What is a molar pregnancy?
According to the American College of Obstetricians and Gynecologists (ACOG), a molar pregnancy, also called gestational trophoblastic disease (GTD), is rare. "This type of pregnancy results in the growth of abnormal tissue and in the United States, molar pregnancy occurs in one of every 1,000 to 1,200 pregnancies," the organization reports.
How Molar Pregnancies Occur
A molar pregnancy and a normal pregnancy both start out with sperm fertilizing an egg. The difference with a molar pregnancy is that something goes wrong during the fertilization process. Instead of a healthy embryo forming, a mass or cluster of cells forms into abnormal tissue. Molar pregnancies fall into two groups: complete or partial.
- A complete molar pregnancy contains no fetus, only the cells that would have made up the placenta.
- A partial molar pregnancy includes the same cells as in the complete, but there is also usually a fetus with severe abnormalities.
The risk of experiencing a subsequent molar pregnancy is low—generally about 1 to 2 percent. Researchers don't know why, but the risks are higher for women in Mexico, Southeast Asia, and the Philippines. Also, African-American women are less likely to experience molar pregnancies than Caucasian women. Age can influence your chances of experiencing a molar pregnancy, too—more molar pregnancies occur in women over the age of 40.
Signs of Molar Pregnancy
Initially a woman who is experiencing a molar pregnancy will have a positive pregnancy test. Her pregnancy hormone levels, or hCG (human chorionic gonadotropin), will rise rapidly and be higher than normal. She may experience vaginal bleeding, nausea, vomiting, or high blood pressure (a sign of preeclampsia). No fetal heartbeat will be audible and no fetal movement will be noted. An ultrasound will show an enlarged uterus and ovaries and the cells forming the "mole" (a Hydatidiform mole, or mola hydatidiforma), which is nonviable embryo implanted within the uterus that has the appearance of a cluster of grapes.
Treatment of Molar Pregnancy
Many molar pregnancies will end with the woman passing the abnormal tissue, which is followed by a D and C (dilation and curettage) or with medication. With a D and C, the tissue is gently removed from the uterus through the cervix. After this procedure further procedures are generally not required. But a follow-up visit with your healthcare provider is very important to make sure there is no regrowth of the abnormal cells.
Recommendations for women after a molar pregnancy include the following:
- Schedule follow-up appointments as recommended by your doctor
- Avoid getting pregnant for one year
- Do not use an IUD (intra-uterine device) for birth control
- Seek genetic counseling before trying to conceive again
After experiencing a molar pregnancy, give yourself time to grieve—this is a loss. Don't blame yourself. There is nothing to prevent these types of pregnancies from occurring. Some women find it helpful to talk with their partner or family, find a support group, or seek a counselor with whom to talk about their feelings related to this loss.