A non-narcotic analgesics allergy label (NNAAL) is associated with several adverse perinatal outcomes, including greater rates of NICU admission, preterm birth, and more.
A non-narcotic analgesics allergy label (NNAAL) is associated with several adverse perinatal outcomes, indicating a need for additional maternal evaluation, according to new research presented at AAAAI 2026.
“There is a paucity of information regarding the effect of a non-narcotic analgesics allergy label on maternal and fetal outcomes,” said lead author Chang Su, MD. “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.”
In this study, researchers conducted a retrospective analysis using the Study of Outcomes in Mothers and Infants, a population-based cohort of all births in California between 2016 and 2021. Both maternal and fetal outcomes were examined by NNAAL status using logistic regression to calculate relative risks (aRRs) and 95% confidence intervals (CIs) adjusted for maternal characteristics.
Of the 2,244,210 singleton livebirths included in the study, 10,460 were born to mothers with NNAALs with a significantly higher proportion of mothers with NNAALs being more than 34 years old. Maternal NNAALs were significantly associated with increased rates of 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]), infants with neonatal withdrawal syndrome (aRR 1.51, 95% CI [1.24, 1.84]), longer infant hospital stay times (p < 0.0001) and a decreased rate of infants who were large for their gestational age (aRR 0.92, 95% CI [0.87, 0.98]). However, NNAALs were not associated with maternal preeclampsia, infants who were small for their gestational age, major structural birth defects or an APGAR score of less than seven.
By exploring the relationship between maternal NNAALs and maternal and fetal outcomes, this study highlights an important need for proactive allergy evaluations of patients with NNAALs and delabeling efforts that may improve perinatal outcomes.
