Association of in vitro fertilization with cesarean delivery in nulliparous, term, singleton, vertex pregnancies.

Objectives: To investigate the potential relationship between in vitro fertility and cesarean delivery among nulliparous, term, singleton, vertex pregnancies.

Methods: Retrospective cohort study involving nulliparous, term, singleton, vertex patients who delivered between 1/2019 and 12/2022. The primary exposure was in vitro fertility. The primary outcome was cesarean delivery. Basic inferential statistics were performed using the chi-square test of association to examine relationships between categorical variables. A logistic regression was used to model the probability of cesarean delivery as a function of in vitro fertility. Odds ratios, and their associated 95 % confidence interval (CI) were computed. An alpha value of 0.05 was considered statistically significant.

Results: A total of 36,703 pregnancies were included for analysis, of which 987 (2.69 %) were conceived by in vitro fertility. The overall cesarean delivery rate was 29.27 % (n=10,743). Using adjusted logistic regression, in vitro fertility was associated with 1.99 times the odds of cesarean delivery (95 % CI 1.75-2.28) compared to non-in vitro fertility pregnancies. The most frequent indications among the IVF cohort were obstetrical (40.82 %) and fetal (36.91 %). A sub-analysis of those who underwent induction of labor found that in vitro fertility was associated with 1.59 times the odds of cesarean delivery (95 % CI 1.35-1.88) compared to non-in vitro fertility pregnancies.

Conclusions: In vitro fertility is associated with higher rates of cesarean delivery in nulliparous, term, singleton, vertex pregnancies. Recognizing this association provides a foundation for future research and quality improvement measures to safely lower the nulliparous, term, singleton, vertex cesarean delivery rate and decrease risk to mother and infant among these highly desired pregnancies.