Maternal education modifies the age-related increase in the birth prevalence of Down syndrome

To test the hypothesis that the age-related increase in the birth prevalence of Down syndrome is less for women with higher levels of education due to their more frequent use of prenatal diagnosis.

We compared the effects of maternal age on the odds of Down syndrome at birth, and on amniocentesis use, in women with <12 years of education with those who had >or=12 years of education. We used a national data set and analyzed the effects of education separately for African Americans (N = 1643054), and non-Hispanic whites (N = 6676885) in the US birth cohorts of 1989-1991. Analyses included Mantel-Haenszel and logistic regression models with the likelihood ratio test to assess interactions between education and age effects.

For both African Americans and non-Hispanic whites, the age-related increase in the odds of Down syndrome was substantially less for women with higher levels of education (p < 0.001). For both ethnic groups, women with higher levels of education were more likely to use amniocentesis (p < 0.001).

Our results suggest that women with higher levels of education are more likely to use prenatal diagnosis. Moreover, this effect of education on prenatal diagnosis use, translates into a lower rate of age-related increase in the birth prevalence of Down syndrome.