Contribution of overweight and obesity to adverse pregnancy outcomes among immigrant and non-immigrant women in Berlin, Germany

Abstract

Background: Maternal excessive weight and smoking are associated with an increased risk of pregnancy complications and adverse pregnancy outcomes. In Germany, immigrant women have a higher prevalence of pre-pregnancy overweight/obesity compared with autochthonous women. We compared the contribution of pre-pregnancy overweight/obesity to adverse pregnancy outcomes among immigrant and autochthonous women in Berlin/Germany. Methods: Data from 2586 immigrant women (from Turkey, Lebanon, other countries of origin) and 2676 autochthonous women delivering in three maternity hospitals of Berlin within 12 months (2011/2012) was used. Cox regression models were applied to estimate the association between overweight/obesity and smoking with the outcomes large-for-gestational-age (LGA), small-for-gestational-age (SGA), preterm birth (PTB) and extreme preterm-birth (E-PTB). Population attributive fractions (PAF) were calculated to quantify the proportion of the outcomes attributable to overweight/obesity and smoking, respectively. Results: Prevalence of overweight and obesity was 33.4% among autochthonous and 53.6% among Turkish women. Prevalence risk ratios of excessive weight were highest for LGA infants among immigrant and autochthonous women. The PAFs were -11.8% (SGA), +16.3% (LGA), +3.6% (PTB) and +16.5% (E-PTB) for the total study population. Conclusions: Overweight/obesity is strongly associated with an increased risk of delivering an LGA infant among both immigrant and autochthonous women. Compared with autochthonous women, the contribution of excessive weight to LGA is even higher among immigrant women, in whom PAFs of overweight/obesity even exceed those of smoking for some outcomes.