Uterine leiomyomas during pregnancy and its impact on obstetric outcome

BACKGROUND: The association of uterine leiomyoma and pregnancy is increasing due to the tendency of couples to delay first pregnancy after age 30. The risk of uterine fibroids is greater with advancing age of the woman. OBJECTIVE: To evaluate the impact of fibroids on the incidence of complications during pregnancy, labor and delivery. PATIENTS AND METHODS: We observed 65 pregnant patients with uterine fibroids and 165 pregnant patients without fibroids. Follow-up ultrasound was performed at weeks 20 to 24, 30 to 32 and 36 to 40. We analyzed the following variables: threatened abortion, pregnancy loss, preterm birth, premature rupture of membranes, abnormal fetal presentation, mode of termination of pregnancy, uterine atony, postpartum hemorrhage and perinatal outcome. RESULTS: The frequency of threatened abortion, risk of pregnancy loss in the second trimester, preterm births, premature rupture of membranes and abnormal fetal presentation was significantly higher in patients with uterine fibroids compared to patients without fibroids. It was not demonstrated that fibroids grow during follow-up even, there was a trend toward reduction in size as pregnancy progressed and until its completion. No significant differences in the frequency of cesarean section between groups (52.3 vs. 47.9%, RR 1.09; 95% CI 0.82-1.45, p = 0.646). Uterine atony was more frequent in patients with fibroids than in patients without fibroids (12.3 vs 4.2%, RR = 2.9, 95% CI 1.2-7.6, p = 0.036). There were no differences in perinatal outcomes between the groups. CONCLUSIONS: Uterine fibroids increase the risk of complications during pregnancy and childbirth. Could not be demonstrated an increased risk of caesarean section.