<prompt> What is the common cause of labial fusion in an adult female?Congenital adrenal hyperplasiaFetal exogenous androgen exposureAbdominal wall defectsAll of the above  <response>: Labial fusion in adult women is most commonly due to classical congenital adrenal hyperplasia. Other causes include, Fetal exogenous androgen exposure Abdominal wall defects Ref: 2010. Chapter 40. Reproductive Tract Abnormalities. In Cunningham F, Leveno K.J., Bloom S.L., Hauth J.C., Rouse D.J., Spong C.Y. Eds, Williams Obstetrics, 23e. 