Effect of parental and ART treatment characteristics on perinatal outcomes.

STUDY QUESTION: Do parental characteristics and treatment with ART affect perinatal outcomes in singleton pregnancies? SUMMARY ANSWER: Both parental and ART treatment characteristics affect perinatal outcomes in singleton pregnancies. WHAT IS KNOWN ALREADY: Previous studies have shown that singleton pregnancies resulting from ART are at risk of preterm birth. ART children are lighter at birth after correction for duration of gestation and at increased risk of congenital abnormalities compared to naturally conceived children. This association is confounded by parental characteristics that are also known to affect perinatal outcomes. It is unclear to which extent parental and ART treatment characteristics independently affect perinatal outcomes. STUDY DESIGN, SIZE, DURATION: All IVF clinics in the Netherlands (n = 13) were requested to provide data on all ART treatment cycles (IVF, ICSI and frozen-thawed embryo transfers (FET)), performed between 1 January 2000, and 1 January 2011, which resulted in a pregnancy. Using probabilistic data-linkage, these data (n = 36 683) were linked to the Dutch Perinatal Registry (Perined), which includes all children born in the Netherlands in the same time period (n = 2 548 977). PARTICIPANTS/MATERIALS, SETTING, METHODS: Analyses were limited to singleton pregnancies that resulted from IVF, ICSI or FET cycles. Multivariable models for linear and logistic regression were fitted including parental characteristics as well as ART treatment characteristics. Analyses were performed separately for fresh cycles and for fresh and FET cycles combined. We assessed the impact on the following perinatal outcomes: birth weight, preterm birth below 37 or 32 weeks of gestation, congenital malformations and perinatal mortality. MAIN RESULTS AND THE ROLE OF CHANCE: The perinatal outcomes of 31 184 out of the 36 683 ART treatment cycles leading to a pregnancy were retrieved through linkage with the Perined (85% linkage). Of those, 23 671 concerned singleton pregnancies resulting from IVF, ICSI or FET. Birth weight was independently associated with both parental and ART treatment characteristics. Characteristics associated with lower birth weight included maternal hypertensive disease, non-Dutch maternal ethnicity, nulliparity, increasing duration of subfertility, hCG for luteal phase support (compared to progesterone), shorter embryo culture duration, increasing number of oocytes retrieved and fresh embryo transfer. The parental characteristic with the greatest effect size on birth weight was maternal diabetes (adjusted difference 283 g, 95% CI 228-338). FET was the ART treatment characteristic with the greatest effect size on birth weight (adjusted difference 100 g, 95% CI 84-117) compared to fresh embryo transfer. Preterm birth was more common among mothers of South-Asian ethnicity. Preterm birth was less common among multiparous women and women with 'male factor' as treatment indication (compared to 'tubal factor'). LIMITATIONS, REASONS FOR CAUTION: Due to the retrospective nature of our study, we cannot prove causality. Further limitations of our study were the inability to adjust for mothers giving birth more than once in our dataset, missing values for several variables and limited information on parental lifestyle and general health. WIDER IMPLICATIONS OF THE FINDINGS: Multiple parental and ART treatment characteristics affect perinatal outcomes, with birth weight being influenced by the widest range of factors. This highlights the importance of assessing both parental and ART treatment characteristics in studies that focus on the health of ART-offspring, with the purpose of modifying these factors where possible. Our results further support the hypothesis that the embryo is sensitive to its early environment. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by Foreest Medical School, Alkmaar, the Netherlands (grants: FIO 1307 and FIO 1505). B.W.M. reports grants from NHMRC and consultancy for ObsEva, Merck KGaA, iGenomics and Guerbet. F.B. reports research support grants from Merck Serono and personal fees from Merck Serono. A.C. reports travel support from Ferring BV. and Theramex BV. and personal fees from UpToDate (Hyperthecosis), all outside the remit of the current work. The remaining authors report no conflict of interests. TRIAL REGISTRATION NUMBER: N/A.

Association of culture medium with growth, weight and cardiovascular development of IVF children at the age of 9 years.

STUDY QUESTION: Is embryo culture media used during an IVF/ICSI treatment associated with differences in growth, body composition and cardiovascular development as determined in 9-year-old singleton IVF children? SUMMARY ANSWER: The choice of in vitro culture medium for human embryos is associated with differences in body weight, BMI, truncal adiposity, waist circumference and waist/hip ratio at the age of 9, while no significant differences were observed in cardiovascular development. WHAT IS KNOWN ALREADY: Children born after IVF/ICSI have an increased risk of low birthweight, which is correlated with a higher risk of cardiovascular diseases. Some studies show that IVF children exhibit a significantly higher systolic and diastolic blood pressure and higher fasting glucose levels compared to naturally conceived children. After alternating assignment to G1™ Version 3 (Vitrolife) or K-SICM (Cook) embryo culture media, birthweight of the resulting children was significantly higher in the Vitrolife group and they remained heavier during the first 2 years of life. STUDY DESIGN, SIZE, DURATION: In this observational cohort study (MEDIUM-KIDS), parents of singletons from a previous study were approached for further follow-up after the ninth birthday of their child. The singletons were born after fresh embryo transfer of cleavage stage embryos resulting from an IVF/ICSI treatment performed between July 2003 and December 2006 in our clinic, when two different culture media were used alternately: either G1™ Version 3 (Vitrolife) or K-SICM (Cook). Follow-up measurements were performed between March 2014 and December 2016. PARTICIPANT/MATERIALS, SETTINGS, METHODS: Parents were invited to attend our clinic with their child for a single visit lasting ~2.5 h. Two experienced clinicians performed all measurements as part of the MEDIUM-KIDS study in a standardized way. Height and weight of the child was measured using calibrated scales, 4-point skinfold thickness measurements were measured in triplicate and waist and hip circumference were measured using a tape measure. The following cardiovascular parameters were measured in a standardized way: blood pressure, heart rate and endothelial function by skin laser-Doppler with iontophoresis using vasodilatory drugs. Cortisol and cortisone concentrations in hair were measured. A blood sample was taken after an overnight fast for insulin, glucose, TSH and lipid analysis. Blood samples of the IVF children were compared with a non-IVF control group. Differences between culture medium groups were analysed by Student's t-test and effects of confounders were analysed using multivariable regression analysis. MAIN RESULTS AND THE ROLE OF CHANCE: Of the 294 eligible children (168 Vitrolife and 126 Cook), 136 children (75 Vitrolife and 61 Cook) participated in the study. Baseline characteristics of the participating children from the Vitrolife and Cook group were similar. Birthweight was higher in the Vitrolife group, in keeping with the full cohort. After correction for confounders, the difference in weight and BMI attributable to culture medium was 1.58 kg (95% CI: 0.01-3.14) and 0.84 kg/m2 (95% CI: 0.02-1.67), respectively, with the Vitrolife children being heavier. Height and height corrected for age and gender (SDS scores) were similar in both groups. Furthermore, waist circumference was significantly higher in the Vitrolife group with a corrected difference of 3.21 cm (95%CI: 0.60-5.81) leading to a 0.03 increase (95% CI: 0.01-0.05) in waist/hip ratio. Subscapular skinfolds combined with suprailiacal skinfolds (defined as truncal adiposity), was also significantly higher in Vitrolife children (adjusted difference 3.44 cm [95% CI: 0.27-6.62]). Both systolic (adj. beta 0.364 [95% CI: -2.129 to 2.856],) and diastolic (adj. beta 0.275 [95% CI: -2.105 to 2.654]) blood pressures (mmHg) were comparable for the two groups. After an overnight fast, cholesterol, glucose, insulin, low and high-density lipoprotein, triglycerides and TSH were normal and similar in the two groups. Endothelial function in the microcirculation was compared by using maximum perfusion units corrected for the baseline value as a measure for vasodilatory capacity. There were no significant differences between the two groups. Cortisol and cortisone concentration in hair samples were comparable. LIMITATIONS, REASONS FOR CAUTION: A limitation of the original study was its pseudo-randomized design. This and the dwindling enthusiasm of families for participation (47.7% after 9 years) prevent us from drawing robust causal conclusions from the observed association. Nevertheless, to date this is oldest cohort of IVF/ICSI children where culture medium was allocated alternatingly and used in a blinded setting, to be studied. We believe that our participants are representative for the full cohort. The current number of participants was sufficient to rule out differences as little as 3 mmHg in systolic and diastolic blood pressures. WIDER IMPLICATIONS OF THE FINDINGS: This study underlines the importance of structured follow-up of IVF/ICSI children to further elucidate possible long-term health effects. Health professionals and culture medium manufacturers should be aware that small changes in culture conditions and culture medium composition for the early embryo can have long-term health effects. The similar cardiovascular results for the two groups are reassuring but the children may still be too young to detect differences in cardiovascular development. Prolonged follow-up and structured investigations up until adulthood are necessary to gain more insight and reassurance in the cardiovascular development of IVF offspring, although long-term follow-up will become more complicated by confounding life-style and environmental factors possibly influencing development. STUDY FUNDING/COMPETING INTEREST(S): The study was financially supported by the March of Dimes (Grant number #6-FY13-153). The sponsor of the study had no role in study design, data collection, data analysis, data interpretation or writing of the report. The authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: NTR4220.

Cost-effectiveness of embryo transfer strategies: a decision analytic model using long-term costs and consequences of singletons and multiples born as a consequence of IVF.

STUDY QUESTION: What is the cost-effectiveness of elective single embryo transfer (eSET) versus double embryo transfer (DET) strategies from a societal perspective, when applying a time horizon of 1, 5 and 18 years? SUMMARY ANSWER: From a short-term perspective (1 year) it is cost-effective to replace DET with single embryo transfer; however when intermediate- (5 years) and long-term (18 years) costs and consequences are incorporated, DET becomes the most cost-effective strategy, given a ceiling ratio of €20 000 per quality-adjusted life years (QALY) gained. WHAT IS ALREADY KNOWN: According to previous cost-effectiveness research into embryo transfer strategies, DET is considered cost-effective if society is willing to pay around €20 000 for an extra live birth. However, interpretation of those studies is complicated, as those studies fail to incorporate long-term costs and outcomes and used live birth as a measure of effectiveness instead of QALYs. With this outcome, both multiple and singletons were valued as one live birth, whereas costs of all children of a multiple were incorporated. STUDY DESIGN, SIZE, DURATION: A Markov model (cycle length: 1 year; time horizon: 1, 5 and 18 years) was developed comparing a maximum of: (i) three cycles of eSET in all patients; (ii) four cycles of eSET in all patients; (iii) five cycles of eSET in all patients; (iv) three cycles of standard treatment policy (STP), i.e. eSET in women <38 years with a good quality embryo, and DET in all other women; and (v) three cycles of DET in all patients. PARTICIPANTS/MATERIALS, SETTING, METHODS: Expected life years (LYs), child QALYs and costs were estimated for all comparators. Input parameters were derived from a retrospective cohort study, in which hospital resource data were collected (n=580) and a parental questionnaire was sent out (431 respondents). Probabilistic sensitivity analysis (5000 iterations) was performed. MAIN RESULTS AND THE ROLE OF CHANCE: With a time horizon of 18 years, DETx3 is most effective (0.54 live births, 10.2 LYs and 9.8 QALYs) and expensive (€37 871) per couple starting IVF. Three cycles of eSET are least effective (0.43 live births, 7.1 LYs and 6.8 QALYs) and expensive (€25 563). We assumed that society is willing to pay €20 000 per QALY gained. With a time horizon of 1 year, eSETx3 was the most cost-effective embryo transfer strategy with a probability of being cost-effective of 99.9%. With a time horizon of 5 or 18 years, DETx3 was most cost-effective, with probabilities of being cost-effective of 77.3 and 93.2%, respectively. LIMITATIONS, REASONS FOR CAUTION: This is the first study to use QALYs generated by the children in the economic evaluation of embryo transfer strategies. There remains some disagreement on whether QALYs generated by new life should be used in economic evaluations of fertility treatment. A further limitation is that treatment ends when it results in live birth and that only child QALYs were considered as measure of effectiveness. The results for the time horizon of 18 years might be less solid, as the data beyond the age of 8 years are based on extrapolation. WIDER IMPLICATIONS OF THE FINDINGS: The current Markov model indicates that when child QALYs are used as measure of outcome it is not cost-effective on the long term to replace DET with single embryo transfer strategies. However, for a balanced approach, a family-planning perspective would be preferable, including additional treatment cycles for couples who wish to have another child. Furthermore, the analysis should be extended to include QALYs of family members. STUDY FUNDING/COMPETING INTERESTS: This study was supported by a research grant (grant number 80-82310-98-09094) from the Netherlands Organization for Health Research and Development (ZonMw). There are no conflicts of interest in connection with this article. TRIAL REGISTRATION NUMBER: Not applicable.

Hospital costs during the first 5 years of life for multiples compared with singletons born after IVF or ICSI.

STUDY QUESTION: Do in vitro fertilization (IVF) multiples generate higher hospital costs than IVF singletons, from birth up to age 5? SUMMARY ANSWER: Hospital costs from birth up to age 5 were significantly higher among IVF/ICSI multiple children compared with IVF/ICSI singletons; however, when excluding the costs incurred during the birth admission period, hospital costs of multiples and singletons were comparable. WHAT IS KNOWN ALREADY: Concern has risen over the long-term outcome of children born after IVF. The increased incidence of multiple births in IVF as a result of double-embryo transfer predisposes children to a poorer neonatal outcome such as preterm birth and low birthweight. As a consequence, IVF multiples require more medical care. Costs and consequences of poorer neonatal outcomes in multiples may also exist later in life. STUDY DESIGN, SIZE, DURATION: All 5497 children born from IVF in 2003-2005, whose parents received IVF or ICSI treatment in one of five participating Dutch IVF centers, served as a basis for a retrospective cohort study. Based on gestational age, birthweight, Apgar and congenital malformation, children were assigned to one of three risk strata (low-, moderate- or high-risk). PARTICIPANTS/MATERIALS, SETTING, METHODS: To enhance the efficiency of the data collection, 816 multiples and 584 singletons were selected for 5-year follow-up based on stratified (risk) sampling. Parental informed consent was received of 322 multiples and 293 singletons. Individual-level hospital resource use data (hospitalization, outpatient visits and medical procedures) were retrieved from hospital information systems and patient charts for 302 multiples and 278 singletons. MAIN RESULTS AND THE ROLE OF CHANCE: The risk of hospitalization (OR 4.9, 95% CI 3.3-7.0), outpatient visits (OR 2.6, 95% CI 1.8-3.6) and medical procedures (OR 1.7, 95% CI 1.2-2.2) was higher for multiples compared with singletons. The average hospital costs amounted to €10 018 and €2093 during the birth admission period (P < 0.001), €1131 and €696 after the birth admission period to the first birthday (not significant (n.s.)) and €1084 and €938 from the second to the fifth life year (n.s.) for multiples and singletons, respectively. Hospital costs from birth up to age 5 were 3.3-fold higher for multiples compared with singletons (P < 0.001). Among multiples and singletons, respectively, 90.8 and 76.2% of the total hospital costs were caused by hospital admission days and 8.9 and 25.2% of the total hospital costs during the first 5 years of life occurred after the first year of life. LIMITATIONS, REASONS FOR CAUTION: Resource use and costs outside the hospital were not included in the analysis. WIDER IMPLICATIONS OF THE FINDINGS: This study confirms the increased use of healthcare resources by IVF/ICSI multiples compared with IVF/ICSI singletons. Single-embryo transfer may result in substantial savings, particularly in the birth admission period. These savings need to be compared with the extra costs of additional embryo transfers needed to achieve a successful pregnancy. Besides costs, health outcomes of children born after single-embryo transfer should be compared with those born after double-embryo transfer. STUDY FUNDING/COMPETING INTERESTS: This study was supported by a research grant (grant number 80-82310-98-09094) from the Netherlands Organization for Health Research and Development (ZonMw). There are no conflicts of interest in connection with this article. TRIAL REGISTRATION NUMBER: Not applicable.

Increased blood pressure and impaired endothelial function after accelerated growth in IVF/ICSI children.

STUDY QUESTION: What is the effect of growth velocity (height and weight) in early infancy on metabolic end-points and endothelial function in children born after ART? SUMMARY ANSWER: Neonatal, infant and childhood growth is positively related to blood pressure in 9-year-old IVF/ICSI offspring, while growth in childhood was negatively associated with endothelial function. WHAT IS KNOWN ALREADY: Offspring of pregnancies conceived after ART are at risk for later cardiometabolic risk factors. It is well established that early growth is related to numerous later cardiometabolic risk factors such as high blood pressure. This concept is known as the Developmental Origin of Health and Disease theory. STUDY DESIGN SIZE DURATION: The relation between early growth and later cardiometabolic risk profile was studied in the MEDIUM-KIDS study, a prospective observational cohort study in children born after an IVF/ICSI treatment. In 131 children (48.1% males) at the average age of 9.4 years, cardiometabolic outcomes were assessed and growth data from birth until age 9 years were collected from child welfare centers. PARTICIPANTS/MATERIALS SETTINGS METHODS: The following cardiometabolic outcomes were assessed: blood pressure, skinfolds, lipid spectrum, hair cortisone and glucose and insulin levels. Data on maximum skin perfusion after transdermal delivery of acetylcholine as a measure of endothelial function were collected.Growth charts were obtained electronically from child welfare centers, which offer free consultations and vaccinations to all Dutch children. At these centers, height and weight are recorded at predefined ages. Growth was defined as z-score difference in weight between two time points. Multivariable linear regression analysis was used to model the relation between growth and cardiometabolic outcomes. The following growth windows were -studied simultaneously in each model: 0-1 month, 1-3 months, 3-6 months, 6-11 months, 11-24 months and 2-6 years. The model was adjusted for height growth in all intervals except for 0-1 month. MAIN RESULTS AND THE ROLE OF CHANCE: In multivariable linear regression analyses, multiple growth windows were positively associated with blood pressure, for example growth from 2-6 years was significantly related to systolic blood pressure: B = 4.13, P = 0.005. Maximum skin perfusion after acetylcholine was negatively associated with height-adjusted weight gain from 2 to 6 years: B = -0.09 (log scale), P = 0.03. Several growth windows (weight 1-3 months, 3-6 months, 6-11 months, 11-24 months, 2-6 years) were positively linked with total adiposity. Lipids, glucose tolerance indices and cortisone were not related to growth. LIMITATIONS REASONS FOR CAUTION: This study is of modest size and of observational nature, and we did not include a control group. Therefore, we cannot assess whether the observed associations are causal. It is also not possible to analyze if our observations are specific for, or exacerbated in, the ART population. Ideally, a control group of naturally conceived siblings of IVF/ICSI children should simultaneously be studied to address this limitation and to assess the impact of the ART procedure without the influence of parental (subfertility) characteristics. WIDER IMPLICATIONS OF THE FINDINGS: The results of this study contribute to our understanding of the reported increased risk for hypertension in ART offspring. We speculate that early, accelerated growth may be involved in the reported increased risk for hypertension in ART offspring, with endothelial dysfunction as a possible underlying mechanism. However, additional research into the mechanisms involved is required. STUDY FUNDING/COMPETING INTERESTS: The study was financially supported by the March of Dimes, grant number #6-FY13-153. The sponsor of the study had no role in study design, data collection, data analysis, data interpretation or writing of the paper. The authors have no conflict of interest to declare. TRIAL REGISTRATION NUMBER: NTR4220.

Erratum: Increased blood pressure and impaired endothelial function after accelerated growth in IVF/ICSI children.

[This corrects the article DOI: 10.1093/hropen/hoz037.].

What is the most accurate estimate of pregnancy rates in IVF dropouts?

BACKGROUND: Dropouts in IVF-programmes affect cumulative pregnancy rates (CPRs), but it is unknown what the impact of loss to follow-up is. METHODS: Data were obtained from 588 couples starting IVF treatment ('as treated group'). Cycle-based and real-time-based CPRs were calculated using three assumptions for dropouts: dropouts having no probability of pregnancy, dropouts having the same probability of pregnancy as those continuing treatment and dropouts stopping because of medical reasons having no chance of pregnancy and those stopping because of other reasons having the same probability of pregnancy as those continuing treatment. CPRs obtained in the 'as treated group' were compared with CPRs calculated using the data set including the follow-up data of the dropouts ('completed group'). RESULTS: In 1.7% of couples, no follow-up could be obtained. The cycle-based CPR after three IVF-cycles ranged from 63% to 71% in the 'as treated group' and was 65% in the 'completed group'. The real-time-based CPR after 9 months ranged from 54% to 59% in the 'as treated group' and was 55% in the 'completed group'. The PR in dropouts was 14% (95% confidence interval 8.22%). CONCLUSIONS: In IVF programmes, outcome data of dropouts remain unknown, and CPRs should be calculated by assuming dropouts to have a PR between no probability and the same probability as those who continue treatment. Our study shows that the most accurate estimate for the PR in dropouts is 14%.

No effect of IVF culture medium on cognitive development of 9-year-old children.

STUDY QUESTION: Do embryo culture media used during an IVF/ICSI treatment have an effect on cognitive development of singleton IVF children at 9 years of age? SUMMARY ANSWER: Cognitive development of children born after culture in two different embryo culture media is comparable. WHAT IS KNOWN ALREADY: Previously, we have shown that the culture medium used in an IVF/ICSI treatment affects birthweight and weight at 2 years of age after alternating assignment to embryo culture in either K-SCICM (Cook) or G1™ Version 3 (Vitrolife). Children with low birthweight are known to have an increased risk for learning disabilities. Data on cognitive development in general of children born after ART are still conflicting, and the only study reporting on the effects of culture medium on cognitive development shows significant differences in cognitive development between two culture medium groups. STUDY DESIGN SIZE DURATION: In this observational cohort follow-up study (MEDIUM-KIDS), parents of all singletons from our abovementioned study were approached after the ninth birthday of their child to participate in an additional follow-up study. Of the 294 eligible children included in the original study, 119 children (70 Vitrolife and 49 Cook) participated in the current study. PARTICIPANTS/MATERIALS SETTING METHODS: All follow-up measurements were performed between March 2014 and December 2016. CITO (Dutch Central Institute for Test Development) developed the Dutch pupil monitoring system, which involves nationwide independent, standardized, academic achievement score tests to monitor the child's school performance twice a year at fixed time points from third grade onward. The tests include language skills (vocabulary and orthography), mathematics and reading capability and comprehension. Results from the tests performed between third and sixth grades, expressed as ability scores, were obtained from the school. To investigate school performance development over the years, we used a mixed effects multilevel model. The least complex model with the best fit was selected to analyze whether culture medium affects cognitive development in our cohort. The study had enough power to detect a difference in ability score that reflects at least one performance category between the two groups. MAIN RESULTS AND THE ROLE OF CHANCE: No differences were seen in baseline characteristics between participants and non-participants (both parental and children characteristics). For all domains, the random intercept model was used. All analyses showed comparable results for the two culture medium groups. No significant differences were observed for any of the cognitive development domains, even after correction for potential confounders. Parental level of education was higher in the IVF group (45%) if compared to the national average level of education (35%), which most likely explains the higher CITO scores for the IVF children if compared to the National ability scores. LIMITATIONS REASONS FOR CAUTION: A limitation of the study was its pseudo-randomized design and the relatively low participation rate of 40.5%. This and the number of missing data prevent us from drawing robust causal conclusions. However, as this is the first and therewith oldest cohort of children where culture medium was allocated alternatingly and used in a blinded setting, in the same period, with all other conditions identical this study gives up until now the best available evidence. WIDER IMPLICATIONS OF THE FINDINGS: Our study analyzes the effects of culture medium on school performance of children born after IVF/ICSI in a prospective cohort study. Although further research on long-term academic skills and also on behavior is essential, our results are reassuring and should make parents of children born after IVF/ICSI feel comfortable with their children's cognitive development. STUDY FUNDING/COMPETING INTERESTS: The study was financially supported by the March of Dimes (Grant no. #6-FY13-153). The sponsor of the study had no role in study design, data collection, data analysis, data interpretation or writing of the report. The authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: NTR4220.

Lack of effect of peritoneal endometriosis on fertility in the rabbit model.

STUDY OBJECTIVE: To study the isolated influence of peritoneal endometrial implants on fertility in an adhesion-free rabbit model. STUDY DESIGN: Thirty-two rabbits with endometrium implants were used; 31 rabbits with fat implants served as controls. In these rabbits parameters of early embryonic development were investigated. RESULTS: No significant differences were noted in ovulation, ovum pick-up, fertilization, tubal transport, and embryonic and fetal development. CONCLUSION: In the adhesion-free rabbit model, peritoneal implants of endometriosis do not have an effect on fertility. This supports the contention that therapies focused toward the implants are unlikely to change the pregnancy outcomes. Alternatively, it may cast doubts onto the relevance of animal models in studying this disease.

High-dose human menopausal gonadotropin stimulation in poor responders does not improve in vitro fertilization outcome.

OBJECTIVE: To study the outcome in poor responders to three ampules (225 IU) of hMG per day in subsequent IVF treatment cycles in which six ampules (450 IU)of hMG per day were administered. DESIGN: Retrospective chart review. SETTING: Academic tertiary center. PATIENTS: Between January 1988 and May 1995, 126 poor response patients had a first treatment cycle on three ampules and a second cycle on six ampules of hMG per day. MAIN OUTCOME MEASURES: Numbers of follicles, oocytes, and embryos, and pregnancy rates. RESULTS: On six ampules, patients had significantly more follicles and oocytes. The number of embryos did not differ significantly. The pregnancy rate on six ampules were low (3.2% pregnancies per cycle started). CONCLUSION: Poor responders do not benefit from high-dose hMG stimulation; their reproduction outcome is poor.

Elevated levels of basal estradiol-17beta predict poor response in patients with normal basal levels of follicle-stimulating hormone undergoing in vitro fertilization.

OBJECTIVE: To evaluate whether the predictive ability of a normal FSH level on cycle day 3 can be enhanced by levels of estradiol-17beta (E2) on cycle day 3. DESIGN: Prospective cohort study. SETTING: University hospital-based, tertiary care infertility center. PATIENT(S): Two hundred thirty-one consecutively seen patients who attended the center for their first IVF attempt. INTERVENTION(S): Blood samples were collected on day 3 of the cycle preceding IVF; IVF was performed in all patients. MAIN OUTCOME MEASURE(S): Patient's age, number of ampules of hMG, cancellation rate, number of oocytes, fertilization rate, and clinical pregnancy rate. RESULT(S): In patients with elevated FSH levels on cycle day 3, a low oocyte yield was achieved (7 versus 11) and a high number of ampules of hMG was necessary (56 versus 33). Their cancellation rate was high (67% versus 16%). In patients with normal basal FSH levels, high E2 levels predicted a high cancellation rate (56%, versus 13% in patients with low E2 levels) and a low oocyte yield (9, versus 11 in patients with low E2 levels). Patients with both normal FSH levels and low E2 levels on cycle day 3 fared best. CONCLUSION(S): The basal E2 level on cycle day 3 is a useful prognosticator of response to stimulation in IVF patients with normal basal FSH levels.

The protective effects of polymers in the cryopreservation of human and mouse zonae pellucidae and embryos.

OBJECTIVES: To evaluate the occurrence of injury due to physical factors in embryo cryopreservation and the effect of the polymers dextran, polyvinylpyrrolidone (PVP), and Ficoll on this mechanical damage. DESIGN: Damage to the zona pellucida (ZP) observed after cryopreservation was taken as indication of cryoinjury caused exclusively by physical factors. Human and mouse ZPs from oocytes remaining unfertilized after previous IVF attempts and mouse two-cell embryos were frozen in the presence of different polymers. After thawing, they were checked carefully for signs of physical damage (cracks). A possible toxicity of the use of the polymers in cryoprotection was evaluated by development to the blastocyst stage of mouse two-cell embryos that survived the freezing and thawing process. RESULTS: Incidences of damaged ZPs in groups of human and mouse ZPs and two-cell embryos frozen without polymers were found to vary between 20% and 29%. The use of any of the tested polymers resulted in significantly lower incidences of damaged ZPs (0% to 15%). Damage to the ZP after freezing and thawing in mouse embryos was accompanied by low survival rates of the embryo itself. Of mouse embryos that survived the cryopreservation process, blastocyst formation was not significantly different in groups frozen without polymer (80%) or in the presence of either dextran (90%) or Ficoll (82%); however, embryos frozen in the presence of PVP showed low blastocyst formation (12%). CONCLUSIONS: Polymers can protect embryos against cryoinjury by avoiding mechanical strain occurring during cryopreservation. Polyvinylpyrrolidine is toxic to mouse two-cell embryos when present during freezing and thawing.

Immaturity and aneuploidy in human oocytes after different stimulation protocols.

OBJECTIVE: To study immaturity and aneuploidy in human oocytes after two different stimulation protocols. DESIGN: Retrospective. SETTING: Outpatient IVF clinic/laboratory. PATIENTS: One hundred forty-three patients of whom 65 were stimulated with clomiphene citrate (CC)/human menopausal gonadotropin (hMG) and 78 were stimulated with gonadotropin-releasing hormone agonist (GnRH-a)/hMG. Only patients with at least one oocyte unfertilized were included in this study. RESULTS: Stimulation with GnRH-a/hMG, as compared with CC/hMG stimulation, resulted in larger numbers of oocytes (P less than 0.00001), a higher fertilization rate (P less than 0.02), and oocyte retrieval at a later average cycle day (P less than 0.000005). Cytogenetic findings of immaturity were observed in 33.9% of unfertilized oocytes after CC/hMG stimulation, compared with only 17.8% after GnRH-a/hMG stimulation (P less than 0.0005). Aneuploidy findings were the same for both groups. CONCLUSION: In GnRH-a/hMG stimulation, oocytes approach the normal day of ovulation more closely. This may allow for better oocyte maturation and higher fertilization and pregnancy rates.

Effect of oxygen concentration on in vitro fertilization and embryo culture in the human and the mouse.

OBJECTIVE: To compare the effect of culturing oocytes, zygotes and embryos under low (5%) versus ambient (20%) oxygen conditions on human IVF results and on mouse blastocyst formation. DESIGN: A prospective, randomized study of 257 consecutive IVF treatment cycles in 186 couples undergoing oocyte retrieval for various reasons of infertility. Gametes and resulting embryos after IVF were alternately allocated to fertilization and culture either under a gas phase of 5% CO2/90% N2/5% O2, or 5% CO2/95% air (20% O2). Oocytes and embryos from randomly bred and hybrid mouse strains were randomly allocated to culture under either of the two gas phases. SETTING: A university hospital-based IVF-ET program. MAIN OUTCOME MEASURE: In the human, rates of fertilization, embryonic development at the time of embryo replacement (42 to 46 hours after insemination), pregnancy, and implantation were compared. In the mouse, the rates of blastocyst formation were compared. RESULTS: Clinical pregnancies occurred in 24.2% versus 19.4% of retrievals when culture took place under low oxygen versus ambient oxygen conditions. Fertilization, embryonic development, pregnancy, and implantation rates did not differ significantly between the groups. Slightly higher blastocyst rates occurred when mouse embryos from hybrid strains were cultured under low oxygen compared with culture under ambient oxygen conditions, whereas no such difference in blastocyst rates was found in randomly bred mouse embryos. CONCLUSIONS: This study failed to demonstrate any improvement in human IVF results associated with the use of a gas mixture of 5% CO2/90% N2/5% O2 during the first two days of development compared with the use of 5% CO2 in air.

Clinical effectiveness of elective single versus double embryo transfer: meta-analysis of individual patient data from randomised trials.

OBJECTIVE: To compare the effectiveness of elective single embryo transfer versus double embryo transfer on the outcomes of live birth, multiple live birth, miscarriage, preterm birth, term singleton birth, and low birth weight after fresh embryo transfer, and on the outcomes of cumulative live birth and multiple live birth after fresh and frozen embryo transfers. DESIGN: One stage meta-analysis of individual patient data. DATA SOURCES: A systematic review of English and non-English articles from Medline, Embase, and the Cochrane Central Register of Controlled Trials (up to 2008). Additional studies were identified by contact with clinical experts and searches of bibliographies of all relevant primary articles. Search terms included embryo transfer, randomised controlled trial, controlled clinical trial, single embryo transfer, and double embryo transfer. Review methods Comparisons of the clinical effectiveness of cleavage stage (day 2 or 3) elective single versus double embryo transfer after fresh or frozen in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI) treatments were included. Trials were included if the intervention differed only in terms of the intended number of embryos to be transferred. Trials that involved only blastocyst (day five) transfers were excluded. RESULTS: Individual patient data were received for every patient recruited to all eight eligible trials (n=1367). A total of 683 and 684 women randomised to the single and double embryo transfer arms, respectively, were included in the analysis. Baseline characteristics in the two groups were comparable. The overall live birth rate in a fresh IVF cycle was lower after single (181/683, 27%) than double embryo transfer (285/683, 42%) (adjusted odds ratio 0.50, 95% confidence interval 0.39 to 0.63), as was the multiple birth rate (3/181 (2%) v 84/285 (29%)) (0.04, 0.01 to 0.12). An additional frozen single embryo transfer, however, resulted in a cumulative live birth rate not significantly lower than the rate after one fresh double embryo transfer (132/350 (38%) v 149/353 (42%) (0.85, 0.62 to 1.15), with a minimal cumulative risk of multiple birth (1/132 (1%) v 47/149 (32%)). The odds of a term singleton birth (that is, over 37 weeks) after elective single embryo transfer was almost five times higher than the odds after double embryo transfer (4.93, 2.98 to 8.18). CONCLUSIONS: Elective single embryo transfer results in a higher chance of delivering a term singleton live birth compared with double embryo transfer. Although this strategy yields a lower pregnancy rate than a double embryo transfer in a fresh IVF cycle, this difference is almost completely overcome by an additional frozen single embryo transfer cycle. The multiple pregnancy rate after elective single embryo transfer is comparable with that observed in spontaneous pregnancies.

Economic evaluations of single- versus double-embryo transfer in IVF.

Multiple pregnancies lead to complications and induce high costs. The most successful way to decrease multiple pregnancies in IVF is to transfer only one embryo, which might reduce the efficacy of treatment. The objective of this review is to determine which embryo-transfer policy is most cost-effective: elective single-embryo transfer (eSET) or double-embryo transfer (DET). Several databases were searched for (cost* or econ*) and (single embryo* or double embryo* or one embryo* or two embryo* or elect* embryo or multip* embryo*). On the basis of five exclusion criteria, titles and abstracts were screened by two individual reviewers. The remaining papers were read for further selection, and data were extracted from the selected studies. A total of 496 titles were identified through the searches and resulted in the selection of one observational study and three randomized studies. Study characteristics, total costs and probability of live births were extracted. Besides this, cost-effectiveness and incremental cost-effectiveness were derived. It can be concluded that DET is the most expensive strategy. DET is also most effective if performed in one fresh cycle. eSET is only preferred from a cost-effectiveness point of view when performed in good prognosis patients and when frozen/thawed cycles are included. If frozen/thawed cycles are excluded, the choice between eSET and DET depends on how much society is willing to pay for one extra successful pregnancy.

Is controlled ovarian stimulation in intrauterine insemination an acceptable therapy in couples with unexplained non-conception in the perspective of multiple pregnancies?

BACKGROUND: Controlled ovarian stimulation (COS) with intrauterine insemination (IUI) is a common treatment in couples with unexplained non-conception. Induction of multifollicular growth is considered to improve pregnancy outcome, but it contains an increased risk of multiple pregnancies and ovarian hyperstimulation syndrome. In this study the impact of the number of follicles (>14 mm) on the ongoing pregnancy rate (PR) and multiple PR was evaluated in the first four treatment cycles. METHODS: A retrospective cohort study was performed in all couples with unexplained non-conception undergoing COS-IUI in the Academic Hospital of Maastricht. The main outcome measure was ongoing PR. Secondary outcomes were ongoing multiple PR, number of follicles of >or=14 mm, and order of treatment cycle. RESULTS: Three hundred couples were included. No significant difference was found in ongoing PR between women with one, two, three or four follicles respectively (P=0.54), but in women with two or more follicles 12/73 pregnancies were multiples. Ongoing PR was highest in the first treatment cycle and declined significantly with increasing cycle order (P=0.006), while multiple PR did not change. CONCLUSIONS: In COS-IUI for unexplained non-conception, induction of more than one follicle did not improve the ongoing PR, but increased the risk of multiple pregnancies. Multiple PR remained high in the first four cycles with multifollicular stimulation. Therefore, in order to reduce the number of multiple pregnancies, in all IUI cycles for unexplained non-conception monofollicular growth should be aimed at.

Intermediate filament protein expression in early developmental stages of the mouse. A confocal scanning laser microscopy study of in vitro fertilized and in vitro cultured pre-implantation mouse embryos.

Expression patterns of intermediate filament proteins have been studied during early mouse embryo development. For this purpose, pre-implantation embryos at different stages of development after in vitro fertilization were studied using antibodies to cytokeratins, vimentin and lamins, using the indirect immunofluorescence assay. The levels of expression were quantitated and localization of the protein constituents was assessed by means of confocal scanning laser microscopy. Our studies showed that, although the embryos grew in culture, vimentin could not be detected in a filamentous organization. Immunofluorescence for cytokeratins was only positive from the 8-cell stage onwards. In the morula stage an increased level of cytokeratin expression was observed with a transitional staining pattern, combining a filamentous and a diffuse occurrence. In the blastocyst stages profound cytokeratin filaments were seen in trophoblast cells but not in the inner cell mass. When the cytokeratin subtypes were analysed separately, it became apparent that expression levels of cytokeratins 8 and 18 increased gradually up to a filamentous pattern in the blastocyst stage. Cytokeratins 7 and 19, although elevated in the latter stage and showing a filamentous distribution, were not found as prominently as cytokeratins 8 and 18. A-type as well as B-type lamins could be detected in all developmental stages examined, as a faintly reactive nuclear lamina. In blastocysts both lamin types were detected in trophoblast as well as in inner cell mass.

Pregnancies during and after homologous intrauterine insemination cycles.

Results of intrauterine insemination (IUI) in 39 couples are presented. Indications were male subfertility, cervical factor, unexplained infertility and immunological factor. The patients received a total of 119 treatment cycles. Nine pregnancies were achieved (23.1%) during IUI treatment. The monthly fecundity rate (MFR) during treatment was 7.6%. After stopping IUI, within a follow-up of 1 year 13 pregnancies occurred. Seven pregnancies occurred spontaneously without invasive treatment methods. The MFR was calculated to be 4.8% for this group. We conclude that couples with IUI treatment do achieve pregnancies more quickly, but IUI does not influence a patient's eventual chance to become pregnant.

Optimal preparation of preimplantation embryo interphase nuclei for analysis by fluorescence in-situ hybridization.

A new method was developed to prepare and isolate interphase nuclei from murine preimplantation embryos for analysis by fluorescence in-situ hybridization. Embryos were washed with phosphate-buffered saline and disaggregated in a small drop of bidistilled water containing HCl and Tween 20. During the disaggregation procedure embryos were watched continuously with an inverted microscope. Embryonic nuclei were digested with pepsin to make them accessible for hybridization to the probes and to remove remnants of cytoplasm. Nuclear and probe DNA were denatured simultaneously and hybridization was done overnight, followed by immunocytochemical detection of the probes. Using this method we were able to perform successful in-situ hybridization on all preimplantation stages of the mouse embryo (pronuclei, 2-cell, 4-cell, morula and blastocyst). Probes for the X and Y chromosomes were applied for sex determination. From the results described in this paper we conclude that the preparation and isolation of interphase nuclei from murine embryos with acid and Tween 20 offers high reproducibility, good morphology of the cells and a high hybridization efficiency.