Lack of change in birthweights of infants by generational status among Indian, Pakistani, Bangladeshi, Black Caribbean, and Black African mothers in a British cohort study.

AIM: To test the hypothesis that an intergenerational increase would occur in birthweights of babies born to UK-born compared with overseas-born (migrant) minority women.
METHOD: Live singleton births to mothers present at the 1991 Census in a national longitudinal study were classified by mother's country of birth and ethnic origin as reported in the census. During 1983-2000, 52,554 White, 1788 Indian, 1538 Pakistani, 995 Bangladeshi, 300 Black Caribbean, and 299 Black African live singleton births were identified. Mean birthweights were adjusted for maternal age, socio-economic circumstances, gender, year of birth, and birth order.
RESULTS: Adjusted mean birthweights were: 3400 g (95% CI: 3395, 3405) for infants of UK-born White mothers; 3033 g (95% CI: 2980, 3087) of UK-born Indian mothers and 3066 g (95% CI: 3034, 3097) of migrant Indian mothers; 3110 g (95% CI: 3049, 3172) of UK-born Pakistani mothers and 3123 g (95% CI: 3087, 3159) of migrant Pakistani mothers; 3026 g (95% CI: 2922, 3130) of UK-born Bangladeshi mothers and 3110 g (95% CI: 3076, 3145) of migrant Bangladeshi mothers; 3268 g (95% CI: 3177, 3359) of UK-born Black Caribbean mothers and 3238 g (95% CI: 3089, 3388) of migrant Black Caribbean mothers; and 3167 g (95% CI: 3004, 3330) of UK-born Black African mothers and 3302 g (95% CI: 3208, 3395) of migrant Black African mothers. The proportions of low birthweight infants (<2500 g), generally greater among migrant mothers than White UK-born mothers, were similar by generational status within the ethnic groups.
CONCLUSION: There are no significant differences in mean birthweights of infants by generational status among mothers from these main ethnic minority groups in the UK.