This is a case study of twin pregnancy, going through a complete hydatidiform mole with living fetus. The pregnant woman had a previous partial hydatidiform mole, diagnosed and confirmed five months before the pregnancy which is the subject of this study. The first suspected diagnosis was made by means of a medical external ultrasound scan, confirmed by other tests, such as the dosage of β-HCG. Besides the bibliographic review, this study addresses legal aspects of the Brazilian system which does not allow termination of pregnancy in these situations. In this particular case, the living fetus was sacrificed through uterine evacuation, featuring a criminal abortion. For the safety of the medical staff and the pregnant woman herself, there was the need for a special authorization from the Public Prosecution to the medical procedure.