Optimizing screening practice for gestational diabetes mellitus in primary healthcare facilities in Tanzania: research protocol

Background
Tanzania, like most low- and middle-income countries, is facing an increasing prevalence of obesity in the general population, including among women of reproductive age. Excess weight pre-pregnancy is a risk factor for the onset of gestational diabetes mellitus (GDM), which is associated with several poor pregnancy outcomes. Screening for GDM, as a primary preventive measure, is not systematically done in Tanzania. This study aims to explore current practices of screening for GDM during routine antenatal care (ANC), estimate the prevalence of GDM among ANC users and compare the performance of two commonly used GDM screening algorithms. We will then explore the best ways for implementing a functional screening practice for GDM at primary level hospitals using perspectives of health care workers, health managers, and pregnant women.

Methods
This will be an observational cross-sectional study design with sequential mixed-methods approach conducted in ANC clinics of two primary level hospitals: Kisarawe District Hospital in Coast region and Mbagala Rangi Tatu Hospital in Dar es Salaam region, Tanzania. Quantitative data will be collected to determine the current structural capacity and screening practices for GDM, the prevalence of GDM among ANC users, and the sensitivity and specificity of the two recommended screening algorithms. Qualitative data will be collected through key informant interviews with health managers and pregnant women and focus group discussions with healthcare workers to understand the rationale, challenges, possible solutions and benefits of the used screening algorithm. We will also explore the meaning of screening/diagnosis to pregnant women, and propose a functional GDM screening algorithm informed by users (i.e. pregnant women, health managers and care workers).

Discussion
ANC is an entry point for pregnant women to access preventive services including screening for GDM. When done appropriately, GDM screening would reduce undesired outcomes attributed to GDM also beyond the pregnancy period. Through this study we will understand the bottlenecks and propose evidence to inform feasible ways to overcome them and establish a functional and standardized GDM screening service.