What Are the Risk Factors for Gestational Trophoblastic Disease?
A risk factor is anything that affects your chance of getting a disease such as cancer. Different cancers have different risk factors. For example, exposing skin to strong sunlight is a risk factor for skin cancer. Smoking is a risk factor for cancers of the lung, mouth, larynx (voice box), bladder, kidney, and several other organs.
But risk factors don't tell us everything. Having a risk factor, or even several risk factors, does not mean that you will get the disease. And some people who get the disease may not have any known risk factors. Even if a person has a risk factor, it is often very hard to know how much that risk factor may have contributed to the cancer.
Researchers have found several risk factors that might increase a woman's chance of developing gestational trophoblastic (jeh-STAY-shuh-nul troh-fuh-BLAS-tik) disease (GTD).
GTD occurs in women of childbearing age. The risk of complete molar pregnancy is highest in women over age 35 and younger than 20. The risk is even higher for women over age 45. Age is less likely to be a factor for partial moles. For choriocarcinoma (KOR-ee-oh-KAR-sih-NOH-muh), risk is lower before age 25, and then increases with age until menopause.
Prior molar pregnancy
Once a woman has had a hydatidiform (HY-duh-TIH-dih-form) mole, she has a higher risk of having another one. The overall risk for later pregnancies is about 1% to 2%. This risk is much higher if she has had more than one molar pregnancy.
Women who have lost pregnancies before have a higher risk of GTD. This may be at least in part because in some cases GTD affected the miscarried pregnancy. Overall, the risk of GTD after a miscarriage is still low.
Women with blood type A or AB are at slightly higher risk than those with type B or O.
Birth control pills
Women who take birth control pills may be more likely to get GTD when they do become pregnant. The link between the use of birth control pills and GTD is weak, and may be explained by other factors. This risk seems to be higher for women who took the pills longer. But the risk is still so low that it doesn't outweigh the benefit of using the pills.
Very rarely, several women in the same family have one or more molar pregnancies.
Last Medical Review: February 6, 2014 Last Revised: February 9, 2016