Strengths and Limitations
Neonatal hypoglycaemia is variously defined, is variably tolerated by
neonates and universal screening is unusual 31-34. In
our cohort neonatal glucose measurement was not universal but neonatal
testing was performed according to BAPM Guidelines; maternal
corticosteroids administration was not a criterion 34.
For this reason we also chose the stricter outcome of ‘severe
hypoglycaemia’ and defined it to include a requirement for NNU
admission. This is reflected in our 1.3% overall incidence of severe
hypoglycaemia compared to the 4.1% incidence of ‘treated hypoglycaemia’
in a recent analysis 22. It is also possible that the
administration of ACS, particularly after 34 weeks, could reflect other
risk factors for hypoglycaemia. This is addressed in the multivariate
logistic regression, but residual confounding cannot be ruled out.
Indeed, this could account for our finding of no reduction in severe
respiratory morbidity. We were unable to adjust for confounders when
assessing the relationship between time and interval and neonatal
glucose level. A further limitation is the largely white ethnicity.
Despite the large numbers, the number of term births exposed to ACS was
relatively small.