Over a four-year period, 88 pregnancies with different malformations detected by ultrasound were examined cytogenetically. Gestational age ranged from 13 to 37 weeks. Chromosomal analysis was performed on amniocentesis, cordocentesis, placental biopsy and fetal body fluid aspiration. Fourteen fetuses(15.9 percent) had abnormal karyotypes, including 5 cases of Trisomy 21, 2 cases of Trisomy 13 and 7 cases of monosomy X. Those all were delivered vaginally. In remained 74 chromosomally normla fetuses, 1 fetus and pleuroamniotic shunt on intrauterine pregnancy at 34 weeks and 7 cases had corrective or palliative surgery neonatally. Another 6 cases took conservative management after delivery. Combined cytogenetic and ultrasonographic techniques allow the distinction between minor isolated, correctable anomalies and severe developmental defects. Knowledge of the fetal chromosome constitution in the setting of an abnormal ultrasound has important obstetric management implications such as in utero surgery, termination of pregnancy, and avoid unnecessary cesarean section or neonatal surgery.