OTC pain-reliever allergy labels linked to maternal and fetal risks

Published online May 5, 2026

Non-narcotic pain relievers, including nonsteroidal anti-inflammatory drugs (NSAIDs; e.g. aspirin, ibuprofen, naproxen, etc.) and acetaminophen, play important roles during and after pregnancy. For example, low-dose aspirin is recommended for many pregnant patients at increased risk of preeclampsia. In addition, non-narcotic pain relievers are the first-line treatment for postpartum pain. In single-institution studies, allergy labels for these medications have been associated with increased postpartum opioid use and other adverse outcomes in the general population. This study aimed to examine whether maternal non-narcotic pain reliever allergy labels were associated with adverse outcomes for pregnant parents and infants at the population level.

In a study published in The Journal of Allergy and Clinical Immunology: In Practice, Su et al. analyzed a population-based database containing all births in California from 2016 to 2021. The analysis included 2,244,210 singleton live births with linked maternal and infant records. Of these, 10,460 births were to birthing parents with a non-narcotic pain reliever allergy label during pregnancy, identified using International Classification of Diseases, 10th edition (ICD-10) coding. The researchers compared maternal and infant outcomes between patients with and without these labels using Poisson log-linear regression, accounting for maternal demographic and clinical characteristics that could affect the results. The outcomes evaluated included preeclampsia and eclampsia, cesarean delivery, preterm birth, infant size at birth, neonatal intensive care unit admission, major structural birth defects, infant hospital length of stay, five-minute APGAR score, and neonatal opioid withdrawal syndrome. 

The large sample size, population-based data, and linked maternal and infant outcomes are major strengths of the study. Because the study used a retrospective observational design and an administrative cohort, the researchers could not evaluate the type or accuracy of the reported allergy, the medications patients received during pregnancy and delivery, or the economic implications. Nevertheless, this was the first study to demonstrate associations between maternal non-narcotic pain reliever allergy labels and maternal and infant outcomes.

Birthing people with non-narcotic pain reliever allergy labels were significantly more likely to be older, to reside in more rural areas, and to have a higher pre-pregnancy BMI, public insurance, and various comorbidities including atopic and autoimmune conditions. After adjusting for these potential confounders, maternal non-narcotic pain reliever allergy labels were significantly associated with increased rates of preeclampsia and eclampsia, cesarean delivery, preterm birth, neonatal intensive care unit admission, neonatal opioid withdrawal syndrome, and prolonged infant hospital stays, as well as a decreased rate of large-for-gestational-age infants. However, the allergy labels were not associated with small-for-gestational-age infants, major structural birth defects, or a five-minute APGAR score below 7. This study showed that maternal non-narcotic pain reliever allergy labels were associated with various adverse outcomes and supported the need for proactive allergy evaluation for all patients of childbearing age with these labels, as such evaluation could potentially improve perinatal outcomes. Further studies are needed to evaluate these relationships, the potential underlying mechanisms, and whether removing inaccurate allergy labels improves outcomes.

The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.

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Corresponding Author
Christina Chambers, PhD, MPH
Department of Pediatrics and Herbert Wertheim School of Public Health and Human Longevity Science
University of California San Diego

First Author
Chang Su, MD
Division of Pulmonary, Critical Care, Allergy and Sleep Medicine
University of California San Francisco Medical Center