Gestational Trophoblastic Disease (GTD)
Definition - What does Gestational Trophoblastic Disease (GTD) mean?
Gestational Trophoblastic Disease (GTD) is a spectrum of pregnancy-related diseases where the cells of the developing placenta (the organ that connects the developing baby to the uterus and nurtures and nourishes the baby) expand and grow abnormally.
The placenta in its developmental stages is called a trophoblast; hence, referred to as trophoblastic disease. These tumors might extend beyond the termination of pregnancy. They range from hydatidiform mole, through to the more aggressive invasive mole, choriocarcinoma, and placental site trophoblastic tumor. The latter three that encompass a more aggressive subset are referred to as gestational trophoblastic neoplasia (GTN). GTD can mimic a normal pregnancy because of the presence of products of conception within the womb and/or abnormally raised human chorionic gonadotropin (hCG) levels. A normal conception is rare in these instances. Occasionally, some abnormal tissue is left behind after evacuation of a molar pregnancy that continues to re-grow as a cancerous tissue: this coined the term "persistent trophoblastic disease."
FertilitySmarts explains Gestational Trophoblastic Disease (GTD)
A majority of GTDs are benign (non-cancerous) and do not invade deep into the body tissues or spread to different parts of the body. These benign GTDs include hydatidiform moles (also termed as molar pregnancies) that arise after an abnormal fertilization of an egg by a sperm.
A hydatidiform mole can be partial or complete. An empty egg (with no genetic material) that is fertilized by one or two sperm is referred to as a complete mole. All of the entire genetic material, therefore, comes from the father's sperm. The fertilized egg that implants in the uterus is non-viable and contains no products of conception.
In contrast, a partial mole results from fertilization of a normal egg by two sperm, which therefore contains products of conception but they fail to develop properly. The risk of progressing to a cancerous GTD (like an invasive mole or a choriocarcinoma), is higher with a complete mole (approximately 2%) as compared to a partial mole in which the odds of converting into an aggressive tumor are relatively lower.
A hydatidiform mole comprises of finger-like projections called villi that swell with fluid. These engorged villi grow in clusters that resemble bunches of grapes. These grape-like vesicles flow out of the vagina with heavy bleeding. The enlarged trophoblastic cells release high amounts of human chorionic gonadotropin (hCG). hCG is the normal pregnancy hormone secreted by the placenta but when secreted in abnormal amounts does not indicate a normal pregnancy. However, a molar pregnancy may have normal hCG levels. Diagnosis is confirmed by an ultrasound scan. The mainstay of treatment is dilatation and curettage (D&C) with or without chemotherapy with methotrexate.
A choriocarcinoma carries a potential to spread to distant organs primarily the lungs and can present with coughing up blood. Its mainstay of treatment is chemotherapy.
The chemotherapy drugs used in GTD may induce early menopause and interfere with the cyclical release of eggs and the fertility potential. Very rarely, GTD warrants removal of the uterus that profoundly impairs the ability to conceive.