Obstetric Outcomes in Surrogacy and Non-Surrogacy

Obstetric outcomes similar for surrogacy and non-surrogacy using fertility treatments suggest a new study published in the JAMA.

Advancements in assisted reproductive technology (ART) have led to an increase in gestational carrier (GC) pregnancies. However, the perinatal outcomes of GC pregnancies remain understudied, necessitating a deeper understanding of their associated risks. A study assessed maternal characteristics and obstetric outcomes associated with GC pregnancies.

Study Methodology

A comprehensive systematic search of publications published before October 31, 2023, using PubMed, Web of Science, Scopus, and Cochrane Library databases was conducted. Two authors selected studies examining obstetric characteristics and outcomes in GC pregnancies with 24 or more weeks’ gestation. Studies with insufficient outcome information, unavailable data on gestational surrogacies, and non-English language studies were excluded. Adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, 2 investigators extracted and synthesized both quantitative and qualitative data.

Both fixed-effect and random-effect analysis were used to pool data. The primary outcomes were obstetric characteristics and outcomes, including:

• Hypertensive disorders
• Preterm birth
• Low birth weight

Secondary outcomes included severe maternal morbidity and mortality associated with GC pregnancies.

Results

Six studies from 2011 to 2023 involving 28,300 GC pregnancies and 1,270,662 non-GC pregnancies were included. GCs accounted for 2.5% of in vitro fertilization cycles (59,502 of 2,374,154 cycles) and 3.8% of ART pregnancies (26,759 of 701,047 ART pregnancies). GC pregnancies were more likely to be conceived by frozen embryo transfer compared with non-GC ART pregnancies (odds ratio [OR], 2.84; 95% CI, 1.56-5.15), and rates of single embryo transfer were similar between the 2 groups (OR, 1.18; 95% CI, 0.94-1.48).

GCs were rarely nulliparous (6 of 361 patients [1.7%]) and were more likely to have multifetal pregnancies compared with non-GC ART patients (OR, 1.18; 95% CI, 1.02-1.35). Comparator studies revealed:

• Lower odds of cesarean delivery (adjusted OR [aOR], 0.42; 95% CI, 0.27-0.65)
• Comparable rates of hypertensive disorders (aOR, 0.86; 95% CI, 0.45-1.64)
• Preterm birth (aOR, 0.82; 95% CI, 0.68-1.00)
• Low birth weight (aOR, 0.79; 95% CI, 0.50-1.26) in GC pregnancies vs non-GC ART pregnancies

Comparatively, GC pregnancies had higher odds of hypertensive disorders (aOR, 1.44; 95% CI, 1.13-1.84) vs general (non-GC ART and non-ART) pregnancies with comparable cesarean delivery risk (aOR, 1.06; 95% CI, 0.90-1.25).

Preterm birth and low birth weight data lacked a comparative group using multivariate analysis. Severe maternal morbidity and maternal mortality were rare among GCs. In this systematic review and meta-analysis, although GC pregnancies had slightly improved outcomes compared with non-GC ART pregnancies, they posed higher risks than general pregnancies. Contributing factors may include ART procedures and increased rates of multiple gestations which influence adverse perinatal outcomes in GC pregnancies.

Reference

Matsuzaki S, Masjedi AD, Matsuzaki S, et al. Obstetric Characteristics and Outcomes of Gestational Carrier Pregnancies: A Systematic Review and Meta-Analysis. JAMA Netw Open. 2024;7(7):e2422634. doi:10.1001/jamanetworkopen.2024.22634