birth, which may also influence foetal growth. A further limitation is that we have no knowledge on growth patterns between implantation and GW 22. Finally, the number of children born extremely preterm or post-term was limited even in this large study population. WIDER IMPLICATIONS OF THE FINDINGS: This is, to date, the largest study on birth weights among preterm and term ART singletons with a population-based design and NC control group. The results suggest that the freeze-thaw process is associated with higher birthweights and greater risk of LGA at least in the last trimester of pregnancy. This is an important aspect of the safety profile of ART. More research is needed on the long-term outcome of these children. STUDY FUNDING/COMPETING INTEREST(S): The CoNARTaS collaboration has received the following funding: the Nordic Trial Alliance: a pilot project jointly funded by the Nordic Council of Ministers and NordForsk [71450], the Central Norway Regional Health Authorities [46045000], the Norwegian Cancer Society [182356-2016], the Nordic Federation of Obstetrics and Gynaecology [NF13041, NF15058, NF16026 and NF17043], the Interreg Öresund-Kattegat-Skagerrak European Regional Development Fund (ReproUnion project) and the Research Council of Norway's Centre of Excellence funding scheme [262700]. None of the authors have any competing interests to declare. TRIAL REGISTRATION NUMBER: ISRCTN11780826.

Type 1 diabetes in children born after assisted reproductive technology: a register-based national cohort study.

STUDY QUESTION: Do children born after assisted reproductive technology (ART) have an increased risk of developing type 1 diabetes? SUMMARY ANSWER: Children born after ART were found to have an increased risk of type 1 diabetes in the unadjusted analysis, while after adjustment this association was only significant in children born after frozen embryo transfer. WHAT IS KNOWN ALREADY?: Some studies raise concerns as to whether fertility treatments may influence long-term morbidity in children born after ART. Elevated blood pressure and altered glucose metabolism have been found after ART in a few studies. STUDY DESIGN, SIZE, DURATION: A register-based national cohort study that included all children born in Sweden between 1985 and 2015-in total, 3 138 540 children-was carried out. PARTICIPANTS/MATERIAL, SETTING, METHODS: The study was population-based and all live-born singleton children born after ART (n = 47 938) or spontaneous conception (SC) (n = 3 090 602) were included. The ART cohort comprised 36 727 children born after fresh embryo transfer and 11 211 children born after frozen embryo transfer. Several national registries were used together with data from Statistics Sweden. MAIN RESULTS AND THE ROLE OF CHANCE: In total, 202 children born after ART and 17 916 children born after SC developed type 1 diabetes, corresponding to 43.4 and 35.5 per 100 000 person-years at risk (hazard ratio [HR] 1.23; 95% confidence interval [CI], 1.07 to 1.42). Mean follow-up was 9.7 (SD 6.4) years for ART children and 16.3 (SD 9.2) years for SC children. After adjustment for calendar year of birth, HR for type 1 diabetes was 1.13; 95% CI, 0.98-1.30. After further adjustment for sex, maternal age, country of birth, educational level, smoking and parental diabetes, HR was 1.07; 95% CI, 0.93-1.23. In subgroup analyses, an association was found between frozen embryo transfer and type 1 diabetes (adjusted HR 1.52; 95% CI, 1.08-2.14 and 1.41; 95% CI, 1.05-1.89 for frozen versus fresh and frozen versus SC, respectively). When comparing intracytoplasmic sperm injection to in vitro fertilization, no difference was found (adjusted HR 1.08; 95% CI, 0.77-1.51). LIMITATIONS, REASONS FOR CAUTION: Limitations were the missing data and residual confounding caused by unknown confounders. Furthermore, the control group consisted of all children not conceived by ART and not non-ART children from subfertile mothers. The study was also performed in only singletons and not in the total ART population. WIDER IMPLICATIONS OF THE FINDINGS: Type 1 diabetes is a serious disease, affecting human life in several ways, including risk of serious complications, reduced life span and a life-long treatment. Our results are generally reassuring, showing no increase in diabetes in ART children compared to children born after SC after adjustment for relevant confounders. The observation of an association between children born after frozen embryo transfer and type 1 diabetes, although based on subgroup analyses with a limited number of children and modest in size, is however a reason for concern. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by Nordforsk 71450, the Swedish state under the agreement between the Swedish government and the county councils, the ALF-agreement 70940, and the Hjalmar Svensson Foundation. The authors have no competing interests. TRIAL REGISTRATION NUMBER: ISRCTN 11780826.

Imprinting disorders in children born after ART: a Nordic study from the CoNARTaS group.

STUDY QUESTION: Is the risk of imprinting disorders increased in children conceived after ART? SUMMARY ANSWER: We found an adjusted odds ratio (AOR) of 2.84 [95% CI: 1.34-6.01] for Beckwith-Wiedemann syndrome in ART children, while the risk of Prader-Willi syndrome, Silver-Russell syndrome or Angelman syndrome was not increased in children conceived after ART. WHAT IS KNOWN ALREADY: Earlier studies, most of them small, have suggested an association between ART and imprinting disorders. STUDY DESIGN, SIZE, DURATION: This was a binational register-based cohort study. All children conceived by ART in Denmark (n = 45 393, born between 1994 and 2014) and in Finland (n = 29 244, born between 1990 and 2014) were identified. The full background populations born during the same time periods in the two countries were included as controls. Odds ratios of imprinting disorders in ART children compared with naturally conceived (NC) children were calculated. The median follow-up time was 8 years and 9 months for ART children and 11 years and 9 months for NC children. PARTICIPANTS/MATERIALS, SETTING, METHODS: From the national health registries in Denmark and Finland, we identified all children diagnosed with Prader-Willi syndrome (n = 143), Silver-Russell syndrome (n = 69), Beckwith-Wiedemann syndrome (n = 105) and Angelman syndrome (n = 72) born between 1994/1990 and 2014, respectively. MAIN RESULTS AND THE ROLE OF CHANCE: We identified a total of 388 children diagnosed with imprinting disorders; 16 of these were conceived after ART. The overall AOR for the four imprinting disorders in ART children compared with NC children was 1.35 [95% CI: 0.80-2.29], but since eight ART children were diagnosed with Beckwith-Wiedemann syndrome, the AOR for this specific imprinting disorder was 2.84 [95% CI: 1.34-6.01]. The absolute risk of Beckwith-Wiedemann syndrome in children conceived after ART was still low: 10.7 out of 100 000 newborns. The risks of Prader-Willi syndrome, Silver-Russell syndrome and Angelman syndrome were not increased in children conceived after ART. LIMITATIONS, REASONS FOR CAUTION: Imprinting disorders are rare events and our results are based on few ART children with imprinting disorders. The aetiology is complex and only partly clarified, and the clinical diagnoses are challenged by a broad phenotypic spectrum. WIDER IMPLICATIONS OF THE FINDINGS: In the existing studies, results on the risk of imprinting disorders in children conceived after ART are ambiguous. This study adds that the risk of imprinting disorders in ART children is very small and perhaps restricted to Beckwith-Wiedemann syndrome. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the Nordic Trial Alliance: a pilot project jointly funded by the Nordic Council of Ministers and NordForsk (grant number: 71450), the Nordic Federation of Obstetrics and Gynecology (grant numbers: NF13041, NF15058, NF16026 and NF17043) and the Interreg Öresund-Kattegat-Skagerak European Regional Development Fund (ReproUnion project). The authors have no conflicts of interest related to this work. TRIAL REGISTRATION NUMBER: N/A.

Obstetric and perinatal risks in 4601 singletons and 884 twins conceived after fresh blastocyst transfers: a Nordic study from the CoNARTaS group.

STUDY QUESTION: Are obstetric and perinatal outcomes in pregnancies after fresh blastocyst transfer (BT) comparable with those born after fresh cleavage stage transfer (CT) and spontaneous conception (SC)? SUMMARY ANSWER: Fresh BT is associated with a higher risk of placental and perinatal complications. WHAT IS KNOWN ALREADY: BT optimizes the selection of top-quality embryos and increases pregnancy and live birth rates per transfer compared to CT. However, concerns have been raised as extended culture duration may increase obstetric complications and impair perinatal outcomes. Previous studies have shown a higher risk of preterm birth (PTB) among infants born after BT compared with CT. Pregnancies after BT are also prone to a higher risk of same-sex twins after single embryo transfer (SET). STUDY DESIGN, SIZE, DURATION: A retrospective register-based cohort study used data from Denmark, Norway and Sweden including three cohorts: 56 557 singletons and 16 315 twins born after fresh IVF/ICSI cycles and 2 808 323 SC singletons in Denmark (birth years 1997-2014), Norway (2010-2015) and Sweden (2002-2015). Of the fresh IVF/ICSI singletons, 4601 were born after BT and 51 956 after CT. The twin cohort consisted of 884 fresh IVF/ICSI children born after BT and 15 431 fresh IVF/ICSI children born after CT. PARTICIPANTS/MATERIALS, SETTING, METHODS: Data were obtained from a large Nordic cohort of children born after ART and SC initiated by the Committee of Nordic ART and Safety (CoNARTaS). The CoNARTaS cohort was established by cross-linking National ART-, Medical Birth-, and National Patients Registers using the unique personal identification number, allocated to every citizen in the Nordic countries. Obstetric and perinatal outcomes after BT, CT and SC were compared using logistic regression analysis. For perinatal outcomes, we calculated gestational age based on the date of oocyte pick-up (OPU) and in sensitivity analyses on data from Denmark and Norway, we also calculated gestational age based on the second-trimester ultrasonography (US) scan. Risk of pregnancies with same-sex twins after SET was used as a proxy for risk of monozygotic twins. Adjustments were made for child's sex, birth year, parity (0 or >1), maternal age, body mass index, smoking, educational level, fertilization method (IVF/ICSI), the number of aspirated oocytes, SET and country. Information on educational level and the number of aspirated oocytes was not available for Norway. Children born after frozen embryo transfer were not included. The birth cohorts were restricted according to the year in which BT was introduced in the different countries. MAIN RESULTS AND THE ROLE OF CHANCE: A higher risk of placenta previa was found in singleton pregnancies after BT compared with CT (adjusted odds ratio [aOR] 2.11 [95% CI 1.76; 2.52]). Singletons born after BT had a higher risk of PTB (aOR 1.14 [95% CI 1.01; 1.29]) compared with CT singletons, when estimated based on OPU. Furthermore, an altered male/female ratio (aOR 1.13 [95% CI 1.06; 1.21]) with more males following BT compared with CT was seen. Risk of same-sex twins after SET was higher after single BT compared with single CT (aOR 1.94 [95% CI 1.42; 2.60]). LIMITATIONS, REASONS FOR CAUTION: Residual confounding cannot be excluded, in particular related to duration and cause of infertility that we could not adjust for due to lack of reliable data. WIDER IMPLICATIONS OF THE FINDINGS: Extended embryo culture to the blastocyst stage has the potential to compromise obstetric and perinatal outcomes in fresh cycles. These results are important since an increasing number of IVF/ICSI treatments are performed as BT. STUDY FUNDING/COMPETING INTEREST(S): NORDFORSK (project no: 71450). The Research Fund of Rigshospitalet, Copenhagen University Hospital. ReproUnion Collaborative study, co-financed by the European Union, Interreg V ÖKS. Grants from Swedish state under the agreement between the Swedish government and the county councils, the ALF-agreement (LUA/ALF 70940), Hjalmar Svensson Research Foundation. The Research Council of Norway through its Centres of Excellence funding scheme, project number 262700. None of the authors has any conflicts of interests to declare regarding this study. TRIAL REGISTRATION NUMBER: ISRCTN11780826.

The addition of anti-Müllerian hormone in an algorithm for individualized hormone dosage did not improve the prediction of ovarian response-a randomized, controlled trial.

Study question: Does the addition of anti-Müllerian hormone (AMH) to a conventional dosage regimen, including age, antral follicle count (AFC) and BMI, improve the rate of targeted ovarian response, defined as 5-12 oocytes after IVF? Summary answer: The addition of AMH did not alter the rate of targeted ovarian response, 5-12 oocytes, or decreased the rate of ovarian hyperstimulation syndrome (OHSS) or cancelled cycles due to poor ovarian response. What is known already: Controlled ovarian hyperstimulation (COH) in connection with IVF is sometimes associated with poor ovarian response resulting in low pregnancy and live birth rates or leading to cycle cancellations, but also associated with excessive ovarian response, causing an increased risk of OHSS. Even though it is well-established that both AMH and AFC are strong predictors of ovarian response in IVF, few randomized trials have investigated their impact on achieving an optimal number of oocytes. Study design, size and duration: Between January 2013 and May 2016, 308 patients starting their first IVF treatment were randomly assigned, using a computerized randomization program with concealed allocation of patients and in the proportions of 1:1, to one of two dosage algorithms for decisions on hormone starting dose, an algorithm, including AMH, AFC, age and BMI (intervention group), or an algorithm, including only AFC, age and BMI (control group). The study was blinded to patients and treating physicians. Participants/materials, setting, methods: Women aged >18 and <40 years, with a BMI above 18.0 and below 35.0 kg/m2 starting their first IVF cycle where standard IVF was planned, were eligible. All patients were treated with a GnRH agonist protocol and recombinant FSH was used for stimulation. The study was performed as a single-centre study at a large IVF unit at a university hospital. Main results and the role of chance: The rate of patients having the targeted number of oocytes retrieved was 81/152 (53.3%) in the intervention group versus 96/155 (61.9%) in the control group (P = 0.16, difference: -8.6, 95% CI: -20.3; 3.0). Cycles with poor response (<5 oocytes) were more frequent in the AMH group, 39/152 (25.7%) versus the non-AMH group, 17/155 (11.0%) (P < 0.01), while the number of cancelled cycles due to poor ovarian response did not differ 7/152 (4.6%) and 4/155 (2.6%) (P = 0.52). An excessive response (>12 oocytes) was seen in 32/152 (21.1%) and 42/155 (27.1%) patients, respectively (P = 0.27). Moderate or severe OHSS was observed among 5/152 (3.3%) and 6/155 (3.9%) patients, respectively (P = 1.0). Live birth rates were 48/152 (31.6%) and 42/155 (27.1%) per started cycle. Limitations, reasons for caution: The categorization of AMH values in predicted low, normal and high responders was originally established using the Diagnostic Systems Laboratories assay and was translated to more recently released assays, lacking international standards and well-established reference intervals. The interpretation of AMH values between different assays should therefore be made with some caution. Wider implications of the findings: An individualised dosage regimen including AMH compared with a non-AMH dosage regimen in an unselected patient population did not alter the number of women achieving the targeted number of oocytes, or the cancellation rate due to poor response or the occurrence of moderate/severe OHSS. However, this study cannot answer the question if using an algorithm for dose decision of FSH is superior to a standard dose and neither which ovarian reserve test is the most effective. Study funding/competing interest: Financial support was received through Sahlgrenska University Hospital (ALFGBG-70 940) and unrestricted grants from Ferring Pharmaceuticals and the Hjalmar Svensson Research Foundation. None of the authors declares any conflict of interest. Trial registration: The study was registered at www.clinicaltrials.gov NCT02013973. Trial registration date: 6 December 2013. DATE OF FIRST PATIENT RANDOMIZED: 14 January 2013.

Obstetric and neonatal complications in pregnancies conceived after oocyte donation: a systematic review and meta-analysis.

BACKGROUND: Approximately 50 000 oocyte donation (OD) treatment cycles are now performed annually in Europe and the US. OBJECTIVES: To ascertain whether the risk of adverse obstetric and perinatal/neonatal outcomes is higher in pregnancies conceived by OD than in pregnancies conceived by conventional in-vitro fertilisation (IVF)/intracytoplasmic sperm injection (ICSI) or spontaneously. SEARCH STRATEGY: A systematic search was performed in the PubMed, Cochrane and Embase databases from 1982-2016. Primary outcomes were hypertensive disorders of pregnancy, pre-eclampsia (PE), gestational diabetes mellitus, postpartum haemorrhage, caesarean section, preterm birth, low birthweight and small for gestational age. SELECTION CRITERIA: Inclusion criteria were original studies including at least five OD pregnancies with a control group of pregnancies conceived by conventional IVF/ICSI or spontaneous conception, and case series with >500 cases reporting one or more of the selected complications. Studies not adjusting for plurality were excluded. DATA COLLECTION AND ANALYSIS: Thirty-five studies met the inclusion criteria. A random-effects model was used for the meta-analyses. MAIN RESULTS: For OD pregnancies versus conventional IVF/ICSI pregnancies the risk of PE was adjusted odds ratio (AOR) 2.11 (95% CI, 1.42-3.15) in singleton and AOR 3.31 (95% CI, 1.61-6.80) in multiple pregnancies. The risks of preterm birth and low birthweight in singletons were AOR 1.75 (95% CI, 1.39-2.20) and 1.53 (95% CI, 1.16-2.01), respectively. CONCLUSIONS: OD conceptions are associated with adverse obstetric and neonatal outcomes. To avoid the additional increase in risk from multiplicity, single-embryo transfer should be the choice of option in OD cycles. TWEETABLE ABSTRACT: Oocyte donation pregnancies have increased risk of a range of obstetric and neonatal complications.

Classification of pregnancies of unknown location according to four different hCG-based protocols.

STUDY QUESTION: How do four protocols based on serial human chorionic gonadotropin (hCG) measurements perform when classifying pregnancies of unknown location (PULs) as low or high risk of being an ectopic pregnancy (EP)? SUMMARY ANSWER: The use of cut-offs in hCG level changes published by NICE, and a logistic regression model, M4, correctly classify more PULs as high risk, compared with two other protocols. WHAT IS KNOWN ALREADY: A logistic regression model, M4, based on the mean of two consecutive hCG values and the hCG ratio (hCG 48 h/hCG 0 h) that classify PULs into low- and high-risk groups for triage purposes, identifies more EPs than a protocol using the cut-offs between a 13% decline and a 66% rise in hCG levels over 48 h. STUDY DESIGN, SIZE, DURATION: A retrospective comparative study of four different hCG-based protocols classifying PULs as low or high risk of being an EP was performed at a gynaecological emergency unit over 3 years. PARTICIPANTS/MATERIALS, SETTING, METHOD: We identified 915 women with a PUL. Initial transvaginal ultrasonography (TVS) findings categorised 187 of the PULs as probable intrauterine pregnancies (IUPs) and 16 as probable EPs. The rate of change in hCG levels over 48 h was calculated for each patient and subjected to three different hCG threshold intervals and a logistic regression model for outcome prediction. Each PUL was subsequently dichotomised to either low-risk (i.e. failed PUL/IUP) or high-risk (i.e. EP) classification, which allowed us to compare the diagnostic performance. In 'Protocol A', a PUL was classified as low risk if >13% hCG level decline or >66% hCG level rise was achieved; otherwise, the PUL was classified as high risk of being an EP. 'Protocol B' classified a PUL as low or high risk using cut-offs of 35-50% declining hCG levels and of 53% rising hCG levels. Similarly, 'Protocol C' used hCG level cut-offs published by NICE, 50% for declining hCG levels and 63% for rising hCG levels. Finally, if a logistic regression model 'Protocol M4' calculated a ≥5% risk of the PUL being an EP, it was classified as high risk, and otherwise the PUL was classified as low risk. When the time interval between two hCG measurements failed to meet an exact 48 h, extrapolation and interpolation of hCG values was made, using log linear transformation. MAIN RESULTS AND THE ROLE OF CHANCE: Protocols A, B, C and M4 classified 73, 66, 55 and 56% of PULs as low risk. The sensitivity for protocols A, B, C and M4 was 68% (95% confidence interval (CI) 61-75%), 81% (74-86%), 87% (82-92%) and 88% (83-93%), respectively. The specificity was 82% (80-85%), 77% (74-80%), 66% (62-69%) and 67% (63-70%) for protocols A, B, C and M4, respectively. All comparisons of sensitivity and specificity between the protocols were statistically significant except for protocol C versus protocol M4. In protocol C, 87% (66-97%) of misclassified EPs had rising hCG levels, compared with 19% (6-41%) for protocol M4 (P < 0.01). In a secondary analysis excluding probable IUPs and probable EPs, the results for 712 PULs were analysed. The sensitivity subsequently remained stable for all protocols. Protocol M4 reached a 78% (74-81%) specificity, which was significantly higher than 70% (66-74%) for protocol C (P = 0.01) and protocol M4 classified 63% of PULs as low risk compared with 58% for protocol C. LIMITATIONS, REASONS FOR CAUTION: The retrospective design of the study is a limitation. The results are derived from a population where laparoscopy played an important role in PUL management and diagnosis of EPs, although it did reflect real clinical practice. Although we tried to adhere to definitions of PUL and final outcomes as in previous studies and a recent consensus statement, potential differences in this regard must be acknowledged. Where the time interval between two serial hCG measurements deviated from 48 h we estimated 48 h hCG values. WIDER IMPLICATIONS OF THE FINDINGS: A logistic regression model, M4, classifies more PULs correctly as low risk in a selected PUL population without probable IUPs and EPs and identifies as many EPs, in comparison with the cut-offs available in the NICE guideline. This advantage for model M4 may result in a reduction of unnecessary follow-up visits, when fewer low-risk PULs are misclassified as high risk. These findings, however, ought to be clarified in a randomised controlled trial. STUDY FUNDING/COMPETING INTERESTS: The study was supported by LUA/ALF grant No. 70940. There are no competing interests.

No benefit of culturing embryos in a closed system compared with a conventional incubator in terms of number of good quality embryos: results from an RCT.

STUDY QUESTION: Does culture in a closed system result in an increased number of good quality embryos (GQE) on Day 2 compared with culture in a conventional system? SUMMARY ANSWER: Culture in a closed system up to 2 days after microinjection results in similar embryo development and morphological quality compared with culture in a conventional incubation system. WHAT IS KNOWN ALREADY: Time-lapse imaging (TLI) incubators are rapidly being introduced into IVF laboratories worldwide, despite the lack of large prospective randomized trials demonstrating improvement in embryo development or pregnancy rates. STUDY DESIGN, SIZE, DURATION: A randomized controlled trial including 364 patients (365 cycles) was conducted between May 2010 and February 2014. After oocyte collection, randomization was carried out and all of a patients' oocytes were allocated to culture in either a conventional incubator or a closed incubator system in proportion 1:2 until embryo transfer on Day 2. A total of 1979 oocytes were injected and cultured in the closed system, and 1000 in the standard incubator. The primary end-point was the number of GQE in the two groups. PARTICIPANTS/MATERIALS, SETTINGS, METHODS: In total, 364 patients undergoing their first IVF cycle using ICSI, where at least one oocyte was retrieved, were randomized in a university hospital setting. Two hundred and forty patients were randomized for culture in a closed system and 124 patients for culture in the conventional incubator system (control group). Embryo assessments and final morphological scoring before transfer and cryopreservation were carried out at the same time points for embryos cultured in the conventional incubator and in the closed system. MAIN RESULTS AND THE ROLE OF CHANCE: There was no significant difference in the mean ± SD number of GQEs between groups: 2.41 ± 2.27 for the closed system group and 2.19 ± 1.82 for the control group (P = 0.34, difference 0.23, 95% confidence interval 0.69; -0.24). No significant differences were found in the number of 4-cell embryos, implantation-, pregnancy- or ongoing pregnancy rates. A significantly higher miscarriage rate was found in the TLI group compared with the control group (33.3 and 10.2%, P = 0.01). LIMITATIONS, REASONS FOR CAUTION: Culture media, temperature and gas levels were similar in the open and closed incubator systems, but different culture dishes were used. Culturing embryos for longer time period (to the blastocyst stage) may give different results. Only ICSI patients were included, which may limit the generalizability of the results. Finally, the number of GQEs on Day 2 was used as a surrogate outcome for live birth. WIDER IMPLICATIONS OF THE FINDINGS: The results are consistent with other, smaller randomized trials showing no difference in embryo quality when comparing culture in a conventional incubator with that of a closed TLI incubator system.

Risk of hypertensive disorders in pregnancies following assisted reproductive technology: a cohort study from the CoNARTaS group.

STUDY QUESTION: Is the risk of hypertensive disorders in pregnancies conceived following specific assisted reproductive technology (ART) procedures different from the risk in spontaneously conceived (SC) pregnancies? SUMMARY ANSWER: ART pregnancies had a higher risk of hypertensive disorders, in particular following cryopreservation, with the highest risk seen in twin pregnancies following frozen-thawed cycles. WHAT IS KNOWN ALREADY: The risk of hypertensive disorders is higher in ART pregnancies than in SC pregnancies. The increased risk may be partly explained by multiple pregnancies and underlying infertility, but a contribution from specific ART procedures has not been excluded. STUDY DESIGN, SIZE, DURATION: Population-based cohort study, including sibling design with nationwide data from health registers in Sweden, Denmark and Norway. PARTICIPANTS/MATERIALS, SETTING, METHODS: All registered ART pregnancies and a sample of SC pregnancies with gestational age ≥22 weeks from 1988 to 2007 were included. ART singleton pregnancies (n = 47 088) were compared with SC singleton pregnancies (n = 268 599), matched on parity and birth year. ART twin pregnancies (n = 10 918) were compared with SC twin pregnancies (46 674). We used logistic regression to estimate adjusted odds ratios and risk differences for hypertensive disorders in pregnancies following IVF, ICSI and fresh or frozen-thawed cycles. We also compared fresh and frozen-thawed cycles within mothers who had conceived following both procedures using conditional logistic regression (sibling analysis). MAIN RESULTS AND THE ROLE OF CHANCE: Hypertensive disorders were reported in 5.9% of ART singleton and 12.6% of ART twin pregnancies. Comparing singleton pregnancies, the risk of hypertensive disorders was higher after all ART procedures. The highest risk in singleton pregnancies was seen after frozen-thawed cycles [risk 7.0%, risk difference 1.8%, 95% confidence interval (CI) 1.2-2.8]. Comparing twin pregnancies, the risk was higher after frozen-thawed cycles (risk 19.6%, risk difference 5.1%, 95% CI 3.0-7.1), but not after fresh cycles. In siblings, the risk was higher after frozen-thawed cycles compared with fresh cycles within the same mother (odds ratio 2.63, 95% CI 1.73-3.99). There were no clear differences in risk for IVF and ICSI. LIMITATIONS, REASONS FOR CAUTION: The number of ART siblings in the study was limited. Residual confounding cannot be excluded. In addition, we did not have information on all SC pregnancies in each woman's history, and could therefore not compare risk in ART versus SC pregnancies in the same mother. WIDER IMPLICATIONS OF THE FINDINGS: Pregnancies following frozen-thawed cycles have a higher risk of hypertensive disorders, also when compared with fresh cycle pregnancies by the same mother. The safety aspects in frozen-thawed cycles merit further attention. STUDY FUNDING/COMPETING INTERESTS: Funding was received from the European Society for Human Reproduction and Embryology, the University of Copenhagen, the Danish Agency for Science, Technology and Innovation, the Nordic Federation of Societies of Obstetrics and Gynecology and the Liaison Committee between the Central Norway Regional Health Authority and the Norwegian University of Science and Technology. None of the authors has any competing interests to declare.

Trends in perinatal health after assisted reproduction: a Nordic study from the CoNARTaS group.

STUDY QUESTIONS: Has the perinatal outcome of children conceived after assisted reproductive technology (ART) improved over time? SUMMARY ANSWER: The perinatal outcomes in children born after ART have improved over the last 20 years, mainly due to the reduction of multiple births. WHAT IS KNOWN AND WHAT THIS PAPER ADDS: A Swedish study has shown a reduction in unwanted outcomes over time in children conceived after ART. Our analyses based on data from more than 92 000 ART children born in four Nordic countries confirm these findings. STUDY DESIGN: Nordic population-based matched cohort study with ART outcome and health data from Denmark, Finland, Norway and Sweden. PARTICIPANTS, SETTING AND METHODS: We analysed the perinatal outcome of 62 379 ART singletons and 29 758 ART twins, born from 1988 to 2007 in four Nordic countries. The ART singletons were compared with a control group of 362 215 spontaneously conceived singletons. Twins conceived after ART were compared with all spontaneously conceived twins (n = 122 763) born in the Nordic countries during the study period. The rates of several adverse perinatal outcomes were stratified into the time periods: 1988-1992; 1993-1997; 1998-2002 and 2003-2007 and presented according to multiplicity. MAIN RESULTS AND ROLE OF CHANCE: For singletons conceived after ART, a remarkable decline in the risk of being born preterm and very preterm was observed. The proportion of ART singletons born with a low and very low birthweight also decreased. Finally, the stillbirth and infant death rates have declined among both ART singletons and twins. Throughout the 20 year period, fewer ART twins were stillborn or died during the first year of life compared with spontaneously conceived twins, presumably due to the lower proportion of monozygotic twins among the ART twins. LIMITATIONS, REASONS FOR CAUTION: We were not able to adjust for some potential confounders such as BMI, smoking, length or cause of infertility. The Nordic ART populations have changed over time, and in recent years, both less as well as severely reproductive ill couples are being treated. This may have affected the observed trends. WIDER IMPLICATIONS OF THE FINDINGS: It is assuring that data from four countries confirm an overall improvement over time in the perinatal outcomes of children conceived after ART. Furthermore, data show the beneficial effect of single embryo transfer, not only in regard to lowering the rate of multiples but also concerning the health of singletons. STUDY FUNDING/COMPETING INTERESTS: The European Society for Human Reproduction and Embryology (ESHRE), the University of Copenhagen and the Danish Agency for Science, Technology and Innovation has supported the project. The CoNARTaS group has received travel and meeting funding from the Nordic Federation of Obstetrics and Gynecology (NFOG). None of the authors has any competing interests to declare.

Obstetric and perinatal risks after the use of donor sperm: A systematic review and meta-analysis.

Donor sperm is widely used in infertility treatments. The purpose of the study was to investigate, whether use of donor sperm in intrauterine insemination (IUI) or in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) treatments affect maternal and perinatal risks compared with spontaneously conceived pregnancies or use of partner sperm in IUI, IVF or ICSI. We provide a systematic review and meta-analyses on the most clinically relevant obstetric and perinatal outcomes after use of donor sperm compared with partner sperm: hypertensive disorders of pregnancy, preeclampsia, low birth weight, and preterm birth. Our meta-analyses showed an increased risk for preeclampsia (pooled adjusted odds ratio (aOR) 1.77, 95% CI 1.26-2.48) and hypertensive disorders of pregnancy (pooled aOR 1.55, 95%, CI 1.20-2.00) in pregnancies resulting from IUI with donor sperm compared with IUI with partner sperm. No increased risk was seen for low birth weight or preterm birth after the use of donor sperm in IUI compared with the use of partner sperm in IUI. Subgroup analysis for singletons only did not change these results. The meta-analysis on low birth weight showed a lower risk after in IVF with donor sperm compared with IVF with partner sperm (pooled aOR 0.89, 95% CI 0.83-0.94). For hypertensive disorders of pregnancy, preeclampsia and preterm birth, no difference was found between IVF with donor sperm vs. partner sperm. Patients need to be informed about the moderately increased risk of hypertensive disorders of pregnancy and preeclampsia in pregnancies after IUI with donor sperm.

ART in Europe, 2018: results generated from European registries by ESHRE.

STUDY QUESTION: What are the data and trends on ART and IUI cycle numbers and their outcomes, and on fertility preservation (FP) interventions, reported in 2018 as compared to previous years? SUMMARY ANSWER: The 22nd ESHRE report shows a continued increase in reported numbers of ART treatment cycles and children born in Europe, a decrease in transfers with more than one embryo with a further reduction of twin delivery rates (DRs) as compared to 2017, higher DRs per transfer after fresh IVF or ICSI cycles (without considering freeze-all cycles) than after frozen embryo transfer (FET) with higher pregnancy rates (PRs) after FET and the number of reported IUI cycles decreased while their PR and DR remained stable. WHAT IS KNOWN ALREADY: ART aggregated data generated by national registries, clinics or professional societies have been gathered and analysed by the European IVF-monitoring Consortium (EIM) since 1997 and reported in 21 manuscripts published in Human Reproduction and Human Reproduction Open. STUDY DESIGN SIZE DURATION: Data on medically assisted reproduction (MAR) from European countries are collected by EIM for ESHRE on a yearly basis. The data on treatment cycles performed between 1 January and 31 December 2018 were provided by either national registries or registries based on initiatives of medical associations and scientific organizations or committed persons of 39 countries. PARTICIPANTS/MATERIALS SETTING METHODS: Overall, 1422 clinics offering ART services in 39 countries reported a total of more than 1 million (1 007 598) treatment cycles for the first time, including 162 837 with IVF, 400 375 with ICSI, 309 475 with FET, 48 294 with preimplantation genetic testing, 80 641 with egg donation (ED), 532 with IVM of oocytes and 5444 cycles with frozen oocyte replacement (FOR). A total of 1271 institutions reported data on IUI cycles using either husband/partner's semen (IUI-H; n = 148 143) or donor semen (IUI-D; n = 50 609) in 31 countries and 25 countries, respectively. Sixteen countries reported 20 994 interventions in pre- and post-pubertal patients for FP including oocyte, ovarian tissue, semen and testicular tissue banking. MAIN RESULTS AND THE ROLE OF CHANCE: In 21 countries (21 in 2017) in which all ART clinics reported to the registry, 410 190 treatment cycles were registered for a total population of ∼ 300 million inhabitants, allowing a best estimate of a mean of 1433 cycles performed per million inhabitants (range: 641-3549). Among the 39 reporting countries, for IVF, the clinical PR per aspiration slightly decreased while the PR per transfer remained similar compared to 2017 (25.5% and 34.1% in 2018 versus 26.8% and 34.3% in 2017). In ICSI, the corresponding rates showed similar evolutions in 2018 compared to 2017 (22.5% and 32.1% in 2018 versus 24.0% and 33.5% in 2017). When freeze-all cycles were not considered for the calculations, the clinical PRs per aspiration were 28.8% (29.4% in 2017) and 27.3% (27.3% in 2017) for IVF and ICSI, respectively. After FET with embryos originating from own eggs, the PR per thawing was 33.4% (versus 30.2% in 2017), and with embryos originating from donated eggs 41.8% (41.1% in 2017). After ED, the PR per fresh embryo transfer was 49.6% (49.2% in 2017) and per FOR 44.9% (43.3% in 2017). In IVF and ICSI together, the trend towards the transfer of fewer embryos continues with the transfer of 1, 2, 3 and ≥4 embryos in 50.7%, 45.1%, 3.9% and 0.3% of all treatments, respectively (corresponding to 46.0%, 49.2%. 4.5% and 0.3% in 2017). This resulted in a reduced proportion of twin DRs of 12.4% (14.2% in 2017) and similar triplet DR of 0.2%. Treatments with FET in 2018 resulted in twin and triplet DRs of 9.4% and 0.1%, respectively (versus 11.2% and 0.2%, respectively in 2017). After IUI, the DRs remained similar at 8.8% after IUI-H (8.7% in 2017) and at 12.6% after IUI-D (12.4% in 2017). Twin and triplet DRs after IUI-H were 8.4% and 0.3%, respectively (in 2017: 8.1% and 0.3%), and 6.4% and 0.2% after IUI-D (in 2017: 6.9% and 0.2%). Among 20 994 FP interventions in 16 countries (18 888 in 13 countries in 2017), cryopreservation of ejaculated sperm (n = 10 503, versus 11 112 in 2017) and of oocytes (n = 9123 versus 6588 in 2017) were the most frequently reported. LIMITATIONS REASONS FOR CAUTION: The results should be interpreted with caution as data collection systems and completeness of reporting vary among European countries. Some countries were unable to deliver data about the number of initiated cycles and/or deliveries. WIDER IMPLICATIONS OF THE FINDINGS: The 22nd ESHRE data collection on ART, IUI and FP interventions shows a continuous increase of reported treatment numbers and MAR-derived livebirths in Europe. Although it is the largest data collection on MAR in Europe, further efforts towards optimization of both the collection and reporting, with the aim of improving surveillance and vigilance in the field of reproductive medicine, are awaited. STUDY FUNDING/COMPETING INTERESTS: The study has received no external funding and all costs are covered by ESHRE. There are no competing interests.

Rain, winds and haze during the Huygens probe's descent to Titan's surface.

The irreversible conversion of methane into higher hydrocarbons in Titan's stratosphere implies a surface or subsurface methane reservoir. Recent measurements from the cameras aboard the Cassini orbiter fail to see a global reservoir, but the methane and smog in Titan's atmosphere impedes the search for hydrocarbons on the surface. Here we report spectra and high-resolution images obtained by the Huygens Probe Descent Imager/Spectral Radiometer instrument in Titan's atmosphere. Although these images do not show liquid hydrocarbon pools on the surface, they do reveal the traces of once flowing liquid. Surprisingly like Earth, the brighter highland regions show complex systems draining into flat, dark lowlands. Images taken after landing are of a dry riverbed. The infrared reflectance spectrum measured for the surface is unlike any other in the Solar System; there is a red slope in the optical range that is consistent with an organic material such as tholins, and absorption from water ice is seen. However, a blue slope in the near-infrared suggests another, unknown constituent. The number density of haze particles increases by a factor of just a few from an altitude of 150 km to the surface, with no clear space below the tropopause. The methane relative humidity near the surface is 50 per cent.

Organophosphate and phthalate esters in air and settled dust - a multi-location indoor study.

UNLABELLED: This paper reports the abundance in indoor air and dust of eleven organophosphate esters and six phthalate esters. Both groups of these semi-volatile compounds are widely incorporated as additives into plastic materials used in the indoor environment, thus contributing to indoor exposure to industrial chemicals. Thirty sampling sites representing three different indoor environments (private homes, day care centers, and workplaces) in the Stockholm area, Sweden, were selected to obtain representative concentration profiles in both ambient air and settled dust. Eight of the target organophosphate esters and all six phthalate esters were found in both air and dust samples at all locations. The phthalate esters were more abundant than the organophosphate esters, typically ten times higher total concentrations. Especially interesting were the high levels of tributoxyethyl phosphate in the day care centers, the relatively high levels of chlorinated organophosphate esters in the air of workplaces and the overall high levels of diethylhexyl phthalate in dust. The air concentration profiles of the phosphate esters differed significantly between the three indoor environments, whereas the concentration profiles of the phthalate esters as well as their total concentrations were similar. The correlation between concentrations found in air and in dust was found to be weak. PRACTICAL IMPLICATIONS: Organophosphate esters and phthalate esters are commonly used as additives in numerous building materials and consumer products. The use of these compounds is increasing, and phosphate and phthalate esters are to be regarded as ubiquitous contaminants in the indoor environment. These compounds comprise a number of different compounds that have been associated with biologic effects in animal studies as well as in humans. Thus, it is of concern to increase the knowledge about human exposure of these compounds because of their presence in indoor air. In this paper, thirty indoor environments have been surveyed with respect to seventeen of the most abundant of these compounds.

Gonadotrophin stimulation and risk of relapse in breast cancer.

STUDY QUESTION: Is gonadotrophin stimulation as part of IVF associated with an increased risk of relapse in breast cancer? SUMMARY ANSWER: Controlled ovarian stimulation (COS) in connection with IVF in women with previous breast cancer was not associated with an increased risk of breast cancer relapse. WHAT IS KNOWN ALREADY: Breast cancer is the most common malignancy among women worldwide and the leading cause of cancer death among females. The use of COS with gonadotrophins with subsequent cryopreservation of oocytes or embryos in order to enhance the chances of pregnancy after cancer treatment is the current most established fertility preservation method for women with breast cancer. To date, there are only a few small retrospective hospital-based controlled studies evaluating the risk of breast cancer relapse in patients undergoing fertility preservation with or without COS, showing no evident risk of relapse in breast cancer after the use of gonadotoxic agents. STUDY DESIGN SIZE DURATION: This was a retrospective, population-based cohort study comprising 5857 women with previous breast cancer of whom 337 were exposed to COS. Exposure (COS) and outcomes (relapse and death) were identified for all patients from 2005 to 2014 by assessing the National Quality Register for Assisted Reproduction, the Swedish Medical Birth Register, the National Patient Register, the Swedish Prescribed Drug Register, the Swedish Cause of Death Register, the National Breast Cancer Register and the Swedish Cancer Register. Matching according to set criteria was possible for 334 women, who constituted the control group. A total of 274 women had undergone IVF after completing breast cancer treatment and 63 women had undergone COS for fertility preservation at the time of breast cancer diagnosis. PARTICIPANTS/MATERIALS SETTING METHODS: Women aged 20-44 years previously diagnosed with breast cancer and exposed to COS were matched for age at breast cancer diagnosis ±5 years, tumour size and lymph node involvement with a non-exposed control group, including women with known T- and N-stages. In a subsequent analysis, the matched cohort was assessed by also including women with unknown T- and N-stages. A secondary analysis comprised the entire non-matched cohort, including all women with known T- and N-stages. Also here, a subsequent analysis included women with missing data for T- and N-stages. The risk of relapse in breast cancer was estimated as crude hazard ratios (HRs) and 95% CI using Cox proportional hazards models in the primary and secondary analyses where T- and N-stages were known: otherwise the risks of relapse were only given descriptively. MAIN RESULTS AND THE ROLE OF CHANCE: In the primary matched analysis, relapse occurred in 20 of 126 women exposed to COS (15.9%) compared with 39 of 126 (31.0%) in the control cohort (HR = 0.70; 95% CI 0.39-1.45; P = 0.22). In the subsequent analysis, also including women with unknown T- and N-stages, relapse occurred in 27 of 337 (8.0%) women having undergone COS compared with 71/334 (21.3%) among the non-exposed. In the secondary adjusted analysis, relapse occurred in 20 of 126 (15.9%) exposed women and in 918 of 3729 (24.6%) non-exposed women (HR = 0.81; 95% CI 0.49-1.33; P = 0.70). In the subsequent analysis, including unknown T- and N-stages, relapse occurred in 27 of 337 (8.0%) women in the exposed group and 1176 of 5520 (21.3%) in the non-exposed cohort. LIMITATIONS REASONS FOR CAUTION: A substantial degree of missing data on important prognostic variables was a limitation, particularly when analysing the total cohort. Furthermore, data on confounding factors, such as BMI, were not completely covered. Another limitation was that a pre-specified variable for relapse was not in use for the majority of the National Breast Cancer Register. Furthermore, the follow-up time from available register data (2005-2014) is rather short. Finally, we cannot be sure whether the prognostic information from receptor status, showing a lower incidence in the exposed group, is representative. Information on T- and N-stages was missing in more than half of the patients. WIDER IMPLICATIONS OF THE FINDINGS: In this large, retrospective, matched cohort study, we found no increased risk of relapse in breast cancer among women who had been exposed to gonadotrophins as part of IVF. This is reassuring but might be confounded by the selection of a group of women with a more favourable prognosis than those not undergoing IVF. The present study strengthens previous findings by being large, national and register based. Its results are applicable to women undergoing fertility preservation as well as to those undergoing regular IVF treatment. STUDY FUNDING/COMPETING INTERESTS: Supported in part by grants from the Swedish state under the agreement between the Swedish government and the county councils the ALF-agreement (ALFGBG-720291), The Assar Gabrielsson Fund (FB 15-20), The Breast Cancer Fund and the Swedish Association of Local authorities and Regions, SKR. There are no conflicts of interest to declare. TRIAL REGISTRATION: N/A.

ART in Europe, 2017: results generated from European registries by ESHRE.

STUDY QUESTION: What are the data on ART and IUI cycles, and fertility preservation (FP) interventions reported in 2017 as compared to previous years, as well as the main trends over the years? SUMMARY ANSWER: The 21st ESHRE report on ART and IUI shows the continual increase in reported treatment cycle numbers in Europe, with a decrease in the proportion of transfers with more than one embryo causing an additional slight reduction of multiple delivery rates (DR) as well as higher pregnancy rates (PR) and DR after frozen embryo replacement (FER) compared to fresh IVF and ICSI cycles, while the number of IUI cycles increased and their outcomes remained stable. WHAT IS KNOWN ALREADY: Since 1997, ART aggregated data generated by national registries, clinics or professional societies have been gathered and analyzed by the European IVF-monitoring Consortium (EIM) and communicated in a total of 20 manuscripts published in Human Reproduction and Human Reproduction Open. STUDY DESIGN SIZE DURATION: Data on European medically assisted reproduction (MAR) are collected by EIM for ESHRE on a yearly basis. The data on treatments performed between 1 January and 31 December 2017 in 39 European countries were provided by either National Registries or registries based on personal initiatives of medical associations and scientific organizations. PARTICIPANTS/MATERIALS SETTING METHODS: Overall, 1382 clinics offering ART services in 39 countries reported a total of 940 503 treatment cycles, including 165 379 with IVF, 391 379 with ICSI, 271 476 with FER, 37 303 with preimplantation genetic testing (PGT), 69 378 with egg donation (ED), 378 with IVM of oocytes, and 5210 cycles with frozen oocyte replacement (FOR). A total of 1273 institutions reported data on 207 196 IUI cycles using either husband/partner's semen (IUI-H; n = 155 794) or donor semen (IUI-D; n = 51 402) in 30 countries and 25 countries, respectively. Thirteen countries reported 18 888 interventions for FP, including oocyte, ovarian tissue, semen and testicular tissue banking in pre- and postpubertal patients. MAIN RESULTS AND THE ROLE OF CHANCE: In 21 countries (20 in 2016) in which all ART clinics reported to the registry, 473 733 treatment cycles were registered for a total population of approximately 330 million inhabitants, allowing a best-estimate of a mean of 1435 cycles performed per million inhabitants (range: 723-3286).Amongst the 39 reporting countries, the clinical PR per aspiration and per transfer in 2017 were similar to those observed in 2016 (26.8% and 34.6% vs 28.0% and 34.8%, respectively). After ICSI the corresponding rates were also similar to those achieved in 2016 (24% and 33.5% vs 25% and 33.2% in 2016). When freeze all cycles were removed, the clinical PRs per aspiration were 30.8% and 27.5% for IVF and ICSI, respectively.After FER with embryos originating from own eggs the PR per thawing was 30.2%, which is comparable to 30.9% in 2016, and with embryos originating from donated eggs it was 41.1% (41% in 2016). After ED the PR per fresh embryo transfer was 49.2% (49.4% in 2016) and per FOR 43.3% (43.6% in 2016).In IVF and ICSI together, the trend towards the transfer of fewer embryos continues with the transfer of 1, 2, 3 and ≥4 embryos in 46.0%, 49.2%, 4.5% and in 0.3% of all treatments, respectively (corresponding to 41.5%, 51.9%. 6.2% and 0.4% in 2016). This resulted in a reduced proportion of twin DRs of 14.2% (14.9% in 2016) and stable triplet DR of 0.3%. Treatments with FER in 2017 resulted in a twin and triplet DR of 11.2% and 0.2%, respectively (vs 11.9% and 0.2% in 2016).After IUI, the DRs remained similar at 8.7% after IUI-H (8.9% in 2016) and at 12.4% after IUI-D (12.4.0% in 2016). Twin and triplet DRs after IUI-H were 8.1% and 0.3%, respectively (in 2016: 8.8% and 0.3%) and 6.9% and 0.2% after IUI-D (in 2016: 7.7% and 0.4%). Amongst 18 888 FP interventions in 13 countries, cryopreservation of ejaculated sperm (n = 11 112 vs 7877 from 11 countries in 2016) and of oocytes (n = 6588 vs 4907 from eight countries in 2016) were the most frequently reported. LIMITATIONS REASONS FOR CAUTION: As the methods of data collection and levels of reporting vary amongst European countries, interpretation of results should remain cautious. Some countries were unable to deliver data about the number of initiated cycles and deliveries. WIDER IMPLICATIONS OF THE FINDINGS: The 21st ESHRE report on ART, IUI and FP interventions shows a continuous increase of reported treatment numbers and MAR-derived livebirths in Europe. Being already the largest data collection on MAR in Europe, efforts should continue to optimize data collection and reporting with the perspective of improved quality control, transparency and vigilance in the field of reproductive medicine. STUDY FUNDING/COMPETING INTERESTS: The study has received no external funding and all costs are covered by ESHRE. There are no competing interests.