The Early Amniocentesis Study: A randomized clinical trial of early amniocentesis versus midtrimester amniocentesis

Objectives: The primary purpose of this pilot study was to determine whether the safety of early amniocentesis (EA; ii weeks to 12 weeks and 6 days) is similar to midtrimester amniocentesis (MA; 15 weeks to 16 weeks and 6 days). The secondary objectives were to determine the cytogenetic success and accuracy of EA compared with MA. Methods: This prospective, randomized clinical trial compared continuous ultrasound-guided EA and MA (22-gauge needle) in patients at a late maternal age (greater than or equal to 35 years). The procedures were compared for safety, success and accuracy, Results: Among the 683 women randomized and followed to pregnancy completion, there was a total of 27/344 (7.8%) and 25/339 (7.4%) fetal losses (spontaneous and induced abortions) in the EA and MA groups, respectively (difference 0.4%; CI -3.6 to 4.4%). The rate of postprocedure spontaneous fetal loss was 2.4% (8/330) in the EA group and 3.3% (10/299) in the MA group (NS), The procedure success rate at the first attempt was 97.6% in the EA group and 99.7% in the MA group, There were no diagnostic errors, and all but 2 EA cultures were successful (both repeated successfully), The perinatal outcome was similar in both groups. Conclusions: EA appears to be as safe and accurate as MA, A large multicentered, randomized trial is currently underway to verify these results.