Frozen autologous and donor oocytes are associated with differences in clinical and neonatal outcomes compared with fresh oocytes: a Society for Assisted Reproductive Technology Clinic Outcome Reporting System Analysis

Objective

To study the clinical and neonatal outcomes of embryos derived from frozen oocytes relative to fresh oocytes in both autologous and donor oocyte cycles after fresh embryo transfer (ET).

Design

This is a retrospective cohort study using the Society for Assisted Reproductive Technology Clinic Outcome Reporting System database between 2014 and 2015.

Setting

The Society for Assisted Reproductive Technology Clinic Outcome Reporting System database was used to identify autologous and donor oocyte cycles that resulted in a fresh ET during 2014 and 2015.

Patients

There were 154,706 total cycles identified that used embryos derived from fresh or frozen oocytes and resulted in a fresh ET, including 139,734 autologous oocyte cycles and 14,972 donor oocyte cycles.

Interventions

Generalized linear regression models were used to compare the clinical and neonatal outcomes of frozen oocytes relative to fresh oocytes. Models were adjusted for maternal age, body mass index, smoking status, parity, infertility diagnosis, number of embryos transferred, and preimplantation genetic testing. An additional sensitivity analysis was performed to examine singleton pregnancies separately.

Main Outcome Measures

The live birth (LB) rate was the primary outcome. Secondary outcomes include pregnancy and birthweight outcomes.

Results

Differences in clinical and neonatal outcomes between fresh and frozen-thawed oocytes after fresh ET were observed. Specifically, our study found a higher incidence of high-birthweight infants after the use of frozen oocytes relative to fresh oocytes in both autologous oocytes (12.5% [frozen] vs. 4.5% [fresh], adjusted risk ratio [aRR] 2.67, 95% confidence interval [CI] 1.65-4.3) and donor oocyte cycles (6.2% [frozen] vs. 4.6% [fresh], aRR 1.42, 95% CI 1.1-1.83). This finding remained true when the analysis was restricted to singleton gestations only for both groups: autologous (17.3% [frozen] vs. 7.1% [fresh], aRR 2.77, 95% CI 1.74-4.42) and donor oocytes (9.4% [frozen] vs. 7.8% [fresh], aRR 1.38, 95% CI 1.07-1.77). Additionally, we observed a decrease in LB (aRR 0.81, 95% CI 0.77-0.85); clinical pregnancy (aRR 0.83, 95% CI 0.8-0.87); and an increase in biochemical pregnancy loss (aRR 1.22, 95% CI 1.05-1.43) after the use of frozen oocytes in donors, but not autologous cycles.

Conclusions

Our findings of an increased incidence of high-birthweight infants after the transfer of embryos derived from frozen oocytes in both autologous and donor oocyte cycles raise questions about oocyte vitrification and deserve further study. Additionally, the finding of a decreased likelihood of LB with frozen-donor oocytes compared with fresh donor oocytes is an important finding, especially because more patients are seeking to use frozen oocytes in their donor egg cycles. Future research should be directed toward these findings to optimize the use of frozen oocytes in clinical practice.

Similar pregnancy outcomes from fresh and frozen donor oocytes transferred to gestational carriers: a SART database analysis isolating the effects of oocyte vitrification

PURPOSE

This work aimed to study clinical and neonatal outcomes of embryos derived from frozen compared to fresh donor oocytes in gestational carrier cycles.

METHODS

This is a retrospective cohort study using the Society for Assisted Reproductive Technology Clinic Outcome Reporting System database between 2014 and 2015, comprising of 1284 fresh transfer cycles to gestational carrier recipients of embryos resulting from fresh (n = 1119) and vitrified/thawed (n = 165) donor oocytes. Models were adjusted for gestational carrier age, preimplantation genetic testing (PGT-A), number of embryos transferred, multiple gestation, and fetal heart reduction. As our models were part of a larger analysis, intended parent BMI, smoking status, and parity were also adjusted for, but did not influence outcomes in this analysis.

RESULTS

There was no significant difference in probability of live birth rates when comparing embryos derived from fresh and frozen donor oocytes in gestational carrier cycles. There were also no significant differences in biochemical pregnancy losses or clinical miscarriage. There were no significant differences noted in low birthweight or high birthweight infants derived from fresh versus frozen donor oocyte after transfer into a gestational carrier.

CONCLUSIONS

The analysis of fresh and frozen donor oocytes in gestational carrier cycles provides the opportunity to assess for a possible effect of vitrification on the oocyte by controlling for differences in the uterine environment. We observed no significant differences in live birth, pregnancy loss, low birthweight or high birthweight infants when comparing fresh and frozen donor oocytes in gestational carrier cycles.

Obstetric outcomes in pregnancies resulting from in vitro fertilization are not different in fertile, sterilized women compared to infertile women: A Society for Assisted Reproductive Technology database analysis

OBJECTIVE

To compare obstetric and neonatal outcomes resulting from assisted reproductive technology in couples with a history of female sterilization to couples with other infertility diagnoses.

DESIGN

Retrospective cohort study.

SETTING

Not applicable.

PATIENT(S)

Fresh, nondonor cycles excluding gestational surrogacy from 2004 to 2013 in the United States.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Preterm birth rates and low birth weight rates from in vitro fertilization (IVF) pregnancies in couples with infertility and in couples with prior tubal ligation as their sole indication for IVF.

RESULT(S)

The mean ages of fertile women (N = 8,478) and infertile women (N = 371,488) were 35.3 and 34.6 years, respectively. Of the singletons born to parous women (N = 26,463), the incidence of preterm birth was not significantly different in fertile, sterilized couples compared to infertile couples (13.7% vs. 12.0%). The incidence of low birth weight among term singletons was also not significantly different between fertile couples compared to infertile couples (3.5% vs. 3.2%).

CONCLUSION(S)

Fertile couples have similar preterm birth and low birth weight rates after IVF compared to infertile couples. This suggests that differences in perinatal outcomes may be due to assisted reproductive technology procedures rather than infertility itself.

Maternal Biomarkers of Nutritional Status Prior to Pregnancy and Newborn Epigenetic Aging

Objectives

Maternal diet prior to and during pregnancy has been related to child health across the lifespan; however, mechanisms remain unclear. Gestational age acceleration (GAA), a measure of epigenetic aging relative to clinically estimated gestational age (GA), has emerged as a potential biomarker predictive of childhood BMI and atopic diseases. Few studies have evaluated the associations of maternal nutrient biomarkers, including methyl donors and fatty acids (FA), with GAA.

Methods

We evaluated associations among 391 mother-child dyads in the Effects of Aspirin in Gestation and Reproduction (EAGeR) trial. Women were randomized to low-dose aspirin (LDA) or placebo, both containing 400 μg folic acid, prior to and through 36 weeks pregnancy. Maternal folate, homocysteine, vitamin B-12, vitamin D, carotenoids, tocopherols, and plasma FAs were quantified from blood samples obtained ≤6 months prior to conception and at 8 weeks gestation. DNA methylation was measured with the Infinium MethylationEPIC BeadChip using cord blood DNA. Epigenetic GA was calculated using the Knight and Bohlin clocks. GAA was defined as the residual from a model regressing GA on epigenetic GA. We assessed associations between nutritional biomarkers and GAA using robust linear regression, controlling for maternal age, race, education, employment status, total cholesterol, and child sex. A false discovery rate (FDR) correction was applied to account for multiple comparisons using the Benjamini-Hochberg method.

Results

Mean (SD, range) clinically estimated GA at delivery was 38.9 (1.5, 31.1–44.9) weeks and was positively correlated with epigenetic age (Knight clock r = 0.51, Bohlin clock r = 0.76). Being female was positively related to GAAKnight. Maternal age was positively associated with GAABohlin. In multivariable regression models, preconception folate was inversely related to GAABohlin (β = −0.004, 95% CI: −0.007–0.000, P = 0.04); however, this was not significant after adjustment for multiple comparisons (FDR P = 0.82). Other nutritional biomarkers and LDA were not related to GAA.

Conclusions

Maternal nutritional biomarkers prior to conception and during early pregnancy were not related to newborn epigenetic age acceleration in predominantly term deliveries among women supplemented with folic acid.

Funding Sources

Supported by the Intramural Research Program of the NICHD.