Missing a period, morning sickness, fatigue and increased urination are all symptoms of pregnancy – and also molar pregnancy. A molar pregnancy is caused when the sperm and egg do not join normally at fertilization, and a molar pregnancy may or may not have an actual embryo present. However, the risks to the mother are high; molar pregnancies can cause excessive uterine bleeding, and a very small percentage can become a highly-treatable form of cancer.
The symptoms of a molar pregnancy are similar to a normal pregnancy. A woman may experience nausea, vomiting, fatigue, increased urination, missed menstruation and breast tenderness. In some cases, she may experience hyperemesis gravidarum, which is extreme morning sickness; however, having hyperemesis gravidarum does not necessarily mean a woman has a molar pregnancy. The most common sign of molar pregnancy is the expulsion of grape-like material from the vagina. A woman may also experience vaginal bleeding, and she may develop symptoms of early preeclampsia, a serious condition involving high blood pressure, protein in the urine and water retention. Also, in a molar pregnancy, no fetal heart beat will be found.
About one in 1,000 women will experience a molar pregnancy. However, women over age 40, with a history of miscarriage or with a history of molar pregnancy are at a higher risk. A diet low in carotene, a form of vitamin A, has also been linked to molar pregnancies, according to WebMD.
Women in Mexico, the Philippines and southeast Asia have a higher rate of molar pregnancies than women in the United States, according to the American Pregnancy Association. In the United States, white women are more likely to experience a molar pregnancy than black women.
Types of molar pregnancy
Two types of molar pregnancy exist – complete molar pregnancy and partial molar pregnancy.
In a complete molar pregnancy, there is no fetus because the sperm has fertilized an empty egg – the egg does not have any genetic information in it, so it cannot develop into a baby, according to WebMD. However, the placenta does grow and produces human chorionic gonadotropin (hCG), a hormone that tells the body that a pregnancy is underway. Instead of a baby, a grape-like formation of cells grows and can fill the uterus. An ultrasound will confirm the absence of a fetus in a complete molar pregnancy.
In a partial molar pregnancy, the placenta grows abnormally, and any fetus that may be present will be overcome by the fast-growing abnormal cells, according to the American Pregnancy Association.
Very rare cases exist where twins were conceived; one is normal, and the other is a molar pregnancy. The abnormal cells can overcome the normal fetus. However, in rare cases, the fetus continues to develop normally, even after surgical removal of the molar pregnancy, according to WebMD. In these cases, the fetus is closely monitored and is delivered as soon as possible.
A partial molar pregnancy may be caused by two sperm fertilizing one egg, according to WebMD.
Diagnosis and treatment of molar pregnancy
A molar pregnancy can be diagnosed by a series of tests, which can include hCG levels in the blood, a pelvic exam or an ultrasound. An abnormally large or small uterus for the age of the pregnancy may indicate a molar pregnancy, and an ultrasound may show grape-like clusters in the uterus.
Most molar pregnancies miscarry without any medical help, according to the American Pregnancy Association. In some cases, medical help is needed to expel the tissue from the uterus. A physician may choose to use suction curettage, dilation and curettage or medication to help expel the tissue. Suction curettage and dilation and curettage are surgical procedures and are usually performed under general anesthesia. Later, a doctor may follow up with blood tests to rule out cancer.
Most women who experience a molar pregnancy are able to carry a normal pregnancy; their chances of getting pregnant are similar to that of the general population, according to WebMD. Their risk is increased for another molar pregnancy, and genetic counseling may be recommended.
Despite the fact that the molar pregnancy could not develop into a child, many women feel a sense of loss and grief, coupled with worries about possible cancer. Counseling and support groups may be beneficial to help deal with the emotions accompanying a molar pregnancy.