The purpose of this study is to examine how obesity and weight loss following bariatric surgery affect reproductive function. The study is particularly interested in how changes in hormones (those produced in the stomach and fat tissue) following weight loss affect reproductive function. Specifically, we, the researchers at Penn State University, propose to characterize reproductive abnormalities in morbidly obese men and women. We hypothesize that morbid obesity leads to reproductive abnormalities in men and women. We plan to examine the short-term effects of alteration in GI hormones after bariatric surgery on reproductive function. We hypothesize that bariatric surgery radically alters GI hormone expression, resulting in immediate changes to the hypothalamic-pituitary-gonadal axis in men and women. Lastly, we, the researchers, plan to examine the long-term effects of weight loss and changes in adipokines on reproductive function. We hypothesize that the changes in adipokine levels resulting from fat mass reduction lead to substantial long-term improvements in reproductive function and fertility. We also hypothesize that there are sexual dimorphisms in adipokine levels following weight loss, with women experiencing larger changes than men.

Obesity may influence female reproduction through a variety of mechanisms including: suppressing ovulation; inhibiting ovarian follicular development; and altering endometrial development and implantation. In males, obesity may impair reproductive function by several mechanisms including: decreasing libido, causing erectile dysfunction, influencing semen composition, or sperm function. Therefore the long term goal of the current project is to understand the impact of severe obesity on reproductive function and how this is influenced by dramatic weight loss.

Inclusion Criteria:

• Body mass index (BMI) of greater than 40 or a BMI between 35.5-39.9 and has a weight related health problem, such as diabetes or high blood pressure.
• Failed medical weight loss
• Ages of 18-40
• Not using hormonal contraception or sex steroids
• Subject is premenopausal and has not undergone a bilateral oophorectomy or hysterectomy
• Subject's obesity has no medical explanation (hypothyroidism, Cushing's Syndrome, genetic)

Exclusion Criteria:

• Not willing to make a lifelong commitment to the diet and exercise guidelines following bariatric surgery
• Subject is pregnant or lactating
• Not willing to use barrier contraceptives or intrauterine device (IUD) to prevent pregnancy for one year following bariatric surgery
• Post-menopausal, either surgical or natural
• Subject has had a vasectomy
• Subject is a smoker