ObjectivesThere exists a body of research regarding ethnic differences in perinatal health whereas this is not the case concerning the role of migration status and acculturation in attenuating these differences. This study aims to investigate determinants of health during pregnancy up to one-year postpartum by migration status.MethodsThe study utilises data collected by the Born in Bradford cohort. The focus of analysis was migration status groupings, based on self-reported country of birth of participants and their parents and grandparents. Chi-Square, one-way ANOVA and correlation coefficients examined relationships between variables.ResultsMigrant women were less likely to smoke (native: 34.4%, 1st generation: 2.8%, 2nd generation: 8.6%) or to be obese (native: 25.5%, 1st generation: 17.4%, 2nd generation: 21.3%) compared to native women. Migrants were less physically active at 6 months (Mean (SD) minutes/week: native 265 (245), 1st generation 113 (162), 2nd generation 147 (182)) with larger increases in BMI over time compared to native women. Migrant women were more likely to be suffering psychological distress at baseline and 6 months postpartum and migrant families were more likely to live in areas of high socio-economic deprivation, despite higher levels of educational attainment.Conclusions for PracticeThis study ethnicity and migration identifies some important differences between ethnic groups with different migration histories, therefore indicating that healthcare professionals should consider eliciting full migration histories to improve care. The impact of these differences on perinatal outcomes is a priority for future research.