Apnoea in very low birthweight infants: outcome at 2 years.

Follow-up data to 2 years are reported for 164 of an initial cohort of 172 consecutively, surviving very low birth-weight infants. The 13 infants who suffered apnoeic episodes at home were not predicted at discharge from hospital. The mean (s.d.) general developmental quotient at 2 years for the total group was 97.3 (12.0), compared with 99.0 (10.2) for the 72 infants who had nil-mild apnoea in the newborn period and 96.0 (13.4) for the 92 infants with moderate-severe apnoea (P less than 0.1). All six infants with general quotients less than 76 had sustained moderate-severe apnoea (P less than 0.05). Multivariate analysis to assess the influence of confounding variables showed that the presence of chronic lung disease decreased the general quotient by 4.0 units, birthweight less than 1000 g 3.3 units, mechanical ventilation 2.2 units and moderate-severe apnoea only 0.1 unit. Moderate-severe apnoea occurred in six of eight babies with neurological handicap and all eight with sensory handicaps (P less than 0.01). Overall, of the 12 (7.3%) handicapped children, two had no apnoea and 10 moderate-severe apnoea (P = 0.07). Moderate or severe apnoea occurred in 58% of very low birthweight infants and was associated with the smallest and sickest infants who had the most handicaps at 2 years. However, when correction for birthweight less than 1000 g, mechanical ventilation and chronic lung disease is made, apnoea per se, as it was detected and managed between 1978-80, had no additional deleterious effect on average intellectual performance though it may have been an important causative factor in functional handicap.