Neonatal outcomes of preterm or very-low-birth-weight infants over a decade from Queen Mary Hospital, Hong Kong: comparison with the Vermont Oxford Network

Introduction: There is a paucity of local data on neonatal outcomes of preterm/very-low-birth-weight infants in Hong Kong. This study aimed to evaluate the survival rate on discharge and morbidity of preterm/very-low-birth-weight infants (≤29+6 weeks and/or birth weight <1500 g) over a decade at Queen Mary Hospital in Hong Kong, so as to provide centre-specific data for prenatal counselling and to benchmark these results against the Vermont Oxford Network.

Methods: Standardised perinatal/neonatal data were collected for infants with gestational age of 23+0 to 29+6 weeks and/or birth weight of <1500 g who were born at Queen Mary Hospital between 1 January 2005 and 31 December 2014. These data were compared with all neonatal centres in the Vermont Oxford Network in 2013. The Chi squared test was used to compare the categorical Queen Mary Hospital data with that of Vermont Oxford Network. A two-tailed P value of <0.05 was considered statistically significant.

Results: The overall survival rate on discharge from Queen Mary Hospital for 449 infants was significantly higher than that of the Vermont Oxford Network (87% versus 80%; P=0.0006). The morbidity-free survival at Queen Mary Hospital (40%) was comparable with the Vermont Oxford Network (44%). At Queen Mary Hospital, 86% of infants had respiratory distress syndrome, 40% bronchopulmonary dysplasia, 44% patent ductus arteriosus, 7% severe intraventricular haemorrhage, 5% necrotising enterocolitis, 10% severe retinopathy of prematurity, 10% late-onset sepsis, and 84% growth failure on discharge. Rates of respiratory distress syndrome, intraventricular haemorrhage, necrotising enterocolitis, and severe retinopathy of prematurity were similar in the two populations. At Queen Mary Hospital, significantly more infants had bronchopulmonary dysplasia (P=0.011), patent ductus arteriosus (P=0.015), and growth failure (P=0.0001) compared with the Vermont Oxford Network. In contrast, rate of late-onset sepsis was significantly lower at Queen Mary Hospital than the Vermont Oxford Network (P=0.0002).

Conclusions: Mortality rate and most of the morbidity rates of our centre compare favourably with international standards, but rates of bronchopulmonary dysplasia and growth failure are of concern. A regular benchmarking process is crucial to audit any change in clinical outcomes after implementation of a local quality improvement project.