Influence of body mass index in anti-Mullerian hormone levels in 951 non-polycystic ovarian syndrome women followed at a reproductive medicine unit

Anti-Mullerian hormone (AMH) is a useful marker of ovarian reserve. Obesity/overweight are increasing and may affect the reproductive health. Previous studies regarding the effect of body mass index (BMI) on AMH levels are discordant. Our main goal was to evaluate the influence of BMI on AMH levels in women without polycystic ovarian syndrome. Revision of medical records of 951 women who performed AMH determinations as part of their fertility workup, between 2011 and 2016. Median AMH concentration was 1.75 [interquartile range (IQR) 2] ng/mL (12.9 pmol/mL) and median age at AMH determination was 35 (IQR 6) years. These women evidenced a median BMI of 23 (IQR 5) kg/m(2). Caucasian women were more represented [889(89.3%)]. Smoking habits (present/past) were present in 359(36.1%), and 147(14.8%) harboured a history of ovarian surgery. On univariable analysis AMH was not correlated with BMI (r = 0.048/p = 0.135); the only factors influencing AMH were age (p < 0.001), ethnicity (p = 0.004), and previous ovarian surgery (p < 0.001). On multivariable analysis, age was the only variable significantly associated with AMH, evidencing a reduction of 6.2% for each additional year (p < 0.0001). Furthermore, we verified a trend suggesting an AMH reduction of 22% (p = 0.08) in black patients comparing with the caucasian ones, when controlling for the other variables. We report one of the largest series evaluating the influence of BMI on AMH levels and, consequently, on ovarian reserve. BMI does not seem to affect AMH levels. The reported concerns on infertility in overweight and obese women may be related to follicular development/oocyte maturation or endometrial disorders, rather than decreased ovarian reserve.