RESUMEN
OBJECTIVE: To evaluate volumetric changes of uterine myomas (fibroids) during pregnancy. METHODS: This was an observational, longitudinal and prospective study of 38 consecutive Caucasian women with singleton pregnancies and a total of 42 uterine myomas, enrolled from a cohort of 1492 women who took part in our first-trimester Down syndrome screening program. Myoma volume was evaluated by ultrasound at 11-14, 20-22 and 32-34 weeks of gestation. RESULTS: Mean myoma volume increased significantly throughout pregnancy. Taking a volumetric change of > 10% between gestational periods to be an increase in size, 71.4% of uterine myomas increased in size between the first and second gestational periods, while this percentage was slightly lower (66.6%) between the second and third periods. Logistic regression analysis revealed that greater maternal age was correlated with a reduction/no change in overall myoma size and multiparity was correlated with a decrease/no change between the first and second trimesters, while a higher prepregnancy maternal body mass index (BMI) was correlated with a volumetric increase between the first and second trimesters and a decrease/no change between the second and third trimesters. CONCLUSIONS: Fibroids enlarge during pregnancy regardless of their initial size or local factors, and maternal age, prepregnancy BMI and parity are apparently correlated with these changes.