There may or may not be an embryo or placental tissue in some cases of molar pregnancy. If there is an embryo, it's not properly formed and can't survive.

A molar pregnancy may seem typical at first, but most cause symptoms, including dark brown to bright red vaginal bleeding during the first trimester. Severe nausea and vomiting also can happen.

The tumor must be removed to avoid serious complications. Often, molar pregnancies are removed by dilation and curettage (D&C). Rarely, a hysterectomy may be needed.