Changes in neonatal morbidity, neonatalcare practices, and length of hospital stay of surviving infants born very preterm in the Netherlands in the 1980s and in the 2000s: a comparison analysis with identical characteristics definitions

Background This study evaluates changes in the neonatal morbidity, the neonatal care practices, and the length
of hospital stay of surviving very preterm (VP) infants born in the Netherlands in the 1980s and in the 2000s; a
period over which historical improvements were introduced into neonatal care. We, herein, also study whether
these changes in neonatal morbidity, neonatal care practices and length of hospital stay are associated with
sociodemographic, prenatal, and infant characteristics.
Methods Two community-based cohorts from 1983 (POPS) and 2002−03 (LOLLIPOP) have provided the perinatal
data for our study. The analysis enrolled 1,228 participants born VP (before the 32nd week of gestation) and surviving
to 2 years of age without any severe congenital malformation. A rigorous harmonisation protocol ensured a precise
comparison of the cohorts by using identical definitions of the perinatal characteristics.
Results In 2003, mothers were older when giving birth, had higher multiple birth rates, and significantly more
parents had received higher education. In 2003, less VP infants had severe intraventricular haemorrhage and sepsis
and relatively more received continuous positive airway pressure, mechanical ventilation and caffeine therapy than
in 1983. Antenatal corticosteroids and surfactant therapy were provided only in 2003. The length of the stay in the
neonatal intensive care unit and in hospital had decreased in 2003 by 22 and 11 days, respectively. Differences
persisted after adjustment for sociodemographic, prenatal, and infant characteristics.
Conclusions Neonatal morbidities of the surviving VP infants in this study have not increased, and exhibit
improvements for various characteristics in two cohorts born 20 years apart with comparable gestational age