Midtrimester genetic amniocentesis has become an accepted part of modern obstetric care. Although its accuracy is well established, the risk of fetomaternal hemorrhage remains controversial. This prospective study was conducted to determine how effective continuous ultrasound guided amniocentesis is in preventing fetomaternal hemorrhage. The authors investigated 30 patients undergoing midtrimester genetic amniocentesis at our institution. Amniocentesis was performed under continuous real-time ultrasound guidance using a 21-gauge, 3.5-inch long spinal needle. Maternal serum alpha-fetoprotein (AFP) levels were determined before, at 5 minutes and at 1 hour after amniocentesis. There were no significant changes in maternal serum AFP levels either at 5 minutes or at 1 hour after amniocentesis. Midtrimester genetic amniocentesis performed by a trained and experienced operator under continuous ultrasound guidance does not significantly increase the risk of fetomaternal hemorrhage after the procedure.