Obstetric-specific compared to general early warning system for predicting severe postpartum maternal morbidity

Severe maternal morbidity is a major global health concern, and early identification of at-risk postpartum women is essential to improving outcomes. We aimed to compare the predictive values of the Modified Early Obstetric Warning System (MEOWS) versus the non-obstetric general Early Warning System (EWS) for predicting severe maternal morbidity in postpartum women. We retrospectively reviewed hospital documentation of 723 postpartum women admitted to the obstetric high dependency unit between October 2020 and March 2021. Severe maternal morbidity was defined using the American College of Obstetricians and Gynecologists' criteria. We assessed the sensitivity, specificity, positive and negative predictive values, as well as positive and negative likelihood ratios, of the MEOWS and the EWS for predicting severe postpartum maternal morbidity. Twenty-four (3.3%) women included in the study met the criteria for severe maternal morbidity. Hypertensive complications and obstetric haemorrhage were the most prevalent causes of maternal morbidity. The sensitivity of the MEOWS was 92%, specificity 62%, positive predictive value 8%, and negative predictive value 100%. The positive likelihood ratio was 2.4, while the negative likelihood ratio was 0.1. In comparison, the EWS had a sensitivity of 63%, specificity of 66%, positive predictive value of 6%, and negative predictive value of 98%. The positive likelihood ratio for the EWS was 1.8, and the negative likelihood ratio was 0.6. The obstetric-specific early warning system proved to be superior for the early prediction of severe postpartum maternal morbidity compared to the general non-obstetric warning system.