The evidence on the growth pattern of fibroids in pregnancy is conflicting. For what is a common condition many of our patients ask us to predict what might happen. There is a consensus based on soft data to point to some growth of myomas in pregnancy and case reports of rare complications.
This retrospective cohort study  from Israel tracks 248 pregnant women discovered to have myomas in pregnancy. They were included if they had at least 2 sonographic assessment in different trimesters in pregnancy.
The main finding is that fibroids tended to grow by an average of over 50% in the 1st trimester but this is attenuated as the pregnancy progresses with minimal growth in the 3rd trimester.
We can translate these findings into advice to patients and it gives obstetricians confidence to monitor rather than interfere even if there is significant growth in early pregnancy.
Prof. Ali Kubba MB ChB FRCOG FFSRH
 Chill et al. – Growth pattern of Uterine Leiomyoma along pregnancy – BMC Women’s Health (2019)