Population-based study shows improved postnatal growth in preterm very-low-birthweight infants between 1995 and 2010

AimTo assess whether the postnatal growth of preterm very-low-birthweight (VLBW) infants, as determined by measures of postnatal growth failure (PNGF), improved during the period 1995-2010 and to evaluate postnatal growth by gestational age (GA) and intrauterine growth groups. MethodsThe study was based on the Israel national VLBW infant database and comprised 13531 VLBW infants of 24-32weeks' GA, discharged at a postmenstrual age of 40weeks. Z-scores were determined for weight at birth and discharge. Severe and mild PNGF was defined as a decrease >2 and 1-2 z-scores, respectively. Three time periods were considered: 1995-2000, 2001-2005 and 2006-2010. Multinomial logistic regression was used to assess the independent effect of time period on PNGF. ResultsSevere PNGF decreased from 11.7% in 1995-2000 to 7.2% in 2001-2005 and 5.2% in 2006-2010. Infants born in 2006-2010 had sixfold lower odds for severe PNGF than babies born in 1995-2000 (adjusted odds ratio 0.17, 95% confidence interval 0.14-0.21) and <twofold lower odds for mild PNGF (adjusted odds ratio 0.42, 95% confidence interval 0.39-0.48). ConclusionWe demonstrated a marked decline in PNGF among preterm VLBW infants from 1995-2000 to 2006-2010. This decline was even present in extremely premature infants.