The obstetrics comorbidity index as a predictive tool for risk-appropriate maternal care

Abstract

Background: The aim of this study was to assess the correlation between obstetric co-morbidity index (OBCMI) and severe maternal morbidity (SMM) in antepartum obstetrics transfers. By utilizing a population of transfers to a level IV maternal care facility, we hope to demonstrate validity for the use of OBCMI in the triage of transfer to provide risk-appropriate maternal care. Methods: Antepartum obstetrics transfers to a single level IV maternal care facility from 1/1/2016 to 12/31/2020 that resulted in delivery during the same encounter were included in this retrospective study. The components of the OBCMI score were retrospectively collected by manual chart review of transfer and admission notes in the electronic medical record (EMR). SMM was determined via ICD-10 and CPT code extraction from time of transfer through six weeks postpartum and confirmed by the same reviewer. Mode of delivery, length of stay, ICU admission, readmission and reoperation were obtained via institutional databases and manual EMR review. Results: Among 561 transfers meeting the inclusion criteria, the median OBCMI was significantly higher for transfers with a maternal-only indication (n = 232) compared to fetal-only(n = 282) (median [IQR], 6 [4–8], 5 [4–6], and 1 [0–2] for maternal-only, maternal–fetal combined (n = 47), and fetal-only; p < 0.001). The prevalence of SMM was 16.8% (39/232), 27.7% (13/47), 2.1% (6/282), p < 0.0001 for those transferred for maternal, fetal and maternal, and fetal only indications respectively. The median (IQR) OBCMI score was 5 (4–8) and 3 (1–5) for those with versus without SMM. A cut-off OBCMI score of ≥ 4 was identified with 81% sensitivity (95% CI 68.6–90.1%) in predicting SMM (P =