Effect of Maternal Retroplacental Leiomyomas on Fetal Growth.

Abstract

To evaluate the association between retroplacental leiomyoma identified on second trimester ultrasound and fetal growth. We performed a retrospective study comparing the presence or absence of one or more retroplacental leiomyomas on birth weight in a cohort of women with singleton pregnancies undergoing second trimester fetal anatomic ultrasound at our institution between 2007 and 2012. The incidence of small for gestational age (SGA) infants was recorded. Secondary analysis evaluated the effect of number and size of retroplacental leiomyomas. Birth weight in women with at least one retroplacental leiomyoma was 177 grams less than in women without leiomyomas (95% CI-295 to-95, P= 0.003). There was a non-significant trend towards a higher incidence of SGA in infants born to women with retroplacental leiomyoma compared with women without leiomyoma (OR 2.84; 95% CI 0.97 to 6.84, P= 0.057). Women with a retroplacental leiomyoma > 4 cm in mean diameter were more likely to deliver an SGA infant than women without leiomyomas (OR 2.84, 95% CI 1.01 to 8.01; P= 0.048). Multiple retroplacental leiomyomas did not have a greater effect on pregnancy outcomes than single leiomyomas. Infants born to women with one or more retroplacental leiomyomas had a lower mean birth weight than infants born to women without leiomyomas. In addition, retroplacental leiomyomas > 4 cm in mean diameter were associated with an increased risk of delivering an SGA infant.