Dynamic volume variation of uterine leiomyomas during pregnancy

Objective To investigate the volume variation of uterine leiomyomas and explore factors predicting their growth trends during pregnancy. Method A retrospective observational study was performed on pregnant women with uterine leiomyomas between January 2016 and April 2020. The uterine leiomyoma volume was acquired from obstetrical ultrasound at the first, second, and third trimesters of gestation. A binary logistic regression analysis was conducted to explore the factors influencing the volume variation of uterine leiomyomas during pregnancy. Results A total of 278 pregnant women diagnosed with uterine leiomyomas were enrolled. The volumetric increase in uterine leiomyomas during pregnancy exhibited a higher growth rate from the first to second trimester (34.09%) than that from the second to third trimester (30.08%). Smaller uterine leiomyomas were more likely to increase in size from the first to second trimester and from the first to third trimester. Retroplacental uterine leiomyomas were more likely to increase in volume than that for uterine leiomyomas located away from the placenta in pregnant women from the second to third trimester. Conclusion The uterine leiomyoma volume was potentially enlarged in a nonlinear growth pattern during pregnancy, which was associated with the former volume of uterine leiomyomas and the spatial relationship between leiomyoma-placental site.