Endocrine Abstracts

Background: Foetus is protected from high quantities of steroids by placental enzyme 11BHSD2. It converts steroids to inactive form (dexamethasone and betamethasone are exceptions). Exposure to high steroids for long time could saturate the enzyme. Maternal steroid use carries a theoretical risk for neonatal adrenal insufficiency (AI). The evidence remains controversial and most NICUs don’t check for AI in those infants. Two units in south Yorkshire recommending synacthen test (SST) based on certain criteria. One of the units using antenatal dose thresholds of 7.5 mg/day prednisolone equivalent for ≥28 days while the other, 5 mg/day prednisolone equivalent for same duration as indication.

Aim: To test the relationship between antenatal steroid use and neonatal AI based on dose and duration set in the local guidelines.

Method: Retrospective cohort study in two centres. Term babies born to mothers on steroid who met criteria and had SST were included. cohort identified from laboratory data and results included cortisol levels at 0 then 30- and 60-minutes post-test. A retrospective notes review for dose and duration of steroid exposure, symptoms, and the outcome after test. Analysis used Spearman correlation coefficient between dose and duration of steroid exposure to test results respectively.

Result: Fifty-nine (59) patients were identified. Average dose of steroid used during pregnancy 19.7 mg prednisolone equivalent (none of the patients were exposed to dexamethasone or betamethasone). Steroids used for various autoimmune conditions in pregnancy. Average time of exposure of 173 days. Forty-eight (48) had full data for analysis. Five patients had abnormal SST, but none had clinical symptoms. There was no statistically significant correlation between dose and basal cortisol level (P=0.51) or peak cortisol response (P=0.44). Also, there was no statistically significant correlation between duration of exposure and basal cortisol level (P=0.42) or peak cortisol response(P=0.44)

Conclusion: We recommend to revise the need for the guidelines based on current dose and duration of exposure. As the study did not include preterm babies, this cannot be generalised to include. We would still recommend low threshold for testing if clinical symptoms or in cases of prolonged exposure to dexamethasone or betamethasone.