Progestin-related breast volume changes in a woman with complete androgen insensitivity syndrome (CAIS)

Abstract

Summary

A 31-year-old woman with complete androgen insensitivity syndrome (CAIS) experienced breast volume fluctuations during biphasic hormone replacement therapy consisting of estradiol and cyclical dydrogesterone, a progestin. 3D breast volume measurements showed a 100 cc volume (17%) difference between estradiol monotherapy and combined estradiol and dydrogesterone treatment. Progestogen-dependent breast volume changes have not been reported in the literature. Our findings suggest a correlation between progestogen use and breast volume. Due to the rapid cyclical changes, we hypothesize that the effect is caused by fluid retention.

Learning points

• There is limited reports available on the effects of progesterone on breast development and volume.

• 3D imaging provides an easy-to-use method to quantify breast volume.

• The patient in our case description clearly showed that cyclic progesterone use might induce substantial cyclic changes in breast volume.

• In women with complete androgen insensitivity syndrome (CAIS), monotherapy with estrogen or continuous supplementation of progesterone might be preferable over cyclic progesterone use.