Outcomes
The primary outcome was a composite of perinatal morbidity, with any of
the following: neonatal death, 5-minute Apgar score of <4,
respiratory distress syndrome (RDS), bronchopulmonary dysplasia (BPD),
sepsis, periventricular leukomalacia (PVL), intraventricular hemorrhage
(IVH) and necrotizing enterocolitis (NE). 5-minute Apgar score of
< 7 was registered as well.
Like other authors[23], we did not use pH at birth
as a primary outcome, as we found a significant interaction with
5-minute Apgar score of <4.
Secondary outcome included neurodevelopmental impairment (NDI) at 2
years of corrected age. Thus, we performed a standardized neurological
examination on children at a corrected age of 2 years. For this purpose,
we used the revised Brunet-Lézine scale to identify NDI. This scale
includes four domains of psychomotor development: language, sociability,
as well as gross and fine motor function. Infants were classified as
having NDI if they had a global developmental quotient (DQ) on the
revised Brunet–Lézine scale of < 85, or level 3 cerebral
palsy (CP), and severe NDI was defined with a DQ of < 60.