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What causes a hydatidiform mole?

What causes a hydatidiform mole?

When a normal sperm cell fertilizes one of these oocytes, the resulting embryo has only one set of chromosomes. Because the embryo has no genes from the mother, the pregnancy cannot develop normally, resulting in a hydatidiform mole.

What hydatidiform mole means?

Listen to pronunciation. (HY-duh-TIH-dih-form…) A slow-growing tumor that develops from trophoblastic cells (cells that help an embryo attach to the uterus and help form the placenta) after fertilization of an egg by a sperm. A hydatidiform mole contains many cysts (sacs of fluid).

What are the symptoms of hydatidiform mole?


  • Abnormal growth of the uterus, either bigger or smaller than usual.
  • Severe nausea and vomiting.
  • Vaginal bleeding during the first 3 months of pregnancy.

How does hydatidiform mole happen?

A hydatidiform mole is growth of an abnormal fertilized egg or an overgrowth of tissue from the placenta. Women appear to be pregnant, but the uterus enlarges much more rapidly than in a normal pregnancy.

How is hydatidiform mole diagnosed?

Diagnosis of Hydatidiform Mole A pregnancy test is done. If women have a hydatidiform mole, results are positive, but no fetal movement and no fetal heartbeat are detected. Blood tests to measure the level of human chorionic gonadotropin (hCG—a hormone normally produced early in pregnancy) are done.

Who is at risk for molar pregnancy?

A molar pregnancy is more likely in women older than age 35 or younger than age 20. Previous molar pregnancy. If you’ve had one molar pregnancy, you’re more likely to have another. A repeat molar pregnancy happens, on average, in 1 out of every 100 women.

What are the two types of hydatidiform mole?

A molar pregnancy — also known as hydatidiform mole — is a rare complication of pregnancy characterized by the abnormal growth of trophoblasts, the cells that normally develop into the placenta. There are two types of molar pregnancy, complete molar pregnancy and partial molar pregnancy.

How do you test for hydatidiform mole?

Blood tests to measure the level of human chorionic gonadotropin (hCG—a hormone normally produced early in pregnancy) are done. If a hydatidiform mole or another type of gestational trophoblastic disease is present, the level is usually very high because these tumors produce a large amount of this hormone.

Is a molar pregnancy a real baby?

Complete molar pregnancies have only placental parts (there is no baby) and form when the sperm fertilizes an empty egg. Because the egg is empty, no baby is formed. The placenta grows and produces the pregnancy hormone, hCG. Unfortunately, an ultrasound will show that there is no fetus, only a placenta.

What is the difference between a complete and incomplete hydatidiform mole?

In complete hydatidiform mole, there is no fetal tissue present; in partial hydatiform moles, there is some residual fetal tissue. Both are due to the over-proliferation of chorionic villi.

Is the hydatidiform mole a full or partial mole?

A hydatidiform mole is a growing mass of tissue inside the womb (uterus) that will not develop into a baby. It is the result of abnormal conception. A hydatidiform mole may be either complete or partial.

When to avoid pregnancy after a hydatidiform mole?

It is important to avoid another pregnancy and to use a reliable contraceptive for 6 to 12 months after treatment for a molar pregnancy. This time allows for accurate testing to be sure that the abnormal tissue does not grow back.

What does a hydatidiform mole in the uterus mean?

It is a type of gestational trophoblastic disease (GTD). HM, or molar pregnancy, results from abnormal fertilization of the oocyte (egg). It results in an abnormal fetus. The placenta grows normally with little or no growth of the fetal tissue. The placental tissue forms a mass in the uterus.

Can a hydatidiform mole be treated with chemotherapy?

It is usually successfully treated with chemotherapy, but can be life threatening. Bouchard-Fortier G, Covens A. Gestational trophoblastic disease: hydatidiform mole, nonmetastatic and metastatic gestational trophoblastic tumor: diagnosis and management.