By Michael A. Thomas, MD, Professor, Reproductive Endocrinology and Infertility; Director, Reproductive Medicine Research, University of Cincinnati College of Medicine. Dr. Thomas reports no financial relationships relevant to this field of study.
Synopsis: In a prospective cohort of obese, reproductive-aged women, there were no changes in the number of ovulatory cycles, but there was a shortening of the follicular phase and an improvement in sexual function after gastric bypass surgery.
Source: Legro RS, et al. Effects of gastric bypass surgery on female reproductive function. J Clin Endocrinol Metab 2012;97:4540-4548.
The investigators performed a prospective study on 29 reproductive-aged women who were documented to be obese. These women had a body mass index (BMI) > 40 kg/m2 or had a BMI between 35-39.9 kg/m2 with weight-related health problems (diabetes, hypertension). All had failed medical weight loss and were not on medications that suppress ovulation (hormonal contraceptives). Subjects were excluded if they smoked, abused alcohol or drugs, and had a medical condition that was thought to contribute to obesity (hypothyroidism, Cushing’s syndrome, or a genetic predisposition). Every woman who qualified underwent a Roux en Y gastric bypass. Forty-one women were consented and screened, but only 29 were enrolled. A preoperative study visit was performed, and visits were scheduled postoperatively at months 1, 3, 6, 12, and 24. Only nine subjects completed the entire 24 months of the study. Over the course of the study, urine was collected daily and measured for estrone 3-glucuronide and pregnanediol 3-glucouronide. Other assessments included fasting serum at each visit for estradiol, progesterone, testosterone, and SHBG; transvaginal ultrasound at months 6 and 12; bone and body composition by DEXA at each visit; Female Sexual Function Index (FSFI) questionnaire preoperatively and at month 12; and a diary of vaginal bleeding. Prior to surgery, 90% of the women had ovulatory cycles; this did not change postoperatively. However, the follicular phase of the menstrual cycle decreased by 6.5 days by month 3 and continued to show a decrease between 7.9-8.9 days in months 6-24. Sexual function improved, with a FSFI score improving from 21.2 ± 9.6 preoperatively to 27.1 ± 7.4 (P = 0.02). Body composition showed a significant decrease in absolute total, fat, and lean mass at months 12 and 24, but bone mineral density did not change. The authors concluded surgical weight loss had a modest effect on overall reproductive hormone function, but it did show an improvement in body composition and sexual function. Although the majority of cycles remained ovulatory, the follicular phase shortened, potentially making the ovulation date more predictable if pregnancy was a possible goal.
An increasing number of hospitals have started a gastric bypass program to meet the needs of obese individuals who have developed medical problems. These serious medical problems, for which a surgical intervention for obesity becomes an option, primarily include metabolic syndrome, sleep apnea, dyslipidemia, diabetes, and high blood pressure. The media has inundated us with the fact that there is an obesity epidemic in the United States with causes including genetics, a high-fat/high-caloric diet, and a lack of adequate physical activity. The authors of this study set out to observe changes in reproductive hormone concentrations, menstrual cyclicity, body composition, and sexual function in obese women who decided to undergo surgical gastric bypass as an alternative to medical therapies, diet, and/or exercise. Surprisingly, the vast majority of the study participants were already ovulatory (90%) and remained that way postoperatively. However, the follicular phase of their cycles shortened over 24 months; this would be helpful for those individuals who were attempting conception or practicing natural family planning. In fact, six of the 29 patients conceived during the first 12 months after surgery. This study as well as others demonstrated an improvement of sexual function by scores from a validated survey.1
Overall, this study highlights the need for similar observations in anovulatory obese women with and without a diagnosis of polycystic ovary syndrome who are actively considering conception as a goal. Though weight loss was accomplished with an improvement in menstrual cyclicity, body composition, and sexual function, it is assumed that their medical issues also improved — a result that is not well outlined. Diet and exercise are thought to be first-line interventions for patients with obesity, but few are able to reduce and then maintain their weight with this approach exclusively over time.2 Whether other surgical gastric procedures, like gastric banding, biliopancreatic diversion, or sleeve gastrectomy, confer any better reproductive hormone, body composition, or sexual function outcomes remains to be seen in this patient population. The American College of Obstetricians and Gynecologists recommends that pregnancy be avoided for 12-18 months after bariatric surgery to minimize any nutritional deficiencies that may arise that potentially could affect the mother or fetus.3 Also, barrier or non-oral hormonal contraceptives should be considered because of the potential absorption concerns that can occur postoperatively.
1. Bond DS, et al. Significant resolution of female sexual dysfunction after bariatric surgery. Surg Obes Relat Dis 2011;7:1-7.
2. Ayyad C, Andersen T. Long-term efficacy of dietary treatment of obesity: A systematic review of studies published between 1931 and 1999. Obes Rev 2000;1:113-119.
3. American College of Obstetricians and Gynecologists. Bariatric surgery and pregnancy. ACOG Practice Bulletin no 105. Obstet Gynecol 2009;113:1405-1413.