Obesity is a major cause of infertility, but new research uncovers another reason why being 
overweight makes it more difficult to have a baby. Extra pounds put women at a higher risk of miscarriage after in-vitro fertilization (IVF). The AP reports on a study conducted at a clinic in London that tracked 318 women who successfully began a pregnancy by IVF. Researchers classified the women as either normal weight or obese according to their BMI. Women with normal weight miscarried at a rate of 22 percent, while 33 percent of obese women miscarried. For women who conceive naturally, miscarriage in the first trimester is between 4 and 23 percent, depending on medical history.
For obese women, however, that number can be three or four times higher. The link between excess fat and infertility is not well understood, but women with BMIs above 30 are not eligible for IVF at many fertility clinics in Europe. Weight loss is often recommended as first step in fertility treatment. Obese women are also at risk for developing diabetes while pregnant, which leads to major complications. “Our aim was not to exclude women from getting treatment, but to help women get the best outcome after they have IVF,” said Dr. Vivian Rittenberg, who led the study.