Influence of antenatal corticosteroids and sex on the mortality and morbidity of extremelyprematurely born infants

Abstract

<b>Background:</b> There have been many advances which have positively impacted survival and morbidity of prematurely born infants including administration of antenatal corticosteroids (ANS). Nevertheless, there remains a difference in neonatal outcomes of male and female infants. <b>Objective:</b> To report, at a whole population level, whether the effect of antenatal corticosteroid exposure differed according to sex on neonatal morbidity and mortality. <b>Methods:</b> Analysis of a whole population dataset of infants born less than 28 weeks of gestation, between 1st Jan 2014 and 31st Dec 2018, admitted to a neonatal network in England. <b>Results:</b> 11,714 infants (54% male) were included with a median gestational age of 26+1 (IQR 24+6 – 27+1) weeks. ANS exposure prior to delivery was reported in 89%, equally in both sexes. Both ANS exposure and female sex resulted in more favourable outcomes in mortality, IVH grade three or greater and days of mechanical ventilation. The difference in mortality between sexes was not evident when not exposed to ANS (29.9% females vs 34.3% males, p=0.192). The adjusted risk of dying before discharge when not exposed to ANS was greater in females (odds ratio (OR) 1.812, 95% CI 1.346 – 2.438) than males (OR 1.355, 95% CI 1.0338 – 1.768). Females demonstrated a greater magnitude of beneficial response to ANS exposure with regard to a reduced risk of mortality. <b>Conclusion:</b> In this whole population analysis, ANS exposure was demonstrated to have a greater beneficial effect in females born extremely premature with regard to the outcome of death before discharge.