Endocrine Abstracts

JOINT245

Objective: To determine an appropriate cut-off of capillary Thyroid stimulating hormone (TSH) for congenital hypothyroidism.

Study design: Cross-sectional.

Participants: 174,000 neonates born in different hospitals of Delhi, India, from November 2014 to October 2016.

Main outcome measures: Correlation between initial and repeat capillary TSH level and subsequent venous free thyroxine (fT4) level.

Results: 102 newborns with initial/repeat capillary TSH level of ≥20 mIU/l (n = 174) were confirmed to have congenital hypothyroidism at mean (SD) age of 5 (4) days. A good correlation between capillary TSH level and confirmatory venous fT4 level and postnatal age of sampling was obtained (r -0.6,-0.4). The area under the ROC curve (AUC) was 0.81 (95%CI 0.75 to 0.88), indicating referral capillary TSH level of 20 mIU/l to be a good predictor of subsequent high venous TSH level.

Conclusion: A cut off of ≥20 mIU/l for capillary TSH screening beyond 24 hours of life is optimal in the Indian setting for deciding further recall and workup, keeping a balance between sensitivity and recall rate.