Spontaneous abortion after midtrimester amniocentesis.

Of 371 consecutive patients who underwent midtrimester diagnostic amniocentesis, 8 subsequently aborted spontaneously (2.2%), and 1 had a stillbirth at 24 weeks of gestation (0.17%). In 3 of the 9 patients who suffered fetal loss, infection appears to have played a significant role. Whereas midtrimester diagnostic amniocentesis is widely considered to be a safe and accurate procedure, the possibility of hazard to the patient and her fetus remains and should be considered during the preliminary counseling session.