Ovarian Stimulators, Intrauterine Insemination, and Assisted Reproductive Technologies Use and the Risk of Major Congenital Malformations-The AtRISK Study

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.

Medically assisted reproduction and the risk of preterm birth: a case-control study using data from the Quebec Pregnancy Cohort

BACKGROUND

The use of fertility treatments has been growing over the past decade, but these treatments are not without risk. We aimed to quantify the risk of preterm birth associated with the use of ovarian stimulators (OS) and assisted reproductive technologies (ART) overall and by type of fertility treatment.

METHODS

We conducted a case-control analysis of data from the Quebec Pregnancy Cohort. We included singleton pregnancies ending in a live birth during the time when Quebec operated a universal reimbursement program for assisted reproduction (2010-2015). Fertility treatments were defined dichotomously, and pregnancies resulting from spontaneous conception were used as the reference. We categorized fertility treatments into subgroups: ovarian stimulators alone, ART alone and OS and ART combined. Preterm birth was defined as birth before 37 weeks' gestation. We estimated odds ratios (ORs) for the association between type of assisted reproduction and preterm birth using generalized estimating equation models and adjusted ORs for potential confounders.

RESULTS

A total of 57 624 pregnancies were included in the study. During the study period, 2055 pregnancies were conceived through the use of OS, ART or both: 419 involved OS alone, 150 involved ART alone and 1486 involved both OS and ART. When we adjusted for potential confounders, conception with OS, ART or both was associated with an increased risk of preterm birth (adjusted OR 1.46, 95% confidence interval [CI] 1.25-1.72, 182 exposed cases). All types of assisted reproduction were associated with an increased risk of preterm birth compared with pregnancies conceived spontaneously (OS alone: adjusted OR 1.47, 95% CI 1.04-2.07; ART alone: adjusted OR 1.76, 95% CI 1.01-3.06; OS and ART combined: adjusted OR 1.43, 95% CI 1.19-1.73). Use of OS or ART or both was associated with an increased risk of late, moderate and extremely preterm birth (extremely preterm birth: adjusted OR 2.39, 95% CI 1.30-4.39).

INTERPRETATION

Compared with pregnancies conceived spontaneously, pregnancies conceived through the use of OS, ART or both were associated with a 46% increased risk of preterm birth. Physicians should advise patients of the increased risks of late, moderate and extremely preterm birth so that they can make informed choices.

Embryo responses to stress induced by assisted reproductive technologies

Assisted reproductive technology (ART) has led to the birth of millions of babies. In cattle, thousands of embryos are produced annually. However, since the introduction and widespread use of ART, negative effects on embryos and offspring are starting to emerge. Knowledge so far, mostly provided by animal models, indicates that suboptimal conditions during ART can affect embryo viability and quality, and may induce embryonic stress responses. These stress responses take the form of severe gene expression alterations or modifications in critical epigenetic marks established during early developmental stages that can persist after birth. Unfortunately, while developmental plasticity allows the embryo to survive these stressful conditions, such insult may lead to adult health problems and to long-term effects on offspring that could be transmitted to subsequent generations. In this review, we describe how in mice, livestock, and humans, besides affecting the development of the embryo itself, ART stressors may also have significant repercussions on offspring health and physiology. Finally, we argue the case that better control of stressors during ART will help improve embryo quality and offspring health.

Impact of high magnification sperm selection on neonatal outcomes: a retrospective study

PURPOSE

The aim of this study was to compare the effect of the deselection of spermatozoa presenting vacuole-like structures using IMSI (intracytoplasmic morphologically selected sperm injection) with ICSI (intracytoplasmic sperm injection) by means of neonatal outcomes.

METHODS

In a retrospective two-center analysis, a total of 848 successful IMSI or ICSI cycles ending with a live birth, induced abortion, or intrauterine fetal death (IUFD) were included.

RESULTS

The IMSI and ICSI groups included 332 and 655 babies or fetuses, respectively. The parents were older in the IMSI group than in the ICSI group (mothers were 35.1 vs 32.9 years, and fathers were 39.1 vs 36.2 years). The multiple pregnancy rate was higher in the IMSI group. The mean pregnancy duration and mean birth weight were almost identical in both groups. There was no significant difference in major congenital malformations between the two groups. However, this rate was decreased in the IMSI group compared to that in the ICSI group (1.8 vs 3.2%), the difference being mainly found in singletons (1.4 vs 3.3%). Boys were more often affected than girls in both groups. The percentages of chromosomal abnormalities did not differ between the IMSI and ICSI groups (0.6 and 0.8%). The reported congenital malformations mainly affected the heart, urogenital, and musculoskeletal systems.

CONCLUSIONS

In the present study, the malformation rates observed in the IMSI and ICSI groups were not significantly different, even if slightly lower after IMSI. However, the observed difference followed the same trends observed in previous reports, indicating the possible impact of IMSI on decreasing congenital malformation occurrences. This highlights the necessity to prospectively evaluate the impact of IMSI on neonatal outcome after IVF treatment.