A new study has shown that women who are thinner ran a larger risk of developing endometriosis than women who were morbidly obese. Endometriosis is a condition resulting from the appearance of endometrial tissue outside the uterus and causing pelvic pain. The study featured more than 100,000 women and showed that women with a body mass index (BMI) higher than 40 kg/m2 had a 39 percent lower chance of developing endometriosis when compared to women with a BMI in the low to normal ranges. It is also important to note that infertile women or those who have been attempting to become pregnant for over a year ran a significantly lower chance for endometriosis at 62 percent less. Even though the connection between body weight and endometriosis was strong, it does not include and preexisting conditions or any other reasons for the occurrence. The condition affects about 1 in 10 women who are at their reproductive age and may account for more than $49 billion in healthcare expenses. 93 percent of the women who took part in the study were white, with those who reported higher BMI’s being older. Reasons for such effects could be attributed to women with higher BMI’s when young having detrimental effects later in life. The study was supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development.