A hydatiform mole is a growth that forms inside the uterus at the beginning of a pregnancy instead of a foetus. A hydatidiform mole results from over-production of the tissue that is supposed to develop into the placenta. The placenta normally feeds a fetus during pregnancy. An anomalous growth containing a nonviable embryo which implants and proliferates within the uterus. In Western countries, 1 of every 1000-1500 pregnancies is affected. Hydatiform mole is an incidental finding in approximately 1 of every 600 therapeutic abortions. In Asian countries, the rate of molar pregnancies is as much as 15 times higher than in the United States.
About 80% of hydatidiform moles are not cancerous and disappear spontaneously. About 15 to 20% invade the surrounding tissue and tend to persist.

Women who have a hydatidiform mole feel as if they are pregnant. Severe nausea and vomiting are common, and vaginal bleeding may occur. Hydatidiform moles can cause serious complications, such as infections, bleeding, and preeclampsia or eclampsia. Choriocarcinomas can spread quickly through the lymphatic vessels or bloodstream. Potential causes may include defects in the egg, problems within the uterus, or nutritional deficiencies. Women under 20 or over 40 years of age have a higher risk. Other risk factors may include diets low in protein, folic acid, and carotene. A diet deficient in animal fat and carotene may be a risk factor of hydatidiform Mole. Hydatidiform moles should be treated by evacuating the uterus by uterine suction. Suction curettage is the treatment of choice to remove a hydatidiform mole.