How can a woman's weight affect her fertility?

Obesity can affect a woman's fertility. When a woman is overweight, fat in her body is converted to hormone and confuses the body.

Women and men who are overweight or obese have significantly lower pregnancy rates when compared with their normal-weight peers. Fat cells are hormonally active, making weak hormones on their own, converting some weak hormones in the blood to stronger ones, and acting as storage depots for many other hormones. In addition, women who are obese have much higher rates of ovulation problems, irregular periods, and miscarriage. Even the most potent fertility treatment options, such as in vitro fertilization, are less successful for women who are obese.

The good news is that weight loss through diet and exercise can reverse the negative effects of being overweight on women's fertility. The other bit of good news is that women do not need to lose 10 dress sizes to improve their fertility. Several well-designed studies have documented improved success with fertility treatments with as little as a 5 percent weight loss. For a woman who weighs 200 pounds, that means losing 10 pounds.

The contents of this website are for informational purposes only and are not intended to be a substitute for professional medical advice, diagnosis, or treatment. Nor does the contents of this website constitute the establishment of a physician patient or therapeutic relationship. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.

Dr. Alice Domar
Psychology Specialist

Current research indicates that weighing too little or too much both play a role in infertility. Women should aim for a BMI in the 20-30 range for maximizing their fertility. Women whose BMI is 35 or above face a higher risk of having infertility, have lower pregnancy rates from treatment, higher rates of miscarriage and more pregnancy complications. Some of the same risks are found in women who are underweight.

Women who are overweight are far more likely to have ovulatory dysfunction than women who are at their normal weight. Being at the other end of the spectrum—underweight—also causes problems.

Unhealthy food intake—whether too much or too little—has been recognized as a contributing factor to infertility for many years, and too little or too much weight can make your reproductive cycle irregular. That causes you to ovulate only now and then, or not at all.

Your ovaries and your fat cells regulate estrogen, which affects ovulation. If you're too thin, you may not be producing enough estrogen, and if you're overweight or obese, you may be producing too much.

The first order of business is to achieve and maintain a healthy weight to keep your reproductive cycle in balance. Check your BMI (body mass index) score. A BMI ranking of 19-24 indicates a healthy weight (athletes may have higher scores due to muscle mass). Anything below or above that range should be discussed with your healthcare provider.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.