The role of multiple birth and birth complications in the association between assisted reproductive technology conception and autism diagnosis.

In recent decades, the use of assisted reproductive technology (ART) has increased rapidly. To assess the relationship between ART and autism diagnosis, we linked California birth records from 2000 through 2016 with contemporaneous records from the National ART Surveillance System (NASS) and autism caseload records from California's Department of Developmental Services from 2000 through November 2019. All 95 149 birth records that were successfully linked to a NASS record, indicating an ART birth, were matched 1:1 using propensity scores to non-ART births. We calculated the hazard risk ratio for autism diagnosis and the proportions of the relationship between ART conception and autism diagnosis mediated by multiple birth pregnancy and related birth complications. The hazard risk ratio for autism diagnosis following ART compared with non-ART conception is 1.26 (95% CI, 1.17-1.35). Multiple birth, preterm birth, and cesarean delivery jointly mediate 77.9% of the relationship between ART conception and autism diagnosis. Thus, increased use of single embryo transfer in the United States to reduce multiple births and related birth complications may be a strategy to address the risk of autism diagnosis among ART-conceived children.

Assisted Reproductive Technology, Multiple Births, and Perinatal Outcomes in Taiwan from 2001 to 2020.

OBJECTIVE: To investigate the effect of the Assisted Reproduction Act, implemented in 2007 in Taiwan to reduce the number of embryos to transfer, on the trends over time regarding the rate of multiple births, preterm delivery, low birth weight (LBW), and small for gestational age (SGA) among deliveries using assisted reproductive technology (ART). STUDY DESIGN: From the Birth Reporting Registry and the Assisted Reproduction Registry, we retrieved data of 4 016 530 live birth deliveries between 2001 and 2020; among them 71 000 (1.77%) were after ART. We calculated the rate of multiples and perinatal outcomes per 1000 deliveries annually from 2001 to 2020 for deliveries using and not using ART and computed the population attributable risk. We performed interrupted time series to assess the effect of the intervention, ie, the Assisted Reproduction Act. RESULTS: The proportion of deliveries following ART was 0.57% in 2001 and increased to 4.03% in 2020. After the intervention, there were decreasing trends over time for rates of multiples (-10.63 per year, P < .001), preterm delivery (-6.74, P = .003), LBW (-9.38, P < .001), and SGA (-4.48, P = .001) among ART deliveries. There was also an immediate decrease right after intervention (-53.45, P = .005) for SGA after ART. The population attributable risk trends before and after intervention were both increasing for all outcomes. CONCLUSIONS: The Assisted Reproduction Act in Taiwan was associated with a decreasing trend of multiples, preterm delivery, LBW, and SGA over time since 2008 among ART deliveries. In particular, there was an immediate decrease of SGA right after the intervention.

Greater risk of type 2 diabetes progression in multifetal gestations with gestational diabetes: the impact of obesity.

BACKGROUND: The relationship between gestational diabetes mellitus and adverse outcomes in multifetal pregnancies is complex and controversial. Moreover, limited research has focused on the risk of gestational diabetes mellitus progression to type 2 diabetes mellitus specifically in multifetal pregnancies, resulting in conflicting results from existing studies. OBJECTIVE: This study aimed to assess the risk of gestational diabetes mellitus progression to type 2 diabetes mellitus between singleton and multifetal pregnancies in a large cohort of parturients with a 5-year follow-up. STUDY DESIGN: A retrospective study was conducted on a prospective cohort of pregnant individuals with pregnancies between January 1, 2017, and December 31, 2020, followed up to 5 years after delivery. Glucose levels during pregnancy were obtained from the Meuhedet Health Maintenance Organization laboratory system and cross-linked with the Israeli National Diabetes Registry. The cohort was divided into 4 groups: singleton pregnancy without gestational diabetes mellitus, singleton pregnancy with gestational diabetes mellitus, multifetal pregnancy without gestational diabetes mellitus, and multifetal pregnancy with gestational diabetes mellitus. Gestational diabetes mellitus was defined according to the American Diabetes Association criteria using the 2-step strategy. Univariate analyses, followed by survival analysis that included Kaplan-Meier hazard curves and Cox proportional-hazards models, were used to assess differences between groups and calculate the adjusted hazard ratios with 95% confidence intervals for progression to type 2 diabetes mellitus. RESULTS: Among 88,611 parturients, 61,891 cases met the inclusion criteria. The prevalence of type 2 diabetes mellitus was 6.5% in the singleton pregnancy with gestational diabetes mellitus group and 9.4% in the multifetal pregnancy with gestational diabetes mellitus group. Parturients with gestational diabetes mellitus, regardless of plurality, were older and had higher fasting plasma glucose levels in the first trimester of pregnancy. The rates of increased body mass index, hypertension, and earlier gestational age at delivery were significantly higher in the gestational diabetes mellitus group among patients with singleton pregnancies but not among patients with multifetal pregnancies. Survival analysis demonstrated that gestational diabetes mellitus was associated with adjusted hazard ratios of type 2 diabetes mellitus of 4.62 (95% confidence interval, 3.69-5.78) in singleton pregnancies and 9.26 (95% confidence interval, 2.67-32.01) in multifetal pregnancies (P<.001 for both). Stratified analysis based on obesity status revealed that, in parturients without obesity, gestational diabetes mellitus in singleton pregnancies increased the risk of type 2 diabetes mellitus by 10.24 (95% confidence interval, 6.79-15.44; P<.001) compared with a nonsignificant risk in multifetal pregnancies (adjusted hazard ratio, 9.15; 95% confidence interval, 0.92-90.22; P=.059). Among parturients with obesity, gestational diabetes mellitus was associated with an increased risk of type 2 diabetes mellitus for both singleton and multifetal pregnancies (adjusted hazard ratio, 3.66; [95% confidence interval, 2.81-4.67; P<.001] and 9.31 [95% confidence interval, 2.12-40.76; P=.003], respectively). CONCLUSION: Compared with gestational diabetes mellitus in singleton pregnancies, gestational diabetes mellitus in multifetal pregnancies doubles the risk of progression to type 2 diabetes mellitus. This effect is primarily observed in patients with obesity. Our findings underscore the importance of providing special attention and postpartum follow-up for patients with multifetal pregnancies and gestational diabetes mellitus, especially those with obesity, to enable early diagnosis and intervention for type 2 diabetes mellitus.

Secular variation and risk factors of preterm birth in Hainan, the Free Trade Port in China from 2010 to 2021.

OBJECTIVES: Preterm delivery rates have increased obviously worldwide over the past decade, yet reliable epidemiological studies on the incidence of preterm birth and temporal trends are not available in Hainan, The Free Trade Port in China. We aimed to describe the rate of preterm birth and trends between 2010 and 2021 and to primarily explore risk factors associated with preterm birth in Hainan, China. METHODS: This was an observational study was based on data from the Hainan Provincial Birth Certificate System (HPBCS) for live births between 1 January 2010 and 31 December 2021. We included pregnancies resulting in at least one live birth, with newborns born at a gestational age of 28 weeks or greater, or with a birth weight of 1000 g or more. The outcome were preterm birth rates and their trends over time. Potential risk factors were collected, including infant gender, maternal age, paternal age, maternal ethnicity, paternal ethnicity, home address, and single or multiple pregnancies. The logistic regression model was used to assess the relationship between preterm birth and potential risk factors. RESULTS: A total of 1,537,239 live births and 86,328 preterm births were investigated, giving a total preterm birth rate of 5.62%. The overall preterm birth rate increased from 4.47% in 2010 to 7.12% in 2021 (compound annual growth rate [CAGR] 4.32). The CAGR of late preterm birth is consistent with the overall preterm birth rate (4.32%). The fastest growth is observed in the rate of very preterm births (5.53%), while the rate of moderate preterm births exhibits the slowest growth (3.87%). Infant gender, multiple pregnancy, home address, parental age, and ethnicity had significant effects on preterm birth. CONCLUSION: The preterm birth rate was increasing year by year from 2010 to 2021 in Hainan, The Free Trade Port in China. Incidence of preterm births in Hainan Province in relation to multiple pregnancies, infant sex, parental age, parental race and residential address.

Mitigating multiples, less is more: examining trends in multifetal gestation rates with assisted reproductive technology.

PURPOSE: Multifetal gestation (MFG) is much more common in pregnancies that utilize assisted reproductive technologies (ART). We assessed how these rates have changed over the previous decade and the impact on live birth rates (LBR). METHODS: This retrospective cohort study uses the National Summary Reports of the Society for Assisted Reproductive Technology (SART) from 2014 to 2020. Data points included only autologous cycles. The data were divided into five age groups as reported in the database: < 35, 35-37, 38-40, 41-42, and > 42 years old. Descriptive statistics and a two-tailed T-test were used to determine the trends and statistical significance (p < 0.05). RESULTS: Rates of twin births decreased substantially from 2014 to 2020 for autologous embryo transfers across all age groups and diagnoses. Surprisingly, the overall LBR for autologous IVF cycles decreased at similar rates from 2014 to 2020 in all age groups. The mean number of embryos transferred has dramatically reduced, especially across age groups < 42. CONCLUSION: Rates of twin and higher-level gestations have decreased substantially over the past decade; the effect correlates with the increased utilization of eSET and PGT. The cause of infertility did not significantly impact the rate of MFG.

Surgical-site infection in multifetal cesarean delivery.

PURPOSE: The relationship between multifetal cesarean delivery and surgical-site infection (SSI) is unclear. If SSI is more common in multifetal cesareans, adjustment of practices such as antibiotic dosing could be warranted. The purpose of this study was to determine whether patients undergoing multifetal cesarean delivery are more likely to experience SSI than those undergoing singleton cesarean delivery. METHODS: This was a retrospective cohort study including all cesarean deliveries at a tertiary hospital from 10/1/2009 to 12/28/2018. The primary outcome was rate of SSI in women after multifetal cesarean delivery as compared to those who underwent singleton cesarean delivery. Univariable analysis and multivariable logistic regression were used to assess independent clinical factors associated with SSI in multifetal cesarean deliveries. RESULTS: 34,340 women underwent cesarean delivery during this period. 33,211 were singletons (96.7%), and 1,129 were multifetal (3.3%). There was no difference in the rate of SSI in multifetal gestations (15/1,129, 1.3%) as compared to singletons (493/33,211, 1.5%) (p = 0.670, OR 0.89 [95% CI 0.53, 1.50], aOR 1.06 [95% CI 0.61, 1.84]). Limiting analysis to multifetal deliveries, prolonged rupture of membranes (p < 0.004, OR 5.43 [95% CI 1.49, 19.88]), labor augmentation (p < 0.001, OR 15.84 [1.74, 144.53]), and chorioamnionitis (p < 0.001, OR 15.43 [95% CI 3.11, 76.62]) were more common in women with SSI. DISCUSSION: SSI is not increased in multifetal cesarean delivery as compared to singleton cesarean delivery. In multifetal cesareans, chorioamnionitis, prolonged rupture of membranes, and labor augmentation were associated with increased odds of SSI.

The role of maternal age on the risk of preterm birth among singletons and multiples: a retrospective cohort study in Lombardy, Norther Italy.

BACKGROUND: All over the world, especially in the developed countries, maternal age at birth is rising. This study aimed to assess the role of maternal age on the occurrence of preterm birth (PTB) in a large birth cohort of Lombardy Region, Northern Italy. METHODS: This population-based study used data from regional healthcare utilization databases of Lombardy to identify women who delivered between 2007 and 2017. PTBs were defined as births before 37 completed weeks of gestation and considered according to the gestational age (two categories: < 32 weeks and 32 to 36 weeks). Six maternal age groups were defined (< 20, 20-24, 25-29, 30-34, 35-39, ≥40 years). Logistic regression models were fitted to estimate the crude and adjusted odds ratio (aOR) and the corresponding 95% confidence interval (CI) for PTB among different maternal age groups. Analyses were separately performed according to type of pregnancy (singletons and multiples). Reference group was the age group with the lowest frequency of PTB. RESULTS: Overall, 49,759 (6.6%) PTBs were observed, of which 41,807 were singletons and 7952 were multiples. Rates of PTB were lowest in the women aged 25-29 years among singletons and in the 30-34 years old group among multiples. Our results described a U-shaped association between maternal age and risk of PTB. In particular, the risk of a singleton PTB between 32 and 36 weeks was significantly higher for women aged less than 20 years (aOR = 1.16, CI 95%: 1.04-1.30) and more than 40 years (aOR = 1.62 CI 95%: 1.54-1.70). The highest risk of a multiple delivery between 32 and 36 weeks was observed among women aged less than 25 years and more than 40 years (aOR = 1.79, CI 95%: 1.01-3.17, aOR = 1.47, CI 95%: 1.16-1.85 and aOR = 1.36, CI 95%: 1.19-1.55 respectively for < 20, 20-24 and > 40 age categories). PTB before 32 completed weeks occurred more frequently in the same age categories, except that among multiples no association with advanced maternal age emerged. CONCLUSION: Our study suggested that, after adjustment for potential confounders, both advance and young maternal age were associated with an increased risk of PTB.

Effects of the early phase of the COVID-19 pandemic on natural and ART-mediated birth rates in Lombardy Region, Northern Italy.

RESEARCH QUESTION: What effects did the early phase of the COVID-19 pandemic have on natural and assisted reproductive technology (ART)-mediated birth rates? DESIGN: Regional registries were consulted with permission from the Health Authorities of Lombardy Region, Northern Italy, an area particularly affected by the early phase of the epidemic. Deliveries occurring in the area between 1 January 2019 and 31 December 2020 from women beneficiaries of the National Health System and resident in Lombardy were identified. Comparisons mainly focused on December 2020, when women who conceived after 8 March (the start of the stringent lockdown imposed by the authorities) were expected to deliver. RESULTS: When comparing the periods January to November in 2019 and 2020, a 5.1% reduction of monthly general birth rate (from 5732 in 2019 to 5438 in 2020) was observed. The contribution of ART births was similar in 2019 and 2020, being 4.4% and 4.5%, respectively. In December 2020, a notable drop in natural (-17.8%), ART-mediated (-86.6%) and overall (-21.0%) births was observed compared with December 2019. After adjusting for the expected 5.1% reduction, the inferred effect of the COVID-19 crisis corresponded to a 16.7% reduction in birth rate, of which 76% was related to natural (707 births) and 24% to ART (218 births) conceptions. CONCLUSIONS: This is the first study providing population-based evidence on the effects of COVID-19 and its related stringent restrictions on birth rates. The birth rate was dramatically reduced following the critical period, and the closure of ART centres played only a marginal role (24%) in the overall detrimental effect.

Celebrating 30 years of ART in Latin America; and the 2018 report.

RESEARCH QUESTION: What are the trends in patient characteristics, effectiveness and safety of assisted reproductive technology (ART) performed in Latin America over the past three decades, as well as the detailed outcomes of procedures initiated in 2018? DESIGN: Retrospective collection of multinational data including epidemiology and outcomes of ART performed between 1990 and 2018. RESULTS: Over these 30 years we report 955,117 initiated cycles, 191,191 deliveries and 238,045 live births. In 1990, 66.5% of women were ≤34 years and 8.7% ≥40 years; in 2018, 26.4% of women were ≤34 years and 32.0% were ≥40 years. In 1990, 60.4% of transfers included ≥3 embryos, falling to 13.5% in 2018, and single embryo transfer (SET) increased from 13.8% to 30.4% between 1990 and 2018. Delivery rate per fresh transfer increased from approximately 17% in the 1990s to 25% in 2018, with a meaningful drop in high-order multiples, from 5-9% in the 1990s to 0.4% in 2018. This drop is associated with increasing use of frozen embryo transfer (FET) (57% in 2018) compared with 10% in 2000. In 2018, delivery rate in FET was 28.3%, reaching 31.2% in freeze-all cycles; and the cumulative live birth rate (fresh + FET) was 41.9%. Elective SET also increased, from 0.9% in 2010 to 10% in 2018. The delivery rate in elective SET (31.7%) was only 5.4% lower than elective double embryo transfer (DET) (37.1%); however, multiple births increased from 2.1% to 25.5% twins and 0.4% triplets in elective DET. CONCLUSION: The Latin American Registry of Assisted Reproduction (RLA) celebrates 30 years of voluntary reporting from a total of nearly 200 centres in 15 countries. This South-South Cooperation network has proven to be an efficient and safe system for technological transfer and regional growth.

Assisted hatching on assisted conception (in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI)).

BACKGROUND: Failure of implantation and conception may result from inability of the blastocyst to escape from its outer coat, which is known as the zona pellucida. Artificial disruption of this coat is known as assisted hatching and has been proposed as a method for improving the success of assisted conception by facilitating embryo implantation. OBJECTIVES: To determine effects of assisted hatching (AH) of embryos derived from assisted conception on live birth and multiple pregnancy rates.  SEARCH METHODS: We searched the Cochrane Gynaecology and Fertility Group Specialised Register (until May 2020), the Cochrane Central Register of Controlled Trials (CENTRAL; until May 2020), in the Cochrane Library; MEDLINE (1966 to May 2020); and Embase (1980 to May 2020). We also searched trial registers for ongoing and registered trials (http://www.clinicaltrials.gov - a service of the US National Institutes of Health; http://www.who.int/trialsearch/Default.aspx - The World Health Organization International Trials Registry Platform search portal) (May 2020). SELECTION CRITERIA: Two review authors identified and independently screened trials. We included randomised controlled trials (RCTs) of AH (mechanical, chemical, or laser disruption of the zona pellucida before embryo replacement) versus no AH that reported live birth or clinical pregnancy data. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures recommended by Cochrane. Two review authors independently performed quality assessments and data extraction. MAIN RESULTS: We included 39 RCTs (7249 women). All reported clinical pregnancy data, including 2486 clinical pregnancies. Only 14 studies reported live birth data, with 834 live birth events. The quality of evidence ranged from very low to low. The main limitations were serious risk of bias associated with poor reporting of study methods, inconsistency, imprecision, and publication bias. Five trials are currently ongoing. We are uncertain whether assisted hatching improved live birth rates compared to no assisted hatching (odds ratio (OR) 1.09, 95% confidence interval (CI) 0.92 to 1.29; 14 RCTs, N = 2849; I² = 20%; low-quality evidence). This analysis suggests that if the live birth rate in women not using assisted hatching is about 28%, the rate in those using assisted hatching will be between 27% and 34%. Analysis of multiple pregnancy rates per woman showed that in women who were randomised to AH compared with women randomised to no AH, there may have been a slight increase in multiple pregnancy rates (OR 1.38, 95% CI 1.13 to 1.68; 18 RCTs, N = 4308; I² = 48%; low-quality evidence). This suggests that if the multiple pregnancy rate in women not using assisted hatching is about 9%, the rate in those using assisted hatching will be between 10% and 14%. When all of the included studies (39) are pooled, the clinical pregnancy rate in women who underwent AH may improve slightly in comparison to no AH (OR 1.20, 95% CI 1.09 to 1.33; 39 RCTs, N = 7249; I² = 55%; low-quality evidence). However, when a random-effects model is used due to high heterogeneity, there may be little to no difference in clinical pregnancy rate (P = 0.04). All 14 RCTs that reported live birth rates also reported clinical pregnancy rates, and analysis of these studies illustrates that AH may make little to no difference in clinical pregnancy rates when compared to no AH (OR 1.07, 95% CI 0.92 to 1.25; 14 RCTs, N = 2848; I² = 45%). We are uncertain about whether AH affects miscarriage rates due to the quality of the evidence (OR 1.13, 95% CI 0.82 to 1.56; 17 RCTs, N = 2810; I² = 0%; very low-quality evidence). AUTHORS' CONCLUSIONS: This update suggests that we are uncertain of the effects of assisted hatching (AH) on live birth rates. AH may lead to increased risk of multiple pregnancy. The risks of complications associated with multiple pregnancy may be increased without evidence to demonstrate an increase in live birth rate, warranting careful consideration of the routine use of AH for couples undergoing in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI). AH may offer a slightly increased chance of achieving a clinical pregnancy, but data quality was of low grade. We are uncertain about whether AH influences miscarriage rates.

Fresh versus frozen embryo transfers in assisted reproduction.

BACKGROUND: In vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI) treatments conventionally consist of a fresh embryo transfer, possibly followed by one or more cryopreserved embryo transfers in subsequent cycles. An alternative option is to freeze all suitable embryos and transfer cryopreserved embryos in subsequent cycles only, which is known as the 'freeze all' strategy. This is the first update of the Cochrane Review on this comparison. OBJECTIVES: To evaluate the effectiveness and safety of the freeze all strategy compared to the conventional IVF/ICSI strategy in women undergoing assisted reproductive technology. SEARCH METHODS: We searched the Cochrane Gynaecology and Fertility Group Trials Register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, and two registers of ongoing trials from inception until 23 September 2020 for relevant studies, checked references of publications found, and contacted study authors to obtain additional data. SELECTION CRITERIA: Two review authors (TZ and MZ) independently selected studies for inclusion, assessed risk of bias, and extracted study data. We included randomised controlled trials comparing a 'freeze all' strategy with a conventional IVF/ICSI strategy including a fresh embryo transfer in women undergoing IVF or ICSI treatment. DATA COLLECTION AND ANALYSIS: The primary outcomes were cumulative live birth rate and ovarian hyperstimulation syndrome (OHSS). Secondary outcomes included effectiveness outcomes (including ongoing pregnancy rate and clinical pregnancy rate), time to pregnancy and obstetric, perinatal and neonatal outcomes. MAIN RESULTS: We included 15 studies in the systematic review and eight studies with a total of 4712 women in the meta-analysis. The overall evidence was of moderate to low quality. We graded all the outcomes and downgraded due to serious risk of bias, serious imprecision and serious unexplained heterogeneity. Risk of bias was associated with unclear blinding of investigators for preliminary outcomes of the study during the interim analysis, unit of analysis error, and absence of adequate study termination rules. There was an absence of high-quality evidence according to GRADE assessments for our primary outcomes, which is reflected in the cautious language below. There is probably little or no difference in cumulative live birth rate between the 'freeze all' strategy and the conventional IVF/ICSI strategy (odds ratio (OR) 1.08, 95% CI 0.95 to 1.22; I2 = 0%; 8 RCTs, 4712 women; moderate-quality evidence). This suggests that for a cumulative live birth rate of 58% following the conventional strategy, the cumulative live birth rate following the 'freeze all' strategy would be between 57% and 63%. Women might develop less OHSS after the 'freeze all' strategy compared to the conventional IVF/ICSI strategy (OR 0.26, 95% CI 0.17 to 0.39; I2 = 0%; 6 RCTs, 4478 women; low-quality evidence). These data suggest that for an OHSS rate of 3% following the conventional strategy, the rate following the 'freeze all' strategy would be 1%. There is probably little or no difference between the two strategies in the cumulative ongoing pregnancy rate (OR 0.95, 95% CI 0.75 to 1.19; I2 = 31%; 4 RCTs, 1245 women; moderate-quality evidence).  We could not analyse time to pregnancy; by design, time to pregnancy is shorter in the conventional strategy than in the 'freeze all' strategy when the cumulative live birth rate is comparable, as embryo transfer is delayed in a 'freeze all' strategy. We are uncertain whether the two strategies differ in cumulative miscarriage rate because the evidence is very low quality (Peto OR 1.06, 95% CI 0.72 to 1.55; I2 = 55%; 2 RCTs, 986 women; very low-quality evidence) and cumulative multiple-pregnancy rate (Peto OR 0.88, 95% CI 0.61 to 1.25; I2 = 63%; 2 RCTs, 986 women; very low-quality evidence). The risk of hypertensive disorders of pregnancy (Peto OR 2.15, 95% CI 1.42 to 3.25; I2 = 29%; 3 RCTs, 3940 women; low-quality evidence), having a large-for-gestational-age baby (Peto OR 1.96, 95% CI 1.51 to 2.55; I2 = 0%; 3 RCTs, 3940 women; low-quality evidence) and a higher birth weight of the children born (mean difference (MD) 127 g, 95% CI 77.1 to 177.8; I2 = 0%; 5 RCTs, 1607 singletons; moderate-quality evidence) may be increased following the 'freeze all' strategy. We are uncertain whether the two strategies differ in the risk of having a small-for-gestational-age baby because the evidence is low quality (Peto OR 0.82, 95% CI 0.65 to 1.05; I2 = 64%; 3 RCTs, 3940 women; low-quality evidence). AUTHORS' CONCLUSIONS: We found moderate-quality evidence showing that one strategy is probably not superior to the other in terms of cumulative live birth rate and ongoing pregnancy rate. The risk of OHSS may be decreased in the 'freeze all' strategy. Based on the results of the included studies, we could not analyse time to pregnancy. It is likely to be shorter using a conventional IVF/ICSI strategy with fresh embryo transfer in the case of similar cumulative live birth rate, as embryo transfer is delayed in a 'freeze all' strategy. The risk of maternal hypertensive disorders of pregnancy, of having a large-for-gestational-age baby and a higher birth weight of the children born may be increased following the 'freeze all' strategy. We are uncertain if 'freeze all' strategy reduces the risk of miscarriage, multiple pregnancy rate or having a small-for-gestational-age baby compared to conventional IVF/ICSI.

Double versus single intrauterine insemination (IUI) in stimulated cycles for subfertile couples.

BACKGROUND: In subfertile couples, couples who have tried to conceive for at least one year, intrauterine insemination (IUI) with ovarian hyperstimulation (OH) is one of the treatment modalities that can be offered. When IUI is performed a second IUI in the same cycle might add to the chances of conceiving. In a previous update of this review in 2010 it was shown that double IUI increases pregnancy rates when compared to single IUI. Since 2010, different clinical trials have been published with differing conclusions about whether double IUI increases pregnancy rates compared to single IUI. OBJECTIVES: To determine the effectiveness and safety of double intrauterine insemination (IUI) compared to single IUI in stimulated cycles for subfertile couples. SEARCH METHODS: We searched the Cochrane Gynaecology and Fertility (CGF) Group trials register, CENTRAL, MEDLINE, Embase and CINAHL in July 2020 and LILACS, Google scholar and Epistemonikos in February 2021, together with reference checking and contact with study authors and experts in the field to identify additional studies. SELECTION CRITERIA: We included randomised controlled, parallel trials of double versus single IUIs in stimulated cycles in subfertile couples. DATA COLLECTION AND ANALYSIS: Two authors independently assessed trial quality and extracted data. We contacted study authors for additional information. MAIN RESULTS: We identified in nine studies involving subfertile women. The evidence was of low quality; the main limitations were unclear risk of bias, inconsistent results for some outcomes and imprecision, due to small trials with imprecise results. We are uncertain whether double IUI improves live birth rate compared to single IUI (odds ratio (OR) 1.15, 95% confidence interval (CI) 0.71 to 1.88; I2 = 29%; studies = 3, participants = 468; low quality evidence). The evidence suggests that if the chance of live birth following single IUI is 16%, the chance of live birth following double IUI would be between 12% and 27%. Performing a sensitivity analysis restricted to only randomised controlled trials (RCTs) with low risk of selection bias showed similar results. We are uncertain whether double IUI reduces miscarriage rate compared to single IUI (OR 1.78, 95% CI 0.98 to 3.24; I2 = 0%; studies = 6, participants = 2363; low quality evidence). The evidence suggests that chance of miscarriage following single IUI is 1.5% and the chance following double IUI would be between 1.5% and 5%. The reported clinical pregnancy rate per woman randomised may increase with double IUI group (OR 1.51, 95% CI 1.23 to 1.86; I2 = 34%; studies = 9, participants = 2716; low quality evidence). This result should be interpreted with caution due to the low quality of the evidence and the moderate inconsistency. The evidence suggests that the chance of a pregnancy following single IUI is 14% and the chance following double IUI would be between 16% and 23%. We are uncertain whether double IUI affects multiple pregnancy rate compared to single IUI (OR 2.04, 95% CI 0.91 to 4.56; I2 = 8%; studies = 5; participants = 2203; low quality evidence). The evidence suggests that chance of multiple pregnancy following single IUI is 0.7% and the chance following double IUI would be between 0.85% and 3.7%. We are uncertain whether double IUI has an effect on ectopic pregnancy rate compared to single IUI (OR 1.22, 95% CI 0.35 to 4.28; I2 = 0%; studies = 4, participants = 1048; low quality evidence). The evidence suggests that the chance of an ectopic pregnancy following single IUI is 0.8% and the chance following double IUI would be between 0.3% and 3.2%. AUTHORS' CONCLUSIONS: Our main analysis, of which the evidence is low quality, shows that we are uncertain if double IUI improves live birth and reduces miscarriage compared to single IUI. Our sensitivity analysis restricted to studies of low risk of selection bias for both outcomes is consistent with the main analysis. Clinical pregnancy rate may increase in the double IUI group, but this should be interpreted with caution due to the low quality evidence. We are uncertain whether double IUI has an effect on multiple pregnancy rate and ectopic pregnancy rate compared to single IUI.

Incidence of multiple births in relation to current regulations in Turkey regarding embryo transfer.

BACKGROUND: Before 2010, there were no regulations in Turkey regarding the number of embryos to be transferred in one cycle. In March 2010, regulations restricting this number were implemented by the Turkish Ministry of Health. These specify the transfer of a maximum of one embryo in the first and second cycles and a maximum of two embryos in subsequent cycles in women aged < 35, and a maximum of two embryos in women aged ≥35 in any one cycle. Our study evaluates the effect of these regulations. METHODS: This large retrospective single center study first evaluates the incidence of multiple pregnancies before and after the implementation of the 2010 regulations. Secondly, it compares the clinical outcomes of double blastocyst transfer (DBT) and single blastocyst transfer (SBT) performed in compliance with these regulations from 2014 onwards. RESULTS: After the introduction of the 2010 regulations, the multiple pregnancy rate decreased significantly from 37.9 to 15.7%. The singleton live birth rate increased significantly, whereas multiiple live birth rates significantly decreased (p = < 0.001). When the clinical outcomes of SBT and DBT performed in compliance with regulations from 2014 onwards were evaluated, in patients < 35 years, the multiple pregnancy rate decreased from 47.2% in the DBT group to 1.7% in the SBT group (p = < 0.001). In patients ≥35 years, in the DBT group, the twin birth rate was again high at 28.4%, whereas in the SBT group, it was only 1.8% (p = < 0.001). Importantly, there was no statistically significant difference in clinical pregnancy rates between these two groups. CONCLUSION: Turkish regulations have led to an encouragement of double embryo transfer (DET) as a routine practice, with many patients understanding it as an absolute right to have two embryos transferred. The results of our study suggest that, especially in the light of the success of blastocyst transfer, the Turkish regulations should be amended to limit the use of DET and encourage the use of single embryo transfer except in exceptional cases and particularly in women under 35 years old.

Women with multiple gestations have an increased risk of development of hypertension in the future.

BACKGROUND: Multiple gestations are associated with an increased incidence of preeclampsia. However, there exists no evidence for an association between multiple gestations and development of hypertension(HTN) later in life. This study aimed to determine whether multiple gestations are associated with HTN beyond the peripartum period. METHODS: In this retrospective nationwide population-based study, women who delivered a baby between January 1, 2007, and December 31, 2008, and underwent a national health screening examination within one year prior to their pregnancy were included. Subsequently, we tracked the occurrence of HTN during follow-up until December 31, 2015, using International Classification of Diseases-10th Revision codes. RESULTS: Among 362,821 women who gave birth during the study period, 4,944 (1.36%) women had multiple gestations. The cumulative incidence of HTN was higher in multiple gestations group compared with singleton group (5.95% vs. 3.78%, p < 0.01, respectively). On the Cox proportional hazards models, the risk of HTN was increased in women with multiple gestations (HR 1.35, 95% CI 1.19, 1.54) compared with those with singleton after adjustment for age, primiparity, preeclampsia, atrial fibrillation, body mass index, blood pressure, diabetes mellitus, high total cholesterol, abnormal liver function test, regular exercise, and smoking status. CONCLUSIONS: Multiple gestations are associated with an increased risk of HTN later in life. Therefore, guidelines for the management of high-risk patients after delivery should be established.

A study of pregnancy after endometrial ablation using linked population data.

INTRODUCTION: Endometrial ablation encapsulates a range of procedures undertaken to destroy the endometrial lining of the uterus as a treatment for heavy menstrual bleeding in women who no longer wish to bear children. Pregnancy following ablation, while unlikely, can occur and may carry higher rates of complications. The aim of this study was to identify factors associated with post-endometrial ablation pregnancy and to describe pregnancy and birth outcomes for post-endometrial ablation pregnancies. MATERIAL AND METHODS: This population-based data linkage study included all female residents of New South Wales, Australia, aged 15-50 years with a hospital admission between July 2001 to June 2014 who birthed between July 2001 and June 2015. Cox proportional hazard regression was used to estimate associations between women's characteristics and post-endometrial ablation pregnancy of at least 20 weeks' gestation. Descriptive statistics were used to characterize pregnancy and birth outcomes. RESULTS: Of 18 559 women with an endometrial ablation, 575 (3.1%) had a post-ablation pregnancy of at least 20 weeks' gestation. Nulliparity (adjusted hazard ratio [aHR] 12.2, 95% confidence interval [CI] 9.1-16.2), older age (35-39 years: aHR 0.39, 95% CI 0.29-0.51; 40-44 years: aHR 0.06, 95% CI 0.04-0.11), marital status (single: aHR 0.67, 95% CI 0.55-0.83; widowed/divorced/separated: aHR 0.58, 95% CI 0.36-0.94) and a diagnosis of heavy menstrual bleeding (aHR 0.09, 95% CI 0.07-0.13) were associated with post-ablation pregnancy. There were high rates of cesarean delivery (43%), preterm birth (13%), twin or higher order pregnancies (9%) and stillbirth (13.3/1000 births) among these post-ablation pregnancies. CONCLUSIONS: Nulliparity at the time of endometrial ablation is associated with increased risk of post-ablation pregnancy, highlighting the importance of careful discussion and consideration of treatment options for heavy menstrual bleeding.

A Comparison of Respiratory Syncytial Viral Prophylaxis in Multiple Births versus Singletons in the Canadian Registry of Palivizumab.

OBJECTIVE: The aim of this study is to compare respiratory illness-related hospitalization (RIH) and respiratory syncytial virus (RSV)-related hospitalization (RSVH) in multiple births versus singletons, who received palivizumab during the RSV season and participated in the Canadian registry of palivizumab (CARESS). STUDY DESIGN: Prospective, observational study of infants aged <2 years recruited across 32 centers over 12 RSV seasons from 2005 to 2017. Demographic data were collected at enrolment and RIH events were recorded monthly. RESULTS: A total of 25,003 infants were enrolled of whom 6,949 (27.8%) were of multiple birth, and 18,054 (72.2%) were singletons. A significantly larger proportion of the multiple births were premature (80.2%) compared with the singleton group (56.8%). Multiples had a lower gestational age (mean ± standard deviation): 31.2 ± 3.2 versus 33.2 ± 5.5 weeks and birth weight (mean: 1,590 ± 606.8 vs. 2,069.4 ± 1068.5 g; both p < 0.0005). They were younger at enrolment (4.5 ± 5.0 vs. 6.1 ± 6.8 months), and fewer attended daycare (1.9 vs. 4.6%), and experienced exposure to smoking (24.5 vs. 29.9%), but more lived in a crowded household (36.7 vs. 19.4%); all p < 0.0005. Multiples had a longer length of neonatal stay (51.1 ± 65.9 vs. 47.9 ± 67.8 days), and more required respiratory support (65.7 vs. 57.7%), but for shorter duration (22.6 ± 32.9 vs. 24.7 ± 40.6 days); all p < 0.001. RIH and RSVH rates (%) in multiples versus singletons were 4.7; 7.7 and 1.4; and 1.6, respectively. Cox regression showed that multiples had a lower risk of RIH compared with singletons (hazard ratio [HR] = 0.616, 95% confidence interval [CI]: 0.543-0.698, p < 0.0005), but not RSVH (HR: 0.77, 95% CI: 0.57-1.02, p = 0.071). CONCLUSION: Multiple birth infants, who are known to be at greater risk for severe RSVH compared with singletons, are well protected by palivizumab, provided adherence to the monthly injection scheme is guaranteed.

Impact of maternal education level on live birth rate after in vitro fertilization in China: a retrospective cohort study.

PURPOSE: To assess the association between maternal education level and live birth after in vitro fertilization (IVF). METHODS: We studied women who underwent the first cycle of fresh or frozen-thawed embryo transfer between 2014 and 2019. Women were divided into four educational categories according to the level of education received (elementary school graduate or less, middle school graduate, high school graduate, college graduate or higher). The live birth rate was compared between different education level groups. We used logistic regression to analyze the association between maternal education level and live birth after IVF. RESULTS: We studied 41,546 women, who were grouped by maternal educational level: elementary school graduate or less (n = 1590), middle school graduate (n = 10,996), high school graduate (n = 8354), and college graduate or higher (n = 20,606). In multivariable logistic regression analysis, we did not demonstrate a statistically significant relationship between educational level and live birth in middle school graduate (adjusted odds ratio [AOR] 0.96; 95% confidence interval [CI], 0.84-1.09), high school graduate (AOR 1.01; 95% CI, 0.87-1.14) or college graduate or higher (AOR 1.01; 95% CI, 0.88-1.14) patients, with elementary school graduate or less as the reference group. CONCLUSIONS: Maternal educational level was not associated with the likelihood of live birth in patients undergoing fresh or frozen embryo transfer.

Reproductive outcomes in women and men using complementary and alternative medicine treatment and not receiving artificial reproductive technology: a systematic review.

PURPOSE: Infertility is a global problem, but only a minority of couples access assisted reproductive technologies due to financial and sociocultural barriers. Complementary and alternative medicine are seen as another option. We aimed to determine the impact of complementary and alternative medicine on conception, miscarriage and live birth rates in couples not receiving assisted reproductive technology treatments. METHODS: The electronic databases EMBASE, PubMed, Web of Science and the Allied and Complementary Medicine Database were systematically searched before March 24th 2020. Reference lists of eligible studies were searched for relevant studies. Eligible studies included trials and observational studies that assessed a complementary or alternative medicine and conception, miscarriage or live births in men or women not undergoing fertility treatment. Data were extracted by two independent reviewers using a pre-designed data collection form. The study protocol was published in the PROSPERO database (CRD42018086980). RESULTS: Twenty randomized controlled trials were identified, including 2748 individuals. Most studies did not demonstrate any effect of a complementary or alternative medicine on pregnancy, live birth or miscarriage rates. Limited evidence was found for a positive effect of herbal therapies taken by women on conception rates. There was substantial diversity in quality across the studies. CONCLUSION: There is limited evidence of the effectiveness of complementary and alternative medicine on improving the chances of conception and live births, or increasing miscarriage risk. Owing to the generally sub-optimal quality and heterogeneous nature of the evidence, rigorous studies are needed to determine the impact of complementary and alternative medicine on fertility.

Transabdominal fetal reduction: a report of 124 cases.

To prevent fetal loss, preterm delivery, and perinatal morbidity of multifetal pregnancies (MPs), fetal reduction (FR) is offered to some patients. We retrospectively analysed the data of 124 MPs that underwent transabdominal FR to twin (n = 63) and singleton (n = 61) pregnancies at a mean gestational age of 12 + 6 weeks between December 2006 and January 2018. FR was performed transabdominally with the injection of potassium chloride into the intracardiac or intrathoracic space of the fetus or fetuses after ultrasound screening for nuchal translucency and anatomical defects. The initial number of embryos were 48 twins, 63 triplets, 11 quadruplets, and 2 quintuplets. The procedure-related pregnancy loss rate was 0.8% (1/124), the overall pregnancy loss rate was 2.4% (3/124), the fetal loss rate was 1.6% (2/124), and the neonatal death rate was 0.8% (1/124). The baby take-home rates were 96% for twin pregnancies and 96.7% for singletons. This study shows that transabdominal FR is an effective and safe procedure with a pregnancy loss rate of 2.4%.Impact statementWhat is already known on this subject? The incidence of multifetal pregnancies has increased over the years. Because multifetal pregnancies increase perinatal morbidity and mortality due to prematurity, fetal reduction is offed to some patients.What the results of this study add? The results of this study add to the growing body of research on fetal reduction. The study showed that transabdominal fetal reduction is a safe procedure with a pregnancy loss rate of 2.4%.What the implications are of these findings for clinical practice and/or further research? The results of this study can be used in counselling couples with multifetal pregnancies who are considering fetal reduction. Further research is needed to confirm the current findings.

Does the transfer of a poor quality embryo with a good quality embryo benefit poor prognosis patients?

BACKGROUND: While single embryo transfer (SET) is widely advocated, double embryo transfer (DET) remains preferable in clinical practice to improve IVF success rate, especially in poor prognosis patients with only poor quality embryos (PQEs) available in addition to one or no good quality embryos (GQEs). Furthermore, previous studies suggest PQE might adversely affect the implantation of a GQE when transferred together. This study aims to evaluate the effect of transferring an additional PQE with a GQE on the outcomes in poor prognosis patients. METHODS: A total of 5037 frozen-thawed blastocyst transfer (FBT) cycles between January 2012 and May 2019 were included. Propensity score matching was applied to control for potential confounders, and we used generalized estimating equations (GEE) models to identify the association between the effect of an additional PQE and the outcomes. RESULTS: Overall, transferring a PQE with GQE (Group GP) achieved significantly higher pregnancy rate (PR), live birth rate (LBR) and multiple pregnancy rate (MPR) than GQE only (group G). The addition of a PQE increased LBR in patients aged 35 and over and in patients who received over 3 cycles of embryo transfer (ET) (48.1% vs 27.2%, OR:2.56, 95% CI: 1.3-5.03 and 46.6% vs 35.4%, OR:1.6, 95% CI: 1.09-2.35), but not in women under 35 and in women who received less than 3 cycles of ET (48.7% vs 43.9%, OR:1.22, 95% CI: 0.93-1.59 and 48.3% vs 41.4%, OR:1.33, 95% CI: 0.96-1.85). Group GP resulted in significantly higher MPR than group G irrespective of age and the number of previous IVF cycles. CONCLUSIONS: An additional PQE does not negatively affect the implantation potential of the co-transferred GQE. Nevertheless, the addition of a PQE contributes to both live birth and multiple birth in poor prognosis patients. Physicians should still balance the benefits and risks of DET.