Molar Pregnancy

What is Molar Pregnancy?

A Molar Pregnancy occurs when tissue growth, instead of a fetus, begins to develop inside the uterus. A complete molar pregnancy materializes when a sperm fertilizes an egg, but instead of emerging as a fetus, the tissue develops into an abnormal growth.

This condition occurs when the mother’s chromosomes are absent soon after fertilization and only the father’s chromosomes remain after they are replicated. A partial molar pregnancy occurs when two sperm fertilizes the same egg and the abnormal growth emerges from the placenta. With this type of molar pregnancy, the chromosomes of the mother are still present but the father’s chromosomes are doubled. These chromosome abnormalities are believed to be caused by genetics in the sperm or egg.

What are the Symptoms of Molar Pregnancy?

There are various symptoms that indicate a molar pregnancy and the first symptoms are identical to the signs of a natural pregnancy, which are morning sickness and the absence of menstruation. Additional symptoms that are prevalent with a molar pregnancy include a vaginal discharge that contains tissue that looks like clusters of grapes, vaginal bleeding and excessive vomiting.

Some women experience profuse sweating, nervousness and an abnormal heartbeat, which are all symptoms of hyperthyroidism. Women who are at a higher risk of having a molar pregnancy include those who are over the age of 35, have an insufficient amount of carotene in their diet and have had previous miscarriages or molar pregnancies.

Molar Pregnancy Causes

Molar pregnancy is caused when sperm erroneously fertilizes the egg, leading to clusters of filled sacs or abnormal cell development within the womb. The imbalanced nature of the chromosomes causes a molar pregnancy. This can occur if an egg does not contain any genetic information. There are typically 23 chromosome pairs in a healthy human cell. The father provides one chromosome from the pair, and the mother provides the other.

A complete molar pregnancy involves having all of the chromosomes for the fertilized egg come from the father. The chromosome from the mother are inactivated or lost soon after fertilization and the chromosome from the father is duplicated. There could be no nucleus or an inactive nucleus in this instance.

A partial molar pregnancy involves having the chromosomes from the mother remain while still taking two pairs of chromosomes from the father. This results in the embryo having not 46, but 69 chromosomes. This is caused by duplications of the father’s chromosomes or if a single egg is fertilized by two sperm.

How is Molar Pregnancy Treated?

Many women who have a molar pregnancy will expel the tissue along with the vaginal secretions. If the tissue does not discharge from the body on its own, a doctor will perform a procedure in which suction curettage, dilation and evacuation are performed to remove the tissue.

After the procedure, individuals must schedule a future visit to the doctor for an examination to ensure the molar pregnancy is entirely absent from the uterus. Tissue that is left inside the uterus can develop into cancer that can spread inside the body.

Molar Pregnancy Prevention

A physician should complete routine prenatal care to identify any potential complications or problems that can be prevented during the pregnancy. Molar pregnancies tend to happen more often for women who are older than 40 or are younger than 20. A major precautionary measure that women can take to avoid molar pregnancies is to prevent conception prior to 20 or over age 40.

A physician should be consulted prior to attempting to conceive for those with a history of molar pregnancy. At least a six-month time frame would be beneficial before becoming pregnant again. Early ultrasounds are often used for subsequent molar pregnancies to ensure normal development. Lack of adequate protein can instigate molar pregnancies as well as ovulation deficiency. When seeking to prevent molar pregnancy, increasing protein and vitamin A intake can be of immense aid.

Last Reviewed:
October 07, 2016
Last Updated:
March 09, 2018