Polycystic Ovary Syndrome Caused by Excess Anti-Muellerian Hormone in Utero– New Scientist

An article in New Scientist describes research published in Nature Medicine that describes the cause of polycystic ovary syndrome (PCOS) — abnormally high levels of anti-Muellerian hormone (AMH) while the patient is still in the womb. AMH is absent in the normal female embryo and when it is present it causes relative masculinization– a precursor to PCOS.

Normally, in the male embryo, AMH produced by the embryonic gonads suppresses the growth of the Muellerian ducts (which grow into the uterus and adnexa) on the same side as the gonad.  If AMH is absent, the ducts grow automatically.

In the adult female, AMH rises at puberty and is expressed to regulate the formation of follicles.  In the male child, AMH production by the Sertoli cells of the testis is high; in puberty, AMH levels fall.  AMH receptors are also present in the brains of embryonic mice and are thought to relate to dimorphic brain development and the regulation of gender-specific behaviors.

The New Scientist article suggests treatment with Gonadotropin Receptor Antagonists, such as are used in infertility, may work.  The article says that a trial of cetrorelix, used during in vitro fertilization (IVF) procedures, is contemplated.  Relief of the symptoms of PCOS may be accompanied by restored ovulation and fertility.