RESULTS
Of 22,678 singleton births between 1st October 2016
and 1st September 2019, 2,576 pregnancies were
excluded: 674 (2.97 %) for suspected congenital abnormalities and 1,902
(8.38 %) because of birth before 37+0 weeks (Fig 1).
Of 20,102 eligible pregnancies, (Fig 1) 330 women (1.6%) received
antenatal corticosteroids: 143 (47.6%) before 34+0weeks; 187 (56.6%) at or after 34+0 weeks, of which
106 (56.7%) were within 7 days of planned caesarean delivery; 19,772
(98.4%) women received no antenatal corticosteroids.
The characteristics of the study population according to groups are
shown in Table 1. Severe hypoglycaemia occurred in 227 (1.13%)
neonates, with a median glucose value of 1.4 mmol/l (IQR: 0.50 mmol/l).
Factors associated with severe hypoglycaemia (Table 2) on univariate
analysis were higher mean BMI, nulliparity, hypertension, pre-existing
and gestational diabetes, earlier gestation at birth, ACS exposure and
birthweight below the 10th centile.
The association between ACS exposure and severe hypoglycaemia in term
neonates is shown in Table 3 for all groups. After adjustment for
covariates, ACS exposure was associated a higher incidence of severe
hypoglycaemia in all exposed groups; whereas the respiratory outcomes
(ventilation or CPAP) were not significantly different. The adjusted
odds ratios for severe neonatal hypoglycaemia were highest when ACS were
administered in later gestation and nearest to delivery.
In pregnancies affected by pre-existing or gestational diabetes, the
risk of severe hypoglycaemia was significantly increased in neonates
exposed to ACS at or after 34 weeks (Table 4). No conclusion can be
drawn for the 13 neonates of diabetic pregnancies exposed to ACS before
34 weeks as none were severely hypoglycaemic.
There was a significant positive correlation between the
corticosteroid-to-birth interval and neonatal glucose in the first 24
hours of life (r = 0.592, p < 0.001) (Fig 2). Lower glucose
values were recorded in neonates exposed to ACS closer to birth.