Gradients in low birthweight by maternal education: A comparative perspective.

Background: Longstanding research has shown strong inequalities in low birthweight by household income. However, most such research has focused on Anglophone countries, while evidence emerging from other developed countries suggest a stronger role of education rather than incomes in creating inequalities at birth. This paper compares gradients in low birthweight by maternal education, as well as explores underlying mechanisms contributing to these gradients, in France, the United States, and the United Kingdom. Methods: Analyses are based on harmonized data from large, nationally-representative samples from France, UK and US. We use regression models and decomposition methods to explore the relative role of several possible mechanisms in producing birthweight inequalities. Results: Inequalities in low birth weight across maternal education groups were relatively similar in the United States, the United Kingdom and France. However, the individual-level mechanisms producing such inequalities varied substantially across the three countries, with income being most important in the US, pregnancy smoking being most evident in France, and the UK occupying an intermediate position. Differences in the mechanisms producing birth health inequalities mirror differences in the policy environment in the three countries. Conclusion: While inequalities in health appear from the earliest moments in many countries, our results suggest research on birth health inequalities, and therefore policies, is not easily generalizable across national contexts, and call for more scholarship in uncovering the "whys" of health inequalities in a variety of contexts.

Differences in birth weight between immigrants' and natives' children in Europe and Australia: a LifeCycle comparative observational cohort study.

OBJECTIVE: Research on adults has identified an immigrant health advantage, known as the 'immigrant health paradox', by which migrants exhibit better health outcomes than natives. Is this health advantage transferred from parents to children in the form of higher birth weight relative to children of natives? SETTING: Western Europe and Australia. PARTICIPANTS: We use data from nine birth cohorts participating in the LifeCycle Project, including five studies with large samples of immigrants' children: Etude Longitudinale Française depuis l'Enfance-France (N=12 494), the Raine Study-Australia (N=2283), Born in Bradford-UK (N=4132), Amsterdam Born Children and their Development study-Netherlands (N=4030) and the Generation R study-Netherlands (N=4877). We include male and female babies born to immigrant and native parents. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome is birth weight measured in grams. Different specifications were tested: birth weight as a continuous variable including all births (DV1), the same variable but excluding babies born with over 4500 g (DV2), low birth weight as a 0-1 binary variable (1=birth weight below 2500 g) (DV3). Results using these three measures were similar, only results using DV1 are presented. Parental migration status is measured in four categories: both parents natives, both born abroad, only mother born abroad and only father born abroad. RESULTS: Two patterns in children's birth weight by parental migration status emerged: higher birth weight among children of immigrants in France (+12 g, p<0.10) and Australia (+40 g, p<0.10) and lower birth weight among children of immigrants in the UK (-82 g, p<0.05) and the Netherlands (-80 g and -73 g, p<0.001) compared with natives' children. Smoking during pregnancy emerged as a mechanism explaining some of the birth weight gaps between children of immigrants and natives. CONCLUSION: The immigrant health advantage is not universally transferred to children in the form of higher birth weight in all host countries. Further research should investigate whether this cross-national variation is due to differences in immigrant communities, social and healthcare contexts across host countries.

Parental migrant status and health inequalities at birth: The role of immigrant educational selectivity.

Immigrants tend to exhibit better health than natives despite immigrants' more disadvantaged socioeconomic status. This paradox has often been attributed to immigrants' pre-migration selectivity. However, most empirical studies investigating the role of selectivity have focused on adult health; less attention has been paid to children's birth outcomes outside the U.S. context. Using data from the Etude Longitudinale Française depuis l'Enfance (ELFE), a nationally representative sample of over 18000 births in France in 2011, we investigate the role of immigrant parents' educational selectivity in shaping four birth outcomes: birthweight, low birthweight, prematurity, and being born small for gestational age. Results from linear and logistic regressions confirm a health advantage for children of immigrants compared to natives despite lower parental socioeconomic status, mainly among children of Middle Eastern and North African parents. Immigrant parents' positive pre-migration educational selectivity explains most of this health advantage, predominantly among children with two immigrant parents. Further, mediation analyses indicate that the effect of educational selectivity is partially mediated by parental health behaviors, particularly smoking during pregnancy. Furthermore, analyses suggest that selectivity improves birth outcomes only for children of recent arrivals, with less than five years of residence in France. The beneficial effect of selectivity declines with length of residence, suggesting that a process of "unhealthy assimilation," coupled with the cumulative exposure to health risks and disadvantaged living conditions, may lead to the erosion of the protective effect of immigrant selectivity.

The perinatal health of immigrant women in France: a nationally representative study.

OBJECTIVES: Despite the healthy migrant effect, immigrants and descendants of immigrants face health challenges and socio-economic difficulties. The objective of this study is to examine the perinatal health of women of migrant origin. METHODS: The nationwide French ELFE (Etude Longitudinale Française Depuis l'Enfance) birth cohort study recruited approximately 18,000 women. We studied pre-pregnancy BMI, gestational diabetes mellitus (GDM), as well as tobacco, and alcohol consumption during pregnancy according to migrant status and region of origin. RESULTS: Women from North Africa and Turkey had a higher risk of pre-pregnancy overweight and GDM, while women from Eastern Europe and Asia had a lower risk of pre-pregnancy overweight and obesity, but a higher risk of GDM compared to non-immigrants. Women from Sub-Saharan Africa had a higher risk of being overweight or obese pre-pregnancy. Compared to non-immigrants, immigrants-but not descendants of immigrants-had lower levels of tobacco smoking, while descendants of immigrants were less likely to drink alcohol during pregnancy. CONCLUSIONS: Pregnant women of migrant origin have particular health needs and should benefit from a medical follow-up which addresses those needs.