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Down's syndrome screening laboratory

Published on 13 July 2022

Laboratory testing is an integral part of the Scottish Down’s Syndrome Screening Programme. The screening programme estimates the probability of a pregnant woman having a baby affected by Down’s syndrome or other rare conditions.

Based in the Western General, Edinburgh, the lab provides screening for women who are in their first trimester of pregnancy. For women in the second trimester, we commission screening services from the Royal Bolton Hospital, Manchester.

What is pregnancy screening for Down’s syndrome?

There are different ways of screening for Down’s syndrome. Women are offered a blood test combined with an ultrasound scan.

A sample of blood is usually taken between 11+2 and 20+0 weeks. The laboratory tests this blood to measure serum levels of certain substances. A computer programme then uses the results of the blood test (and ultrasound scan if a first trimester screen), along with mother’s age, weight, stage of pregnancy and any other relevant factors, to work out the chance of the baby having Down’s syndrome.

More information about Down's syndrome screening is available on the NHS Inform website.

Lead clinician

Dr Lorna Rashid, Principal Clinical Scientist, Lothian

Dr Carolyn Williams, Consultant Biochemist & Director of Antenatal Screening, Bolton


Pregnancy Screening Laboratory
Western General Hospital
Crewe Road

Dept of Lab Medicine
Royal Bolton Hospital
Minerva Road

NSD contact

Please note that NSD does not directly provide medical services and we won't be able to answer queries about your own care or appointments. If you would like to discuss any aspects of your care, please contact your primary healthcare provider. This might be your GP, Consultant, Nurse or other healthcare professional. They will be best placed to give you the right advice.