Obesity and reproductive function.

Obesity is associated with multiple adverse reproductive outcomes, but the mechanisms involved are largely unknown. Obesity has been referred to as a "complex system," defined as a system of heterogeneous parts interacting in nonlinear ways to influence the behavior of the parts as a whole. Human reproduction is also a complex system; hence the difficulty in identifying the mechanisms linking obesity and adverse reproductive function. This review discusses the adverse reproductive outcomes associated with obesity and the mechanisms involved and concludes with a discussion of public health policy with respect to the treatment of infertility in obese women.