AMNIOCENTESIS-RELATED FETAL LOSS - A COHORT STUDY

Objective: To assess the risk of fetal loss attributable to second-tri mester amniocentesis. Methods: A cohort study was undertaken among sin gleton pregnant women undergoing genetic amniocentesis and controls ma tched prospectively on a one-to-one basis, matched strictly for matern al age, parity, and socioeconomic status. Both groups were recruited a t 15-24 weeks' gestation and observed until delivery. The fetal loss r ates of the groups were compared. Results: A total of 2256 pairs were recruited to the study. After excluding those pairs lost to follow-up, those with fetal malformation, and those later proven to have major c hromosomal abnormalities, 2045 matched pairs were compared by pregnanc y outcomes. There were no significant differences in fetal loss rates, premature deliveries, or placental abruptions between the study and c ontrol groups (P >.05). However, this study did not have enough statis tical power to identify differences of less than 1%. Conclusion: Secon d-trimester amniocentesis is probably not associated with a greater fe tal loss rate than that of matched controls. (C) 1998 by The American College of Obstetricians and Gynecologists.