What is a Hydatidiform Mole?

A hydatidiform mole is a cluster of abnormal cells which develop in the uterus. The mole can cause false positives on pregnancy tests, leading a women to believe that she is pregnant, and hydatidiform moles are not uncommon. Most abort spontaneously if they are not discovered first, but in some cases the cells can burrow into the side of the uterus and become cancerous. The state of having a hydatidiform mole is sometimes known as a molar pregnancy.

In a partial molar pregnancy, an egg is fertilized normally, but the cells around it develop into fluid-filled vesicles, instead of a placenta. The fertilized egg may develop into an embryo, but the embryo will not survive. In a complete molar pregnancy, an egg lacking a nucleus is fertilized by sperm, and a cluster of abnormal cells develops with no embryo inside. In both cases, hormones associated with pregnancy rise, and the uterus starts to enlarge, as though it is expanding to accommodate an embryo.

An ultrasound examination can diagnose a hydatidiform mole. The doctor will usually recommend an immediate procedure to remove the cells so that they do not have a chance to turn cancerous. While this procedure may be described as an abortion, it is important to note that a hydatidiform mole is not a pregnancy, and has no chance of developing into a fetus. While women may want to wait to see if it aborts spontaneously, this is not advised, as it can increase the risk of developing cancer.

In some rare cases, it is possible for a woman to have a hydatidiform mole and a regular pregnancy, in a form of twinning. In these instances, it is possible to carry the regular pregnancy to term, with the mole being delivered when the mother delivers the baby. There may be some special precautions to take during and after pregnancy which a doctor can discuss with a patient if it becomes evident that she is carrying both a regular fetus and a hydatidiform mole.

Some women may not realize that they have a hydatidiform mole until they experience symptoms such as vomiting, nausea, and abnormal vaginal bleeding. In some cases, molar cells may be left behind after a pregnancy or spontaneous abortion, later leading to the development of a cancer. Women who think that they are pregnant should always make an appointment with a doctor for a full workup, in the interests of initiating prenatal care and checking for issues such as molar or tubal pregnancies.