(726) Impact of Penicillin Allergy Labels on Maternal and Neonatal Healthcare Utilization and Clinical Outcomes

Penicillin allergy labels (PALs) are frequently reported in pregnancy but >90% are unverified. Unverified PALs lead to avoidance of first-line antibiotics increasing the risk for adverse events. However, >95% of patients reporting PALs are penicillin tolerant when tested. We aimed to assess the impact of maternal PALs on maternal and neonatal healthcare utilization and clinical outcomes using a large population dataset.

Study Design:
Retrospective cohort study included 75,236 maternal-neonatal dyads at a major academic medical center with live births at 24 weeks or beyond from 2/1995-12/2024. Two groups were derived: Patients with PALs in the medical record and those without PALs documented in pregnancy. Clinical characteristics and outcomes were extracted. Using logistic regression, adjusted odds ratios (aOR) were calculated between cohorts and assessed for the following outcomes controlling for significant covariates as appropriate: maternal emergency (ER) visits during pregnancy or within 3 months postpartum, maternal hospital admissions excluding delivery during pregnancy or within 3 months postpartum, maternal ICU admission, maternal death, neonatal ER visits in the first 3 months of life, neonatal hospital readmission in the first 3 months of life, NICU admission and neonatal death. P</span> < .05 was considered significant for all analyses.

Results:
Maternal PALs significantly increased the odds of maternal ER admission (aOR 1.69), additional maternal hospital admission (aOR 1.66), maternal ICU admission (aOR 1.38) and maternal death (aOR 1.86) compared to those without PALs. For infants, maternal PALs significantly increased the odds of NICU admission (aOR 1.34) and neonatal death (aOR 1.38).

Conclusion:
Maternal PALs increased maternal and neonatal healthcare utilization and adverse outcomes with higher odds of maternal ER admission, additional maternal hospital admission, maternal ICU admission, maternal death, NICU admission, and neonatal death. However, PALs are modifiable as >95% are penicillin tolerant when tested, suggesting a need for greater uptake of testing.