Fertility affected by dramatic weight loss

Rapidly losing weight while trying for a baby could make it harder to conceive


Obese women who are trying for a baby may harm, rather than improve, their chances of conceiving by dramatically losing weight, an expert suggests.


Sudden and extreme reductions in calories and increases in activity could put stress on a woman’s reproductive system, according to a report from Professor Richard Legro of Pennsylvania State University College of Medicine. The risk is greater for would-be mums who have had trouble conceiving.

Evidence suggests women who are very underweight or obese can find it difficult to become pregnant, either naturally or through IVF. For every one unit of BMI over 29 a woman’s chance of conceiving falls by 4%, says Professor Legro. But, according to his study, dramatic weight loss while trying for a baby or undergoing treatment could also cause problems.

“We don’t know how many calories are needed, how long women should diet, or whether they should do it at all during infertility treatment,” said Professor Legro, who is pushing for further studies into this area.

Weight and fertility is a hot topic for would-be mums. In the past experts have suggested that obese women shouldn’t be given IVF. On a more positive note, last year we reported on the woman told to lose weight before having IVF who went on to conceive naturally, after losing eight and a half stone!


If you’re TTC, check out MFM’s top tips for conceiving.

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