A molar pregnancy is a rare complication of pregnancy. It involves unusual growth of cells called trophoblasts. These cells typically become the organ that feeds a growing fetus. That organ also is known as the placenta.
There are two types of molar pregnancy — complete molar pregnancy and partial molar pregnancy. In a complete molar pregnancy, the placental tissue swells and appears to form fluid-filled cysts. There is no fetus.
In a partial molar pregnancy, the placenta might have both regular and irregular tissue. There may be a fetus, but the fetus can't survive. The fetus usually is miscarried early in the pregnancy.
A molar pregnancy can have serious complications, including a rare form of cancer. A molar pregnancy requires early treatment.
Symptoms
A molar pregnancy may seem like a regular pregnancy at first. But most molar pregnancies cause symptoms that can include:
- Dark brown to bright red bleeding from the vagina during the first three months
- Severe nausea and vomiting
- Sometimes grapelike cysts that pass from the vagina
- Pelvic pressure or pain
Because of improved ways of detecting a molar pregnancy, most are found in the first trimester. If it is not found in the first three months, symptoms of a molar pregnancy might include:
- A uterus growing quickly and being too large early in the pregnancy
- Preeclampsia — a condition that causes high blood pressure and protein in the urine — before 20 weeks of pregnancy
- Ovarian cysts
- Overactive thyroid, also known as hyperthyroidism
