BackgroundPregnancy-related Pelvic Girdle Pain (PPGP) is a very common complaint. Although many women recover after a birth, about a third continue to have symptoms three months postpartum and 8.5% of women still have persistent symptoms two years afterwards. Knowledge of prognostic factors may help understand the course of PPGP and inform management. ObjectivesTo determine the prognostic factors for PPGP by systematically reviewing the literature. DesignSystematic review. MethodsWe searched PubMed, Embase, CINAHL, PsycINFO, MIDIRS, and ClinicalTrial.gov (15 April 2017) with no filters. Only studies reported in English were included. Two review authors independently selected studies. Any factors that might affect the course of PPGP up to one year postpartum were of interest. We excluded interventions and diagnostic studies. We conducted double independent data extraction, risk of bias and quality of evidence (GRADE) assessment. FindingsWe identified 4374 citations of which three studies were included in our analysis. Previous low back pain, pain in three to four pelvic locations, and being overweight/obese made recovery 12 weeks postpartum less likely. Six months postpartum, Pelvic Girdle Syndrome (PGS) was more likely to persist in women who used crutches or had severe pain in three pelvic locations during pregnancy, had other pain conditions, a younger age of menarche, previous low back pain or a high co-morbidity index, were obese, or experienced emotional distress during pregnancy. For women who used crutches during pregnancy, an instrumental birth or caesarean section was associated with persistent PGS. However, the quality of evidence (GRADE) was low to very low for all factors, hence, findings are uncertain. Key conclusionsThe limited number of studies and lack of replication prevents us from drawing definitive conclusions. Implications for practicePotentially modifiable factors during pregnancy seem to impact the prognosis of PPGP postpartum.