Non invasive serum-screening (NIS) for M. Down in pregnant women under
35 years of age should be seen critically. The existing age-dependent
screening programmes can detect only 50% of the affected pregnancies
in the under-35 age group. The Ulm-Index improves the detection rate u
p to 85% including a false positive rate of 8%. In our findings the Ul
m-Index is able to reduce invasive procedures such as amniocentesis an
d consecutive abortions in pregnant women under 35 years when NIS is d
one correctly. Unfortunately, insufficient information of the pregnant
women, incorrect gestational age and poor quality of the laboratories
reduce the value of NIS programmes.