Combined First Trimester Screening (cFTS)
What is a Combined First Trimester Screening?
A Combined First Trimester Screening (cFTS) is a prenatal screening test that combines a blood test with an ultrasound to estimate the risk of certain chromosomal conditions.
What conditions does it screen for?
The cFTS looks for the likelihood of the following chromosomal abnormalities:
- Down syndrome (Trisomy 21)
- Edwards syndrome (Trisomy 18)
- Patau syndrome (Trisomy 13)
How does it work?
A combination of age, ultrasound and blood test results are used to give a risk for the above mentioned syndromes. If blood test results are available the risk is calculated and the patient counselled with the results.
The high risk cut off is 1:300 for Trisomy 21 and 1:150 for Trisomy 13 and 18. A “high risk” result does not mean your fetus has a chromosome abnormality but you are in the group of women to whom further testing is recommended.
The high risk cut off is 1:300 for Trisomy 21 and 1:150 for Trisomy 13 and 18. A “high risk” result does not mean your fetus has a chromosome abnormality but you are in the group of women to whom further testing is recommended.
What is the Nuchal Translucency scan?
The ultrasound component of the test involves measuring the nuchal translucency, which is the fluid filled area at the back of the fetus's neck. A thinner measurement is typical at this stage of pregnancy, while an increased thickness may indicate a higher chance of a chromosomal condition.
During your ultrasound, your sonographer will carefully measure this area, along with checking other key markers of fetal development.
During your ultrasound, your sonographer will carefully measure this area, along with checking other key markers of fetal development.
When is the cFTS performed?
The Combined First Trimester Screening is performed between 11+3 to 13+6 weeks of pregnancy, when the fetal crown-rump length (CRL) measures between 45mm and 84mm.
The ultrasound software license is provided by the Fetal Medicine Foundation. All our sonographers are accredited and required to perform an annual audit (RANZCOG) to ensure high standards are maintained.
Please note: the Combined First Trimester Screening is a screening , not a diagnostic, test.
Please note: the Combined First Trimester Screening is a screening , not a diagnostic, test.
