Prenatal diagnosis and elective termination of Down syndrome in a raciallymixed population in Hawaii, 1987-1996

The impact of demographic factors on the prenatal diagnosis and elective te rmination of Down syndrome in Hawaii between 1987 and 1996 were examined. D ata were obtained from a population-based birth defects registry and includ ed 306 Down syndrome cases. 131 (43 per cent) of the cases were prenatally diagnosed. Of the prenatally diagnosed cases, 110 (84 per cent) were electi vely terminated. Advanced maternal age or having a maternal serum alpha-fet oprotein screen performed increased the probability of having an affected p regnancy prenatally diagnosed and electively terminated. Far East Asians we re substantially more likely to have an affected pregnancy prenatally diagn osed and electively terminated. Pacific Islanders and Filipinos were less l ikely to have cases prenatally diagnosed and electively terminated. Prenata lly diagnosed and electively terminated Down syndrome cases had disproporti onately fewer additional birth defects than live births or fetal demises, s uggesting that for many of the electively terminated cases additional birth defects may not have been identified. This implies that the elective termi nation of Down syndrome-affected pregnancies may influence not only the Dow n syndrome prevalence but also that of other birth defects. Copyright (C) 1 999 John Wiley & Sons, Ltd.