Exploring weathering: effects of lifelong economic environment and maternal age on low birth weight, small for gestational age, and preterm birth in African-American and white women.

White women experience their lowest rate of low birth weight (LBW) in their late 20s; the nadir LBW for African-American women is under 20 years with rates rising monotonically thereafter, hypothesized as due to "weathering" or deteriorating health with cumulative disadvantage. Current residential environment affects birth outcomes for all women, but little is known about the impact of early life environment. The authors linked neighborhood income to a transgenerational birth file containing infant and maternal birth data, allowing assessment of economic effects over a woman's life course. African-American women who were born in poorer neighborhoods and were still poor as mothers showed significant weathering with regard to LBW and small for gestational age (SGA) but not preterm birth (PTB). However, African-American women in upper-income areas at both time points had a steady fall in LBW and SGA rate with age, similar to the pattern seen in white women. No group of white women, even those always living in poorer neighborhoods, exhibited weathering with regard to LBW, SGA, or PTB. In contrast, the degree of weathering among African-American women is related to duration of exposure to low-income areas and disappears for those with a life residence in non-poor neighborhoods.