Obesity and infertility.
OBJECTIVE
To summarize major factors affecting fertility in obesity.


RESULTS
Fertility can be negatively affected by obesity. In women, early onset of obesity favours the development of menses irregularities, chronic oligo-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/m. 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 hypotestosteronemia may favour infertility. Moreover, the frequency of erectile dysfunction increases with increasing body mass index.


CONCLUSIONS
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.
Pasquali
Renato
R
Division of Endocrinology, Department of Internal Medicine, S. Orsola-Malpighi Hospital, University Alma Mater Studiorum of Bologna, Bologna, Italy. renato.pasquali@unibo.it
Patton
Laura
L
Gambineri
Alessandra
A
D004196:Disease Outbreaks; D007172:Erectile Dysfunction / Q000150:complications / Q000209:etiology / Q000503:physiopathology; D005260:Female; D005298:Fertility; D006801:Humans; D007247:Infertility, Female / Q000209:etiology* / Q000503:physiopathology / Q000628:therapy; D007248:Infertility, Male / Q000097:blood / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D008597:Menstrual Cycle; D009765:Obesity / Q000097:blood / Q000150:complications* / Q000453:epidemiology / Q000503:physiopathology; D010060:Ovulation; D011085:Polycystic Ovary Syndrome / Q000150:complications / Q000209:etiology / Q000503:physiopathology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000209:etiology / Q000503:physiopathology; D011256:Pregnancy Outcome; D027724:Reproductive Techniques, Assisted; D013091:Spermatogenesis; D013739:Testosterone / Q000097:blood; D016896:Treatment Outcome
D013739:Testosterone