by maintaining patient's consciousness one can diagnose the complications like uterine perforation, cardiopulmonary distress and thyroid storm at an earlier stage than when the patient is sedated or is under general anesthesia. Prognosis More than 80% of hydatidiform moles are benign. The outcome after treatment is usually excellent. Close follow-up is essential to ensure that treatment has been successful. Highly effective means of contraception are recommended to avoid pregnancy for at least 6 to 12 months. Women who have had a prior partial or complete mole, have a slightly increased risk of a second hydatidiform mole in a subsequent pregnancy, meaning a future pregnancy will require an earlier ultrasound scan. In 10 to 15% of cases, hydatidiform moles may develop into invasive moles. This condition is named persistent trophoblastic disease (PTD). The moles may intrude so far into the uterine wall that hemorrhage or other complications develop. It is for this reason that a post-operative full abdominal and chest X-ray will often be requested. In 2 to 3% of cases, hydatidiform moles may develop into choriocarcinoma, which is a malignant, rapidly growing, and metastatic (spreading) form of cancer. Despite these factors which normally indicate a poor prognosis, the rate of cure after treatment with chemotherapy is high. Over 90% of women with malignant, non-spreading cancer are able to survive and retain their ability to conceive and bear children. In those with metastatic (spreading) cancer, remission remains at 75 to 85%, although their childbearing ability is usually lost. Epidemiology Hydatidiform moles are a rare complication of pregnancy, occurring once in every 1,000 pregnancies in the US, with much higher rates in Asia (e.g. up to one in 100 pregnancies in Indonesia). Etymology The etymology is derived from hydatisia (Greek "a drop of water"), referring to the watery contents of the cysts, and mole (from Latin mola = millstone/false conception). The term, however, comes from the similar appearance of the cyst to a hydatid cyst in an Echinococcosis. References External links Humpath #3186 (Pathology images) Clinically reviewed molar pregnancy and choriocarcinoma information for patients from Cancer Research UK MyMolarPregnancy.com: Resource for those diagnosed with molar pregnancy. Links, personal stories, and support groups. Germ cell neoplasia Pregnancy with abortive outcome