Neonatal outcomes in women with sonographically identified uterine leiomyomata.

OBJECTIVE: We sought to compare perinatal outcomes between women with and without leiomyomata.

STUDY DESIGN: This is a retrospective cohort study comparing neonatal outcomes in women with and without uterine leiomyomata discovered at routine second trimester obstetric ultrasonography, all of whom delivered at a single institution. Potential confounders such as maternal age, parity, race, ethnicity, medical insurance, previous uterine surgery, fetal presentation, length of labor, mode of delivery, presence of placenta previa, placental abruption, chorioamnionitis, and epidural use were controlled for using multivariable logistic regression.

RESULTS: From 1993 to 2003, 15,104 women underwent routine second trimester prenatal ultrasonography, with 401 (2.7%) women identified with at least one leiomyoma. By univariate and multivariable analyses, the presence of leiomyomata was associated with statistically significant increased risks for preterm delivery at <34 weeks [adjusted odds ratio (AOR) 1.7, 95% confidence interval (CI) 1.1-2.6], <32 weeks (AOR 1.9, 95% CI 1.2-3.2), and <28 weeks (AOR 2.0, 95% CI 1.1-3.8). An association with increased risk for intrauterine fetal demise (IUFD) was also demonstrated (AOR 2.7, 95% CI 1.0-6.9). When IUFD was examined before and after 32 weeks' gestation, the finding only persisted at earlier gestational ages (<32 weeks: AOR 4.2, 95% CI 1.2-14.7 vs. >32 weeks: AOR 0.82, 95% CI 0.1-6.2).

CONCLUSION: Regardless of maternal age, ethnicity, and parity, pregnant women with leiomyomata are at increased risk for preterm birth and IUFD. This did not translate to lower birth weight outcomes among term patients, suggesting that LBW is more likely due to preterm birth than growth restriction. These results may be useful for preconception and prenatal counseling of women with leiomyomata.