Objective: To determine the extent to which uterine leiomyomas are associated with characteristics of pregnancy, labor, and neonatal outcome recorded on birth certificates.
Methods: In a population-based series of women who delivered singleton live infants in Washington state from 1987-1993, we linked computerized birth certificates and hospital discharge records to investigate the relationship between uterine leiomyomas and complications in pregnancy and delivery. Subjects were 2065 women with uterine leiomyomas noted on computerized hospital discharge records. From the remaining records, a comparison group of women without uterine leiomyomas diagnoses were selected at random and frequency-matched by birth year to women with leiomyomas. We used unconditional logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) of pregnancy or delivery complications in relation to uterine leiomyomas after multivariate adjustment.
Results: Women with leiomyomas were more likely than controls to be over age 35 at delivery, nulliparous, or black. We observed independent associations between uterine leiomyomas and abruptio placentae (OR 3. 87, 95% CI 1.63, 9.17), first trimester bleeding (OR 1.82, 95% CI 1. 05, 3.20), dysfunctional labor (OR 1.85, 95% CI 1.26, 2.72), and breech presentation (OR 3.98, 95% CI 3.07, 5.16). The risk of cesarean was also higher among women with uterine leiomyomas (OR 6. 39, 95% CI 5.46, 7.50), but a portion of the excess risk might have been due to biased detection of leiomyomas at cesarean delivery.
Conclusion: Leiomyomas appear to increase likelihood of complications during pregnancy, labor, and delivery.