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.