Molar Pregnancy

A molar pregnancy occurs when an egg and sperm join incorrectly at fertilization and create a noncancerous tumor. The tumor looks like tiny water-filled sacs, similar to a cluster of grapes. The tumor can’t support a developing embryo and the pregnancy ends. Some people have a miscarriage. If this doesn’t happen, surgery is needed to remove the pregnancy. If left untreated, molar pregnancies can cause serious complications.

Molar pregnancies are a type of gestational trophoblastic disease. Gestational trophoblastic disease (GTD) is a group of conditions that cause tumors to grow in your uterus. Molar pregnancies are also called hydatidiform moles.

What are the types of molar pregnancies?

Molar pregnancies fall into two categories: complete and partial.

Complete molar pregnancy

In complete molar pregnancies, no embryo forms. It happens when a sperm fertilizes an empty egg. Because the egg is empty, the embryo can’t grow. The placental tissue grows but is abnormal and contains fluid-filled cysts (or tumors). This tissue produces the pregnancy hormone HCG (human chorionic gonadotropin), which is made by a healthy placenta during pregnancy. This can make you feel like you’re pregnant and give you a positive pregnancy test.

Partial molar pregnancy

A partial molar pregnancy occurs when an abnormal placenta forms along with an embryo, and two sperm fertilize one egg. In these cases, the growing embryo has an extra set of chromosomes. The embryo may start to develop but generally can’t survive.

Who is likely to have a molar pregnancy?

Although molar pregnancies are rare, anyone can have a molar pregnancy. You’re more likely to have a molar pregnancy if you:

• Are younger than age 20.
• Are over 40.
• Have a history of molar pregnancies.
• Have had two or more miscarriages.
• Are of Asian descent.

How common are molar pregnancies??

Less than 1% of all pregnancies — about 1 in 1,000 — are molar pregnancies.

Can a molar pregnancy lead to a normal pregnancy?

Unfortunately, a molar pregnancy results in the loss of the pregnancy.