Outcome of pregnancies in women with uterine leiomyomas identified by sonography in the first trimester.

PURPOSE

We assessed the outcome of pregnancies in women with uterine leiomyomas (fibroids) documented by sonography in the first trimester of pregnancy.

METHODS

We collected cases of women who had undergone first-trimester sonography and had uterine fibroids and singleton pregnancies with documented fetal heartbeats. We compared pregnancy loss rates and modes of delivery in these cases to a maternal-age-matched and gestational-age-matched control group of women who had normal uteruses and first-trimester pregnancies with documented fetal heartbeats. Sonograms in patients with fibroids were reviewed to determine the number of fibroids, their sizes, and their locations. Within the group of patients with fibroids, the pregnancy loss rate was also compared based on the number of fibroids and fibroid size and location.

RESULTS

Our study population consisted of 143 women with leiomyomas, and our control group comprised 715 patients with a normal uterus. Among patients with fibroids, 14.7% of pregnancies resulted from assisted conception; in the control group, 6.4% of pregnancies resulted from assisted conception. The rate of spontaneous pregnancy loss in women with fibroids was almost twice the rate in women with normal uteruses (14.0% versus 7.6%; p < 0.05), and the loss rate was higher in women with multiple fibroids than in women with a single leiomyoma (23.6% versus 8.0%, p < 0.05). The loss rate was not significantly associated with fibroid size or location. The rate of cesarean-section delivery was higher in patients with fibroids than in patients with normal uteruses (38% versus 28%, p < 0.05).

CONCLUSIONS

Uterine fibroids are associated with an elevated risk of spontaneous pregnancy loss. The loss rate is higher in patients with multiple fibroids than with a single fibroid. The cesarean-section rate is also higher in patients with fibroids than in patients with a normal uterus.