[Ultrasonic diagnosis in the first trimester of multiple pregnancy].

Higher rate of morbidity and mortality has been noted in tween pregnancies comparing to singleton pregnancies. Early ultrasound investigation between 6 and 12 week of gestation is useful in determining time of gestation, amniocity and chorionicity (adequacy of diagnosis ranged from 95 to 100%). Determining of chorionicity and amniocity is extremly important in monozygotic twins, because of high risk of complications during next stages of pregnancy. First trimester ultrasound investigation allows to define abnormalities commonly associated with twin pregnancy and is useful in monitoring of fetal well-being.