Women's Health

September 8, 2020

Fibroids and birth outcomes

Women with three or more uterine fibroids — non-cancerous growths — during pregnancy are more likely to have infants with reduced birthweight and may need additional surveillance.

Uterine fibroids — non-cancerous growths — are found in 10-20% of pregnancies and have been suspected of impairing fetal growth and causing lower birthweight and earlier gestational age at birth. Previous studies, however, have produced conflicting results on the association of fibroids and birth outcomes. 

Digna Velez Edwards, PhD, and colleagues now report in Annals of Epidemiology that women with three or more fibroids are more likely to have infants with reduced birthweight. 

The researchers analyzed data from participants in Right from the Start, a prospective, community-based pregnancy cohort. They found that among 3,926 women enrolled during early pregnancy, 416 had one or more fibroids, as determined by transvaginal ultrasound. Average infant birthweight and gestational age were similar among women with and without fibroids. The researchers were not able to determine whether race or ethnicity modified the associations. 

The findings add to evidence supporting targeted prenatal counseling and additional surveillance during pregnancy for women with multiple fibroids.

This research was supported by grants from the National Institutes of Health (HD043883, HD049675, TR000445) and the American Water Works Association Research Foundation.