In Reply We appreciate the opportunity to provide the following response to the letter by Amitai in JAMA Pediatrics. Among the 64 322 mothers in the cohort for hyperkinetic disorder diagnosis and attention-deficit/hyperactivity disorder (ADHD) medication end points, 36 187 women reported having used acetaminophen during pregnancy and 28 135 did not. The proportions of several important indications for acetaminophen use (for acetaminophen users vs nonusers, respectively) include maternal fever (33% vs 23%), muscle and joint disease (13% vs 8%), infections and inflammation (13% vs 9%), and maternal psychiatric illness (17% vs 13%). Similar distributions were observed in the subcohort, for which we had information on ADHD-like behavior patterns using strength and difficulty questionnaires (n = 40 916). The numbers and percentages can be calculated from the Table presented in the article by Liew et al.1