Magnitude of screening for gestational diabetes mellitus in an urban setting in Tanzania; a cross-sectional analytic study.

Background: Medical screening detects risk factors for disease or presence of disease in otherwise well persons in order to intervene early and reduce morbidity and mortality. During antenatal care (ANC) it is important to detect conditions that complicate pregnancy, like gestational diabetes mellitus (GDM). Despite international and local guidelines recommending screening for GDM during ANC, there is evidence to suggest that the practice was not being carried out adequately. A major challenge may be lack of consensus on uniform GDM screening and diagnostic guidelines internationally and locally. The primary objective was to determine the magnitude of screening for GDM among women receiving ANC at the Aga Khan Hospital, Dar es Salaam and Muhimbili National Hospital, Dar es Salaam. Secondary objectives were: to determine the methods used by health practitioners to screen for GDM, to determine the magnitude of undiagnosed gestational diabetes mellitus among women attending ANC and factors associated with screening for GDM among these women.

Methods: A cross-sectional analytical study was done. Data collection was done using pre-tested questionnaires and reviewing antenatal care records. The proportion of women attending ANC who were screened for GDM was determined. The 75 g Oral Glucose Tolerance Test (OGTT) was offered to women who had not been screened after education and consent.

Results: Only 107 out of 358 (29.9%) had been offered some form of GDM screening. Tests used for GDM screening were random blood sugar (56.8%), fasting blood sugar (32.8%), HbA1C (6%) and 75 g OGTT (3.4%). The uptake of the OGTT was 27%. Of these women the prevalence of GDM was 27.9%. Factors associated with screening for GDM were history of big baby, history of pregnancy induced hypertension and participant awareness of GDM (all p: < 0.05).

Conclusions: Screening for GDM among women attending ANC was lower than the World Health Organization target. Efforts should be directed towards promoting GDM screening, increasing awareness about GDM and developing more effective screening methods.