Effects of phenobarbital and multiple-dose corticosteroids on developmental outcome at age 7 years

Abstract

Objective To determine the effects of phenobarbital and repeated antenatal steroid use on the primary outcome (intelligence and achievement) and secondary outcomes (behavior and head circumference) at age 7 years. Methods This study was a secondary analysis of a double-blind clinical trial (phenobarbital–vitamin K versus placebo). Intelligence (Wechsler Intelligence Scale for Children, third edition), achievement (Wide Range Achievement Test, third edition), and behavioral (Achenbach Teacher’s Report Form and the Child Behavioral Check List) testing and head circumference measurement were performed on 7-year-old children whose mothers participated in a trial to determine if antenatal phenobarbital and vitamin K prevented severe intracranial hemorrhage. Antenatal steroid therapy in these women was repeated weekly. Results Two hundred ninety-nine of 372 newborns (80%) whose mothers participated in the trial were followed up at age 7 years. Comparing mean (± standard deviation [SD]) Wechsler Intelligence Scale for Children scores in the placebo versus treatment groups, there were no differences ( P > .4) in Full Scale IQ (100.3 ± 14.2 versus 100.6 ± 14.2), Performance IQ (100.3 ± 14.6 versus 101.5 ± 15.6), and Verbal IQ (100.2 ± 14.9 versus 99.6 ± 13.7). Comparing mean (± SD) Wide Range Achievement Test standardized scores in the placebo versus treatment groups, there were no differences ( P > .4) in Reading (97.3 ± 13.9 versus 98.0 ± 14.9), Spelling (95.8 ± 12.7 versus 95.3 ± 13.3), Mathematics (95.9 ± 13.8 versus 94.5 ± 14.5), or head circumference measurements (20.3 ± 0.6 cm versus 20.4 ± 0.6, P > .2). Similarly, there were no differences in the mean Achenbach Teacher’s Report Form and Child Behavioral Check List scores between the placebo and treatment groups. Conclusion Antenatal phenobarbital and repetitive antenatal corticosteroid therapy was not associated with adverse effects on intelligence, achievement, behavior, or head circumference at age 7 years.