Second Trimester Down's Screening. Quadruple Test (Total HCG, AFP, UE3, INHIBIN A).

Immunology

Description

First trimester Down's screening is carried out using the combined test which is the Foetal Anomaly Screening Programme ( FASP ) recommended protocol [1]. The combined test measures PAPPA and free beta HCG ( FB HCG ) in the maternal serum between 11+2 and 14+1 weeks gestation. The FASP model of best practice recommends that the quadruple test ( FB HCG/Total HCG, AFP, Inhibin A and UE3 ) is performed on women who are booked in for Down's screening after 14+1 weeks. A Down's risk factor is calculated by modifying the maternal age alone risk with the biochemistry results and the nuchal translucency measurement. It has been shown that the detection rate of foetuses with Down's syndrome is better when performed at 11 weeks.

Indications

Prenatal screening for Downs syndrome.

Sample Type

2mL Serum ( Gel 5mL Yellow tube ). Requests from outside Sheffield: Transport at ambient temperature via Royal Mail or Courier.

Reference Range

Risk factor cut off 1:150. Risk factor less than 1:150 is low risk.Cut off determined by FASP.

Turnaround Time

Within 3 days

Testing Frequency

DAILY

External Notes

Must include: weight; smoking status; ethnicity; number of foetuses; head circumference or CRL measurement.

References

FASP UKNSC policy Recommendations 2007-2010: Model of Best Practice. 2008. [Ref 1].NICE Clinical Guideline 6. Antenatal Care. 2008. Wald NJ et al. First and second trimester antenatal screening for Down's syndrome: the results of the SURUSS. HTA. 2003. 7:11.NHS Fetal Anomaly Screening Programme Handbook 2018. Public Health England. Published August 2018.

Your contact for this test

Clare Del-Duca BSc (Hons) Biomedical Science, MSc Pathological Science

Laboratory Manager - Immunology and Protein Reference Unit

You are enquiring about

Second Trimester Down's Screening. Quadruple Test (Total HCG, AFP, UE3, INHIBIN A).