title: Frequency of Down syndrome in livebirths by single-year maternal age interval: results of a Massachusetts study.
abstract: An analysis of rates of intra-state Down syndrome livebirths to Massachusetts residents by single-year maternal age interval in 1958-1965 inclusive was carried out. A gradual increase of rate of the Down syndrome occurred from age 20 to about age 31, and a steeper increase thereafter. Different regression equations were derived in the 20-31 and the 33-45 age group. The regression equations were ln y = 0.04515 x -1.45759 for those age 20-31 and ln y = 0.24302x-7.57870, for those age 33-45, where y = rate per 1,000 and x = maternal age. The regression-derived rates are slightly lower than those reported in similar analyses of data from Sweden and New York State, but they are not markedly discrepant.
mesh_terms: D000293:Adolescent; D000328:Adult; D004314:Down Syndrome / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008404:Massachusetts; D008423:Maternal Age; D008875:Middle Aged; D009518:New York; D013548:Sweden