Uterine fibroids may interfere with conception

Because uterine fibroids typically develop during the childbearing years, women with fibroids are often concerned about their chances of a successful pregnancy. While fibroids themselves don’t usually interfere with conception, they can distort or block your fallopian tubes or interfere with the passage of sperm from your cervix to your fallopian tubes.

Submucosal fibroids, or those fibroids that grow inside the uterus, may prevent implantation and growth of an embryo. If you have fibroids and you’ve experienced repeated pregnancy losses, your doctor may recommend removing one or more fibroids to improve your chances of carrying a baby to term, especially if no other causes of miscarriage can be found and if your fibroids distort the shape of your uterine cavity.

Research indicates that pregnant women with fibroids are at slightly increased risk of miscarriage, premature labor and delivery, abnormal fetal position, and separation of the placenta from the uterine wall. But not all studies confirm these associations. Furthermore, complications vary based on the number, size and location of fibroids. Multiple fibroids and large submucosal fibroids that distort the uterine cavity are the type most likely to cause problems. A more common complication of fibroids in pregnancy is localized pain, typically between the first and second trimesters. This is usually easily treated with pain relievers.

In most cases, fibroids don’t interfere with pregnancy, and treatment isn’t necessary. It was once believed that fibroids grew faster during pregnancy, but multiple studies suggest otherwise. Most fibroids remain stable in size, although some may increase or decrease slightly, usually in the first trimester.