Maternal early warning system (MEWS) model for predicting and reducing severe maternal outcomes in Ethiopia

BACKGROUND: Maternal mortality in Ethiopia remains high, while most of these deaths are preventable. Early detection of deterioration and prompt response are essential to reduce these preventable deaths. The Maternal Early Warning System (MEWS) is a reliable clinical tool for this purpose. However, its effectiveness is underexplored and its bedside use is inconsistent. This study evaluated the MEWS model for predicting and reducing severe maternal outcomes. METHOD: A parallel, quasi-experimental study design was conducted among 1138 obstetric inpatients at four public hospitals of North Shewa Zone, Ethiopia. The recruitment period was from 05/05/2025-31/8/2025. The intervention group (n = 569) was monitored using the MEWS chart, which included vital signs, oxygen saturation, urine output, consciousness, and pain, and for the postpartum women; vaginal bleeding, uterine contraction, and perineal tear, were categorized as Green, Yellow, or Red. The control group (n = 569) received the standard clinical monitoring. A multivariate generalized estimating equation (GEE) model with Poisson regression was used to compare the outcomes and estimate adjusted risk ratios (aRR) with 95% confidence intervals. RESULT: The mean duration from admission to the first trigger was shorter by 4.7 hours (5.61 vs. 10.27 hours), trigger to physician evaluation by 22.6 minutes (49.3 vs. 71.9 minutes), and trigger to clinical intervention by 11.3 minutes (14.6 vs. 25.9 minutes) among women in the intervention group. Women also underwent fewer ultrasound scans (1.32 vs. 2.30) and had a shorter hospital stay by about 0.5 days (4.83 vs. 5.29 days). Women monitored with the MEWS chart had a 20% lower risk of severe maternal outcomes (aRR = 0.85, 95% CI: 0.73-0.99). Additionally, MEWS-monitored women were 9% more likely to be triggered for timely clinical response (aRR = 1.15, 95% CI: 1.03-1.28). CONCLUSION: Implementation of the MEWS was associated with earlier detection of maternal deterioration, shorter clinical response, fewer ultrasound investigations, shorter hospital stays, and lower severe maternal outcomes. Further studies with larger number of clusters are needed to evaluate the effectiveness of MEWS across different risk groups and settings. TRIAL REGISTRATION: Pan African Clinical Trial Registry (PACTR), PACTR202506739780428, https://pactr.samrc.ac.za.