Systemic postnatal corticosteroids and magnetic resonance imaging measurements of corpus callosum and cerebellum of extremely preterm infants.

AIM: To compare the size of the corpus callosum (CC) and cerebellum on magnetic resonance imaging (MRI) brain scans conducted at term equivalent age (TEA) in extremely preterm infants who received systemic postnatal corticosteroids (PCS) to extremely preterm infants who did not receive systemic PCS and determine the dose-dependent effects on these outcomes.

METHODS: Single-centre retrospective cohort study including extremely preterm infants (born < 26 weeks' gestation) who had MRI brain scans at TEA. CC and cerebellar measurements were evaluated by two radiologists who were blinded to steroid use and their independent measurements were averaged. Comparative analyses were conducted between exposed (to systemic PCS) and non-exposed groups.

RESULTS: Eighty-three extremely preterm infants with mean (SD) 24.9 (0.91) weeks' gestational age, 721.8 (156) g birthweight were included; 38 with systemic PCS exposure and 45 without exposure. After adjustment for birthweight and other significant neonatal morbidities, there was no significant difference noted in corpus callosum length (CCL) between unexposed and exposed groups (adjusted mean (SE) 39.5 (0.57) mm vs. 38.5 (0.62) mm; P = 0.29). Similarly, the ratios of CCL/fronto-occipital diameter (FOD) and CCL/biparietal diameter (BPD) were not significantly different between the groups (CCL/FOD (0.40 (0.01) vs. 0.41 (0.01); P = 0.70) and CCL/BPD (0.51 (0.01) vs. 0.52 (0.01); P = 0.62)). Finally, no significant differences in cerebellar measurements, such as vermian height (adjusted mean (SE) 24.0 (0.46) mm vs. 23.5 (0.51 mm); P = 0.47) and transcerebellar diameter (adjusted mean (SE) 49.3 (0.74) mm vs. 4.78 (0.82) mm; P = 0.22) were found. No dose-dependent effects of systemic PCS on CC and cerebellar measurements were identified.

CONCLUSIONS: Systemic PCS use in extremely preterm infants was not associated with a change in the CC and cerebellar measurements on MRI brain scan at TEA.