Molar pregnancy can be a scary thing, and it can be even scarier if you have one and then end up hearing a lot of technical terms that you don’t understand. Here’s a quick rundown of what you need to now about the terms behind molar pregnancy.
Gestational Trophoblastic Disease
Gestational trophoblastic disease (GTD) is a term used to describe a group of conditions that are characterized by abnormal growth of placental type tissue. There are five types of gestational trophoblastic disease. Two are benign and three are considered malignant. A small percentage of women with benign gestational trophoblastic disease will develop a malignant form of GTD.Hydatidiform Mole (Molar Pregnancy)
This term refers to the two types of benign GTD which are complete moles and partial moles. Molar pregnancies result from specific chromosomal abnormalities that happen at the time of fertilization.Complete Hydatidiform Mole
Complete hydatidiform molar pregnancies result from a sperm fertilizing an "empty" egg. A complete hydatidiform mole has no fetal tissue and is the more likely of the two types of molar pregnancies to progress into malignant gestational trophoblastic disease.Partial Hydatidiform Mole
A partial hydatidiform mole occurs when two sperm fertilize a single egg. The resulting pregnancy might develop a baby, even with a heartbeat, but the pregnancy isn't viable -- the chromosomal abnormalities are incompatible with life. Partial molar pregnancy usually does not cause further complications after treatment.Invasive Mole
An invasive mole is a hydatidiform mole has penetrated the wall of the uterus and may spread to the rest of the body.Choriocarcinoma
Choriocarcinoma is a type of cancer that can occur in the uterine lining after a molar pregnancy; most but not all cases of choriocarcinoma are related to molar pregnancy. (Choriocarcinoma can occur after any pregnancy -- even a full-term, normal birth.)Placental Site Trophoblastic Tumors
This is a form of GTD in which a malignant tumor develops at the former site of a placenta in the uterus. It can occur after any pregnancy but is extremely rare.
Sources:
American Cancer Society, “What Is Gestational Trophoblastic Disease?” Detailed Guide: Gestational Trophoblastic Disease May 2006. Accessed 26 Jan 2008.
American Pregnancy Association, “Molar Pregnancy.” Mar 2006. Accessed 26 Jan 2008.
