The Washington State Intergenerational Study of Birth Outcomes: methodology and some comparisons of maternal birthweight and infant birthweight and gestation in four ethnic groups

A statewide database of vital records and hospital discharge summaries of o bstetric and neonatal admissions for Washington State in 1987-95 was linked to the birth certificates of mothers born in the state. A total of 46 000 births to mothers of four racial/ethnic groups were studied: Whites, Africa n-Americans, Native Americans and Hispanics. For all four groups inverse as sociations were found between maternal birthweight and infant low birthweig ht and preterm birth. The birthweight distribution of African-American moth ers was displaced markedly downwards compared with the Whites; this differe nce in maternal birthweight is offered as a partial explanation of the grea ter prevalence of suboptimal pregnancy outcomes in the former. In contrast, the maternal birthweight distributions of Whites, Native Americans and His panics are similar; differences in pregnancy outcomes are probably more rel ated to maternal preconceptional and postnatal factors in these groups as w ell as differences in pregnancy-related factors. Mothers' birthweight may h ave clinical value in identifying high-risk pregnancies.