Weight loss does not improve fertility

October 17, 2012, Pennsylvania State University

(Medical Xpress)—Losing weight does not lead to improved fertility in women, but does improve sexual function, according to Penn State College of Medicine researchers.

"Obesity in women has been linked to lack of ovulation and thus infertility," said Richard Legro, M.D., professor of obstetrics and gynecology. "Obesity, especially centered in the abdomen, among seeking pregnancy is also associated with poor response to ovulation induction and with decreased ."

are often told to lose weight prior to conception, so researchers looked at changes in reproductive function after gastric bypass surgery. One way to learn more about the effects of obesity on reproduction is to study women after bariatric surgery, since a large amount of weight is lost in a relatively short period of time. Each person can be studied while obese and after surgery to detect changes. Researchers report their findings in the Journal of Clinical .

Researchers followed 29 women—women whose body fat accumulated to the extent that it may have an adverse effect on health—of reproductive age for up to two years after Roux en Y gastric bariatric bypass surgery. Roux en Y is a procedure that creates a small pouch in the stomach that is directly connected to the midsection of the , bypassing the rest of the stomach and the upper portion of the small intestine.

Ovulation frequency and quality was determined by collecting daily urine specimens over the course of a menstrual cycle and measuring ovarian hormones. The researchers were surprised to find that ovulation rates remained high (more than 90 percent at all time points before surgery and at one, three, six, 12, and 24 months after surgery). The quality of the ovulation also remained unchanged, and there was little effect on the ovarian cycle.

The exception is a notable shortening of eight to nine days of the follicular phase. The follicular phase is the first half of the menstrual cycle, from the end of the previous menstrual flow until the release of the egg (ovulation). Three months after surgery, the phase is six and a half days shorter, and then up to nine days shorter by 24 months post-surgery.

Obesity is associated with longer menstrual cycles, specifically because of an increase in the follicular phase. The reason the phase shortens with is not yet known.

Sexual function at one year as detected by the Female Sexual Function Index, a self-reporting index of sexual health collected through questionnaires, is most noticeable. This improvement is independent of changes in hormone levels and body composition. and arousal increase the most. Researchers did not track sexual activity or desire to conceive. However, increased sexual desire may have led to increased frequency of sexual activity.

"The effects of weight loss on reproductive function are more modest than we hypothesized. In terms of ovulation, there doesn't appear to be a window after surgery where fertility is improved," Legro said. "The door appears to be open at all times. Other factors may be involved with infertility in obese women, such as diminished sexual desire and thus less intercourse. This study, to our knowledge, is the largest, most comprehensive and longest study of female reproductive function before and after Roux en Y gastric bariatric ."

Explore further: Timing crucial in achieving pregnancy

Related Stories

Timing crucial in achieving pregnancy

September 3, 2012
A survey of women seeking fertility assistance to become pregnant found most did not know which days of the menstrual cycle they were fertile and most likely to conceive.

Weight loss surgery may be associated with increased substance use following surgery

October 15, 2012
Patients who undergo bariatric weight loss surgery may be at increased risk for substance use (drug use, alcohol use and cigarette smoking) following surgery, particularly among patients who undergo laparoscopic Roux-en-Y ...

Surgery-related weight loss in men reverses testosterone deficiency

June 4, 2011
Low testosterone levels and symptoms of male sexual dysfunction due to obesity may be reversible with weight loss after bariatric surgery, a new study finds.

Recommended for you

Evening hours may pose higher risk for overeating, especially when under stress, study finds

January 16, 2018
Experiments with a small group of overweight men and women have added to evidence that "hunger hormone" levels rise and "satiety (or fullness) hormone" levels decrease in the evening. The findings also suggest that stress ...

Bariatric surgery prolongs lifespan in obese

January 16, 2018
Obese, middle-age men and women who had bariatric surgery have half the death rate of those who had traditional medical treatment over a 10-year period, reports a study that answers questions about the long-term risk of the ...

Sugar-sweetened drinks linked to overweight and obesity in children, adults: Analysis of new studies

December 23, 2017
A new review of the latest evidence on sugar-sweetened beverages (SSBs)- which includes 30 new studies published between 2013 and 2015 (and none of them industry sponsored) - concludes that SSB consumption is associated with ...

As income rises, women get slimmer—but not men

December 21, 2017
(HealthDay)—A comprehensive survey on the widening American waistline finds that as paychecks get bigger, women's average weight tends to drop.

Policy and early intervention can curb obesity rates

December 18, 2017
More information and emphasis on dietary lifestyle changes that prevent obesity, and its comorbidities, have not reduced the rise in obesity in U.S. adults and adolescents, according to a recent study in the New England Journal ...

Warning labels can help reduce soda consumption and obesity, new study suggests

December 15, 2017
Labels that warn people about the risks of drinking soda and other sugar-sweetened beverages can lower obesity and overweight prevalence, suggests a new Johns Hopkins Bloomberg School of Public Health study.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.