SGA– small for gestational age; FiO2– fraction of inspired oxygen; CPAP- nasal continuous positive airway pressure; NIPPV- non-invasive intermittent positive pressure ventilation; MV – conventional invasive mechanical ventilation; HFV - high-frequency ventilation; RRaj - adjusted relative risks (using gestational age and antenatal corticosteroids as covariates) and its 95% confidence interval.
a Excluded 1 patient where it was not possible to obtain data on maternal hypertension.
bExcluded 4 patients where it was not possible to obtain data on maternal smoking.
cExcluded 25 patients where it was not possible to calculate the value due to the use of a simple nasal oxygen catheter.