Research: Heavier Women May Have Less IVF Success

The heavier a woman is, the more trouble she may have getting pregnant and having a baby through in vitro fertilization, or IVF — and may lose the baby more often, according to a U.S. study.

Researchers led by Barbara Luke of Michigan State University found that women who were overweight or obese were less likely to become pregnant using fertility treatments than normal-weight women.

Past studies have also hinted at worse IVF outcomes in heavier women, although they don’t prove that the extra weight is directly responsible for the reproductive troubles those women experience.

“Treatment and pregnancy failures with increasing obesity significantly increased starting with overweight women,” Luke and her colleagues wrote in Fertility and Sterility.

They drew data from a reporting system that includes more than 90 percent of IVF treatments done in the United States — information on 150,000 fertility treatment cycles done in 2007 and 2008 at 361 different clinics.

For each cycle, the reporting system included whether the cycle was canceled, if it led to a pregnancy, and whether that pregnancy ended early in a miscarriage or stillbirth, or if the woman gave birth to a live baby. For most cycles, it also had data on women’s height and weight before starting treatment.