Fetal anomaly screening laboratory handbook: Down’s, Edwards’ and Patau’s syndromes

This document sets out screening laboratory guidelines and recommendations for the 3 screened Trisomy conditions.



This publication explains laboratory standards and processes for antenatal chromosomal abnormality screening:

  • Down’s syndrome (Trisomy 21)
  • Edwards’ syndrome (Trisomy 18)
  • Patau’s syndrome(Trisomy 13)

The document includes:

  • an overview of the fetal anomaly screening programme (FASP)
  • explanation of screening tests and markers
  • screening options for singleton and twin pregnancies
  • risk measurement criteria
  • quality assurance recommendations and procedures
  • education and training resources
Published 1 January 2015
Last updated 17 September 2018 + show all updates
  1. New edition of laboratory handbook valid from August 2018.
  2. First published.