The round ligament: a target organ for steroid hormones.

Samples of the round ligament from pre- and post-menopausal women were analyzed immunohistochemically for estrogen and progesterone receptors. The steroid hormone receptors were localized in the smooth muscle cell nuclei, with stronger staining for progesterone receptors and somewhat weaker for estrogen receptors. Our findings support the view that the round ligament is a target organ influenced by hormones, which has implications for the changes in the ligament during pregnancy and pre- and postmenopausally.