Birth outcomes of singleton vaginal deliveries to ART-treated, subfertile, and fertile primiparous women

Purpose: To determine whether differences in birth outcomes among assisted reproductive technology (ART)-treated, subfertile, and fertile women exist in primiparous women with, singleton, vaginal deliveries. Methods: Society for Assisted Reproductive Technology Clinic Outcome Reporting System (SART CORS) data were linked to Massachusetts vital records and hospital discharges for deliveries between July 2004 and December 2010. Primiparous women with in-state vaginal deliveries, adequate prenatal care, and singleton birth at ≥ 20 weeks (n = 117,779) were classified as ART-treated (linked to ART data from SART CORS, n = 3138); subfertile (not ART-treated but with indicators of subfertility, n = 1507); or fertile (neither ART-treated nor subfertile, n = 113,134). Outcomes of prematurity (< 37 weeks), low birthweight (< 2500 g), perinatal death (death at ≥ 20 weeks to ≤ 7 days), and maternal prolonged length of hospital stay (LOS > 3 days) were compared using multivariable logistic regression. Results: Compared to fertile, higher odds were found for prematurity among ART-treated (adjusted odds ratio [AOR] 1.40, 95% confidence interval [CI] 1.25–1.50) and subfertile (AOR 1.25, 95% CI 1.03–1.50) women, low birthweight among ART-treated (AOR 1.41, 95% CI 1.23–1.62) and subfertile (AOR 1.40, 95% CI 1.15–1.71) women, perinatal death among subfertile (AOR 2.64, 95% CI 1.72–4.05), and prolonged LOS among ART-treated (AOR 1.33, 95% CI 1.19–1.48) women. Differences remained despite stratification by young age and absence of pregnancy/delivery complications. Conclusions: Greater odds of prematurity and low birthweight in ART-treated and subfertile, and perinatal death in subfertile deliveries are evident among singleton vaginal deliveries. The data suggest that even low-risk pregnancies to ART-treated and subfertile women be managed for adverse outcomes.