TRANSPLACENTAL AMNIOCENTESIS - IS IT REALLY A HIGHER-RISK PROCEDURE

The aim of this study was to compare transplacental with non-transplac ental amniocentesis in terms of related complications. Between January 1991 and December 1992, 4564 genetic amniocenteses were performed in 4527 patients (4491 singleton, 35 twin, and one triplet pregnancy) at 15-16 weeks of gestation. All the procedures were ultrasound-guided an d performed by the same operator. In 1487 cases, an anterior placenta was traversed with the needle, whereas in 3077 cases, the needle was i nserted directly into the amniotic cavity without traversing the place nta. After the exclusion of patients in whom amniotic cell culture fai led or in whom an abnormal karyotype was obtained, and of patients los t to follow-up, a total of 4454 patients (98 per cent) were followed f or 30 days after amniocentesis. Two spontaneous abortions occurred aft er a transplacental procedure, and five after a nontransplacental proc edure (P=not significant). There were no episodes of amniotic fluid le akage in the first group, whereas 16 ruptures of the membranes that re solved spontaneously occurred in the second group (P<0.01). Our data s uggest that transplacental amniocentesis carries a similar abortive ri sk to and a lower risk of transient rupture of the membranes than non- transplacental amniocentesis and may therefore be preferred at the ges tational period examined (15-16 weeks). However, the risk of feto-mate rnal haemorrhage, which is reported to be higher for a transplacental procedure, must be considered in the case of an anterior placenta.