Fetal-maternal bleeding associated with genetic amniocentesis: real-time versus static ultrasound.

Abstract

The incidence of fetal to maternal bleeding was studied in 773 consecutive patients having genetic amniocentesis by measuring maternal serum alpha-fetoprotein elevation following the procedure. The frequency of fetal to maternal bleeding was significantly lower in patients having amniocentesis immediately after real-time ultrasound (21 of 429 cases, 4.9%) when compared with patients having static B-mode ultrasound before the procedure (31 of 344 cases, 9.0%). A lower frequency of fetal to maternal bleeding was observed in the real-time group for anterior or partially anterior placentas (8.1%) and posterior or fundal posterior placentas (0%) when compared with the static B-mode group (12.9 and 5.2%, respectively). The rate of spontaneous abortion in patients with fetal to maternal bleeding (12.8%) was significantly higher than the rate in patients who did not demonstrate such bleeding (1.45%). The implications of these findings with regard to the safety of amniocentesis and the benefit of routine preliminary ultrasound evaluation are discussed.