Isolated mental developmental delay in very low birth weight infants: association with prolonged doxapram therapy for apnea.

Abstract

We investigated factors associated with isolated mental delay in infants weighing < 1250 g at birth. With a case-control design, matching variables for 40 cases included gestation, birth weight, sex, grade of intraventricular hemorrhage, and socioeconomic status. Case subjects had a mental developmental index < 70, and controls had a mental developmental index > or = 85, according to the Bayley Scales of Infant Development II at 18 months' corrected age. There were no differences between the case and control subjects for neonatal complications and antenatal or postnatal steroid use. There was a marked difference in the cumulative dosage and duration of doxapram therapy used for apnea of prematurity (total dose 2233 +/- 1927 mg vs 615 +/- 767 mg, P < .001; duration 45.2 +/- 32.5 days vs 19.4 +/- 23.4 days, P < .001 for case subjects and control subjects, respectively). Multivariate analysis did not identify additive predictive variables. Isolated mental delay in infants weighing < 1250 g at birth was associated with the total dosage and duration of doxapram therapy for severe apnea. Although this may be a marker for cerebral dysfunction manifesting as apnea of prematurity, possible adverse effects of doxapram or its preservative, benzyl alcohol, on the developing brain deserve further study.