To undertake a systematic review of diabetes in pregnancy (DIP), determining prevalence and impact on maternal and child health outcomes for Indigenous and Aboriginal women. Method: Electronic searches of MEDLINE, Embase, CINAHL, ERIC, DARE, CDSR, PsycINFO, Austhealth and HealthInfoNet were undertaken. Changes in diagnostic criteria for DIP and variability in methodology meant a qualitative synthesis of the data was undertaken. Results: From the 142 potential studies, 42 peer reviewed journal articles met the inclusion criteria. GDM prevalence in 65% of studies was greater for Indigenous and Aboriginal women than the comparison groups; Pacific Islander 8.1%, Canadian Aboriginal 11.5%, American Indian 7.9%, Australian Aboriginal 8.4% compared with 2-5% worldwide. Of studies reporting high birth weight (>4000. g) and DIP, 75% had a higher than expected prevalence, 86% had higher macrosomia prevalence and 63% had higher stillbirth rates. Studies with Alaskan, Australian Aboriginal and Pacific Islander women had GDM prevalence both greater and less than comparison groups. Conclusion: Correcting the health disparity for Indigenous and Aboriginal women with DIP is a health priority. DIP prevalence is not the same for all Indigenous and Aboriginal women. Inconsistent study design without robust data is interfering with accurate prevalence of DIP. New international consensus guidelines provide opportunities for high quality studies of DIP for Indigenous and Aboriginal women.