Growth in infants with bronchopulmonary dysplasia, endocrine and pulmonary aspects : clinical and follow-up studies

Abstract

In the last decades important advances in neonatal intensive care have been made leading to an increased survival of especially very preterm infants. Major changes in survival rate have been attributed to the use of antenatal steroids and surfactant in the prevention and treatment of respiratory distress. In the United States survival rates of very low birth weight infants have increased between 1991 and 1996. The overall survival in VLBW infants increased slightly from 79.8% to 83% but major increases in survival have been reported in the lower weight groups of 501 to 750 g and 751 to 1000 g, respectively. Birth weight specific survival rates of infants born in 1991 and 1995/1996 have been published. Survival to discharge from the neonatal intensive care unit (NICU) increased from 42% and 81% for infants with a birth weight of 501-700 g and 751-1000 g in 1991, to 52% and 82% in 1996, respectively. Associated with the decline in mortality there was an increase in major morbidity over the 6-year interval partly due to an increase in chronic lung disease (CLD) defined as oxygen need at 36 weeks postmenstrual age. CLD increased from 19% to 23 % between 1991 and 1996 for the entire cohort of VLBW survivors. The largest increase in CLD from 41% to 56% occurred in infants born with a weight between 501-750 g. Survival rates vary across countries as consequence of differences in obstetric and neonatal management leading to differences in major morbidity. Therefore the data from the United States cannot be applied directly to the Netherlands, although a similar trend is observed.