EXPERIENCE WITH EARLY AMNIOCENTESIS

Literature concerning early genetic amniocentesis, obtained before 14- 15 weeks of gestation, has been examined and compared. Key figures of post-procedural spontaneous fetal losses have been compared as well as cytogenetic data from the published series. Cytogenetically more samp les fail to grow in the early weeks, but the diagnostic accuracy seems to be comparable with that of amniocentesis obtained in the later wee ks. A sampling method, improving the cell yield by means of filtration , has been developed in order to lower the risk of culture failure and reduce the reporting time in the gestational weeks 11 to 13. The filt er technique is under evaluation in a randomized trial. Detection of n eural tube defects with early amniotic fluid sampling is possible, but whether the detection rate is comparable to that of standard amniocen tesis remains to be seen. Although the safety of early amniocentesis h as not yet been evaluated in a randomized study, data from almost 5,00 0 cases suggest that the procedure related loss rate is approximately 1%, and thus the same as for standard amniocentesis and chorionic vill us sampling.