Obesity-associated infertility - the earliest known description.

Polycystic ovarian syndrome is a leading cause of anovulatory infertility. It was originally described as a syndrome by Stein and Leventhal in 1935. Its frequent association with obesity and the beneficial effects of weight loss are well established. In 1328, the French Rabbi Levi ben Gershom (1288-1344 AD), in a detailed commentary on the Bible, states that: '...it is recognized that excess fat and obesity are reasons for infertility'. He explains that Sarah and Rachel allowed Abraham and Jacob respectively to have children with their maids, expecting this to reduce their own appetite, lead to weight loss and consequent conception. Even if one doubts the historical accuracy of this explanation of the ancestors' situation, one cannot doubt that Rabbi Levi ben Gershom is describing a situation familiar to him, to explain the seemingly paradoxical behaviour of the two mothers.