RANDOMIZED TRIAL TO ASSESS SAFETY AND FETAL-OUTCOME OF EARLY AND MIDTRIMESTER AMNIOCENTESIS

Background Most published reports on early amniocentesis are of cohort studies rather than randomised trials, This study was designed to ass ess the safely and cytogenetic accuracy of early amniocentesis in cont rast to midtrimester amniocentesis in a randomised multicentre setting , Methods Pregnant women were randomly allocated early amniocentesis ( between 11(+0) and 12(+6) gestational weeks(days)) or midtrimester (be tween 15(+0) and 16(+6) amniocentesis. A detailed fetal ultrasound exa mination was done between 15 and 20 gestational weeks in ail women. Al l amniocenteses were done under continuous ultrasound guidance: 11 mt (early amniocentesis) or 20 mt (midtrimester amniocentesis) of amnioti c fluid were removed for cytogenic analysis, No more than two needle i nsertions were done on the same day, All fetal losses (spontaneous or induced abortions) were counted as outcome events and post-procedural losses had cytogenic analysis, Maternal and fetal health were assessed at 20-22 weeks and 5 weeks after delivery, Logistic regression analys is was used to assess the significance of the differences between the early amniocentesis and midtrimester amniocentesis groups. Findings 43 74 pregnant women took part in the study, 1916 (87.8%) of 2183 women i n the early amniocentesis group had their amniocentesis before 13 gest ational weeks. 1775 (81.2%)) of 2185 women in the midtrimester group h ad their amniocentesis after 15 gestational weeks, There was a signifi cant difference in total fetal losses for early amniocentesis compared with midtrimester amniocentesis (7.6% vs 5.9%; difference 1.7%, one-s ided CI 2.98%, p=0.012). There was a significant increase in talipes e quinovarus in the early amniocentesis group compared with the midtrime ster amniocentesis group (1.3% vs 0.1%, p=0.0001). There was a signifi cant difference in postprocedural amniotic-fluid leakage (early amnioc entesis 3.5% vs midtrimester aminocentesis 1.7%, p=0.0007). Interpreta tion Our study shows that early amniocentesis is associated with an in creased risk of fetal loss and talipes equinovarus, Our results should be taken into consideration when invasive prenatal diagnosis is being offered.