Is high birthweight a blind spot in research on health inequalities? Evidence on adverse birth outcomes and immigrant status from a German panel study

Frederik Peters, Erasmus Medical Centre, Rotterdam
Nadja Milewski, University of Rostock

Our paper analyses birth outcomes of immigrant women in Germany compared to non-migrant mothers. In Germany, about one third of all newborns were born to immigrant mothers. Since immigrant status and socio-economic disadvantages are highly correlated, the health of immigrant children and their mothers has received increasing attention. When investigating perinatal outcomes, the effect of the immigrant status of the mother on the health of her child is not clear. We exploit a recently available panel dataset – the newborn sample of the German Socio-economic Panel (SOEP) – that contains both pre-, peri- and postnatal variables that allow analyzing determinants of adverse birth outcomes. The data is on about 1500 births occurred between 2001 and 2009. Our study investigates the risk of low and of high birthweight applying logistic-regression analyses. We use four indicators and find that immigrant status is less associated with higher prevalences of low birthweight (LBW) and newborns that are small for gestational age (SGA). By contrast, immigrant status is associated with higher prevalences of infant macrosomia (HBW) and increased prenatal growth (LGA). At the same time, higher LGA correlates with higher shares of pre-term births. Control variables of the mother – age, parity, height, BMI – cannot not explain the differences between migrants and non-migrants. The results suggest that birth outcomes of immigrant mothers are double-disadvantaged: The share of high birthweight outcomes is higher among immigrants than among non-migrants, and higher birthweight correlates with preterm birth. We argue that this health disadvantage is a blind spot in the literature on perinatal health of immigrants, as a large part of previous papers deals with pre-term birth in combination with a too low birthweight. Since high birthweight is a risk factor for developing overweight and obesity prevention efforts should be made already during pregnancy and in early childhood.