Obesity Could Mean Infertility for Future Generations

Levels of the hormone ghrelin are low in obese women, and a study by Yale School of Medicine researchers reports that mice whose mothers had low ghrelin levels were less fertile due to a defect in implantation. The results appear in the April issue of Endocrinology, a publication of The Endocrine Society.

Hormones involved in energy balance and metabolism, such as ghrelin, have been shown to regulate reproductive function in animals and humans. However ghrelin's role in reproductive tract development remains unclear. The current study examined the effect of ghrelin deficiency on the developmental programming of female fertility.

"While our study involved mice, we believe our findings have significant implications for women," said lead author Hugh Taylor, M.D., in the Department of Obstetrics, Gynecology & Reproductive Sciences at Yale School of Medicine. "Our results suggest that low ghrelin levels could program the development of the uterus in the female children of obese women. These women may then be less fertile as adults."

In this study, researchers observed that female mice born of mice with ghrelin deficiency had diminished fertility and produced smaller litters than mice born of mice with normal ghrelin levels. Mice exposed to ghrelin deficiency in-utero demonstrated alterations in uterine gene expression, which lead to impaired embryo implantation and consequently low fertility.

Other Yale researchers on the study include: J. Ryan Martin, Sarah Lieber, James McGrath, Marya Shanabrough and Tamas Horvath.