Abstract: The sharp increase of the prevalence of obesity is accompanied with the decline of reproductive health index in both sexes. Obese is associated with the changes of reproductive regulatory mechanisms. The level of estrogen in obesity males is increased due to the over-expression of aromatase in the adipose tissue, and followed by hypogonadism due to the negative feedback regulation of estrogen. These hormonal changes, along with the increased oxidative stress, directly affect the functions of testes and sex, and even lead to male infertility. Clinical evidence showed worse semen parameters and higher incidence of erectile dysfunction. In the cycles of assisted reproductive technology, the dose of ovulation induction is increased in obesity females, and the live birth rate is decreased. The clinical outcomes in PCOS patients with insulin resistance are similar to the outcomes in obesity women. The lifestyle changes, medical therapy and bariatric surgery may improve the reproductive outcomes, although the evidence remains inconclusive. In this review, we discuss the association between obesity and fertility, and the effect of weight-loss interventions on reproductive potential in obesity individuals.

Key words: Obesity；, Infertility, male；, Infertility, female；, Reproductive techniques, assisted；, Body mass index；, Polycystic ovary syndrome