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