The artifactual nature of effects of maternal age on risk of stillbirth

Abstract

SummaryAnalysis of stillbirth data from the State of Wisconsin demonstrates that the association of stillbirth rate with mother's age is basically an artifact of analysis rather than a reflection of genuine effects of age on risk. When births to mothers of a single parity are subdivided according to the amount of education completed by the mother, the association between stillbirth rate and maternal age in each educational group differs substantially from the others. The association observed for all births of a single parity is inapplicable to any educational subdivision of the data.It is argued that the associations which are observed are the consequence of social forces which distribute women of varying intrinsic risk of stillbirth unevenly among age–parity categories.