Comprehensive appraisal of pregnancy and neonatal outcomes in singleton pregnancies conceived via fertilization in the USA (2016-2021).

Objectives: We set out to compare adverse pregnancy and neonatal outcomes in singleton gestations conceived via fertilization (IVF) to those conceived spontaneously.

Methods: Retrospective, population-based cohort using the CDC Natality Live Birth database (2016-2021). All singleton births were stratified into two groups: those conceived via IVF, and those conceived spontaneously. The incidence of several adverse pregnancy and neonatal outcomes was compared between the two groups using Pearson's chi-square test with Bonferroni adjustments. Multivariate logistic regression was used to adjust outcomes for potential confounders.

Results: Singleton live births conceived by IVF comprised 0.86 % of the cohort (179,987 of 20,930,668). Baseline characteristics varied significantly between the groups. After adjusting for confounding variables, pregnancies conceived via IVF were associated with an increased risk of several adverse pregnancy and neonatal outcomes compared to those conceived spontaneously. The maternal adverse outcomes with the highest risk in IVF pregnancies included maternal transfusion, unplanned hysterectomy, and maternal intensive care unit admission. Increased rates of hypertensive disorder of pregnancy, preterm birth (delivery <37 weeks of gestation), and cesarean delivery were also noted. The highest risk neonatal adverse outcomes associated with IVF included immediate and prolonged ventilation, neonatal seizures, and neonatal intensive care unit admissions, among others.

Conclusions: Based on this large contemporary United States cohort, the risk of several adverse pregnancy and neonatal outcomes is increased in singleton pregnancies conceived via IVF compared to those conceived spontaneously. Obstetricians should be conscious of these associations while caring for and counseling pregnancies conceived via IVF.