Guidance

Down바카라 사이트™s syndrome, Edwards바카라 사이트™ syndrome and Patau바카라 사이트™s syndrome screening pathway

Updated 30 January 2025

Applies to England

This flowchart (text description and illustration below) describes the screening pathway for Down바카라 사이트™s syndrome, Edwards바카라 사이트™ syndrome and Patau바카라 사이트™s syndrome including non-invasive prenatal testing (NIPT).

1. Offer information and screening for T21, T18 and T13

Offer the pregnant woman screening for Down바카라 사이트™s syndrome (trisomy 21), Edwards바카라 사이트™ syndrome (trisomy 18) and Patau바카라 사이트™s syndrome (trisomy 13) and information about the screening test(s).

Before screening is carried out, the baby바카라 사이트™s crown rump length (CRL) is measured at the .

2. Does the woman accept screening?

Yes: The woman accepts screening for:

  • Down바카라 사이트™s syndrome, Edwards바카라 사이트™ syndrome and Patau바카라 사이트™s syndrome
  • Edwards바카라 사이트™ syndrome and Patau바카라 사이트™s syndrome
  • Downs바카라 사이트™ syndrome only

Go to question 3.

No: Offer 20-week screening scan. End of pathway.

3. Is the baby바카라 사이트™s CRL less than 45.0mm?

Yes: Recall the woman for a repeat scan when CRL measures 45.0mm or more. Then go to question 4.

No: Go to question 4.

4. Is the baby바카라 사이트™s CRL between 45.0mm and 84.0mm?

Yes: Carry out combined screening test for chosen conditions. Go to question 7.

No: Go to question 5.

Please note: if it is not possible to measure the baby바카라 사이트™s nuchal translucency (NT) despite 2 attempts (바카라 사이트˜twice on the couch바카라 사이트™), further attempts do not need to be offered. The woman should be offered quadruple screening.

5. Is the baby바카라 사이트™s head circumference (HC) between 101.0mm and 172.0mm

Yes: Offer T21 quadruple screening (Down바카라 사이트™s syndrome only). Go to question 6.

No: Offer 20-week screening scan. End of pathway.

6. Does the woman accept quadruple screening?

Yes: Carry out quadruple test. Go to question 7.

No: Offer 20-week screening scan. End of pathway.

7. Is the result lower chance?

Yes: Offer 20-week screening scan. End of pathway.

No: Refer for discussion of further choices. Go to question 8.

8. Does the woman want further tests?

Yes: Go to question 9.

No: Offer 20-week screening scan. End of pathway.

9. Which test does the woman want?

NIPT: Carry out NIPT. Go to question 10.

CVS or amniocentesis: Carry out CVS or amniocentesis test. Go to question 12.

10. What is the result of NIPT?

Lower chance result: Offer 20-week screening scan. End of pathway.

Higher chance result: Discuss options. Go to question 11.

11. Does the woman want further tests?

Yes: Carry out CVS or amniocentesis test. Go to question 12.

No: Offer 20-week screening scan and follow-up support. End of pathway.

12. Does baby have Down바카라 사이트™s syndrome, Edwards바카라 사이트™ syndrome or Patau바카라 사이트™s syndrome?

Yes: Discuss options with the woman. Go to question 13.

No: Offer 20-week screening scan. End of pathway.

13. What is the woman바카라 사이트™s choice?

Continue pregnancy: Offer 20-week screening scan and follow-up support. End of pathway.

Terminate pregnancy: Offer follow-up support.