Do uterine leiomyomas influence pregnancy outcome?

To evaluate the clinical significance of the presence, location, size, and number of uterine leiomyomas in pregnancy, a retrospective cohort study in which pregnancy complications and outcome of pregnant women with uterine myomas was undertaken by routine second trimester ultrasound examination. The case group consisted of 183 consecutive women with uterine myomas detected and followed during the years 1983-1989; the control group was made up of all pregnancies diagnosed and followed at the obstetric clinic during the period 1985-1987. The incidences of preterm delivery (less than 37 weeks), preterm premature rupture of membranes, in utero growth retardation (less than 5th percentile), placental abruptio, placenta previa, postpartum hemorrhage (more than 500 cc), and retained placenta were not significantly increased in the group of women with myomas compared with the general population. However, cesarean sections were more common in women with myomas (23 vs 12%; P < 0.001). Within the group of women with myomas, the incidence of cesarean section was not different in cases with multiple rather than solitary myomas, but it was significantly higher in cases of lower uterine segment compared with fundal myomas (39 vs 18%; P < 0.01) and when the mean diameter of the myoma was greater than 5 cm (35 vs 17%; P = 0.01). Stepwise logistic regression analysis showed that both myoma location and size were independent predictors of the odds of cesarean section.