(701) Evaluating Indicators for Severe Maternal Morbidity from Pregnancy Onset through 1-Year Postpartum

Severe maternal morbidity (SMM) is frequently evaluated exclusively during the delivery admission or immediate postpartum period. This may under-ascertain true pregnancy risk as a substantial portion of maternal complications may occur in the extended postpartum period, and complications during pregnancy have more significant implications for the maternal-fetal dyad. This study classifies an expanded SMM composite outcome by indication from week 0 of pregnancy through the extended postpartum period (1 year).

Study Design:

This is a descriptive, retrospective cohort study in a multihospital health system including all deliveries from 1/1/2017-12/31/2024 (N = 57,092). SMM was defined by the CDC diagnosis codes as well as expanded codes for hemorrhage and puerperal infection (classified by Vizient), all occurring within 12 months of delivery, and ICU admission or hospital readmission within 12 weeks of delivery. Data were extracted from the electronic health record and plotted by pregnancy time point.

Results:

Figure 1 demonstrates the distribution of SMM by indication starting from onset of pregnancy, and extending through “week 85.” The highest volume of SMM cases was the 33-week time point, which likely represents patients who required preterm delivery due to SMM or SMM as a sequela of a pregnancy complication necessitating preterm delivery. Major drivers of this peak in SMM at this time point were readmission, ICU admission, and hemorrhage. Table 1 demonstrates the distribution of SMM indicators at the 10 time points with the highest incidence of SMM, defined relative to delivery (“week 0” = week of delivery). The highest incidence of SMM was the week of delivery, followed by the week after and the week before, respectively. The remainder of the SMM burden occurred largely between weeks 2-8 postpartum.

Conclusion:

Trends in SMM indicators and volume over the expanded pregnancy course can inform focused prevention strategies and surveillance. Future institutional research and quality improvement efforts exploring targeted interventions can use this strategy for assessing SMM broadly as an outcome.