Maternal birth weight and cesarean delivery in four race-ethnic groups

We hypothesized that maternal birth weight was associated with the risk of cesarean delivery for nulliparous women.

In a population-based cohort study, maternal birth data were linked to a Washington State database, including the birth certificates of 18,905 first-born singleton infants (1987-1995).

Among non-Hispanic white subjects, maternal birth weight of 2500 to 3999 g was associated with a 20.9% risk of cesarean delivery, which was the lowest risk, compared with 24.5% for a maternal birth weight <2500 g (P <.05) and 24.0% for a maternal birth weight > or =4000 g (P <.05). Similar patterns of risk were noted among Hispanic and Native American subjects, although the associations did not reach statistical significance. Risk of cesarean delivery was not associated with maternal birth weight among African American subjects. Among non-Hispanic white subjects, the risk of cesarean delivery was 3.23 times greater with a maternal birth weight <2500 g and an infant birth weight > or =4000 g compared with pregnancies with both maternal and infant birth weights between 2500 and 3999 g (P <. 001). Adjustment for socioeconomic factors did not alter these results.

Low and high maternal birth weights exert an intergenerational risk of cesarean delivery in nulliparous non-Hispanic white women.