Association between in vitro fertilization and preeclampsia: a multicenter cohort study with subgroup analysis by maternal age, BMI, and parity.

BACKGROUND

Preeclampsia (PE) is a significant complication of pregnancy, and its association with in vitro fertilization (IVF) remains unclear, especially across different demographic groups.

METHODS

We conducted a retrospective multicenter cohort study including 61,329 singleton pregnancies from three hospitals in China, with 3,902 conceived via IVF and 57,427 conceived naturally. Multivariate logistic regression and Kaplan-Meier analyzes were used to assess the associations between IVF and preeclampsia, preterm birth, and small for gestational age (SGA), adjusting for maternal age, BMI, parity, and other clinical variables. Subgroup analyzes were performed by age (< 35 vs. ≥ 35), BMI (< 24 vs. ≥ 24 kg/m²), and parity.

RESULTS

IVF was significantly associated with increased risks of preeclampsia (adjusted OR = 1.34, 95% CI: 1.14-1.57, p = 0.0004) and preterm birth (adjusted OR = 1.68, 95% CI: 1.43-1.97, p < 0.0001), but not with SGA. Subgroup analyzes showed that the association between IVF and preeclampsia was consistent across subgroups defined by age, BMI, and parity, with no significant interactions. For preterm birth, a significant age interaction was observed (p = 0.0005), with a stronger association in women under 35 years.

CONCLUSION

IVF is independently associated with an increased risk of preeclampsia and preterm birth. Enhanced monitoring and tailored prenatal care are warranted in IVF pregnancies.