Elective Single Embryo Transfer in the Setting of Funded In Vitro Fertilization: Two Years’ Experience in an Ontario Hospital-Based Fertility Clinic

Effect of publicly funded assisted reproductive technology on maternal and infant outcomes: a pre- and post-comparison study

STUDY QUESTION

Does publicly funded assisted reproductive technology result in improved maternal and infant outcomes?

SUMMARY ANSWER

Publicly funded ART in Quebec was associated with reduced risks of preeclampsia, cesarean delivery, preterm birth, low birth weight and other adverse outcomes.

WHAT IS KNOWN ALREADY

Publicly funded ART programs that provide free access to single embryo transfer are known to decrease the rate of multiple pregnancy, but the impact on other pregnancy outcomes is unknown.

STUDY DESIGN, SIZE, DURATION

We conducted a pre- and post-comparison study of 597 416 pregnancies conceived between July 2008 and September 2015 in Quebec, Canada, a region where public funding of ART began in August 2010.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We included all pregnant women who conceived by ART (n = 14 309) or spontaneously (n = 583 107) and delivered a live or stillborn infant in hospitals of Quebec. The main exposure measure was conception before versus during the publicly funded ART program. Outcomes included measures of maternal and infant morbidity and mortality. We estimated risk ratios (RR) and 95% confidence intervals for the association of publicly funded ART with maternal and infant outcomes using log-binomial regression models adjusted for maternal characteristics.

MAIN RESULTS AND THE ROLE OF CHANCE

In this study, 2638 pregnancies were conceived by ART before, and 11 671 were conceived by ART, during public funding. Compared with no public funding, ART funding was associated with reduced risks of severe maternal morbidity (RR 0.64, 95% CI 0.50-0.83), preeclampsia (RR 0.55, 95% CI 0.44-0.68), cesarean delivery (RR 0.83, 95% CI 0.77-0.89), preterm birth (RR 0.67, 95% CI 0.60-0.75), low birth weight (RR 0.63, 95% CI 0.55-0.72), severe neonatal morbidity (RR 0.75, 95% CI 0.57-0.99) and neonatal intensive care unit admission (RR 0.65, 95% CI 0.53-0.78). When multiple pregnancies were excluded, ART funding continued to be associated with a lower risk of preeclampsia (RR 0.61, 95% CI 0.48-0.79) and preterm birth (RR 0.85, 95% CI 0.73-0.99). However, ART funding was associated with increased risk of gestational diabetes.

LIMITATIONS, REASONS FOR CAUTION

We had no information on the type of ART, number of in-vitro fertilization cycles or number of embryos transferred. We lacked data on body mass index, ethnicity and smoking and cannot rule out residual confounding.

WIDER IMPLICATION OF THE FINDINGS

Our findings suggest that publicly funded ART programs that encourage single embryo transfer may have substantial benefits for a range of maternal and infant outcomes, beyond prevention of multiple births.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by grant 6D02363004 from the Public Health Agency of Canada. N.A. acknowledges a career award from the Fonds de recherche du Québec-Santé (34695). The authors declare no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Neonatal outcomes of singleton live births with vanishing twin syndrome following double embryos transfer in assisted reproductive technology: a retrospective cohort study

Background

Women with vanishing twin syndrome are associated with increased risks of adverse neonatal outcomes, such as preterm birth (PTB) and low birthweight (LBW), compared with those in singleton live births following single embryo transfer (SET) in assisted reproductive technology (ART).

Methods

Anonymized data on all cycles performed in China were obtained from the Reproductive Medicine Department at the Third Affiliated Hospital of Zhengzhou University, which had involved 127597 cycles following double embryos transfer (DET), including 54585 fresh embryos transfer (ET) cycles and 73012 frozen embryos transfer (FET) cycles. In addition, the obstetric outcomes, such as gestation age, PTB, small for gestation age (SGA), birthweight (BW), LBW, congenital malformation, pediatric admission and Neonatal Intensive Care Unit (NICU) admission in the fresh ET and FET cycles, were analyzed. Moreover, logistic regression analysis was performed to adjust the confounders, including age of women, body weight index (BMI), value of AMH, infertile years, current cycle, antral follicles, cause of infertility, number of oocytes retrieved, endometrial thickness at the date of transplantation, number of high-quality embryos, and embryo stage.

Results

In the fresh ET cycles, the BW and gestational age in study group were lower than those in control group, which were (2962.4 ± 563.1vs. 3104.9 ± 498. 5, p = 0.000) and (262.8 ± 8.4 vs. 268.9 ± 13.9, p = 0.000), respectively. Relative to control group, the study group was linked with increased risks of PTB (adjusted odds ratio (aOR) 2.45, 95% CI:1.98–3.03, adjusted p = 0.000), LBW (aOR2.11, 95% CI:1.67–2.65, adjusted p = 0.000), pediatric admission (aOR 2.55, 95% CI2.07–3.13, adjusted p = 0.000), and NICU admission (aOR 1.98, 95% CI1.32–2.96, adjusted p = 0.001), but there were no statistically significant differences in the risks of SGA (aOR 1.09, 95% CI0.82–1.45, adjusted p = 0.960) and congenital malformation (aOR 0.94, 95% CI0.53–1.68, adjusted p = 0.640) between the two groups. In the FET cycles, the gestational age and BW in study group were lower than those in control group, which were (263.0 ± 15.7vs. 273.0 ± 10.5, p = 0.000) and (3099 ± 662.1vs. 3352 ± 671.5), respectively. The study group was associated with increased risks of PTB (aOR2. 45, 95% CI: 2.23–3.43, adjusted p = 0.000), LBW (aOR 2.67, 95% CI: 2.13–3.34, adjusted p = 0.000), pediatric admission (aOR2.62, 95% CI2.14–3.21, adjusted p = 0.000), and NICU admission (aOR 2.22, 95% CI1.43, 3.46, adjusted p = 0.001) compared with those in control group, but differences in the risks of SGA (aOR 0.98, 95% CI0.71–1.36, adjusted p = 0.730) and congenital malformation (aOR 0.99, 95% CI 0.60,1.63, adjusted p = 0.940) between the two groups were not statistically significant.

Conclusions

Our study finds that singleton live births with VTS have higher risks of LBW, PTB, pediatric admission and NICU admission than those without VTS in both the fresh and frozen cycles, even after adjusting for confounders. However, no increased risks of SGA or congenital malformation are observed in singleton live births in both the fresh and frozen ART cycles following DET.