Gestational Trophoblastic Disease
Gestational trophblastic disease (GTD) represents a spectrum of diseases characterized by the abnormal growth of trophoblastic tissue. Trophoblasts are special cells that develop from a fertilized egg at conception, and develop into the placental tissues. GTD has many types, including hydatidiform molar pregnancy, invasive molar disease, and choriocarcinoma.
GTD develops within the uterus, as it is associated with pregnancy. GTD, however, may spread outside of the uterus and require treatment with chemotherapy.
Women with gestational trophoblastic disease often show some of the following signs:
- Vaginal bleeding during the first trimester of pregnancy
- Uterine size larger than expected for the length of pregnancy
- Severe nausea and vomiting
More rarely, women with advanced GTD may have severe abdominal pain, shortness of breath, or headache/dizziness.
There are risk factors that are known to be associated with an increased likelihood of developing GTD. These include:
- Prior molar pregnancy
- Maternal age (both adolescents and women over the age of 40 years)
There are other risk factors reported to increase the chance of developing molar pregnancies, but are not as well defined; these may include women of Southeast Asia, blood type, and nutritional factors (such as deficiencies in protein or animal fat, and fat-soluble carotene).
Women with a positive urine pregnancy test and any of the described symptoms should see their health care provider for a gynecologic evaluation. Blood testing should include examination of the human chorionic gonadotropin (hCG), commonly known as the pregnancy hormone. Ultrasonography, utilizing high-frequency sound waves, may be diagnostic of GTD.
Women with a diagnosis of molar pregnancy typically undergo suction dilation and curettage. After evacuation of the molar gestation, women with GTD should undergo close surveillance of hCG levels until they normalize. A plateau or rise in the hCG should prompt further evaluation for the possibility of invasive molar disease and the potential need for chemotherapy.