ARE DOWN-SYNDROME FETUSES DETECTED THROUGH MATERNAL SERUM SCREENING SIMILAR TO THOSE REMAINING UNDETECTED

This study was designed to examine whether fetuses with Down syndrome (DS) identified through serum screening are different from those whose mothers have normal serum screening results. It was a retrospective f ollow-up study of pregnancies where maternal serum alpha-fetoprotein ( MSAFP) concentrations were measured to identify women at increased ris k of having a baby with a neural tube defect (NTD). An enhanced risk f or NTD was the only reason for intervention in the screened population . Clinical features of fetuses or children with DS were related to the screening results. A retrospectively calculated term risk of 1/250 cl assified a pregnancy as having been at an elevated risk of DS. The out come measures were fetal or neonatal death and severe somatic disease. Human chorionic gonadotrophin (hCG) and unconjugated oestriol (uE3) w ere measured retrospectively in frozen samples of the DS pregnancies a nd the same cut-off level was used for classification (so-called 'trip le test'). Ten thousand women were included in the study. Pregnancy ou tcome was known in 93.5 per cent of the cases. Children with and witho ut anatomic defects were found in all subgroups of test result combina tions. All mothers of children with a congenital heart defect (CHD) ha d a DS risk of greater than or equal to 1/250 according to the triple test.