Background: This analysis focuses on determining differences in the risk of stillbirth in Spain by comparing native and foreign mothers with regard to bio-demographic factors.

Methods: The study is based on micro-data, one record per delivery for 2,869,329 births occurring from 2007 to 2012.

Results: For a total of 2,287,819 single deliveries the average stillbirth rate for Spanish mothers (S) was 2.51 per 1000; for non-Spanish mothers (NS) it was 3.99 per 1000. Two multivariate Poisson regression models were applied to obtain adjusted stillbirth risk ratios (RR), one for S and another for NS mothers. For both groups the following variables were included in the model: Caesarean, mother’s age, birth weight, duration of gestation, and maternal education. Parity, however, was incorporated only for Spanish mothers, while for the non-Spanish the relationship status and the father’s nationality were included. The increase in RR is similar for certain variables, such as in cases where no Caesarean was performed (S: 3.356; NS: 3.439); while for other variables differences are observed with regard to maternal origin, for example weight at birth <1500g in relation to ≥ 2500g (S: 4.154; NS: 21.367).

Conclusions: Immigration, together with differential reproductive maternal characteristics, had an influence on RR. Maternal education, as an indicator of socioeconomic conditions, is one of the most important socio-cultural variables in this respect. Certain reproductive and socio-cultural maternal variables affected RR differently in Spanish and foreign women, suggesting the benefit of implementing policies to achieve a decrease in the risk of stillbirths in the NS group.