Miscarriage is one the most common pregnancy complications. Some estimates suggest that half of all pregnancies may end this way, since many miscarriages occur before a woman knows she’s pregnant. Doctors are still trying to gain a clear picture of the many factors that increase the likelihood of miscarriage, from infections to genetics to environmental exposures.

This week, celebrity Bethenny Frankel spoke out about her own miscarriage, citing uterine fibroids—non-cancerous tumors that grow in the uterus—as possible culprits.

Uterine fibroids are common. Most women will develop them during their lives, according to the National Institutes of Health (NIH) website, and up to 80% will have them by age 50. For the majority of women, uterine fibroids, which vary in size, do not cause complications, and most women who get them will not have any symptoms and may not be aware that they have them. But in some rare cases, they can cause pain and bleeding and harm a women’s fertility, the NIH website says. Uterine fibroids may also play a role in contributing to a woman’s miscarriage. Some doctors recommend that women get fibroids removed before attempting to get pregnant or if a woman has experienced several miscarriages.

Through surgeries, women can remove especially problematic fibroids, and some women may undergo hysterectomies when the symptoms are serious. More than 200,000 hysterectomies happen each year due to uterine fibroids. The NIH says it is funding research to offer affected women more options in the form of drugs and genetic therapies. The goal is to help women deal with problematic fibroids without taking a toll on their fertility.

This article originally appeared on Time.com.