Differences in Preterm and Low Birth Weight Deliveries Between Spanish and Immigrant Women: Influence of the Prenatal Care Received

Objectives To compare the risk of preterm and low birth weight among newborns from native and immigrant women and to assess the role of prenatal care in the association between the ethnic origin of the women and their reproductive outcomes. Methods Cross-sectional study of 21,708 women giving birth between 1997 and 2008 in a region of Spain. Multinomial logistic regression models were adjusted to evaluate associations between mother’s area of origin and adverse reproductive outcomes and to assess the role of prenatal care in the occurrence of adverse reproductive results. Results Our results indicate a worse prenatal control in immigrants than in natives. Very preterm birth (VPTB) and very low birth weight (VLBW) were greater among immigrants (odds ratio [OR], 1.78; 95% confidence interval [95% CI], 1.14−2.79 for VPTB and OR, 1.73; 95% CI, 0.89−3.33 for VLBW) but after adjustment for prenatal care the differences were substantially reduced (OR, 1.43; 95% CI 0.85−2.42 for VPTB and OR 1.15; 95% CI 0.53−2.52 for VLBW). Conclusions Given the positive impact of prenatal care on reproductive results, strategies to improve it among immigrant women should be implemented. The difference found in the direction of the association between area of origin and different categories of low birth weight and preterm suggest that very and moderate categories should be analyzed separately in immigrant studies.