Objective: To obtain information about health outcomes in neonates in 9 subgroups of the Asian population in the United States.

Design: Cross-sectional comparison of outcomes for births to mothers of Cambodian, Chinese, Filipino, Indian, Japanese, Korean, Laotian, Thai, and Vietnamese origin and for births to non-Hispanic white mothers. Regression models were used to compare neonatal mortality across groups before and after controlling for various risk factors.

Setting: All California births between January 1,1991, and December 31, 2001.

Participants: More than 2.3 million newborn infants.

Main Exposure: Racial and ethnic groups.

Main Outcome Measure: Neonatal mortality (death within 28 days of birth).

Results: The unadjusted mortality rate for births to non-Hispanic white mothers was 2.0 per 1000. The unadjusted mortality rate for births to Chinese and Japanese mothers was significantly lower (Chinese: 1.2 per 1000, P.001; Japanese: 1.2 per 1000, P=.004), and for births to Korean mothers the rate was significantly higher (2.7 per 1000, P=.003). For infants of Chinese mothers, observed risk factors explain the differences observed in unadjusted data. For infants of Cambodian, Japanese, Korean, and Thai mothers, differences persist or widen after risk factors are considered. After risk adjustment, infants of Cambodian, Japanese, and Korean mothers have significantly lower neonatal mortality rates compared with infants born to non-Hispanic white mothers (adjusted odds ratios, 0.58 for infants of Cambodian mothers, 0.67 for infants of Japanese mothers, and 0.69 for infants of Korean mothers; all P.05); infants of Thai mothers have higher neonatal mortality rates (adjusted odds ratio, 1.89; P.05).

Conclusions: There are significant variations in neonatal mortality between subgroups of the Asian American population that are not entirely explained by differences in observable risk factors. Efforts to improve clinical care that treat Asian Americans as a homogeneous group may miss important opportunities for improving infant health in specific subgroups.

Using data from two surveys in three counties in which the prevalence of uxorilocal marriage differs greatly, this article analyzes the effects of marriage form, individual, family, and social factors on age at first marriage and spousal age difference. The results show that, under the Chinese patrilineal joint family system, compared with the dominant virilocal marriage form, uxorilocal marriage significantly lowers women's age at first marriage, increases men's age at first marriage, and consequently increases spousal age difference. Education, number of brothers, adoption status, marriage arrangement, and marriage circle also significantly affect age at first marriage for both genders. Age at first marriage and spousal age difference vary greatly among the three counties. These findings address the process and consequences of change in rural family and marriage customs during the current demographic and social transition and may help to promote later marriage and later childbearing under the present low fertility conditions in rural China.