Maternal nativity status and birth outcomes in Asian immigrants.

BACKGROUND: The study examines the relationship between maternal nativity, maternal risks and birth outcomes in six Asian sub-populations.

METHODS: U.S.- versus foreign-born immigrants of Chinese (67,222), Japanese (18,275) and Filipino (87,1208), Vietnamese (45,229), Cambodian/Laotian (21,237), and Korean (23,430) singleton live births were assessed for maternal risks and birth outcomes.

RESULTS: U.S.-born Chinese and Japanese mothers had lower risk and increased preterm births but similar infant mortality, while U.S.-born Filipino mothers had higher risk and higher infant mortality. U.S.-born mothers of more recent Cambodian/Laotian and Vietnamese immigrants had higher risk and delivered more small and preterm births, while U.S.-born Korean mothers had higher risk but no differences in preterm and low birthweight delivery.

DISCUSSION: Asians in America are a distinctly heterogenous population in terms of the relationship between maternal risk factors and birth outcomes and the influence of maternal nativity on this relationship.