Résumé : Background One of the mechanisms explaining perinatal health inequalities could be inadequate antenatal care among some immigrant groups. Few European studies compared antenatal care use between different groups of immigrants taking into account individual characteristics. This research investigates the associations of three birth regions with the use of antenatal care, by also considering socioeconomic and migration-related determinants. Methods We included 879 mothers born in Belgium, North Africa, and Sub-Saharan Africa, and interviewed them in four Brussels hospitals after they gave birth, using an adapted version of the Migrant-Friendly Maternity Care Questionnaire. We additionally collected clinical data from hospital records. We carried out descriptive analyses and ran univariate and multivariable logistic regression models to estimate the associations of socioeconomic and migration characteristics with a) late start of antenatal care and b) less than minimum recommended number of consultations. Results The vast majority of women in this study had adequate care in terms of timing (93.9%), frequency of consultations (82.2%), and self-reported access (95.9%). Region of birth was an independent risk factor for late initiation of care, but not for infrequent consultations. Women born in Sub-Saharan Africa were more prone to accessing care late (OR 3.3, 95%CI 1.5- 7.7), but were not more at risk of infrequent consultations. Women born in North Africa, had similar adequacy of care compared to the Belgium-born population. The three groups also differed in terms of socioeconomic profiles and socioeconomic predictors of antenatal care use. Housing type, professional activity, and health insurance status were important predictors of both outcomes. Conclusions This study showed that the region of birth was partly associated with adequacy of care, in terms of initiation, but not number of consultations. Further dimensions of adequacy of care (content, quality) should be studied in the future. Socioeconomic factors are also key determinants of antenatal care use. Copyright: