The effect of maternal age on the risk of fetal death (FD) among different races for the U.S. population has not been reported. Using data from the National Center for Health Statistics from 1983-1990, we used logistic regression for aggregate data to analyze the effect of maternal age on the risk of FD in Whites, Blacks, and Others. Mothers who were 25-29 years of age had the lowest risk for FD in Whites and Others. On the other hand, for Blacks, mothers who were 20-24 years of age had the lowest risk. For all three groups, older maternal age had a greater effect on the risk of FD compared with younger maternal age (Table). In this period, FD rate decreased by 14.0% in Whites and 18.7% in Others; however, there was only a 1.5% decrease in FD rate in Blacks. We used Kitagawa's method to separate the effect of changes in maternal age distribution (MAD) and maternal age specific (MA-S) FD rates in producing the overall changes in FD rate among the three racial groups. Reductions in FD rate in Whites and Others were mainly due to decreases in MA-S FD rates and not due to changes in MAD. In Blacks, FD rate decreased from 1983-84 to 1985-86 and increased thereafter; these changes were also mainly due to changes in MA-S FD rates.

Table 1
Full size table

We conclude that: 1) the effect of maternal age on the risk of FD varies among different races in the United States; 2) changes in FD rate between 1983-1990 in all three racial groups were mainly due to changes in MA-S FD rates and had very little to do with changes in MAD.