Why De-Labeling NNAALs Should Be Routine Obstetrics Care, With Chang Su, MD

With maternal non-narcotic analgesic allergy labels significantly associated with 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), and neonatal withdrawal syndrome (aRR, 1.51; 95% CI, 1.24–1.84) across a California birth cohort of 2,244,210 singleton livebirths, the case for integrating allergy de-labeling into routine obstetric care is compelling.

In the second part of HCPLive’s conversation at the American Academy of Allergy, Asthma & Immunology (AAAAI) 2026 Annual Meeting held in Philadelphia, Pennsylvania, from February 27 to March 2, with Chang Su, MD, allergist-immunologist at Yale New Haven Hospital, who conducted the research during her time at University of California San Francisco, she situated the NNAAL findings within a broader de-labeling effort already underway in obstetrics. Her group has had significant success with beta-lactam allergy de-labeling in collaboration with OB and primary care colleagues — driven in part by prior data showing that penicillin allergy labels, like NNAALs, divert patients away from first-line therapy, in that case for Group B streptococcal infection around the time of delivery. Approximately 90% of patients with a beta-lactam allergy label do not have a true allergy on formal evaluation, with emerging data suggesting the true negative rate may be even higher. A similar dynamic appears to apply to NNAALs: one prior study found that approximately 85% of patients carrying such a label can ultimately tolerate NSAIDs, suggesting a substantial proportion of the 10,460 NNAAL-carrying mothers in the SABLE cohort may have been unnecessarily restricted from first-line analgesics and aspirin-based preeclampsia prevention.

Critically, Su emphasized that de-labeling is not an all-or-nothing proposition. For patients who cannot be fully cleared — due to the nature of their prior reaction — a formal allergy evaluation can still produce a concrete, individualized action plan specifying dose thresholds and tolerable agents. In the context of preeclampsia prevention, for example, a patient who cannot tolerate the recommended 162 mg aspirin dose may still safely receive 81 mg, a clinically meaningful alternative that would otherwise go unprescribed without specialist input. Su described ongoing efforts to expand this model beyond beta-lactams to other drug classes — including NNAALs — and stressed that the referral pipeline from OB-GYN colleagues is central to making de-labeling scalable as a component of routine prenatal care.

“For example, for preeclampsia prevention, aspirin 162 milligrams is often recommended. But for certain patients, perhaps they can tolerate 81 milligrams based on the types of reaction that they had. And if we can prove that, then perhaps we can't get them the most recommended therapy, but we can get the second best of them,” Su said.

Su has no relevant disclosures to report.

References

1. Su C, Baer R, Otani I, Schatz M, Chambers C. The relationship between maternal non-narcotic analgesics allergy labels and maternal and fetal outcomes: results from a large, administrative cohort. Presented at: AAAAI 2026 Annual Meeting, February 27-March 2, Philadelphia, Pennsylvania. Abstract #L24

2. Non-Narcotic Analgesics Allergy Labels Linked to Adverse Maternal and Fetal Outcomes. News release. AAAAI. February 26, 2026. https://www.aaaai.org/about/news/news/2026/narcotic