Prevalence of gestational diabetes mellitus in Sub-Saharan Africa: a systematic review and meta-analysis

Gestational diabetes mellitus (GDM) is a significant cause of adverse perinatal outcomes and major risk factor for type 2 diabetes in mother and child. Although global prevalence is estimated at 14%, the burden in sub-Saharan Africa remains unclear due to limited data and variable diagnostic protocols. This study aimed to generate a robust estimate of GDM prevalence in sub-Saharan Africa using methodologically comparable studies, and to assess subregional variation.

We systematically searched Embase, MEDLINE, CINAHL, Global Health, African Journals Online, and African Index Medicus from January 1990 to March 2025 for observational studies of pregnant women in sub-Saharan Africa screened for GDM at ≥24 weeks' gestation using an oral glucose tolerance test and internationally recognized criteria. Studies using inconsistent, unclear or incomplete diagnostic protocols or self-reported data were excluded. Quality was assessed using the Joanna Briggs Institute checklist. Prevalence estimates were pooled using random-effects meta-analysis of Freeman-Tukey-transformed proportions. Subgroup analyses were conducted by subregion, and mixed-effects meta-regression examined study-level moderators.

Fifty-nine studies met the inclusion criteria, of which 49 were selected for meta-analysis based on use of comparable diagnostic criteria. Studies represented 16 countries and involved 27,540 participants. The pooled GDM prevalence was 14.0% (95% CI, 11.6 to 16.5; prediction interval 1.9 to 34.3) with substantial heterogeneity (I²=97.1%). Prevalence varied across subregions: Southern Africa 10.2%, Eastern Africa 13.9%, Western Africa 15.1%, and Central Africa 18.0%. Meta-regression showed that small studies (<300 participants), studies using point-of-care testing, and studies conducted before 2016 reported higher prevalence. Subregional differences persisted after adjustment.

When comparable diagnostic protocols are applied, GDM prevalence in sub-Saharan Africa matches the global average, challenging perceptions of a lower regional burden. Subregional variability highlights the need for locally representative data. Standardized diagnostic criteria for epidemiological studies would improve comparability and inform targeted public health interventions.