Background: Maternal education has been shown repeatedly to be inversely associated with preterm birth. Both preterm birth and educational level of families are correlated across generations, but it is not clear if educational level of grandparents affects the risk of preterm delivery of their grandchildren, and, if so, if the association with grandmother's education is independent of mother's education.
Methods: We used New Jersey birth certificates to create a transgenerational dataset to examine the effect of grandmother's education on risk of PTB in White, Black and Hispanic grandchildren. We matched birth certificates of girls born in 1979-1983 to mothers listed on NJ birth certificates for the years 1999-2011. Thus, grandmothers were the women delivering in 1979-1983, and mothers were those born to the grandmothers who in turn delivered grandchildren in 1999-2011. We performed descriptive tabulations and multivariate logistic regression to develop risk estimates.
Results: Overall, maternal education was associated inversely with PTB in each of the demographic groups. There was a substantial inter-generational increase in education between grandmothers and mothers in each group, which was most striking in Hispanics After adjusting for maternal age and education, grandmother's education continued to be associated with preterm birth of her grandchildren.
Conclusions: Grandmother's education was an additional, independent predictor of PTB in her grandchildren. This result supports the idea that mother's childhood and preconception socioeconomic environment, including the educational level of her childhood household affect her reproductive health.
Keywords: Birth certificate; Education; Grandmother; Intergenerational; Preterm birth; Race/ethnicity; Socioeconomic status.