Endocrine Abstracts

Background: Limited evidence exists regarding the effect of antenatal prednisolone (ANP) on neonatal adrenal function. Our regional neonatal unit screens these babies by measuring three random serum cortisol levels 8 h apart on day 3 of life. Adrenal function is considered adequate if two cortisol levels are >100 nmol/l. Those with inadequate random cortisol levels undergo a low-dose Synacthen test (LDST). Our survey of UK tertiary Paediatric Endocrinology centres revealed that only one other unit screens for adrenal suppression in these babies, using LDST.

Objectives: i) To identify the proportion of neonates born to mothers on ANP with adrenal suppression.

ii) To determine the relationship between ANP and neonatal cortisol.

Methods: Neonates who had screening cortisols performed between Jan 2008 and Feb 2013 were retrospectively reviewed. The relationship between ANP and neonatal cortisol was investigated using Spearman’s correlation.

Results: Thirty-nine neonates potentially affected by ANP were screened. Inadequate random cortisol levels were identified in 15% babies (6/39); all subsequently had a normal LDST. Two babies (5%) had three cortisol levels <100 nmol/l and were empirically commenced on hydrocortisone before LDST. All had normal adrenal function when re-tested with LDST at 3 months of age. The mean dose of ANP was 16.2±2.7 mg/day. The highest of the three random cortisol levels did not correlate with ANP dose (Spearman’s ρ 0.166; P=0.36).

Assessing specificity and sensitivity of our screening test was not possible.

Conclusion: In our small cohort we did not detect any newborn with adrenal suppression secondary to ANP. The day three cortisol levels did not correlate with the dose of ANP. Studies suggest that prednisolone has limited transfer across the placenta. Larger scale studies are required to determine the necessity of screening these neonates for adrenal suppression using serial random cortisol levels or LDST.