Maternal Non-Narcotic Analgesic Allergy Labels Linked to Adverse Perinatal Outcomes

Maternal non-narcotic analgesics allergy labels (NNAALs) are significantly associated with an increased risk for adverse maternal and fetal outcomes, including eclampsia and preterm birth, according to research presented at the 2026 American Academy of Allergy, Asthma & Immunology (AAAAI) Annual Meeting.^1,2

“There is a paucity of information regarding the effect of a non-narcotic analgesics allergy label on maternal and fetal outcomes,” said lead investigator Chang Su, MD, University of California, San Francisco. “Our study showed that having such a label can be associated with various adverse maternal and fetal outcomes. These findings are potentially practice-expanding because evaluating women of childbearing age who have a history of non-narcotics analgesics allergy could lead to delabeling for approximately 80% of patients and potentially improved perinatal outcomes.”

Non-narcotic analgesics are currently the recommended first-line treatment for postpartum pain, and aspirin is recommended for up to 85% of pregnant patients presenting with preeclampsia risk factors. Despite their clinical utility, a significant knowledge gap has existed regarding how an allergy label for these medications impacts pregnancy.

In a retrospective analysis of the Study of Outcomes in Mothers and Infants, investigators examined a population-based cohort of all births in California between 2016 and 2021. The study included 2,244,210 singleton livebirths, of which 10,460 were born to mothers with NNAALs. Using logistic regression adjusted for maternal characteristics, the study calculated relative risks (aRRs) for various outcomes.

The data revealed a significantly higher proportion of mothers with NNAALs were older than 34 years of age (RR, 1.13; 95% CI, 1.09-1.18).

Maternal NNAALs were significantly associated with several adverse perinatal outcomes:

• Eclampsia: aRR 1.5 (95% CI, 1.06-2.12).
• Preterm birth: aRR 1.21 (95% CI, 1.14-1.28).
• NICU admission: aRR 1.17 (95% CI, 1.10-1.25).
• Neonatal withdrawal syndrome: aRR 1.51 (95% CI, 1.24-1.84).
• Length of stay: Infants had a significantly longer mean hospital stay (P < .0001).
• Growth: A decreased rate of large for gestational age infants (aRR 0.92; 95% CI, 0.87-0.98).

Conversely, NNAALs were not associated with maternal preeclampsia, small for gestational age infants, major structural birth defects, or a 5-minute APGAR score of less than 7.

The investigators concluded proactive allergy evaluations and delabeling efforts for patients with NNAALs may be a critical step in improving perinatal health.

References:

1. Non-Narcotic Analgesics Allergy Labels. Aaaai.org. Published February 10, 2026. Accessed March 3, 2026. https://www.aaaai.org/about/news/news/2026/narcotic
2. Chang S, Baer R, Otani I, et al. The relationship between maternal non-narcotic analgesics allergy labels and maternal and fetal outcomes. Presented at: 2026 American Academy of Allergy, Asthma & Immunology (AAAAI) Annual Meeting; February 27 – March 2, 2026; Philadelphia, Pennsylvania