The impact of chorionicity and assisted reproductive therapies in obstetric and neonatal outcomes

Congenital anomalies observed in children conceived through assisted reproductive technology-a systematic review and meta-analysis

Congenital anomalies (CAs) are a leading cause of perinatal and child mortality. With the increasing use of assisted reproductive technology (ART), there is a growing need for research on the health outcomes of children conceived through ART. This systematic review was performed to assess the incidence of CAs in ART-conceived children compared to those conceived naturally. This review followed the PRISMA 2020 guidelines and was registered with PROSPERO. A total of 113 studies were included in this meta-analysis, comprising 768,929 children in the ART group and 40,709,337 children in the control group which comprised spontaneously conceived (SC) children. The primary findings indicated that ART-conceived children have a marginally higher risk of CAs compared to the control group. Subgroup analyses showed that children conceived via ICSI, Day 3 transfer, and fresh embryo transfer (ET) had a slightly higher risk of CAs than those conceived via IVF, Day 5 transfer, or frozen embryo transfer (FET). The study highlights a slightly increased incidence of CAs among ART-conceived children over SC children, underscoring the importance of improving ART methods and closely monitoring the health of these children to reduce the risk of CAs.

Assisted reproduction and congenital malformations: A systematic review and meta-analysis

Prior studies have explored the links between congenital anomalies and assisted reproduction techniques, among other factors. However, it remains unclear whether a particular technique harbors an inherent risk of major congenital anomalies, either cumulatively or in an organ-specific manner. A meta-analysis was conducted using relevant studies from inception to February 2023 using six databases and two appropriate registers. Sources of heterogeneity were explored using sub-group analysis, using study weight, risk of bias and geographical location of original studies. Neonates conceived through assisted reproduction appear to have a higher risk of major congenital anomalies compared to naturally conceived neonates, OR 0.67 [95% CI 0.59, 0.76], I2 = 97%, p < 0.00001, with neonates conceived through intracytoplasmic sperm injection (ICSI) at a 9% higher chance of being affected in comparison to neonates conceived through in vitro fertilization (IVF). The increase in cardiac, gastrointestinal (GI), and neurological congenital anomalies appears to be independent of the assisted reproduction technique, while urogenital and musculoskeletal (MSK) anomalies were found to be increased in ICSI compared with IVF, OR 0.83 [95% CI 0.69, 0.98]; p = 0.03, I2 = 0%, and OR 0.65 [95% CI 0.49, 0.85]; p = 0.002, I2 = 80%, respectively. Neonates conceived using assisted reproduction techniques appear to be at higher risk of major congenital anomalies, with a higher risk attributable to conception using ICSI. The increase in cardiac, neurological, and GI congenital anomalies does not appear to be technique-specific, while the opposite held true for urogenital and MSK anomalies.

Maternal and perinatal risks for monozygotic twins conceived following frozen-thawed embryo transfer: a retrospective cohort study

BACKGROUND

The present study aimed to explore the maternal and perinatal risks in cases of monozygotic twins (MZT) following frozen-thawed embryo transfer (FET).

METHODS

All twin births that were conceived following FET from 2007 to 2021 at Shanghai Ninth People's Hospital in Shanghai, China were retrospectively reviewed. The exposure variable was twin type (monozygotic and dizygotic). The primary outcome was the incidence of neonatal death while secondary outcomes included hypertensive disorders of pregnancy, gestational diabetes, intrahepatic cholestasis of pregnancy, placenta previa, placental abruption, preterm premature rupture of the membranes, Cesarean delivery, gestational age, birth weight, weight discordance, stillbirth, birth defects, pneumonia, respiratory distress syndrome, necrotizing enterocolitis, and neonatal jaundice. Analysis of the outcomes was performed using logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (CIs). The causal mediation analysis was conducted. A doubly robust estimation model was used to validate the results. Kaplan-Meier method was used to calculate survival probability. The sensitivity analysis was performed with a propensity score-based patient-matching model.

RESULTS

Of 6101 dizygotic twin (DZT) and 164 MZT births conceived by FET, MZT showed an increased risk of neonatal death based on the multivariate logistic regression models (partially adjusted OR: 4.19; 95% CI, 1.23-10.8; fully adjusted OR: 4.95; 95% CI, 1.41-13.2). Similar results were obtained with the doubly robust estimation. Comparing MZT with DZT, the neonatal survival probability was lower for MZT (P < 0.05). The results were robust in the sensitivity analysis. Females with MZT pregnancies exhibited an elevated risk of preterm premature rupture of the membranes (adjusted OR: 2.42; 95% CI, 1.54-3.70). MZT were also associated with higher odds of preterm birth (prior to 37 weeks) (adjusted OR: 2.31; 95% CI, 1.48-3.67), low birth weight (adjusted OR: 1.92; 95% CI, 1.27-2.93), and small for gestational age (adjusted OR: 2.18; 95% CI, 1.21-3.69) in the fully adjusted analyses. The effect of MZT on neonatal death was partially mediated by preterm birth and low birth weight (P < 0.05).

CONCLUSIONS

This study indicates that MZT conceived by FET are related to an increased risk of neonatal death, emphasizing a potential need for comprehensive antenatal surveillance in these at-risk pregnancies.