Variation in Prenatal Cytogenetic Diagnosis - Policies in 13 European Countries. EUROCAT Working Group. European Registration of Congenital Anomalies.

The livebirth prevalence of autosomal chromosomal anomalies is determined by several factors, including maternal age distribution and the impact of prenatal cytogenetic diagnosis (PCD). The impact of PCD varies between countries, as the indications and the uptake vary. In a previous study we described differences in Down syndrome prevalence and the proportion of older mothers. We have now made a survey of the official PCD policies in 25 regions in 13 European countries for the period 1989-1991. In two countries, termination of pregnancy was not available. In the other 11 countries, international agreement existed on five indications: advanced maternal age, a previous child with a chromosomal anomaly, parents who are carries of a balanced translocation, mothers who are carriers of an X-linked disorder, and malformations at ultrasound. The exact limit for advanced maternal age varied from 35 to 38 years. There was a considerable variation for the indications advanced paternal age, amniocentesis for AFP or DNA, parental anxiety, a previous child with a congenital anomaly, abnormal maternal serum markers, and exposure to radiation/chemotherapy. The PCD uptake for mothers above the maternal age limit varied from 10 to 88 per cent. International harmonization of the indications for PCD is not considered feasible at present, because of the rapid changes in PCD policies even within countries.