Pathology Handbook

Antenatal Sickle and Thalassaemia screening

Synonyms

FOQ, AN Thalassaemia screen, Sickle screen, Haemoglobin variant, Haemoglobinopathy Screen

Clinical Indications

Testing as part of national screening programme of all antenatal patients for the early detection of haemoglobin abnormalities including sickle cell and thalassaemia conditions.

Test Includes

FBC and HPLC (if indicated by the information provided on Family Origin Questionnaire (FOQ) and/ or from the FBC indices).  Additional test/ s may be performed if the HPLC results detect a possible abnormality these include:-Sickle solubility test, cellulose acetate electrophoresis and Kleihauer film examination.

Request Form 

Request via ICE plus FOQ

Availability

On request; daily routine working day.

Specific Criteria

Ethnic origin required; Test must be performed within 10 weeks of pregnancy and a FOQ sent with sample.

Patient Preparation

Genetic counselling must be considered. Patient consent required for completion of FOQ.

Turnaround Time

An Interim report will always be issued within 3 days where full confirmatory tests are not yet completed.

Specimen

EDTA

Volume

4.5 m

Container

Purple top (EDTA) tube

Vacutainer purple top

Causes for Rejection

Incorrect sample identification, clotted, inadequate, grossly haemolysed samples. Previously reported (x2) Haemoglobinopathy screen.

Reference Range

The national programme algorithm is used for reporting results and suggesting follow up testing, which may include partner testing / DNA analysis. Positive results are sent to the Antenatal Screening co-ordinator at Southend Hospital who will contact the patient directly to arrange further testing / counselling/ referral.

Hb variants requiring confirmation / DNA/ globin chain analysis will be sent to Reference Centre