In 2017, 0.7% of women who delivered in NSW had type 1 or type 2 Diabetes Mellitus. Corticosteroids, in the form of either betamethasone or dexamethasone, have been routinely used to enhance fetal lung maturation and in women who are at risk of pre-term vaginal birth (less than 34 weeks’ gestation), and in some centres also, to women who have caesarean deliveries up to 39 weeks’ gestation. Administration of corticosteroids has been shown to reduce the rates of perinatal mortality, and also respiratory distress syndrome (RDS). With regards to women with pre-gestational diabetes, concerns have been expressed about the destabilising effect of corticosteroids on blood glucose level (BGL) control and the potential effect this may have on the mother and her baby. Women with pre-gestational diabetes receiving corticosteroids require admission to hospital for glycaemic management, causing anxiety for themselves and their families. Corticosteroid administration to women with poorly controlled diabetes may precipitate diabetic ketoacidosis (DKA) in the mother as well as acidosis in the fetus. Corticosteroid-induced maternal hyperglycaemia could also lead to subsequent hypoglycaemia in the neonate, and paradoxically in some studies an increased risk of RDS.
At the tertiary centre where the authors practice, we currently admit women 1 week prior to elective delivery in order to administer corticosteroids and stabilise BGLs.
We conducted a was a retrospective observational study at a tertiary centre in Sydney, in order to assess the risk of neonatal hypoglycaemia and RDS in women with pre-existing diabetes who were given Corticosteroids for fatal lung maturation.
A total of 410 cases were identified over the specified time period. The final data set consisted of 232 cases in 190 women. Antenatal corticosteroids were administered in 22.4% of the cases analysed. Comparison was made for the two main outcomes between women who were administered steroids and those who did not receive steroids prior to delivery. Paradoxically, significantly more of the women who were administered steroids gave birth to infants with respiratory distress syndrome (25.5%), compared to women who did not receive steroids prior to delivery (8.9%). Although the rate of hypoglycaemia in neonates of women who received steroids was also higher (61.5%), the comparison with women not receiving steroids (46.7%) did not achieve statistical significance.
Our results showed that the benefits of corticosteroid administration in women with pre-gestational diabetes is unclear.