Guidance

Down’s syndrome, Edwards’ syndrome and Patau’s syndrome screening: learning from incidents

Published 21 June 2021

Applies to England

Failsafe in screening programmes

When things don’t go as planned, failsafe processes help to identify these in real time so that action can be taken before harm occurs. Here’s an example.

Mrs. Russell books for maternity care and accepts screening for Down’s syndrome, Edwards’ syndrome and Patau’s syndrome at 12 weeks of pregnancy. Her blood sample (along with details of the ultrasound scan) is taken and dispatched to the screening laboratory.

Do you have processes to check that you have her results within 3 working days? Screening laboratories will report most results within 3 working days from sample receipt (FASP-S05).

Do you have processes to follow up with the screening laboratory if you don’t have a result within 3 working days? Or do you wait until her next appointment which might be around 16 weeks?

Mrs. Russell’s blood sample taken at 12 weeks was lost and never arrived in the laboratory. If you only checked her results before her appointment at 16 weeks you would have lost 4 weeks and delayed the screening pathway. Mrs. Russell can be offered a less sensitive test, the quadruple test for Down’s syndrome only at this stage.

We have evidence from screening safety incidents that some providers do not have processes in place for checking screening results in line with national standards. They therefore do not find out if a screening sample was inadequate, needs repeating or never arrived in the screening laboratory sometimes; until reporting on key performance indicators 3 months later.

For failsafe processes to be effective, they must be timely.

Learning scenarios

We provide the following real scenarios to demonstrate situations where the screening pathway was not delivered as specified. We hope that you will be able to use these scenarios to look at your local pathway and confirm you have failsafe processes or to address any gaps that may exist.

All parts of the screening test not completed

Example 1

A woman booked for maternity care at 11 weeks of pregnancy and chose to have combined screening. Nuchal translucency was measured but blood sample was not taken. This was not detected until the woman was 28 weeks pregnant and too late to offer any screening.

Example 2

A woman had booking appointment at 12 weeks of pregnancy and chose to have combined screening. The nuchal translucency could not be measured despite 2 attempts and the woman was offered the quadruple test which she accepted. The woman was informed that an appointment for the quadruple test would be sent to her by post but this did not happen. This was not detected until the maternity service was submitting key performance coverage data 3 months later.

Example 3

A woman booked early and chose to have combined screening. At the dating scan she was only 9 weeks gestational age, which is too early to measure the nuchal translucency. A request was made to rescan in 3 weeks, but her appointment was sent for 5 weeks later and when scanned was too late to have combined screening. She was offered the quadruple test instead.

Documentation errors

A woman had combined screening for Down’s syndrome, Edwards’ syndrome and Patau’s syndrome at 11 weeks. The result was a higher chance of having a baby with Down’s syndrome. The woman was invited for counselling and prenatal diagnostic testing which she accepted. Prior to the prenatal diagnostic testing the screening midwife discovered that the nuchal translucency measurement was incorrectly transcribed on the request form. On correcting this the result changed from higher chance to lower chance.

Samples not arriving in the screening laboratory

Fifteen Down’s syndrome, Edwards’ syndrome and Patau’s syndrome screening samples taken on a Friday were not dispatched to the screening laboratory. The samples were discovered in a tray in the antenatal clinic the following Monday. These samples will need repeating as the sample quality was compromised.