Fetal transient clitoromegaly and transient hypertrophy of the labia minora in early and mid pregnancy.

Objective: The purpose of this study was to describe a series of cases of transient changes in the female fetal external genitalia.
Methods: In our practice area, most pregnant women usually undergo a detailed sonographic survey of all fetal organs, including the external genitalia in early and mid pregnancy.
Results: During the study period (1987-2010), 62,145 consecutive pregnant women were scanned. We detected 4 fetuses with an isolated finding of clitoromegaly at 15 to 16 weeks' gestation, which disappeared at 22 to 26 weeks. Maternal hormonal study results were normal. There was 1 case of clitoromegaly and a cloacal anomaly at 15 weeks' gestation, in which the clitoris retuned to a normal size at 22 weeks. In addition, there were 3 cases of hypertrophy of the labia minora in early pregnancy, which disappeared at 26 to 32 weeks. All fetuses in these series had a normal XX karyotype and normal external genitalia at birth.
Conclusions: Transient changes in the appearance of the fetal external genitalia may occur in chromosomally normal female fetuses.