Pregnancy, delivery, and neonatal outcomes in women with uterine fibroids carrying singleton vs. multiple gestations: A retrospective population database cohort study.

PURPOSE: While uterine leiomyomas and multiple gestations are both independent risk factors for perinatal outcomes, little research has examined their combined effects. This study aimed to assess pregnancy, delivery, and neonatal outcomes in women with uterine leiomyomas carrying singleton vs. multiple gestations.

METHODS

A retrospective population-based cohort study was performed by extracting data from the Healthcare Cost and Utilization Project (HCUP) database from 2004 to 2014, inclusively. The study group consisted of women with uterine fibroids carrying singleton gestations (n = 87,014), and the experimental group of women with uterine fibroids carrying multiple gestations (n = 2,303). Demographics were compared using chi-squared tests, and confounding effects in pregnancy outcomes were controlled using multivariate logistic regression analysis.

RESULTS

When compared to women carrying singleton gestations complicated by fibroids, those carrying multiple gestations complicated by fibroids were more likely to be over the age of 35, have a higher income, have private health insurance, and have used in vitro fertilization. They were less likely to smoke tobacco, use Medicaid, or have had a prior cesarean (all p < 0.01). Women carrying multiple gestations complicated by fibroids had increased risks of pregnancy-induced hypertension (aOR 1.89, 95% CI 1.71-2.09), preeclampsia (aOR 2.45, 95% CI 2.17-2.77), and superimposed preeclampsia/eclampsia (aOR 1.43, 95% CI 1.12-1.85), but not gestational hypertension, gestational diabetes, or placenta previa. While they were also more likely to deliver neonates who were small for gestational age (aOR 2.33, 95% CI 2.02-2.68) or who had experienced intrauterine fetal demise (aOR 1.77, 95% CI 1.09-2.86), rates of congenital anomalies did not differ. Severe maternal outcomes, thromboembolic events, and infections did not differ significantly between the two groups.

CONCLUSION

The coexistence of uterine fibroids and multiple gestations is associated with maternal and neonatal risks, including hypertensive disorders, preterm birth, cesarean delivery, postpartum hemorrhage, and adverse neonatal outcomes. Fibroids may intensify the physiological demands of multiple gestations, highlighting the need for further research into how fibroid characteristics shape pregnancy outcomes.