Molar Pregnancy

woman grabbing stomach in pain

Molar pregnancy, also referred to as Hydatidiform Mole, occurs when something goes wrong during conception. Ideally, conception occurs when 1 sperm from a male fertilizes 1 egg from a female. The fertilization causes an amazing fusion of genetic material from the father and mother to create a new person. With a molar pregnancy, sperm does fertilize an egg but something is missing genetically.

Types of Molar Pregnancies

There are two types of molar pregnancy, complete and partial. A complete molar pregnancy occurs when a sperm fertilizes an empty egg. With the egg being empty, a baby will never be formed. When the empty egg is fertilized, a placenta begins to grow just as it does in a normal pregnancy. Since the placenta developing creates HCG, a woman would test positive for pregnancy with a home pregnancy test and also may begin to feel symptoms typical of pregnancy.

A partial molar pregnancy occurs when 2 sperm fertilize the same egg. The difference between a complete molar pregnancy and a partial molar pregnancy is with a partial molar pregnancy, a fetus may actually be developing but due to genetics will not be able to survive.

In extremely rare cases, twin formation has occurred where one fetus results in a molar pregnancy and the other fetus goes on to develop into a normal, healthy pregnancy.

What Causes a Molar Pregnancy?

While researchers are not exactly sure what causes a molar pregnancy to develop, they do understand that molar pregnancies are a result of genetic abnormalities with either the sperm or the egg.

Women who become pregnant early on in their reproductive years and women who become pregnant late in their reproductive years are at a higher risk for developing a molar pregnancy.

Women who have previously experienced a molar pregnancy are at a higher risk for a molar pregnancy.

woman getting ultrasound

Molar Pregnancy Symptoms

A molar pregnancy, whether complete or partial, has many of the same symptoms as a normal pregnancy. A woman may experience breast tenderness, a missed period, and nausea/morning sickness.

As the molar pregnancy continues, other symptoms typically develop.
These include:

  • vaginal bleeding (light or heavy),

  • lower abdominal pain/discomfort

  • discharge of tissue vaginally

  • severe morning sickness

  • weight loss

  • swelling of the abdomen (much larger than it should be for a typical pregnancy stage)

How Is a Molar Pregnancy Diagnosed?

Molar pregnancies are diagnosed by performing several diagnostic tests. If a molar pregnancy is suspected, a blood test to determine a woman’s level of HCG is typically ordered. Normal pregnancies follow a pretty predictable pattern of HCG levels. Molar pregnancies will show a much higher level of HCG in the blood than there should be for the pregnancy period. Molar pregnancies are also diagnosed with ultrasound images. Molar pregnancies appear in the ultrasound as tiny clusters of grapes inside the uterus.

woman talking to doctor

Treatment for Molar Pregnancy

Many molar pregnancies will end themselves early on in the pregnancy. The body will expel the tissue on its own without any complications. In some instances, this is not the case. If a molar pregnancy is diagnosed and does not resolve on its own, a doctor will either have to prescribe a medication to assist the body in expelling the tissue or perform a procedure to remove the tissue. A molar pregnancy, left untreated, can lead to serious complications such as severe infection and future infertility.

In some instances, although rare, molar pregnancies can develop into cancerous tumors. During pregnancy, a fertilized egg travels down the Fallopian tubes and into the uterus where specialized cells of the now developing embryo burrow themselves into the lining of the uterus. This action is what maintains a normal pregnancy and allows an embryo to develop into a healthy baby. When you’re dealing with a molar pregnancy, which mimics a normal pregnancy except the cells are abnormal, it performs the same actions. The abnormal cells burrow into the lining of the uterus but instead of doing so to nourish a new living thing, it is burrowing to nourish abnormal cells. These abnormal cells divide rapidly and can quickly invade other tissues and travel throughout the body. If left untreated, death can occur. Treatment for molar pregnancies that develop into cancer or Choriocarcinoma depends on the severity of the cancer and the location.

Any questions or concerns regarding your health should be directed to your health care provider.