Smaller fetal size in singletons after infertility therapies: the influence of technology and the underlying infertility

Correlation between the severity of endometriosis and the occurrence of placenta accreta spectrum in the subsequent pregnancy

Objective

To investigate the correlation between endometriosis (EMs) severity and placenta accreta spectrum (PAS) risk in the subsequent pregnancy.

Method

Clinical records of 2,142 patients who underwent laparoscopic surgery for EMs at Fujian Provincial Maternal and Child Health Hospital from January 2014 to January 2018, who had achieved pregnancy and were delivered, were analyzed. Baseline data, EMs stage, The Revised American Fertility Society (R-AFS) score, levels of serum indexes, and pregnancy and neonatal outcomes were recorded. The outcome of interest was the occurrence of PAS. The correlation between the R-AFS score, endometriosis staging, and PAS was explored, and the R-AFS threshold was identified.

Results

PAS was associated with a higher incidence of chronic pelvic pain (OR = 8.68, 95% CI: 1.18-45.79, P = 0.014) and infertility for >five years (OR = 2.5, 95% CI: 1.35-4.65, P = 0.003), elevated serum levels of cancer antigens, higher incidence of postpartum hemorrhage, and placenta previa (P < 0.05). PAS rate was higher in women with higher EMs staging and R-AFS score and ovarian EMs combined with deep infiltrating endometriosis (DIE) (P < 0.001). After adjusting for confounders, both R-AFS score (AOR = 1.02, 95% CI: 1.01-1.03, P < 0.001) and ovarian EMs with DIE (AOR = 3.31, 95% CI: 1.54-6.67, P = 0.001) were independent risk factors for PAS. R-AFS score of 29 was identified as a threshold for an increased risk of PAS.

Conclusion

The risk of PAS in patients with endometriosis increases with the R-AFS score. PAS is more likely to occur in women with ovarian EMs combined with DIE. It is necessary to implement a specific monitoring program during pregnancy in patients with a history of severe EMs.

The interplay between mitochondrial DNA genotypes, female infertility, ovarian response, and mutagenesis in oocytes

STUDY QUESTION

Is there an association between different mitochondrial DNA (mtDNA) genotypes and female infertility or ovarian response, and is the appearance of variants in the oocytes favored by medically assisted reproduction (MAR) techniques?

SUMMARY ANSWER

Ovarian response was negatively associated with global non-synonymous protein-coding homoplasmic variants but positively associated with haplogroup K; the number of oocytes retrieved in a cycle correlates with the number of heteroplasmic variants in the oocytes, principally with variants located in the hypervariable (HV) region and rRNA loci, as well as non-synonymous protein-coding variants.

WHAT IS KNOWN ALREADY

Several genes have been shown to be positively associated with infertility, and there is growing concern that MAR may facilitate the transmission of these harmful variants to offspring, thereby passing on infertility. The potential role of mtDNA variants in these two perspectives remains poorly understood.

STUDY DESIGN SIZE DURATION

This cohort study included 261 oocytes from 132 women (mean age: 32 ± 4 years) undergoing ovarian stimulation between 2019 and 2020 at an academic center. The oocyte mtDNA genotypes were examined for associations with the women's fertility characteristics.

PARTICIPANTS/MATERIALS SETTING METHODS

The mtDNA of the oocytes underwent deep sequencing, and the mtDNA genotypes were compared between infertile and fertile groups using Fisher's exact test. The impact of the mtDNA genotype on anti-Müllerian hormone (AMH) levels and the number of (mature) oocytes retrieved was assessed using the Mann-Whitney U test for univariate analysis and logistic regression for multivariate analysis. Additionally, we examined the associations of oocyte maturation stage, infertility status, number of ovarian stimulation units, and number of oocytes retrieved with the type and load of heteroplasmic variants using univariate analysis and Poisson or linear regression analysis.

MAIN RESULTS AND THE ROLE OF CHANCE

Neither homoplasmic mtDNA variants nor haplogroups in the oocytes were associated with infertility status or with AMH levels. Conversely, when the relationship between the number of oocytes retrieved and different mtDNA genotypes was examined, a positive association was observed between the number of metaphase (MII) oocytes (P = 0.005) and haplogroup K. Furthermore, the presence of global non-synonymous homoplasmic variants in the protein-coding region was significantly associated with a reduced number of total oocytes and MII oocytes retrieved (P < 0.001 for both). Regarding the type and load of heteroplasmic variants in the different regions, there were no significant associations according to maturation stage of the oocyte or to fertility status; however, the number of oocytes retrieved correlated positively with the total number of heteroplasmic variants, and specifically with non-synonymous protein-coding, HV and rRNA variants (P < 0.001 for all).

LIMITATIONS REASONS FOR CAUTION

The current work is constrained by its retrospective design and single-center approach, potentially limiting the generalizability of our findings. The small sample size for specific types of infertility restricts this aspect of the findings.

WIDER IMPLICATIONS OF THE FINDINGS

This work suggests that mitochondrial genetics may have an impact on ovarian response and corroborates previous findings indicating that the size of the oocyte cohort after stimulation correlates with the presence of potentially deleterious variants in the oocyte. Future epidemiological and functional studies based on the results of the current study will provide valuable insights to address gaps in knowledge to assess any prospective risks for MAR-conceived offspring.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by the Research Foundation Flanders (FWO, Grant numbers 1506617N and 1506717N to C.S.), by the Fonds Wetenschappelijk Fonds, Willy Gepts Research Foundation of Universitair Ziekenhuis Brussel (Grant numbers WFWG14-15, WFWG16-43, and WFWG19-19 to C.S.), and by the Methusalem Grant of the Vrije Universiteit Brussel (to K.S.). M.R. and E.C.d.D. were supported predoctoral fellowships by the FWO, Grant numbers 1133622N and 1S73521N, respectively. The authors declare no conflict of interests.

TRIAL REGISTRATION NUMBER

N/A.

Obstetric and Perinatal Outcomes following Ovulation Induction and Unassisted Pregnancies in the Same Mother

OBJECTIVE

We aimed to assess whether ovulation induction treatments affect obstetric and neonatal outcomes.

STUDY DESIGN

This was a historic cohort study of deliveries in a single university-affiliated medical center between November 2008 and January 2020. We included women who had one pregnancy following ovulation induction and one unassisted pregnancy. The obstetric and perinatal outcomes were compared between pregnancies following ovulation induction and unassisted pregnancies, so that each woman served as her own control. The primary outcome measure was birth weight.

RESULTS

A total of 193 deliveries following ovulation induction and 193 deliveries after unassisted conception by the same women were compared. Ovulation induction pregnancies were characterized by a significantly younger maternal age and a higher rate of nulliparity (62.7 vs. 8.3%, p < 0.001). In pregnancies achieved by ovulation induction, we found a higher rate of preterm birth (8.3 vs. 4.1%, p = 0.02) and instrumental deliveries (8.8 vs. 2.1%, p = 0.005), while cesarean delivery rates were higher following unassisted pregnancies. Birth weight was significantly lower in ovulation induction pregnancies (3,167 ± 436 vs. 3,251 ± 460 g, p = 0.009), although the rate of small for gestational age neonates was similar between the groups. On multivariate analysis, birth weight remained significantly associated with ovulation induction after adjustment for confounders, while preterm birth did not.

CONCLUSION

Pregnancies following ovulation induction treatments are associated with lower birth weight. This may be related to an altered placentation process following uterine exposure to supraphysiological hormonal levels.

KEY POINTS

· Ovulation induction entails lower birthweight.. · This may relate to supraphysiological hormonal levels.. · Monitoring fetal growth is advised in such cases..

Children born after assisted reproduction more commonly carry a mitochondrial genotype associating with low birthweight

Children conceived through assisted reproductive technologies (ART) have an elevated risk of lower birthweight, yet the underlying cause remains unclear. Our study explores mitochondrial DNA (mtDNA) variants as contributors to birthweight differences by impacting mitochondrial function during prenatal development. We deep-sequenced the mtDNA of 451 ART and spontaneously conceived (SC) individuals, 157 mother-child pairs and 113 individual oocytes from either natural menstrual cycles or after ovarian stimulation (OS) and find that ART individuals carried a different mtDNA genotype than SC individuals, with more de novo non-synonymous variants. These variants, along with rRNA variants, correlate with lower birthweight percentiles, independent of conception mode. Their higher occurrence in ART individuals stems from de novo mutagenesis associated with maternal aging and OS-induced oocyte cohort size. Future research will establish the long-term health consequences of these changes and how these findings will impact the clinical practice and patient counselling in the future.

The Impact of Endometriosis on Pregnancy

Despite the increased frequency of endometriosis, it remains one of the most enigmatic disorders regarding its effects on pregnancy. Endometriosis adversely affects both natural and assisted conception. Impaired folliculogenesis, which causes follicular dysfunction and low egg quality, as well as luteal phase problems, reduced fertilization, and abnormal embryogenesis, are some of the mechanisms advocated to explain reproductive dysfunction. There is a rising need for a comprehensive study of the potential negative consequences of this condition on pregnancy outcomes, including the postpartum period, as more women with a medical history of endometriosis become pregnant. Obstetrical complications (small for gestational age [SGA], cesarean section [CS], miscarriage, hemorrhage, low placental adhesion, and preterm delivery) are statistically elevated in women with endometriosis. Furthermore, ruptured ovarian endometrioma, appendicitis, intestinal perforation, and hemoperitoneum have been described in pregnancy. Obstetricians are largely unfamiliar with these complications, as they have not been thoroughly investigated. The development and pathogenesis of endometriosis is an important field of study and has not yet been fully elucidated. Finding these mechanisms is crucial for the development of new and more effective strategies to treat this condition. Endometriosis can have an impact on obstetric and neonatal outcomes of pregnancy, in addition to its potential effects on conception. To date, no additional monitoring is recommended for pregnancies with a history of endometriosis. However, more studies are urgently needed to assess the need for the tailored pregnancy monitoring of women with endometriosis.

Does endometrial thickness affect birth weight and serum levels of pregnancy-associated plasma protein-A in frozen cycles?

OBJECTIVE

To investigate whether endometrial thickness (EMT) affects birth weight and maternal serum pregnancy-associated plasma protein-A (PAPP-A) level in singleton pregnancies following frozen-thawed blastocyst transfer (FET).

METHODS

This retrospective study included women who underwent first-trimester combined screening for aneuploidy after FET, and subsequently delivered a singleton live birth after 24 weeks of gestation at a private in-vitro fertilization centre. The subjects were stratified into three groups based on EMT percentiles: <7.7 mm (<10th percentile), 7.7-12 mm (10-90th percentile), and > 12 mm (>90th percentile). Multi-variable linear regression analysis was undertaken to identify the association between birth weight and EMT after adjusting for variables with p < 0.1 on univariate analysis.

RESULTS

In total, 560 women met the inclusion criteria. Mean (±standard deviation) birth weight was 3127 ± 783 g in those with EMT < 7.7 mm, 3225 ± 644 g in those with EMT 7.7-12 mm, and 3256 ± 599 g in those with EMT > 12 mm (p = 0.577). Mean PAPP-A and PAPP-A < 0.5 rates were similar in the three groups. On multi-variate analysis, maternal serum PAPP-A was found to be a significant predictor of birth weight (p = 0.013), but EMT was not found to be predictive of birth weight on univariate or multi-variate analysis.

CONCLUSION

This study provided a new angle to evaluate the association between EMT and neonatal birth weight by analysing this association along with maternal serum PAPP-A as a marker for placental function, suggesting that EMT is not an independent factor for neonatal birth weight.

Cerebral palsy in children born after assisted reproductive technology: a meta-analysis

BACKGROUND

Several studies have assessed the association between cerebral palsy (CP) and assisted reproductive technology (ART), but the results remain controversial. We conducted a meta-analysis to evaluate the risk of CP after ART compared with natural conceptions and to examine CP risk separately in ART singletons, multiples and preterm births.

METHODS

Web-based databases (PubMed, Embase, the Cochrane Library, and Web of Science) were searched until November 22, 2020. Studies which compare CP rates after ART with natural conceptions were included. The Newcastle-Ottawa Scale was used to assess the quality of the included studies. Effect estimates were extracted and combined using the fixed-effects or random-effects model depending on the heterogeneity test.

RESULTS

There were nine studies included in the meta-analysis. The included studies were of moderate or high quality. A significantly higher risk of CP [odds ratio (OR) = 2.17, 95% confidence interval (CI) 1.72-2.74] was found in ART children (n = 89,214) compared with naturally conceived children (n = 4,160,745). The significantly higher risk decreased when data were restricted to singletons (OR = 1.36, 95% CI 1.16-1.59) and disappeared when data were restricted to multiples (OR = 1.05, 95% CI 0.86-1.29) or preterm births (OR = 1.53, 95% CI 0.66-3.56). Subgroup and sensitivity analyses indicated that the overall results were robust.

CONCLUSIONS

The risk of CP is increased more than two-fold after ART. This increased risk is largely due to increased rates of multiple birth and preterm delivery in ART children.

The effect of repeated cryopreservation and thawing using cryotip on the clinical outcomes of embryos

PURPOSE

To compare the clinical outcomes of embryo transfers that were cryopreserved and thawed two or three times with those cryopreserved and thawed once by CryoTip.

METHODS

Data for 388 single cryopreserved-thawed blastocyst transfer cycles, performed from April 2012 to March 2014, were assessed. The blastocysts were classified into three groups: blastocysts (A) cryopreserved once, (B) cryopreserved twice, and (C) cryopreserved three times.

RESULTS

The pregnancy rate was 43.8% (134/306) in group A and 46.3% (38/82) in group B, while the miscarriage rate was 29.1% (39/134) in group A and 23.7% (9/38) in group B. The rate of improvement/maintenance of blastocyst grade was 84.0% (257/306) in group A and 80.5% (66/82) in group B. The pregnancy and miscarriage rates of the blastocysts that showed improvement/maintenance in the grade were 45.9% (118/257) and 29.7% (35/118) in group A and 48.5% (32/66) and 21.9% (7/32) in group B, respectively. The pregnancy rate was 33.3% (2/6), while the miscarriage rate was 0.0% (0/2) in group C.

CONCLUSIONS

Pregnancy rates achieved with re-cryopreserved and rethawed blastocyst transfer were comparable to those achieved with single cryopreserved-thawed blastocyst transfer.

Neonatal outcomes in singleton pregnancies conceived by fresh or frozen embryo transfer compared to spontaneous conceptions: a systematic review and meta-analysis

Purpose

The use of assisted reproductive technology (ART) has increased in the last 2 decades and continuous surveillance is needed. This systematic review aims to assess the risk of adverse neonatal outcomes (preterm birth [PTB], low birth weight [LBW], small-for-gestationalage [SGA] and large for gestational-age [LGA]), in singleton pregnancies conceived by fresh or frozen embryo transfer (FET) compared to spontaneous conceptions.

Methods

Cohort studies were identified from MEDLINE, Embase, Cochrane Library (January 2019), and manual search. Meta-analyses were performed to estimate odds ratios (OR) using random effects models in RevMan 5.3 and I-squared (I²) test > 50% was considered as high heterogeneity.

Results

After 3142 titles and abstracts were screened, 1180 full-text articles were assessed, and 14 were eligible. For fresh embryo transfer, the pooled ORs were PTB 1.64 (95% CI 1.46, 1.84); I² = 97%; LBW 1.67 (95% CI 1.52, 1.85); I² = 94%; SGA 1.46 [95% CI 1.11, 1.92]; I² = 99%, LGA 0.88 (95% CI 0.80, 0.87); I² = 80%). For frozen, the pooled ORs were PTB 1.39 (95% CI 1.34, 1.44); I² = 0%; LBW 1.38 (95% CI 0.91, 2.09); I² = 98%; SGA 0.83 (95% CI 0.57, 1.19); I² = 0%, LGA 1.57 (95% CI 1.48, 1.68); I² = 22%).

Conclusions

When compared with spontaneous pregnancies, fresh, but not frozen was associated with LBW and SGA. Both fresh and frozen were associated with PTB. Frozen was uniquely associated with LGA. Despite improvements in ART protocols in relation to pregnancy rates, attention is needed towards monitoring adverse neonatal outcomes in these pregnancies.

Electronic supplementary material

The online version of this article (10.1007/s00404-020-05593-4) contains supplementary material, which is available to authorized users.

Examination of fetal growth trajectories following infertility treatment

PURPOSE

The objective of this retrospective cohort study was to compare fetal growth during the second and third trimesters for ovulation induction with intrauterine insemination (IUI), fresh embryo transfer (ET), frozen embryo transfer (FET), and spontaneous conception following infertility.

METHODS

Three hundred ninety-five women with viable pregnancies confirmed at a single academic fertility center participated. All women achieved pregnancy either by treatment or spontaneously after a diagnosis of infertility. Inclusion criteria included autologous singleton pregnancies. Exclusion criteria included pregnancies from donor oocytes, twins, unavailable ultrasound data, and treatment methods with small number of participants. Primary outcomes of interest were head circumference (HC), abdominal circumference (AC), HC/AC ratio, and estimated fetal weight (EFW). Conditional growth curve models were created, and growth curves were selected for each outcome of interest.

RESULTS

For ovulation induction with IUI, fresh ET, FET, and spontaneous conception, the slope analysis of growth curves for per-week growth rate of HC, AC, HC/AC ratio, and EFW demonstrated no difference. A subgroup analysis of fresh ET and FET groups, for same outcomes, also showed no difference.

CONCLUSION

These findings contribute to the very limited literature on fetal growth trajectories following infertility treatment and suggest no significant differences in fetal growth for ovulation induction with IUI, fresh ET, FET, and spontaneous conception following infertility. It is possible there were no differences in growth trajectories between these conception methods because the majority of children born following infertility are of normal birth weight. While results are reassuring, further research with larger populations is warranted.

Maternal and Fetal Risk Associated With Assisted Reproductive Technology

Infertility is a disease that affects up to 15.5% of reproductive-aged couples. Until the birth of the first neonate born from in vitro fertilization (IVF) in 1978, many infertile couples did not have an opportunity to conceive a biological child. Over the past 40 years, access to and effectiveness of IVF have increased; currently 1.7% of births in the United States result from IVF. As with any medical intervention, potential risk exists. In the case of IVF, both maternal risks (ovarian stimulation, oocyte retrieval, and subsequent pregnancy) and fetal risks that vary based on maternal age and fetal number must be considered. Importantly, risk quantification varies by comparison group, which is typically either spontaneous conception in a fertile couple or assisted non-IVF conception in an infertile couple. It must also be considered compared with the alternative of not undergoing IVF, which may mean not having a biological child. Although increased compared with spontaneous conception, absolute maternal-fetal-assisted reproductive technology risks are low and can be minimized by optimizing ovarian stimulation and transferring a single embryo. In this article, we aim to summarize maternal and fetal risk associated with use of assisted reproductive technology. The review focuses on ovarian stimulation and procedural risks as well as adverse perinatal outcomes among resultant singleton and twin pregnancies in young women and women of advanced maternal age.

Endometrial thickness and IVF cycle outcomes: a meta-analysis

RESEARCH QUESTION

In this meta-analysis, the association between endometrial thickness (EMT) and cycle outcomes after IVF is explored. Associations between EMT and cycle outcomes according to study and individual characteristics were also assessed.

DESIGN

Studies evaluating associations between EMT and pregnancy, implantation, miscarriage, live birth or ongoing pregnancy and ectopic pregnancy rates in individuals after IVF were identified on PubMed, Embase and the Cochrane Library (from their inception up to December 2018). Pooled odds ratios with 95% confidence intervals, calculated using the random-effects model, were used.

RESULTS

Nine prospective and 21 retrospective studies, including a total of 88,056 cycles, were retrieved. The summary odds ratios indicated that women with lower EMT were associated with lower pregnancy rates than those with higher EMT (n = 30, OR 0.61; 95% CI 0.52 to 0.70; P < 0.001). Moreover, the implantation rate in women with lower EMT was significantly reduced (n = 9, OR 0.49; 95% CI 0.32 to 0.74; P = 0.001). Furthermore, no significant association was found between EMT and the miscarriage rate (n = 12). In addition, women with lower EMT were associated with reduced live birth or ongoing pregnancy rate (11 studies, OR 0.60; 95% CI 0.48 to 0.73; P < 0.001). Finally, the incidence of ectopic pregnancy rate between lower and higher EMT showed no statistically significant association (n = 3).

CONCLUSIONS

Lower EMT was associated with lower pregnancy, implantation and live birth or ongoing pregnancy rates.

Epigenetically regulated imprinted gene expression associated with IVF and infertility: possible influence of prenatal stress and depression

PURPOSE

Despite the growing body of research implying an impact of in vitro fertilization (IVF) on imprinted genes and epigenetics, few studies have examined the effects of underlying subfertility or prenatal stress on epigenetics, particularly in terms of their role in determining infant birthweights. Both subfertility and prenatal stressors have been found to impact epigenetics and may be confounding the effect of IVF on epigenetics and imprinted genes. Like IVF, both of these exposures-infertility and prenatal stressors-have been associated with lower infant birthweights. The placenta, and specifically epigenetically regulated placental imprinted genes, provides an ideal but understudied mechanism for evaluating the relationship between underlying genetics, environmental exposures, and birthweight.

METHODS AND RESULTS

In this review, we discuss the impacts of IVF and infertility on birthweight, epigenetic mechanisms and genomic imprinting, and the role of these mechanisms in the IVF population and discuss the role and importance of the placenta in infant development. We then highlight recent work on the relationships between infertility, IVF, and prenatal stressors in terms of placental imprinting.

CONCLUSIONS

In combination, the studies discussed, as well as two recent projects of our own on placental imprinted gene expression, suggest that lower birthweights in IVF infants are secondary to a combination of exposures including the infertility and prenatal stress that couples undergoing IVF are experiencing. The work highlighted herein emphasizes the need for appropriate control populations that take infertility into account and also for consideration of prenatal psychosocial stressors as confounders and causes of variation in IVF infant outcomes.

Endometrial thickness of less than 7.5 mm is associated with obstetric complications in fresh IVF cycles: a retrospective cohort study

RESEARCH QUESTION

Does endometrial thickness affect the occurrence of obstetric complications in fresh IVF cycles?

DESIGN

We conducted a retrospective cohort study that included all singleton deliveries resulting from fresh embryo transfers in a single centre between 2008 and 2014. Obstetric complications, i.e. preeclampsia, placental abruption, placenta previa, small for gestational age and preterm delivery, in singleton live births were compared among patients with an endometrial thickness of less than 7.5 mm and 7.5 mm or over on day of HCG triggering. We adjusted for confounders, including maternal age, body mass index, smoking, peak oestradiol, parity, chronic hypertension, pre-gestational diabetes, gestational diabetes, vanishing twin, inherited or acquired thrombophilia, and past pregnancy complications.

RESULTS

A total of 5546 fresh embryo transfer cycles were carried out during the study period, of which 864 singleton deliveries met inclusion criteria. After adjusting for potential confounders, an endometrial thickness of less than 7.5 mm was found to be associated with increased risk for adverse obstetric outcome (adjusted OR 1.53; 95% CI 1.03 to 2.42; P = 0.04) even after excluding patients with prior pregnancy complications (adjusted OR 2.2; 95% CI 1.05 to 4.59; P = 0.035).

CONCLUSIONS

Our results demonstrated that a thin endometrial lining was associated with obstetric complications that might be related to poor placentation. These findings should be validated in large prospective cohort studies.

Identifying a possible factor for the increased newborn size in singleton pregnancies after assisted reproductive technology using cryopreserved embryos, in comparison with fresh embryos

PURPOSE

To determine whether the cycle regimens that are used for endometrial preparation are associated with the birthweight (BW) after assisted reproductive technology (ART) using frozen-thawed embryo transfer (FET).

METHODS

The BW of singletons who were born by ART using FET was compared retrospectively, according to whether a FET was conducted in a hormone replacement therapy cycle (HRT, n = 403) or an ovulatory cycle (OVL, n = 117). The BW after timed intercourse (NAT, n = 162) also was investigated.

RESULTS

There were no significant differences in the age of the mothers, percentage of primiparas, gestational periods, Body Mass Index, and sex ratio between the HRT and OVL cycles. The average BW from HRT was significantly greater than that of OVL. The BW from HRT was also greater, compared with NAT, while statistical significance was not achieved between OVL and NAT. The putative factors affecting the BW, such as ovarian stimulation protocols, endometrial thickness, and the stage and quality of embryos, could not explain the difference in the BW between the HRT and OVL cycles.

CONCLUSION

An increased BW from ART using FET seems to be ascribable to conditions of the endometrium, but not cryopreservation procedures per se, which might provide a mechanistic framework for understanding heavier neonates who are born by FET.

First trimester pregnancy ultrasound findings as a function of method of conception in an infertile population

PURPOSE

The aim of this study was to determine whether first trimester ultrasound measurements of crown rump length (CRL) and gestational sac diameter (GSD) differ depending on the method of conception among infertile women.

METHOD

Infertile women, ages 21-50 years old, who conceived viable, singleton pregnancies via fresh embryo transfer (ET), frozen ET, non-in vitro fertilization (IVF) fertility treatment, or spontaneously were included in this observational cohort study at an academic fertility practice. Embryonic growth trajectories defined by the CRL and GSD at 6 and 8 weeks' gestation were analyzed and compared among the methods of conception.

RESULTS

Crown rump length at 6 weeks' gestation was smaller for conceptions achieved via fresh ET compared with frozen ET in a natural cycle (1.50 vs. 2.50 mm, p = 0.017). Crown rump length was smaller at 8 weeks' gestation in conceptions achieved via fresh ET compared to frozen ET in a programmed cycle (16.13 vs. 17.02 mm, p = 0.039).

CONCLUSION

Among infertile women, embryo growth may differ between fresh and frozen ET as early as 6 and 8 weeks' gestation.

Pregnancy and birth outcomes in couples with infertility with and without assisted reproductive technology: with an emphasis on US population-based studies

Infertility, defined as the inability to conceive within 1 year of unprotected intercourse, affects an estimated 80 million individuals worldwide, or 10-15% of couples of reproductive age. Assisted reproductive technology includes all infertility treatments to achieve conception; in vitro fertilization is the process by which an oocyte is fertilized by semen outside the body; non-in vitro fertilization assisted reproductive technology treatments include ovulation induction, artificial insemination, and intrauterine insemination. Use of assisted reproductive technology has risen steadily in the United States during the past 2 decades due to several reasons, including childbearing at older maternal ages and increasing insurance coverage. The number of in vitro fertilization cycles in the United States has nearly doubled from 2000 through 2013 and currently 1.7% of all live births in the United States are the result of this technology. Since the birth of the first child from in vitro fertilization >35 years ago, >5 million babies have been born from in vitro fertilization, half within the past 6 years. It is estimated that 1% of singletons, 19% of twins, and 25% of triplet or higher multiples are due to in vitro fertilization, and 4%, 21%, and 52%, respectively, are due to non-in vitro fertilization assisted reproductive technology. Higher plurality at birth results in a >10-fold increase in the risks for prematurity and low birthweight in twins vs singletons (adjusted odds ratio, 11.84; 95% confidence interval, 10.56-13.27 and adjusted odds ratio, 10.68; 95% confidence interval, 9.45-12.08, respectively). The use of donor oocytes is associated with increased risks for pregnancy-induced hypertension (adjusted odds ratio, 1.43; 95% confidence interval, 1.14-1.78) and prematurity (adjusted odds ratio, 1.43; 95% confidence interval, 1.11-1.83). The use of thawed embryos is associated with higher risks for pregnancy-induced hypertension (adjusted odds ratio, 1.30; 95% confidence interval, 1.08-1.57) and large-for-gestation birthweight (adjusted odds ratio, 1.74; 95% confidence interval, 1.45-2.08). Among singletons, in vitro fertilization is associated with increased risk of severe maternal morbidity compared with fertile deliveries (vaginal: adjusted odds ratio, 2.27; 95% confidence interval, 1.78-2.88; cesarean: adjusted odds ratio, 1.67; 95% confidence interval, 1.40-1.98, respectively) and subfertile deliveries (vaginal: adjusted odds ratio, 1.97; 95% confidence interval, 1.30-3.00; cesarean: adjusted odds ratio, 1.75; 95% confidence interval, 1.30-2.35, respectively). Among twins, cesarean in vitro fertilization deliveries have significantly greater severe maternal morbidity compared to cesarean fertile deliveries (adjusted odds ratio, 1.48; 95% confidence interval, 1.14-1.93). Subfertility, with or without in vitro fertilization or non-in vitro fertilization infertility treatments to achieve a pregnancy, is associated with increased risks of adverse maternal and perinatal outcomes. The major risk from in vitro fertilization treatments of multiple births (and the associated excess of perinatal morbidity) has been reduced over time, with fewer and better-quality embryos being transferred.

Endometrial thickness influences neonatal birth weight in pregnancies with obstetric complications achieved after fresh IVF-ICSI cycles

PURPOSE

Pregnancy-associated complications, duration of gestation and parity are well-known predictors of neonatal birth weight. Assisted reproductive technology (ART) affects neonatal birth weight as well. Endometrial thickness as measured on the day of HCG triggering may therefore impact on the neonatal birth weight.

METHODS

The data of 764 singleton deliveries achieved after fresh transfer between November 1997 and 2014 were collected retrospectively with the intention to analyze the relationship of maternal and neonatal characteristics with endometrial thickness and the possible predictive value of endometrial thickness on neonatal birth weight.

RESULTS

Higher maternal age (p < 0.001), diminished ovarian reserve (p < 0.001), endometriosis (p = 0.008) and hypogonadotropic hypogonadism (p < 0.001) predicted thin endometrium. Neonatal birth weight (p = 0.004), longer duration of pregnancy (p = 0.008), parity (p = 0.026) and higher maternal BMI (p = 0.003) were correlated significantly with the degree of endometrial proliferation. Endometrial thickness strongly predicted neonatal birth weight (p = 0.004). After adjusting regression analysis for maternal age and BMI, parity, neonatal gender and pregnancy duration, endometrial thickness remained predictive for neonatal birth weight in pregnancies with obstetric complications (p = 0.017). In uneventful pregnancies duration and parity are determinants of neonatal birth weight.

CONCLUSIONS

Our findings suggest that endometrial thickness is an additional ART-related factor influencing neonatal birth weight. This finding should be confirmed in large cohort studies.

Fresh and Frozen-Thawed Embryo Transfer Compared to Natural Conception: Differences in Perinatal Outcome

BACKGROUND/AIM

To compare the pregnancy outcome of singletons conceived after transfer of cryopreserved and thawed embryos (frozen embryo transfer [FET]) to singletons conceived after fresh embryo transfer (fresh ET) and natural conceived singletons.

METHODS

Using a retrospective data analysis on a study population consisting of 1,261 singletons born after FET and 2,519 singletons born after fresh ET between 2006 and 2015. The control group consisted of singletons born after natural conception. Main outcome measures consisted of birth weight (in grams), gestational age, preterm birth (<37 weeks of gestation), being large for gestational age (LGA, above 90th weight percentile adjusted for gestational age) and Apgar scores.

RESULTS

Babies born after FET had an increased risk of high birth weight (adjusted OR [AOR]) 2.92; 1.503-3.482) and being LGA (AOR fresh ET vs. FET 1.47; 1.210-1.787) compared to singletons born after fresh ET, as well as higher birth weights compared to natural conceived children.

CONCLUSIONS

Singletons born after FET have a higher risk of high birth weight and being LGA compared to singletons after fresh ET and compared to natural conceived singletons. We assume that the freezing process might be the underlying cause.

Birthweights and Down syndrome in neonates that were delivered after frozen-thawed embryo transfer: The 2007-2012 Japan Society of Obstetrics and Gynecology National Registry data in Japan

Aim

To evaluate the use of frozen embryos on the outcome of assisted reproductive technology (ART), a retrospective study of the Japanese Assisted Reproductive Technology Registry data during the years 2007-2012 was conducted.

Methods

A total of 124 946 singleton neonates who reached term gestation following ART from 2007-2012, with 80 660 achieved through frozen-thawed embryo transfer (ET) and 44 286 being achieved through fresh ET, were analyzed for their birthweights and chromosomal abnormalities.

Results

The birthweight of the neonates from the frozen-thawed ETs was significantly higher than that of those from the fresh ETs throughout all the study years. The frequency of Down syndrome was 0.17% for the fresh ETs and 0.13% for the frozen-thawed ETs in the period 2007-2012. This study showed that frozen-thawed ETs result in a constant increase of the average birthweight between 37 and 41 weeks gestational age and lower frequencies of Down syndrome.

Conclusion

Frozen-thawed ETs were comparable to the fresh ET method, with the exceptions of higher birthweights and a lower frequency of Down syndrome in the neonates that were born from frozen-thawed ET. The increase in birthweights was not proportional to the gestational ages. This cannot be explained with any well-known mechanism. The frequency of chromosomal abnormalities needs detailed data for analysis.

Ovarian stimulation perturbs methylation status of placental imprinting genes and reduces blood pressure in the second generation offspring

OBJECTIVE(S)

Assisted reproductive technology (ART) is associated with DNA methylation dysfunction of offspring. However, it is unclear whether ovarian stimulation (OS) is responsible for DNA methylation dysfunction of offspring STUDY DESIGN: We built the first-generation (F1) and second-generation (F2) offspring mice model of ovarian stimulation. Bodyweight of F1 and F2 were measured. Expression levels of several imprinted genes (Impact, H19, Igf2, Plagl1, Mest, and Snrpn) in F1 placenta were tested. Methylation status of Plagl1 and H19 promoters was examined with bisulfite sequencing. Glucose tolerance, blood pressure, and heart rate were evaluated in F2 mice.

RESULTS

The OS F1 showed elevated bodyweights in the 2nd, 3rd and 4th weeks, but the difference disappeared in the 5th week. Plagl1 was down-regulated in OS F1. Promoters of Plagl1 and H19 were also hypermethylated in OS F1. F2 of OS mice had the similar bodyweight and glucose tolerance compared with the control F2. However, F2 of OS ♂F1+OS♀ F1 showed the decreased systolic pressure, diastolic pressure, and heart rate.

CONCLUSIONS

Ovarian stimulation perturbs expression levels and methylation status of imprinted genes in offspring. The effect of ovarian stimulation may be passed to F2.

Differential effect of mode of conception and infertility treatment on fetal growth and prematurity

Objectives To examine perinatal outcomes in pregnancies conceived by different methods: fertile women with spontaneous pregnancies, infertile women who achieved pregnancy without treatment, pregnancies achieved by ovulation induction (OI) and in vitro fertilization or intra-cytoplasmic sperm injection (IVF/ICSI). Methods Retrospective single-center cohort study including 200 fertile and 748 infertile women stratified according to infertility treatment. The outcome measurements were preterm delivery (PTD), small-for-gestational-age (SGA), gestational diabetes, placenta previa or preeclampsia. Results The overall rate of pregnancy complications was significantly increased in all infertility groups regardless of the infertility treatment (adjusted odds ratio (OR): infertile without treatment 2.3 versus OI 2.2 versus IVF/ICSI 3.4). While PTD was mainly associated to IVF/ICSI (adjusted OR: infertile without treatment 1.3 versus OI 1.6 versus IVF/ICSI 3.3), SGA was significantly associated to both OI and IVF/ICSI (adjusted OR: infertile without treatment 1.9 versus OI 2.7 versus IVF/ICSI 2.6). All these associations remained statistically significant after adjusting by maternal age and twin pregnancy. Conclusions This study confirms the higher prevalence of pregnancy complications in infertile women irrespectively of receiving infertility treatment or not, and further describes a preferential association of prematurity with IVF/ICSI, and SGA with treated infertility (OI and IVF/ICSI).

Is the wrong question being asked in infertility research?

A persistent finding is that assisted reproductive technology (ART) is associated with compromised birth outcomes, including higher risks for prematurity, low birthweight, and congenital malformations, even among singletons. Over the past decade, our research group, the Massachusetts Outcome Study of Assisted Reproductive Technology (MOSART), has evaluated pregnancy and birth outcomes among three groups of women, those women treated with ART, those with indicators of subfertility but without ART treatment, and fertile women. We have also explored the influence of infertility-related diagnoses on outcomes for women and infants. Over the course of our research, we have changed our perspective from an original focus on ART treatment parameters as the primary cause of excess morbidity to one centered instead on the underlying infertility-related diagnoses. This paper summarizes the research findings from our group that support this change in focus for infertility-based research from a primary emphasis on ART treatment to greater attention to the contribution of preexisting pathology underlying the infertility and suggests directions for future analyses.

Birth Outcomes by Infertility Diagnosis Analyses of the Massachusetts Outcomes Study of Assisted Reproductive Technologies (MOSART)

OBJECTIVE

To evaluate assisted reproductive technology (ART) pregnancy outcomes by infertility diagnosis.

STUDY DESIGN

ART data on women who were treated and gave birth in Massachusetts were linked to vital records and hospital utilization data. Live births were categorized by 8 mutually exclusive ART diagnoses. Risks of prematurity, low birthweight (LBW), small-for-gestational age (SGA), large-for-gestational age (LGA), pregnancy hypertension, gestational diabetes, prenatal hospitalizations, and primary cesarean delivery were modeled using logistic regression, adjusted for parental characteristics, treatment parameters, and plurality (adjusted odds ratios [AORs] and 95% confidence intervals); the reference group were pregnancies with the diagnosis of malefactor.

RESULTS

Among the 7,354 singleton and twin pregnancies, there were nonsignificant differences in the risks for LBW, SGA, or LGA. Significantly increased risks included gestational diabetes (ovulation disorders, AOR 1.80, 1.35-2.41), prematurity (ovulation disorders, AOR 1.36, 1.08-1.71; other factors, AOR 1.33, 1.05-1.67), prenatal hospital admissions (endometriosis, tubal and other factors, ovulation disorders, and uterine factors, AORs ranging from 1.66-2.68), and primary cesarean section (uterine factors, AOR 1.96, 1.15-3.36).

CONCLUSION

Although the infant outcomes of LBW, SGA, and LGA were generally similar across diagnosis groups, specific diagnoses had greater risks for prematurity, gestational diabetes, prenatal hospital utilization, and primary cesarean delivery. (J Reprod Med 2015;

Perinatal outcomes of patients who achieved pregnancy with a morphologically poor embryo via assisted reproductive technology

PURPOSE

To learn more about the perinatal outcomes of conception via the use of low-grade embryos, we evaluated the relationship between the status of transferred embryos and the resultant perinatal outcomes.

METHODS

A total of 340 patients who achieved pregnancy via ART treatment and consequently delivered in our clinic between April 2009 and March 2014 were recruited for this study. Patients were divided into two groups according to a morphological assessment of the transferred embryos, which relegated 79 patients into a poor-embryo group with the remainders (n = 261) placed into a good-embryo group.

RESULTS

The mean maternal age for the poor-embryo group was 36.0 years, which was similar to the good-embryo group (36.8). In both groups, the percentages of fresh ET cycles were similar. The values for the mean birth weight and birth height of infants in the poor-embryo group were 3055 g and 50.3 cm, respectively, and there were no significant differences with the good-embryo group. The umbilical blood gas analysis in the poor-quality group was similar to that in the good-embryo group. There were no obvious major anomalies among the infants of either group.

CONCLUSIONS

The perinatal outcomes of the poor-embryo group were comparable to those of the good-embryo group. Based on these results, we can provide qualified assurance for a normal perinatal outcome to patients who had no choice but to undergo embryo transfer with a poor-quality embryo.

Perinatal outcomes associated with assisted reproductive technology: the Massachusetts Outcomes Study of Assisted Reproductive Technologies (MOSART)

OBJECTIVE

To compare on a population basis the birth outcomes of women treated with assisted reproductive technologies (ART), women with indicators of subfertility but without ART, and fertile women.

DESIGN

Longitudinal cohort study.

SETTING

Not applicable.

PARTICIPANT(S)

A total of 334,628 births and fetal deaths to Massachusetts mothers giving birth in a Massachusetts hospital from July 1, 2004, to December 31, 2008, subdivided into three subgroups for comparison: ART 11,271, subfertile 6,609, and fertile 316,748.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Four outcomes-preterm birth, low birth weight, small for gestational age, and perinatal death-were modeled separately for singletons and twins with the use of logistic regression for the primary comparison between ART births and those to the newly created population-based subgroup of births to women with indicators of subfertility but no ART.

RESULT(S)

For singletons, the risks for both preterm birth and low birth weight were higher for the ART group (adjusted odds ratios [AORs] 1.23 and 1.26, respectively) compared with the subfertile group, and risks in both the ART and the subfertile groups were higher than those among the fertile births group. For twins, the risk of perinatal death was significantly lower among ART births than fertile (AOR 0.55) or subfertile (AOR 0.15) births.

CONCLUSION(S)

The use of a population-based comparison group of subfertile births without ART demonstrated significantly higher rates of preterm birth and low birth weight in ART singleton births, but these differences are smaller than differences between ART and fertile births. Further refinement of the measurement of subfertile births and examination of the independent risks of subfertile births is warranted.

First trimester trophoblast and placental bed vascular volume measurements in IVF or IVF/ICSI pregnancies

STUDY QUESTION

Are first trimester trophoblast volume (TV) and placental bed vascular volume (PBVV) different in IVF or IVF/ICSI pregnancies in comparison with spontaneously conceived pregnancies?

SUMMARY ANSWER

Any possible abnormal placentation in IVF or IVF/ICSI pregnancies in comparison with spontaneously conceived pregnancies is not detected by a difference in PBVV or TV at an early gestational age (GA).

WHAT IS KNOWN ALREADY

Assisted reproductive technology pregnancies have been associated with an increased risk of placenta-related adverse pregnancy outcomes. It is unclear whether these effects originate from infertility or from the technique itself.

STUDY DESIGN, SIZE, DURATION

We performed a retrospective cohort study in which 154 pregnant patients qualified for participation.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Out of 154 pregnant patients, 84 conceived spontaneously and 70 conceived after IVF or IVF/ICSI. We determined the TV at 10 weeks GA by Virtual Organ Computer-aided AnaLysis measuring application and the PBVV at 12 weeks GA by the virtual reality operating system of BARCO I-Space in both subgroups. The investigators were blinded to the mode of conception during the measurements. Analysis was limited to singleton pregnancies with only one sac ever detectable.

MAIN RESULTS AND THE ROLE OF CHANCE

There were no differences in TV (mean 42.7, SD 15.9 versus mean 41.2, SD 13.9, P = 0.70) and PBVV (mean 27.6, SD 16.9 versus mean 24.8, SD 19.9, P = 0.20) between IVF or IVF/ICSI pregnancies and spontaneously conceived pregnancies. There was a significant correlation between TV and PBVV (rs = 0.283, P = 0.004).

LIMITATIONS, REASONS FOR CAUTION

The limitations of the present study concern the small size of the study groups.

WIDER IMPLICATIONS OF THE FINDINGS

IVF or IVF/ICSI does not seem to be associated with abnormal placentation.

STUDY FUNDING/COMPETING INTERESTS

This study was financially supported by the Erasmus Trustfonds, the Meindert de Hoop foundation and the Fonds NutsOhra. No competing interests are declared.

The influence of IVF/ICSI treatment on human embryonic growth trajectories

STUDY QUESTION

Is in vitro fertilization treatment with or without intracytoplasmatic sperm injection (IVF/ICSI) associated with changes in first and second trimester embryonic and fetal growth trajectories and birthweight in singleton pregnancies?

SUMMARY ANSWER

Embryonic and fetal growth trajectories and birthweight are not significantly different between pregnancies conceived with IVF/ICSI treatment and spontaneously conceived pregnancies with reliable pregnancy dating.

WHAT IS KNOWN ALREADY

IVF/ICSI treatment has been associated with increased risks of preterm birth, fetal growth restriction and low birthweight. Decreased first-trimester crown-rump length (CRL) in the general population has been inversely associated with the same adverse pregnancy outcomes.

STUDY DESIGN, SIZE, DURATION

In a prospective periconception birth cohort study conducted in a tertiary centre, 146 singleton pregnancies with reliable pregnancy dating and nonmalformed live borns were investigated, comprised of 88 spontaneous and 58 IVF/ICSI pregnancies.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Serial 3D ultrasound scans were performed from 6 to 12 weeks of gestation. As estimates of embryonic growth, CRL and embryonic volume (EV) were measured using the I-Space virtual reality system. General characteristics were obtained from self-administered questionnaires at enrolment. Fetal growth parameters at 20 weeks and birthweight were obtained from medical records. To assess associations between IVF/ICSI and embryonic growth trajectories, estimated fetal weight and birthweight, stepwise linear mixed model analyses and linear regression analyses were performed using square root transformed CRL and fourth root transformed EV.

MAIN RESULTS AND THE ROLE OF CHANCE

In 146 pregnancies, 934 ultrasound scans were performed of which 849 (90.9%) CRLs and 549 (58.8%) EVs could be measured. Embryonic growth trajectories were comparable between IVF/ICSI pregnancies and spontaneously conceived pregnancies (CRL: βIVF/ICSI = 0.10√mm; P = 0.10; EV: βIVF/ICSI = 0.03(4)√cm³; P = 0.13). Estimated fetal weight and birthweight were also comparable between both groups (βIVF/ICSI = 6 g; P = 0.36 and βIVF/ICSI = 80 g; P = 0.24, respectively).

LIMITATIONS, REASONS FOR CAUTION

Variations in embryonic growth trajectories of spontaneously conceived pregnancies with reliable pregnancy dating may partially be a result of less precise pregnancy dating and differences in endometrium receptivity compared with IVF/ICSI pregnancies.

WIDER IMPLICATIONS OF THE FINDINGS

The absence of a significant difference in embryonic and fetal growth trajectories suggests safety of IVF/ICSI treatment with regard to early embryonic growth. However, further research is warranted to ascertain the influence of IVF/ICSI treatments in a larger study population, and to estimate the impact of the underlying causes of the subfertility and other periconceptional exposures on human embryonic and fetal growth trajectories.

FUNDING STATEMENT

This study was supported by the Department of Obstetrics and Gynaecology of the Erasmus MC, University Medical Centre.

CONFLICT OF INTEREST

No competing interests are declared.

Extended embryo culture is not associated with increased adverse obstetric or perinatal outcome

OBJECTIVE

We sought to compare obstetric and perinatal outcomes of singletons born after extended embryo culture and a single blastocyst stage embryo vs a single cleavage stage embryo transfer.

STUDY DESIGN

This was a retrospective cohort study of 1543 fresh single embryo transfers using nondonor oocytes in women ≤40 years old from December 2008 through December 2012 at the reproductive unit of McGill University Health Center. The main outcome measures were perinatal outcomes including birthweight, low birthweight, small for gestational age, preterm delivery, preeclampsia, placental abruption, and neonatal complications. Covariates were maternal age, body mass index, smoking, cause of infertility, parity, and sex of the baby.

RESULTS

Transfers of 693 fresh single cleavage embryos and 850 fresh single blastocysts resulting in 564 pregnancies and 381 singleton deliveries were analyzed. Blastocyst transfer resulted in a higher clinical pregnancy rate (50.1% and 19.9%) and live birth rate (33.5% and 13.8%) compared to cleavage embryo transfer, respectively (P < .001). Multivariate analyses for pregnancy revealed no increased risk of maternal or neonatal complications in pregnancies resulting from extended embryo culture.

CONCLUSION

Live births resulting from extended embryo culture and a single blastocyst transfer are not associated with increased adverse obstetric and perinatal outcome compared to live births from a single cleavage embryo transfer in women ≤40 years old.

Birthweight distribution in ART singletons resulting from embryo culture in two different culture media compared with the national population

STUDY QUESTION

Is there a difference in birthweight distribution in ART singletons born after IVF culture in two different culture media?

SUMMARY ANSWER

There is no effect of culture media on both crude and adjusted birthweight distributions in ART singletons from nulliparous mothers.

WHAT IS KNOWN ALREADY

Studies on human ART singletons have reported a difference in birthweight in singletons following IVF culture in different culture media. However, other studies comparing different culture media have not shown any significant differences in birthweight.

STUDY DESIGN, SIZE, DURATION

This study was a retrospective comparison of birthweights in IVF/ICSI singletons conceived after fresh embryo transfer following embryo culture in Cook or Medicult medium and in a national cohort of naturally conceived singletons in nulliparous women. The study compares four independent groups consisting of singletons in nulliparous women from Cook-d2: 2-day culture in Cook medium at Rigshospitalet (n = 974), Medicult-d2: 2-day culture in Medicult EmbryoAssist medium at Rigshospitalet (n = 147), Medicult-d3: 3-day culture in Medicult EmbryoAssist medium with and without added GM-CSF (n = 204), and DK: pregnancies from the Danish birth registry (n = 106842).

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study compares the birthweights of singletons from nulliparous women in the four independent groups mentioned above; Cook-d2: Medicult-d2: Medicult-d3: and DK. In addition, distributions of large and small for gestational age infants were compared between the groups and a multiple linear regression analysis was used to determine which factors determined birthweight.

MAIN RESULTS AND THE ROLE OF CHANCE

We found no significant difference in the crude birthweight distributions between singletons born after culture in Cook-d2 or Medicult-groups. Singleton girls from the Cook-d2 group weighed 3302 ± 28 g, versus 3252 ± 76 in the Medicult-d2 group (difference 50 g; P = 0.547). Singleton boys from the Cook-d2 group weighed 3430 ± 27 g, versus 3354 ± 56 in the Medicult-d2 group (difference 76 g; P = 0.279). In the background population, mean birthweights for singleton girls and boys were 3383 ± 2.4 g and 3494 ± 2.5 g, respectively. The mean birthweights of girls, 3315 ± 61 g, and boys, 3383 ± 64 g, in the Medicult-d3 group were not significantly different from that in the Medicult-d2 group. When pooling data from all culture media groups, we found the same slightly lower mean birthweight in IVF/ICSI singletons when compared with the national birth cohort as has been previously reported (Cook-d2 + Medicult-d2 + d3 versus birth cohort; girls: P < 0.001, boys: P < 0.001). We also pooled data on boys and girls and calculated the mean birthweight for the Cook-d2, Medicult-d2 and Medicult-d3 groups and found no significant differences.

LIMITATIONS, REASONS FOR CAUTION

The retrospective design and the inherent risk of confounding factors is a limitation. Selection bias cannot be excluded as the embryos cultured in Cook-d2 and Medicult-d2 were from single centre studies while data in Medicult-D3 group were derived from a multicentre study.

WIDER IMPLICATIONS OF THE FINDINGS

This large cohort of singletons born after IVF/ICSI shows no difference in crude mean birthweight after culture in two different culture media, indicating that if such a difference exists, this must be specific for certain culture media. As expected we found a slightly lower mean birthweight in ART compared with naturally conceived singletons. This suggests that parental characteristics or IVF technique related factors other than type of culture medium may influence the birthweight in ART singletons.

STUDY FUNDING/COMPETING INTERESTS

No external funding was used for this study. No conflicts of interest are declared.

The association between embryo quality and perinatal outcome of singletons born after single embryo transfers: a pilot study

STUDY QUESTION

Does the quality of a single transferred embryo have an effect on the pregnancy outcome?

SUMMARY ANSWER

After adjusting for confounding maternal variables, poor embryo quality was not associated with adverse obstetric or perinatal outcome in this small pilot study.

WHAT IS ALREADY KNOWN

Embryo quality is a major predictor of the success of in vitro fertilization treatment and studies have demonstrated a strong association between embryo morphology, implantation and clinical pregnancy rates. However, the association with obstetric and perinatal outcomes has not been evaluated.

STUDY DESIGN, SIZE AND DURATION

This single center, retrospective cohort study included 1541 fresh single embryo transfers (SETs) using non-donor oocytes in women ≤40 years between December 2008 and 2012. We compared the cycle outcome and singleton live births resulting from the transfer of a single fresh good quality (Grade 2) embryo with those resulting from the transfer of a single poor quality (fair, Grade 3 or poor, Grade 4) embryo in the cleavage or blastocyst stages.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The cycle outcome parameters were biochemical pregnancy and clinical intrauterine pregnancy. The pregnancy outcomes were live birth, miscarriages and stillbirths after 20 weeks of gestation. Among the live births, perinatal outcome parameters included birthweight, small for gestational age, preterm delivery, pre-eclampsia, placental abruption and neonatal complications. Covariates were maternal age, body mass index, smoking status, parity and gender of the baby.

MAIN RESULTS AND ROLE OF CHANCE

There were 1193 good quality SETs and 348 poor quality embryo transfers. SETs performed during the study period resulted in 563 pregnancies and 440 singleton births. There was a higher clinical pregnancy rate (41.5%) and live birth rate (32.3%) in the good quality embryo transfer group compared with that in the poor quality transfer group (19.2 and 15.5%, respectively; P < 0.0001). There was no significant difference in the miscarriage rate between the transfers of a single good or poor quality embryo. Multivariable logistic regression analyses for pregnancy complications revealed no increased risk of maternal or neonatal complications with the transfer of a poor quality embryo. There was no difference in the obstetric or perinatal outcome of the live births resulting from a good or poor quality embryo after stratification by day of transfer.

LIMITATIONS, REASONS FOR CAUTION

The main limitations of this study are the retrospective nature of the study, the relative subjectivity of embryo scoring and the small number of live births after transfer of poor quality embryos.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings may be used to reassure women that transfer of a single poor quality embryo, whether a cleavage or a blastocyst, does not appear to be associated with increased risks of adverse obstetric and perinatal outcomes.

STUDY FUNDING/COMPETING INTEREST (S)

Only internal funding was used. There is no conflict of interest in relation to the study.

Pregnancy outcome after ICSI with thawed testicular sperm from men with non-obstructive azoospermia compared to ICSI with ejaculated sperm from men with severe oligoasthenoteratozoospermia and IVF with normal ejaculated sperm

The aim of the study was to evaluate the clinical pregnancy outcomes, fetal complications and malformation rate of intracytoplasmic injection of thawed cryopreseverd sperm extracted by testicular aspiration from men with non-obstructive azoospermia (NOA) compared with intracytoplasmic injection of fresh ejaculated sperm from men with severe oligoteratoasthenozoospermia (OTA) and standard in vitro fertilization using ejaculated sperm from normospermic men. The mean oocyte fertilization rate was significantly lowest for ICSI with testicular aspirated sperm (NOA group). However, there was no significant difference among the three groups in pregnancy outcomes, namely rates of spontaneous abortion, biochemical pregnancy, extrauterine pregnancy, singleton multifetal pregnancy, preterm delivery before 36 weeks' gestation, maternal complications, transfer to the neonatal intensive care unit, intrauterine growth restriction or fetal malformations. These results suggest that despite some earlier findings that intracytoplasmic injection of aspirated sperm from men with NOA is associated with lower fertilization rates and embryo quality, the pregnancy and immediate neonatal outcomes may be unaffected.

Adequate prenatal care reduces the risk of adverse pregnancy outcomes in women with history of infertility: a nationwide population-based study

OBJECTIVES

To investigate the effects of various measures of prenatal care on adverse pregnancy outcomes in women with a history of infertility.

STUDY DESIGN

A retrospective cohort study.

METHODS

Data were derived by linking 2 large nationwide population-based datasets, the National Health Insurance Research Database and Taiwan Birth Certificate Registry. The study sample included 15,056 women with an infertility diagnosis and 60,224 randomly selected women without infertility matched to the study sample by maternal age. A conditional logistic regression analysis was performed for the analysis.

RESULTS

Women diagnosed with infertility respectively had 1.39 (95% CI, 1.06~1.83), 1.15 (95% CI, 1.08~1.24), 1.13 (95% CI, 1.08~1.18), and 1.08 (95% CI, 1.05~1.12) higher odds of having very low birth weight (VLBW) babies, preterm births, labor complications, and cesarean sections (CSs) compared to women without infertility. Inadequate numbers of total and major prenatal visits and late initiation of prenatal care increased the risks of adverse pregnancy outcomes in women with infertility, especially the risk of a VLBW baby. However, no significant associations were found for the risks of adverse birth outcomes in infertile women with adequate prenatal care compared to fertile women with adequate care.

CONCLUSIONS

Study findings suggest that adequate prenatal care can reduce the risk of adverse pregnancy outcomes in women with infertility.

Identifying women with indicators of subfertility in a statewide population database: operationalizing the missing link in assisted reproductive technology research

OBJECTIVE

To identify a group of deliveries to mothers with indicators of subfertility (SUBFERTILITY).

DESIGN

Longitudinal cohort study.

SETTING

Hospital.

PATIENT(S)

A total of 334,152 deliveries to Massachusetts mothers in a Massachusetts hospital between July 1, 2004, and December 31, 2008.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Subfertility was defined by an indication on a current or past birth certificate or hospital utilization data of infertility or assisted reproductive technology (ART) cycle before index delivery and no indication of ART use with index delivery.

RESULT(S)

Initially, 12,367 deliveries met the inclusion criteria for SUBFERTILITY (8,019 from birth certificates, 2,777 from hospital data, 1,571 from prior ART treatment). Removing deliveries from more than one data source resulted in 10,764 unique deliveries. Removing deliveries resulting from ART treatments left 6,238 deliveries in the SUBFERTILITY category. Demographic analysis indicated that deliveries in SUBFERTILITY were more similar to those in the ART population than to those in the fertile population.

CONCLUSION(S)

We have demonstrated the feasibility of using existing population-based linked public health data sets to identify SUBFERTILITY deliveries, and we have used ART data to distinguish ART and SUBFERTILITY births. The SUBFERTILITY category can serve as a comparison group of subfertile patients for studies of ART delivery and longitudinal health outcomes.

Sex-related growth differences are present but not enhanced in in vitro fertilization pregnancies

OBJECTIVE

To determine whether IVF modifies the effect of fetal sex on growth.

DESIGN

Retrospective cohort study.

SETTING

Tertiary care center and related facilities.

PATIENT(S)

Singleton live births without fetal/maternal comorbidities from fertile women who conceived without the use of assisted reproductive technologies and infertile women who conceived with IVF.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The primary outcome was birth weight (BW). Secondary outcomes were fetal crown-rump length (CRL) in the first trimester, biparietal diameter (BPD), and estimated fetal weight (EFW) in the second trimester.

RESULT(S)

There were no differences in baseline characteristics between women carrying male fetuses and those carrying female fetuses in either mode of conception. In unadjusted analyses, the male-female differentials in fetal BPD and BW were more pronounced in the IVF cohort than in the unassisted cohort. In multivariable regression analysis, male BPD exceeded female BPD by 0.12 cm, male EFW exceeded female EFW by 12 g, and male BW exceeded female BW by 172 g. IVF did not have a significant effect on BPD but was associated with a 52 g increase in EFW in the midgestation. IVF was associated with an 81-g reduction in BW. IVF did not modify the magnitude of size differences between the sexes in the midgestation or at birth.

CONCLUSION(S)

Comparable sex-dependent differential growth occurs in unassisted and IVF pregnancies.

Health outcomes of children born after IVF/ICSI: a review of current expert opinion and literature

The Sixth Evian Annual Reproduction (EVAR) Workshop Group Meeting was held to evaluate the impact of IVF/intracytoplasmic sperm injection on the health of assisted-conception children. Epidemiologists, reproductive endocrinologists, embryologists and geneticists presented data from published literature and ongoing research on the incidence of genetic and epigenetic abnormalities and congenital malformations in assisted-conception versus naturally conceived children to reach a consensus on the reasons for potential differences in outcomes between these two groups. IVF-conceived children have lower birthweights and higher peripheral fat, blood pressure and fasting glucose concentrations than controls. Growth, development and cognitive function in assisted-conception children are similar to controls. The absolute risk of imprinting disorders after assisted reproduction is less than 1%. A direct link between assisted reproduction and health-related outcomes in assisted-conception children could not be established. Women undergoing assisted reproduction are often older, increasing the chances of obtaining abnormal gametes that may cause deviations in outcomes between assisted-conception and naturally conceived children. However, after taking into account these factors, it is not clear to what extent poorer outcomes are due to the assisted reproduction procedures themselves. Large-scale, multicentre, prospective epidemiological studies are needed to investigate this further and to confirm long-term health consequences in assisted-conception children. Assisted reproduction treatment is a general term used to describe methods of achieving pregnancy by artificial means and includes IVF and sperm implantation. The effect of assisted reproduction treatment on the health of children born using these artificial methods is not fully understood. In April 2011, fertility research experts met to give presentations based on research in this area and to look carefully at the evidence for the effects of assisted reproduction treatment on children's health. The purpose of this review was to reach an agreement on whether there are differences in the health of assisted-conception children with naturally conceived children. The researchers discovered no increased risk in birth defects in assisted-conception children compared with naturally conceived children. They found that IVF-conceived children have lower birth weights and higher fat under the skin, higher blood pressure and higher fasting glucose concentrations than naturally conceived children; however, growth, development and cognitive function are similar between groups. A very low risk of disorders of genetic control was observed in assisted-conception children. Overall, there did not appear to be a direct link between assisted reproduction treatment and children's health. The researchers concluded that the cause of some differences in the health of children conceived using assisted reproduction treatment may be due to the age of the woman receiving treatment. Large-scale, research studies are needed to study the long-term health of children conceived using assisted reproduction treatment.

Obstetric and perinatal outcomes in IVF versus ICSI-conceived pregnancies at a tertiary care center--a pilot study

BACKGROUND

Although most pregnancies after IVF result in normal healthy outcomes, an increased risk for a number of obstetric and neonatal complications, compared to naturally conceived pregnancies, has been reported. While there are many studies that compare pregnancies after assisted reproductive techniques with spontaneously conceived pregnancies, fewer data are available that evaluate the differences between IVF and ICSI-conceived pregnancies. The aim of our present study was, therefore, to compare obstetric and perinatal outcomes in pregnancies conceived after in vitro fertilization (IVF) versus intracytoplasmatic sperm injection (ICSI).

METHODS

Three-hundred thirty four women who had become pregnant after an IVF or ICSI procedure resulted in a total of 530 children referred between 2003 und 2009 to the Department of Obstetrics and Gynecology of the Medical University of Vienna, a tertiary care center, and were included in this retrospective cohort study. We assessed maternal and fetal parameters in both groups (IVF and ICSI). The main study outcomes were preterm delivery, the need for neonatal intensive care, and congenital malformations. Moreover, we compared the course of pregnancy between both groups and the occurrence of complications that led to maternal hospitalization during pregnancy.

RESULTS

There were 80 children conceived via ICSI and 450 children conceived via IVF.Mean gestational age was significantly lower in the ICSI group (p = 0.001). After ICSI, the birth weight (p = 0.008) and the mean APGAR values after 1 minute and after 10 minutes were lower compared to that of the IVF group (p = 0.016 and p = 0.047, respectively). Moreover, ICSI-conceived children had to be hospitalized more often at a neonatal intensive care unit (p = 0.004). There was no difference in pH of the umbilical artery or in major congenital malformations between the two groups. Pregnancy complications (i.e., premature rupture of membranes, cervical insufficiency, and premature uterine contractions) and the need for maternal hospitalization during pregnancy were found significantly more often after IVF (p = 0.0016 and p = 0.0095, respectively), compared to the ICSI group.

CONCLUSIONS

When comparing IVF versus ICSI-conceived pregnancies at a tertiary care center, we found the course of pregnancy to be more complicated after IVF, whereas the primary fetal outcome seemed to be better in this group than after ICSI treatment.

Low birth weight: is it related to assisted reproductive technology or underlying infertility?

Since 1978, we have witnessed a successful evolution of assisted reproductive technology (ART), with improvement of the pregnancy rates and a growing demand. However, in recent years, there has been increasing concern regarding its safety due to the potential health impact on its infants. The raise of the developmental origins of adult disease has positioned low birth weight (LBW) as a significant health issue. Although multiple studies have associated ART with LBW, the etiology of this association remains largely unknown. We review the potential association between different components of ART and infertility with LBW, while acknowledging the limitations of interpretation of the existing literature.

Reproductive outcomes after assisted conception

The last three decades have witnessed a dramatic increase in the use of assisted reproductive technology (ART) so that now, in developed countries, 1.7% to 4.0% of all children are born after ART. Although absolute risks appear small, data from prospective and retrospective studies indicate increased risks of adverse maternal and perinatal outcomes after ART as compared with spontaneous conception. Recent studies suggest that underlying maternal factors and subfertility play an important role in some of these outcomes rather than the ART procedure itself. A significant risk of assisted conception is multiple pregnancies, but even singleton pregnancies achieved by ART are at a higher risk of hypertensive disease, diabetes, prematurity, low birth weight, and perinatal mortality even after adjusting for confounders. Couples undergoing ART procedures should be counseled in advance regarding increased risks of pregnancy complications and higher rates of obstetric interventions. Although conflicting data exist, studies of children born from ART suggest increased rates of congenital malformations, imprinting disorders (Beckwith-Wiedemann syndrome and Angelman syndrome), and marginally increased risk of cancer. However, the current evidence is inadequate, and prospective long-term studies are needed to eliminate the effect of confounders and draw definite conclusions about the long-term outcomes after ART. The absolute risk of imprinting disorders remains small, and routine screening is not recommended at present. The long-term outcomes after ART are difficult to evaluate because of the variability in ART methods and data reporting, and there is a need for standardized methodology for follow-up after ART.

Why do singletons conceived after assisted reproduction technology have adverse perinatal outcome? Systematic review and meta-analysis

BACKGROUND

Assisted reproduction technology (ART) is used worldwide, at increasing rates, and data show that some adverse outcomes occur more frequently than following spontaneous conception (SC). Possible explanatory factors for the well-known adverse perinatal outcome in ART singletons were evaluated.

METHODS

PubMed and Cochrane databases from 1982 to 2012 were searched. Studies using donor or frozen oocytes were excluded, as well as those with no control group or including <100 children. The main outcome measure was preterm birth (PTB defined as delivery <37 weeks of gestation), and a random effects model was used for meta-analyses of PTB. Other outcomes were very PTB, low-birthweight (LBW), very LBW, small for gestational age and perinatal mortality.

RESULTS

The search returned 1255 articles and 65 of these met the inclusion criteria. The following were identified as predictors for PTB in singletons: SC in couples with time to pregnancy (TTP) > 1 year versus SC singletons in couples with TTP ≤ 1 year [adjusted odds ratio (AOR) 1.35, 95% confidence interval (CI) 1.22, 1.50]; IVF/ICSI versus SC singletons from subfertile couples (TTP > 1 year; AOR 1.55, 95% CI 1.30, 1.85); conception after ovulation induction and/or intrauterine insemination versus SC singletons where TTP ≤ 1 year (AOR 1.45, 95% CI 1.21, 1.74); IVF/ICSI singletons versus their non-ART singleton siblings (AOR 1.27, 95% CI 1.08, 1.49). The risk of PTB in singletons with a 'vanishing co-twin' versus from a single gestation was AOR of 1.73 (95% CI 1.54, 1.94) in the narrative data. ICSI versus IVF (AOR 0.80, 95% CI 0.69-0.93), and frozen embryo transfer versus fresh embryo transfer (AOR 0.85, 95% CI 0.76, 0.94) were associated with a lower risk of PTB.

CONCLUSIONS

Subfertility is a major risk factor for adverse perinatal outcome in ART singletons, however, even in the same mother an ART singleton has a poorer outcome than the non-ART sibling; hence, factors related to the hormone stimulation and/or IVF methods per se also may play a part. Further research is required into mechanisms of epigenetic modification in human embryos and the effects of cryopreservation on this, whether milder ovarian stimulation regimens can improve embryo quality and endometrial conditions, and whether longer culture times for embryos has a negative influence on the perinatal outcome.

Implications of assisted reproductive technologies on term singleton birth weight: an analysis of 25,777 children in the national assisted reproduction registry of Japan

OBJECTIVE

To evaluate the implications of assisted reproductive technologies (ART) on neonatal birth weight.

DESIGN

A retrospective study using analysis of covariance and multiple logistic regression analysis of the Japanese ART registry.

SETTING

Japanese institutions providing ART treatment.

PATIENT(S)

A total of 25,777 singleton neonates reaching term gestation following ART during the years 2007-2008, with 11,374 achieved through fresh embryo transfers (fresh ET) and 14,403 achieved through frozen-thawed embryo transfers (FET).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Birth weight.

RESULT(S)

The mean birth weight after FET was significantly higher compared with fresh ET and all Japanese births (3,100.7 ± 387.2 g, 3,009.8 ± 376.8 g, and 3,059.6 ± 369.6 g, respectively). The risk for low birth weight in FET was significantly lower compared with fresh ET. In fresh ET, ovarian stimulations were associated with about twofold risk of low birth weight compared with natural cycle. Regarding to the duration of embryonic culture, the risks resulting from a shorter culturing time were significantly higher compared with a longer culturing time in fresh ET.

CONCLUSION(S)

The best method of embryo transfer for fetal growth was FET after extended culturing until blastocyst stage. However, further investigations should be performed to understand the safety of ART treatment.