Maternal known drug allergy and long-term neurological hospitalizations of the offspring

Problem: Drug allergies are increasingly common. Immunological factors, implicated in many neurological diseases, also influence an individual's susceptibility. We sought to ascertain a possible association between maternal drug allergy and long-term neurological-related hospitalizations in the offspring. Method of study: This is a population-based cohort analysis, comparing the long-term risk of neurological-related hospitalization, involving a predefined set of ICD9 codes as recorded in hospital records, of children born to mothers with and without drug allergies. Deliveries occurred between the years 1991 and 2014 in a tertiary medical center. Twin pregnancies, fetal malformations, and cases of perinatal mortality were excluded. A Kaplan-Meier survival curve was constructed to compare cumulative neurological hospitalizations. A Cox proportional hazards model was used to control for time to event. Results: The study included 242 342 patients, 9714 with known drug allergy (4%). Offspring born to mothers with drug allergies had significantly more neurological hospitalizations compared to controls (4.2% vs 3.1%; P ≤.001; Kaplan-Meier log-rank test P ≤.001), specifically for psychiatric disorders including eating disorders (0.3% vs 0.2%;P =.002), attention-deficit/hyperactivity disorder (0.124% vs 0.056%; P =.008), emotional disorders (0.8% vs 0.5%; P ≤.001), and movement disorders (2.3% vs 1.8%; P =.002). While controlling for birth year, gestational age, maternal age, maternal diabetes, hypertensive disorders, and cesarean delivery, using a Cox proportional hazards model, maternal drug allergy was found to be an independent risk factor for neurological hospitalization of the offspring (adjusted HR 1.3, 95% CI 1.19-1.45 P <.001). Conclusion: Being born to a mother with known drug allergy is an independent risk factor for long-term neurological hospitalization of the offspring.