[The diagnostic potential of amniocentesis in the first 12 weeks of pregnancy]

Prenatal diagnosis of chromosomal and biochemical defects is accepted as a routine in high-risk patients. To eliminate the disadvantages of traditional amniocentesis (late diagnosis) and of chorion villus sampling (placentar mosaics, higher fetal loss rate) we evaluated the facts on amniocentesis during the first 12 weeks of pregnancy. 42 samples were analysed. 21 amniotic fluid samples were from pregnancies before the 13th week of gestation, 21 further punctures were performed between the 13th to 15th week and served as comparative figures. Of 21 samples, diagnosis was possible in 16 cases. Four cultures did not show any growth of cells; in one case, amniotic fluid could not be aspirated. In the comparison group chromosomal diagnosis could be done in every case. An average of 12.3 ml of amniotic fluid were taken. Chromosomal disorders found, included a translocation in chromosome 13/14 as well as a trisomy of chromosome 18. Biochemical defects such as Gaucher's disease and Niemann-Pick disease were excluded. 30 pregnancies without pathological symptoms were seen (mean birth weight 3200 g, mean duration of pregnancy 39 weeks). One case of abortion following amniocentesis was found in the 16th week of gestation. One case of premature delivery occurred in the 34th week and the pregnancy of a 40-year old women was complicated by EPH gestosis while 9 pregnancies were terminated by interruption following the patients' wish. Because chromosomal diagnosis could not be performed in five of 21 cases, amniocentesis during the 13th week of gestation cannot be recommended as a routine method. Early amniocentesis, however, is an alternative to the traditional amniocentesis at the 16th week of gestation.