Body fat, Exercise and Fertility

Numerous studies have repeatedly shown that women athletes who have a low body mass index, ("BMI"), have a difficult time starting a family. We have found with our patient population that a number of female athletes have a low BMI.

Sex hormones are fat soluble and they are stored in the body's fat layers.

Women that have a low BMI produce a reduced amount of estrogen which can lead to an abnormal menstrual cycle.

Fertility can be negatively affected by obesity. In women, early onset of obesity favors the development of menstrual irregularities, chronic lack or irregular anovulation and infertility in the adult age.

Obesity in women can also increase risk of miscarriages and impair the outcomes of assisted reproductive technologies and pregnancy, when the body mass index exceeds 30 kg/m2.

The main factors implicated in the association may be insulin excess and insulin resistance.

These adverse effects of obesity are specifically evident in polycystic ovary syndrome.

In men, obesity is associated with low testosterone levels. In massively obese individuals, reduced spermatogenesis associated with severe low testosterone may favor infertility.

Moreover, the frequency of erectile dysfunction increases with increasing body mass index. Much more attention should be paid to the impact of obesity on fertility in both women and men.

This appears to be particularly important for women before assisted reproductive technologies are used. Treatment of obesity may improve androgen imbalance and erectile dysfunction, the major causes of infertility in obese men.