Neonatal hypoglycemia associated with the antenatal corticosteroids may be secondary to fetal adrenal suppression

• Antenatal corticosteroid
• adrenal suppression
• betamethasone
• fetus
• maternal hyperglycemia
• neonatal hypoglycemia

We read with great interest the article by Pettit et al. [1] that reported the association of antenatal betamethasone with neonatal hypoglycemia and hyperbilirubinemia. They proposed that antenatal corticosteroid administration may cause maternal hyperglycemia, and then maternal hyperglycemia leads to fetal pancreatic beta cell hyperplasia/hyperinsulinemia and subsequent neonatal hypoglycemia [1]. The advocated possible mechanism of corticosteroid-induced hyperglycemia in mothers is directly promotion of hepatic gluconeogenesis, thus hyperglycemia [2]. However, secondary fetal adrenal suppression may be another, possibly the main, mechanism for neonatal hypoglycemia due to antenatal corticosteroids which never mentioned by the authors in their article.

The corticosteroids administered during pregnancy or maternal Cushing’s syndrome can cause suppression of fetal adrenal glands [3–5]. During pregnancy taken high doses and/or long period prednisolone and methylprednisolone itself can saturate the placental enzymes and, as a result, large amount of corticosteroids can cross the placental barrier causing significant suppression of the fetal adrenal glands. So, the neonate develops hyponatremia, hypoglycemia and hypotension due to adrenal gland insufficiency which becomes prominent on postnatal day three [5]. Saulnier et al. [4] reported a case of neonatal acute adrenal insufficiency following the administration of low-doses corticosteroid during pregnancy. Similarly, a case of fetal adrenal suppression due to maternal methylprednisolone use presenting with early hypoglycemia and late hyponatremia in neonatal period and requiring three-month replacement therapy reported by Kurtoğlu et al. [5].

In conclusion, corticosteroid use in pregnancy may cause to fetal adrenal suppression and thus would be the main reason of presenting neonatal hypoglycemia. Therefore, primary or secondary hypoadrenalism should be taken in mind in the etiology of neonatal hypoglycemia.