Background
Current Australasian Diabetes in Pregnancy Society guidelines recommend that pregnancy oral glucose tolerance testing (POGTT) be routinely performed between 24 to 28 gestational weeks to detect and manage gestational diabetes (GDM). Furthermore, early testing should be considered in women with risk factors for GDM, such as the use of corticosteroids1. Despite this, we have observed a concerning practice whereby the latter is the very reason for a delay in routine POGTT, with early POGTT not even being considered. We herein present 2 such cases.
Case presentations
Case 1 – A 36 year old woman was prescribed 25mg of prednisolone at 25/40 for pemphigoid gestationis. She was advised repeatedly that her POGTT should be delayed until her glucocorticoids were weaned, even though plans for prednisolone cessation were documented. Upon review by our service, a POGTT was arranged which was normal: 3.0/7.1/3.8. However, a random blood glucose level (BGL) taken in clinic 8 hours post prednisolone was 10.3mmol/L. Subsequent monitoring revealed persistent hyperglycaemia requiring insulin. At 32/40, premature rupture of membranes necessitated emergency caesarean section. Associated neonatal complications included hypoglycaemia, respiratory distress syndrome and icterus.
Case 2 – A 37 year old woman with long standing ulcerative colitis was commenced on 40mg of prednisolone at 20/40 for a flare. POGTT was delayed due to steroid use, despite the additional GDM risk factor of pre-pregnancy obesity (BMI 38kg/m2). Nevertheless, BGL monitoring (instituted upon endocrine review at 33/40) was unremarkable, as was the remainder of her pregnancy and delivery.
Conclusion
Corticosteroid use should prompt screening for hyperglycaemia, particularly in pregnancy. Despite clear guidelines for POGTT in all pregnant women, especially those taking glucocorticoids, it seems to be purposefully omitted in this group. Increased awareness of the guideline is clearly needed. Furthermore, the role of BGL testing 8 hours post prednisolone dose, when blood glucose usually peaks, should be explored, as this may more accurately identify underlying hyperglycaemia within this patient group2.