92 - Severe Maternal Morbidity Among Births in U.S. Freestanding Children’s Hospital Delivery Units in the PHIS Database

Publication Number: 3088.92

Katey E. Mari, Childrens Hospital of Philadelphia, Philadelphia, PA, United States; Matthew Huber, Childrens Hospital of Philadelphia, Philadelphia, PA, United States; Kevin Dysart, Children's Hospital of Philadelphia, Philadelphia, PA, United States; Abigail Wilpers, Childrens Hospital of Philadelphia, Philadelphia, PA, United States; Heather Burris, Children's Hospital of Philadelphia, Philadelphia, PA, United States; Sara Handley, Childrens Hospital of Philadelphia, Philadelphia, PA, United States

Background: A growing number of U.S. freestanding children's hospitals (FCHs) house on-site delivery units to provide co-located obstetric and neonatal care for otherwise healthy women carrying fetuses with anomalies. While this model allows for timely, subspecialty care and intervention for neonates after birth, limited specialized obstetrics services are available in FCHs. Prenatal risk assessments determine eligibility to give birth at FCHs, and women with comorbidities (e.g., obesity and severe hypertension) are often deemed ineligible. As the number of births at FCHs increases, analyzing maternal outcomes is crucial to ensure optimal outcomes for the maternal-infant dyad.

Objective: To compare severe maternal morbidity (SMM) rates among women who gave birth at FCHs with those who gave birth in tertiary perinatal hospitals.

Design/Methods: This retrospective cohort study compared SMM rates at U.S. FCHs to rates at tertiary perinatal hospitals between 2014-2023 using electronic health record data from the Pediatric Health Information System (PHIS) database. FCH delivery units were defined as having >80% of births with fetal diagnoses (e.g., congenital diaphragmatic hernia, critical congenital heart disease), determined using diagnostic codes. Tertiary perinatal hospitals were defined as sites with ≥5 consecutive years of births with ≥2000 births/year and < 50% of births with fetal diagnoses. We calculated SMM rates with and without blood transfusions using ICD-9 and ICD-10 codes. SMM rates at PHIS hospitals were also compared to rates from two national estimates.

Results: Of the 50 PHIS hospitals, 4 were FCHs with delivery units and 5 were tertiary perinatal hospitals. Among 9,288 FCH births, 150 (1.61%) patients experienced SMM; significantly lower than tertiary perinatal hospitals (2.96%, P < 0.001) (Table 1). In both FCHs and tertiary perinatal hospitals, SMM rates were higher among individuals with the following characteristics: Black or Hispanic race/ethnicity; hypertension; and cesarean birth. In perinatal hospitals only, higher SMM rates were observed among older, publicly insured, parous, and obese individuals. FCH SMM rates were similar to national estimates of 1.80% and 1.92% (Table 2).

Conclusion(s): FCH SMM rates were significantly lower than tertiary perinatal hospital rates. These findings suggest that prenatal screening for maternal eligibility to give birth at children's hospitals effectively prevents some, but not all, SMM. Counseling parents about birth at FCHs should include balancing fetal and infant benefits with maternal risks where subspecialty obstetrics services may be limited.

Table 1. SMM rates by patient characteristics in the PHIS database among FCHs and tertiary perinatal hospitals (2014-2023).
Abbreviations: Severe maternal morbidity (SMM); Pediatric Health Information Systems (PHIS) database; freestanding children's hospitals (FCHs).
aChi-square test comparing SMM rates in freestanding children's hospitals to tertiary perinatal hospital; bChi-square test in freestanding children's hospitals of SMM rates by characteristic; cChi-square test in integrated perinatal hospital of SMM rates by characteristic; dHypertensive disorders of pregnancy was calculated exclusive of eclampsia, one of the 21 SMM indicators.

Table 2. Comparison of SMM rates with and without blood transfusions among PHIS FCHs, PHIS tertiary perinatal hospitals, and published results from two national estimates.
Abbreviations: Severe maternal morbidity (SMM); Pediatric Health Information Systems (PHIS) database; freestanding children's hospitals (FCHs).