Three-arm age-matched retrospective cohort study of obstetric outcomes of donor oocyte pregnancies

Perinatal outcomes in 6640 singleton pregnancies after donor oocyte IVF across three continents over 7 years

PURPOSE

Are trends in singleton donor oocyte IVF perinatal outcomes consistent over time among four international ethnically diverse infertility centers?

METHODS

This retrospective cohort consisted of an infertility network of four international IVF centers across three continents. Singleton live births resulting from fresh and frozen donor oocyte embryo transfers from January 1, 2012 to December 31, 2018 were included. The main outcome measures were birth weight (BW), preterm birth (PTB), large for gestational age (LGA), small for gestational age (SGA) and gestational age (GA) at delivery.

RESULTS

The entire cohort (n = 6640) consisted of 4753 fresh and 1887 frozen donor oocyte embryo transfers. Maternal age, parity, body mass index, neonatal sex and GA at delivery were similar for fresh and frozen donor oocyte embryo transfers in the entire cohort and within each infertility center. All four centers had a trend of decreased BW and rates of PTB before 32 weeks annually, although significance was not reached. Three of the four centers had annual increased trends of PTB before 37 weeks and LGA newborns, although significance was not reached. BWs for the entire cohort for fresh and frozen donor embryo transfers were 3166 g ± 601 g and 3137 g ± 626 g, respectively.

CONCLUSION

Similar trends in perinatal outcomes were present across four international infertility centers over 7 years. The overall perinatal trends in donor oocyte IVF may be applicable to centers worldwide, but further studies in more geographic regions are needed.

Assisted reproductive technology and hypertensive disorders of pregnancy: systematic review and meta-analyses

Background

Hypertensive disorders of pregnancy (HDP) is one of the most common pregnancy complications and causes of maternal morbidity and mortality. Assisted reproductive technology (ART) has been associated with adverse pregnancy outcomes, including HDP. However, the impact of multiple pregnancies, oocyte donation, as well as fresh and frozen embryo transfer needs to be further studied. We conducted a systematic review and meta-analyses to evaluate the association between ART and HDP or preeclampsia relative to spontaneous conception (SC).

Methods

We identified studies from EMBASE, MEDLINE, and Cochrane Library (up to April 8, 2020) and manually using structured search strategies. Cohort studies that included pregnancies after in vitro fertilization (IVF) with or without intracytoplasmic sperm fertilization (ICSI) relative to SC with HDP or preeclampsia as the outcome of interest were included. The control group was women who conceived spontaneously without ART or fertility medications. The pooled results were reported in odds ratios (OR) with 95% confidence intervals based on random effects models. Numbers needed to harm (NNH) were calculated based on absolute risk differences between exposure and control groups.

Results

Eighty-five studies were included after a screening of 1879 abstracts and 283 full text articles. Compared to SC, IVF/ICSI singleton pregnancies (OR 1.70; 95% CI 1.60–1.80; I² = 80%) and multiple pregnancies (OR 1.34; 95% CI 1.20–1.50; I² = 76%) were both associated with higher odds of HDP. Singleton pregnancies with oocyte donation had the highest odds of HDP out of all groups analyzed (OR 4.42; 95% CI 3.00–6.51; I² = 83%). Frozen embryo transfer resulted in higher odds of HDP (OR 1.74; 95% CI 1.58–1.92; I² = 55%) than fresh embryo transfer (OR 1.43; 95% CI 1.33–1.53; I² = 72%). The associations between IVF/ICSI pregnancies and SC were similar for preeclampsia. Most interventions had an NNH of 40 to 100, while singleton and multiple oocyte donation pregnancies had particularly low NNH for HDP (16 and 10, respectively).

Conclusions

Our meta-analysis confirmed that IVF/ICSI pregnancies are at higher odds of HDP and preeclampsia than SC, irrespective of the plurality. The odds were especially high in frozen embryo transfer and oocyte donation pregnancies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03938-8.

Risk of Lower Birth Weight and Shorter Gestation in Oocyte Donation Pregnancies Compared With Other Assisted Reproductive Technology Methods: Systematic Review

OBJECTIVE

Oocyte donation (OD) is associated with an increased risk of pregnancy-induced hypertension, but the evidence of an association between OD and infant outcomes, including birth weight and gestational age, is conflicting. This study sought to determine the associations between oocyte donation and birth weight or gestational age compared with other forms of autologous oocyte assisted reproductive technology (ART).

METHODS

Medline, Embase, and the CENTRAL Trials Registry of the Cochrane Collaboration were searched using a comprehensive search strategy. Studies of women over 24 weeks gestation compared infant outcomes among OD pregnancies versus other ART. Study quality was assessed, and a meta-analysis of mean birth weight and gestational age was conducted using a random effects model.

RESULTS

Nineteen studies were included. Four studies showed a significant association between OD and lower birth weights, and five studies found significant differences in gestational age between OD and autologous oocyte ART. The pooled difference in birth weight means between OD and autologous ART was -42 (-88, 4) . The pooled difference in gestational age was -0.4 weeks (-0.8, 0.0 weeks).

CONCLUSION

A high degree of interstudy heterogeneity exists, and the association between OD and infant outcomes remains unclear.

What are the Predictive Factors for Preeclampsia in Oocyte Recipients?

Objectives:

Oocyte donation pregnancies are more frequently complicated by preeclampsia (PE), which cause significant fetal-maternal morbidity and mortality. Our objective was to determine risk factors for PE in oocyte recipients (OR). Our secondary objective was to describe the course of pregnancy and the neonatal outcome in this group.

Methods:

This was a historical-prospective study. One hundred and fifty OR who gave birth to children at over 22 weeks of amenorrhea between January 2010 and June 2018 were included in the study.

Results:

Risk factors for PE in OR found in univariate analysis were as follows: primiparity, primipaternity, body mass index (BMI), and anti-Müllerian hormone (AMH) of the OR and age and AMH of the oocyte donors (OD). In multivariate analysis, the BMI of the OR (odds ratio [OR]: 1.2, 95% confidence interval [CI]: [1.1–1.4], P = 0.0474) and the AMH of the OD (OR: 1.2, 95% CI: [1.2–1.4], P = 0.0481) were found to be statistically significant risk factors for PE. In addition, we observed an increase in the rate of prematurity in the OR that were not associated with fetal growth retardation, despite the occurrence of PE.

Conclusion:

In OR, the allogeneic nature of pregnancy induces an increased risk of PE, the pathophysiology of which seems different from that in other methods of conception. Thus, risk factors for PE should be reconsidered to take into account the impact of certain characteristics of OD such as age and AMH.

Perinatal outcomes among young donor oocyte recipients

STUDY QUESTION

Is the use of donor oocytes in women <35 years of age associated with an increased risk of adverse perinatal outcomes compared to use of autologous oocytes?

SUMMARY ANSWER

Among fresh assisted reproductive technology (ART) cycles performed in women under age 35, donor oocyte use is associated with a higher risk of preterm birth, low birth weight and stillbirth (when zero embryos were cryopreserved) as compared to autologous oocytes.

WHAT IS KNOWN ALREADY

Previous studies demonstrated elevated risk of poor perinatal outcomes with donor versus autologous oocytes during ART, primarily among older women.

STUDY DESIGN, SIZE, DURATION

Retrospective cohort study using data reported to Centers for Disease Control and Prevention's National ART Surveillance System (NASS) during the period from 2010 to 2015 in order to best reflect advances in clinical practice. Approximately 98% of all US ART cycles are reported to NASS, and discrepancy rates were <6% for all fields evaluated in 2015.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We included all non-banking fresh and frozen ART cycles performed between 2010 and 2015 in women under age 35 using autologous or donor eggs. Cycles using cryopreserved eggs, donated embryos or a gestational carrier were excluded. Among fresh embryo transfer cycles, we calculated predicted marginal proportions to estimate the unadjusted and adjusted risk ratios (aRRs) and 95% confidence intervals (CIs) for the association between donor versus autologous oocyte use and stillbirth, spontaneous abortion, preterm delivery and low birth weight among singleton pregnancies or births. Stillbirth models were stratified by number of embryos cryopreserved. All models were adjusted for patient and treatment characteristics.

MAIN RESULTS AND THE ROLE OF CHANCE

Among the 71 720 singleton pregnancies occurring during 2010-2015, singletons resulting from donor oocytes were more likely to be preterm (15.6% versus 11.0%; aRRs 1.39: CI 1.20-1.61) and have low birth weight (11.8% versus 8.8%; aRRs 1.34; CI 1.16-1.55) than those resulting from autologous oocytes. With zero embryos cryopreserved, donor versus autologous oocyte use was associated with increased risk for stillbirth (2.1% versus 0.6%; aRRs 3.73; CI 1.96-7.11); no association with stillbirth was found when ≥1 embryo was cryopreserved (0.54% versus 0.56%; aRR 1.15; CI 0.59-2.25).

LIMITATIONS, REASONS FOR CAUTION

The data come from a national surveillance system and is thus limited by the accuracy of the data entered by individual providers and clinics. There may be unmeasured differences between women using donor eggs versus their own eggs that could be contributing to the reported associations. Given the large sample size, statistically significant findings may not reflect clinically important variations.

WIDER IMPLICATIONS OF THE FINDINGS

Risks of preterm birth, low birth weight and stillbirth among singleton pregnancies using donor oocytes were increased compared to those using autologous oocytes. Further study regarding the pathophysiology of the potentially increased risks among donor oocyte recipient pregnancy is warranted.

STUDY FUNDING/COMPETING INTEREST(S)

None.

TRIAL REGISTRATION NUMBER

N/A.

Risk of adverse perinatal outcomes after oocyte donation: a systematic review and meta-analysis

RESEARCH QUESTION

In women with singleton pregnancies conceived after assisted reproductive technologies, does the in vitro fertilization with oocyte donation (IVF-OD) affect the perinatal and maternal outcomes compared to autologous in vitro fertilization (IVF-AO)?

DESIGN

Systematic review and meta-analysis of studies comparing perinatal and maternal outcomes in singleton pregnancies resulting from IVF-OD versus IVF-AO. An electronic literature search in Pubmed, MEDLINE, and Cochrane database was performed. The main outcome measures were hypertensive disorders in pregnancy, preeclampsia, severe preeclampsia, pregnancy-induced hypertension, preterm birth, early preterm birth, low birth weight, and very low birth weight.

RESULTS

Twenty-three studies were included. IVF-OD is associated with a higher risk of hypertensive disorders in pregnancy (OR 2.63, 2.17-3.18), preeclampsia (OR 2.64; 2.29-3.04), severe preeclampsia (OR 3.22; 2.30-4.49), pregnancy-induced hypertension (OR 2.16; 1.79-2.62), preterm birth (OR 1.57; 1.33-1.86), early preterm birth (OR 1.80; 1.51-2.15), low birth weight (OR 1.25, 1.20-1.30), very low birth weight (OR 1.37, 1.22-1.54), gestational diabetes (OR 1.27; 1.03-1.56), and cesarean section (OR 2.28; 2.14-2.42). There was no significant difference in the risk of preterm birth or low birth weight when adjusted for preeclampsia.

CONCLUSIONS

IVF-OD patients should be considered an independent risk factor for some adverse perinatal outcomes, mainly hypertensive disorders in pregnancy, preeclampsia, and severe preeclampsia. Immunological and hormonal aspects may be involved in these results, and further research focusing in the etiopathogenesis of these pathologies are needed.

Health and Disease After Assisted Reproductive Technology

Long-term health outcomes after ART have largely focused on offspring health and perinatal parameters. Longer-term health outcomes in female patients remain difficult to fully assess. Hypothetical concerns about the effects of endocrine manipulation on hormone-sensitive conditions, e.g. breast disease, are confounded by variable factors in patients and treatments. Obstetric and perinatal factors endow an additional layer of complexity to the overall analysis and more research is required to appreciate all aspects of ART. Notwithstanding the knowledge gap, clinicians must endeavour to individualise management plans, taking into account the pros and cons of ART in the context of immediate, maternity-related and long-term health risks for their patients.

This review of recent literature examines current ART practice in terms of female health and disease as we strive for best practice in an ever-changing clinical and demographic fertility landscape.

The impact of using donor sperm in assisted reproductive technology cycles on perinatal outcomes

OBJECTIVE

To assess the impact of using donor sperm in assisted reproductive technology (ART) cycles on perinatal outcomes.

DESIGN

Historical cohort study.

SETTING

US national database from the Society of Assisted Reproductive Technology Clinic Outcome Reporting System (SART CORS) from 2012 to 2013.

PATIENT(S)

Patients undergoing the first fresh autologous ART cycle using either donor or partner sperm.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Miscarriage, preterm birth, low birthweight rates.

RESULTS

A total of 134,710 fresh autologous ART cycles were evaluated from the SART CORS database. Following exclusion criteria and after restricting to the first cycle, 2,123 donor sperm and 42,799 partner sperm ART cycles were included in the final analyses. After adjusting for all confounding variables (including maternal age, race, body mass index, smoking status, gravidity, history of preterm birth, highest follicle stimulating hormone count, blastocyst transfer percentage, total embryo transferred, and etiology of infertility), no statistically significant differences in miscarriage rates, preterm births, very preterm births, low birthweight, and very low birthweight were observed. Birthweight was significantly lower in the partner sperm group than in the donor sperm group (3,292 ± 601 and 3,233 ± 592 g in donor and partner sperm groups, respectively, adjusted P value 0.003); however, this small absolute difference (adjusted effect estimate 42 g, 95% CI 14.7-70.9) does not carry clinical significance.

CONCLUSIONS

The use of donor sperm in fresh autologous ART cycles was not associated with increased miscarriage, preterm births, or low birthweights, as compared to cycles using partner sperm. This information can be used in patient counseling to reassure patients using donor sperm in ART cycles.

Risk of ischemic placental disease in fresh and frozen embryo transfer cycles

OBJECTIVES

To evaluate the association of fresh and frozen embryo transfer with the development of ischemic placental disease (IPD), hypothesizing that differences in implantation environment affect placentation and thus pregnancy outcomes.

DESIGN

We performed a secondary analysis of a retrospective cohort study of deliveries linked to IVF cycles.

SETTING

Tertiary hospital and infertility treatment center.

PATIENT(S)

We included all women who underwent an autologous IVF cycle and had a live-born infant or an intrauterine fetal demise (IUFD). We excluded women less than 18 years of age.

INTERVENTION(S)

We compared pregnancies resulting from frozen embryo transfer (frozen) cycles with those resulting from fresh embryo transfer (fresh) cycles.

MAIN OUTCOME MEASURE(S)

The primary outcome was a composite outcome of IPD or IUFD due to placental insufficiency. Ischemic placental disease included pre-eclampsia, placental abruption, and small for gestational age (SGA). We calculated risk ratios (RRs) and 95% confidence intervals (CIs).

RESULT(S)

Compared with fresh cycles, frozen cycles had a lower risk of IPD or IUFD from placental insufficiency (RR 0.75, 95% CI 0.59-0.97). Frozen cycles also conferred a lower risk of SGA than fresh cycles (RR 0.58, 95% CI 0.41-0.81). Risks of pre-eclampsia (RR 1.3, 95% CI 0.84-1.9) and abruption (RR 1.2, 95% CI 0.56-2.4) were similar.

CONCLUSION(S)

There was a lower risk of IPD among frozen cycles compared with fresh cycles. This association was largely driven by lower risk of SGA among frozen cycles.

Comparison of perinatal outcomes following frozen embryo transfer cycles using autologous versus donor oocytes in women 40 to 43 years old: analysis of SART CORS data

OBJECTIVE

To study the differences in perinatal outcomes after frozen embryo transfer cycles using autologous or donor oocytes in women of advanced maternal age.

DESIGN

Historical cohort study.

SETTING

US national database from the Society of Assisted Reproductive Technology Clinic Outcome Reporting System (SART CORS) from 2009 to 2013.

PATIENT(S)

Women at 40-43 years of age undergoing autologous frozen embryo transfers (a-FET) or donor oocyte frozen embryo transfers (d-FET) resulting in singleton pregnancies that were entered in the SART CORS database from 2009 to 2013.

RESULTS

a-FET resulted in 4402 singleton live births whereas d-FET resulted in 2703 singleton live births. d-FET resulted in a higher risk of preterm births (< 37 weeks), with adjusted odds ratio (aOR) 1.33 (95% CI 1.02-1.75), but similar risk of small for gestational age (SGA), with aOR 1.75 (95% CI 0.85-3.7), when compared to a-FET. However, when only single blastocyst transfer cycles are considered, d-FET and a-FET showed no difference in preterm births or other adverse perinatal outcomes.

CONCLUSIONS

Singletons resulting from d-FET are at increased risk for perinatal morbidity. However, the risk was diminished in single blastocyst transfer cycles. Our study supports the current American Society for Reproductive Medicine (ASRM) guidelines of transferring a single blastocyst in d-FET cycles.

Is the risk of preeclampsia higher in donor oocyte pregnancies? A systematic review and meta-analysis

Objective

Preeclampsia (PE) occurs in 4.6% of pregnancies worldwide. The social phenomenon of increasing maternal age has raised the demand for donor oocytes. Egg donation has allowed women with poor ovarian reserve, premature ovarian failure, genetic disorders or surgical menopause to get pregnant. Recipients provide a unique model of immune response because of the differences in the genetic makeup of mothers and fetuses. In PE, immune tolerance may be impaired as a result of having non-autologous eggs implanted. Egg donation is a highly successful assisted reproductive technology, despite the significant number of issues arising from the implantation of non-autologous eggs. This study aimed to determine whether there is an association between egg donation and preeclampsia.

Methods

A systematic review of the literature available in PubMed and Google Scholar was carried out from January of 1995 to August of 2016 using the terms 'oocyte donation, preeclampsia', 'oocyte donation, in vitro fertilization, preeclampsia', 'oocyte donation, preeclampsia, outcomes pregnancies', 'oocyte donation, obstetric outcome.' Only six retrospective cohort studies met the selection criteria.

Result

The meta-analysis revealed a statistically significant association between egg donation and onset of preeclampsia (OR 4.50; 95% CI: 3.28-6.19; p<0.0001).

Conclusion

Oocyte donation is associated with increased risk of preeclampsia in singleton pregnancies. Therefore, it is crucial to properly record and assess this finding when egg donation is the chosen assisted reproductive technology to attain pregnancy.

Why natural killer cells are not enough: a further understanding of killer immunoglobulin-like receptor and human leukocyte antigen

The immune system's role in recurrent reproductive failure is a controversial issue in assisted reproduction. Most studies into immune system implication in reproduction have focused on finding markers of peripheral blood and less on the uterine environment. Peripheral blood natural killer cells have become an "immune study core" for women with recurrent miscarriage or recurrent implantation failure, based on the mistaken notion that they cause reproductive failure by killing or "rejecting" the embryo. Maternal-fetal tolerance begins at the uterine level, so successful adaptation to the fetus occurs after a complicated process. Insufficient uterine lining invasion by an invading extravillous trophoblast is the primary defect in pregnancy disorders such as recurrent miscarriage. This process is regulated by the interaction between maternal killer immunoglobulin-like receptors (KIRs), expressed by uterine natural killer cells (uNK), and their ligand human leukocyte antigen (HLA) C, expressed by the extravillous trophoblast. Pregnancies are an increased risk of disorders in mothers with KIR AA when the fetus has paternal HLA-C2. A recent report has indicated that the expression of more than one paternal HLA-C by the extravillous trophoblast in assisted reproduction may affect placentation in mothers with KIR AA. This review provides insight into the immune system's role in assisted reproductive treatments. These insights can have an impact on the selection of single-embryo transfer and/or oocyte/sperm donor according to HLA-C in patients with recurrent implantation failure and recurrent miscarriage depending on their KIR haplotype.

Risk of adverse pregnancy and perinatal outcomes after high technology infertility treatment: a comprehensive systematic review

In the literature, there is growing evidence that subfertile patients who conceived after infertility treatments have an increased risk of pregnancy and perinatal complications and this is particularly true for patients who conceived through use of high technology infertility treatments. Moreover, high technology infertility treatments include many concomitant clinical and biological risk factors. This review aims to summarize in a systematic fashion the current evidence regarding the relative effect of the different procedures for high technology infertility treatments on the risk of adverse pregnancy and perinatal outcome. A literature search up to August 2016 was performed in IBSS, SocINDEX, Institute for Scientific Information, PubMed, Web of Science and Google Scholar and an evidence-based hierarchy was used to determine which articles to include and analyze. Data on prepregnancy maternal factors, low technology interventions, specific procedures for male factor, ovarian tissue/ovary and uterus transplantation, and chromosomal abnormalities and malformations of the offspring were excluded. The available evidences were analyzed assessing the level and the quality of evidence according to the Oxford Centre for Evidence-Based Medicine guidelines and the Grading of Recommendations Assessment, Development, and Evaluation system, respectively. Current review highlights that every single procedure of high technology infertility treatments can play a crucial role in increasing the risk of pregnancy and perinatal complications. Due to the suboptimal level and quality of the current evidence, further well-designed studies are needed.