Lorch SA, D'Agostino JA, Zimmerman R, Bernbaum J. "Benign" extra-axial fluid in survivors of neonatal intensive care. Arch Pediatr Adoles Med. 2004;158(2):178-182.

The presence of benign extra-axial fluid (BEAF) in the brains of infants has long been regarded a situation that does not affect the infant. This retrospective study followed infants who had head circumferences greater than the 95th percentile after discharge from a neonatal intensive care unit. The object of the research was to determine whether these infants were different from their normal peers 3 years later.

Data were gathered on all infants born from January 1998 through December 2001 in one major medical center. Identification of infants through chart reviews found 77 infants who met these criteria. They constituted 3.8% of the infants born during that time period. The infants were divided into 2 groups: the control group of 43 infants, and the research group (BEAF group) of 26 participants. When the groups were compared, it was found that there were more males than females in the entire sample, and that infants in the BEAF group were more likely to have been diagnosed with bronchopulmonary dysplasia, had received ECMO or high-frequency ventilation, and were more likely to have experienced an intraventricular hemorrhage.

The infants were followed over the next 3 years measuring their growth and developmental status. Developmental delays were identified using the Bayley Scales of Infant Development II, the Mental Development Index, and the Physical Development Index. Data showed that the infants in the BEAF group were more likely to be developmentally delayed and had a higher proportion of diagnoses of cerebral palsy than the control infants. In addition, it was interesting to note that BEAF infants who had cerebral palsy had histories of ECMO utilization.

The authors concluded that the benign fluid in the brain was not that at all; but an indicator that infants would show some developmental delays as they grew. While the study did not investigate the sources of the BEAF nor the reasons for the delays, the researchers did note that infants with BEAF should be followed carefully so that if they show signs of developmental delay that they receive early intervention.