Laboratory guide to screening for CHT in the UK

Guidelines for laboratories screening newborns for congenital hypothyroidism (CHT) in the UK.



This handbook is for laboratories that provide an NHS newborn blood spot screening service for CHT in the UK. It provides information and guidelines to support screening laboratories, including:

  • the CHT screening protocol
  • details of the revised thyroid stimulating hormone (TSH) cut-off value introduced in April 2018
  • the CHT preterm repeat policy
  • laboratory quality assessment procedures
  • the process for communicating results
  • programme standards and data collection

Contact the screening helpdesk at with any queries about this guidance, making sure you include its full title.

Published 1 February 2014
Last updated 20 October 2020 + show all updates
  1. Updated the laboratory guide including the screening protocol: removed dated clinical referral guidelines and the requirement to complete ‘affected not detected forms’. Converted content from PDF to HTML to improve accessibility.

  2. Added addendum to guidance valid from 2 April 2018.

  3. First published.