This study was designed to assess the feasibility of amniocentesis and amnion cell culture for prenatal diagnosis in early weeks of gestation (less than 15 weeks). Within a period of 18 months (1/88-6/89) 135 diagnostic amniocenteses were performed between 10 and 14 weeks and amniotic fluid was obtained in all instances. In all cases but one, sufficient cell cultures and chromosomal analyses were achieved. In the follow up, one miscarriage (0.7%) occurred, in two cases transient amniotic fluid leakage ceased spontaneously. All of the aforementioned complications were related to amniocenteses in weeks 11 and 12. The course of the continued pregnancies as well as fetal outcome were without any further complications. Comparing specimens of early and regular (16-18 weeks) amniocenteses in terms of time required for cell culture and karyotyping as well as the quality of chromosomal banding no significant differences were found. In contrast to maternal serum AFP which increased continuously, amniotic AFP levels could be seen to increase to a peak at 13 weeks' gestation but afterwards gradually declined. Based on these first experiences and results of early amniocenteses the specific problems of this method are discussed. In summary, it is concluded, that early amniocentesis between 12 and 14 weeks of gestation is feasible with regard to both the technique of amniotic fluid retrieval and the technique of chromosomal analysis. Early amniocentesis, therefore, could fill up the diagnostic gap between chorionic villi sampling (CVS) between 9 and 11 weeks of gestation and "classical" amniocentesis during weeks 16-18.
