Enhanced First Trimester Screening (eFTS) | Prenatal Screening Ontario

You can get publicly-funded Enhanced First Trimester Screening (eFTS) in the first trimester of pregnancy. This test is safe because it uses only an ultrasound and blood test. It can tell you the chance of having a baby with trisomy 21 (Down syndrome) or trisomy 18 (Edwards syndrome). It does not check for trisomy 13 in Ontario.

How to get eFTS

Talk with your health-care practitioner if you would like to get eFTS. In Ontario, this test can be ordered by:

doctors (such as family doctors, obstetricians)
nurse practitioners
midwives

If you don’t have a family doctor, you can still arrange this test through a walk-in clinic. Use Health811 to find walk-in clinics near you.

eFTS can be done from 11 weeks 2 days to 13 weeks 3 days of pregnancy. During this time window, you will first have a special ultrasound called the 11-14 week (nuchal translucency) ultrasound, followed by a blood test.

Download Instructions

For Health-Care Practitioners

Requisitions and How to Order

Who should not have eFTS?

You should not have eFTS if you:

already have a "low risk" result from Non-Invasive Prenatal Testing (NIPT), or you are waiting for your NIPT results.
had a "vanishing" twin / co-twin demise. This is a pregnancy that started as twins, but one of the twins was lost.
are expecting more than one baby (twins, triplets, quadruplets etc).

What does eFTS look for?

eFTS detects most pregnancies with trisomy 21 and trisomy 18. As other screening tests, eFTS cannot detect all pregnancies with these chromosome differences. The ultrasound can give extra information about the baby's health, including some serious birth defects.

How does eFTS work?

This screening test will combine all the information below to tell you about the chance to have a baby with trisomy 21 and trisomy 18:

Your age at the time of birth

You have a higher chance for chromosome differences like trisomy 21 and trisomy 18 as you get older. If you got pregnant through in vitro fertilization, it is the age of the egg that is used. The egg may be your own or from a donor.

11-14 week (nuchal translucency) ultrasound result

The nuchal translucency (NT) refers to the pocket of fluid at the back of the baby's neck. This pocket of fluid is measured during the ultrasound. When there is more fluid than what we typically see, there is an increased chance for trisomy 21, trisomy 18 and other conditions.

Blood test result

The blood test for eFTS will measure the amount of 3 or 4 proteins or chemicals made by your pregnancy.

Other information about you

Your health-care practitioner will ask you some questions about you that improve the accuracy of test. You will be asked about your racial identity, diabetes status, smoking history in the pregnancy, weight and whether the pregnancy happened through in vitro fertilization.

How long does it take to get results?

The results are expected to be received by your health-care practitioner within approximately 7 working days. Talk to your health-care practitioner about how they plan to give you these results.

If your health-care practitioner does not receive the results within this time, they are encouraged to fax a request to the screening laboratory the blood sample was sent to:

Mount Sinai Hospital: 416-586-4640

North York General Hospital: 416-756-6108

Trillium Health Partners / Credit Valley Hospital: 905-813-4335.

What type of results will I get?

When you get your eFTS report, it will most likely say that you have a “screen negative” result. This means that you have a lower chance to have a baby with trisomy 21 and trisomy 18. It does not mean "no chance".

Some individuals will get a “screen positive” result, which means that there is a higher chance to have a baby with trisomy 21 or trisomy 18. It does not mean your baby definitely has one of these chromosome differences. You would have more options for testing, including publicly-funded NIPT and diagnostic testing.

How does eFTS compare to NIPT?

You might have the option of doing another prenatal screening test, called Non-Invasive Prenatal Testing (NIPT), instead of eFTS. In this section, you will learn how eFTS and NIPT compare to help you make a decision.

Accessible version of above visual (text only)

eFTS and NIPT side-by-side

Questions to Consider	eFTS	NIPT
When in the pregnancy is it done?	Between 11 weeks 2 days and 13 weeks and 3 days	After 9 or 10 weeks of pregnancy depending on the laboratory
What does it include?	11-14 week (nuchal translucency) ultrasound Blood work	Blood work
What does it screen for?	Trisomy 21 Trisomy 18	Trisomy 21 Trisomy 18 Trisomy 13 Sex chromosome differences (optional)
What does it not screen for?	Only above conditions are tested. Extra information about the baby's health can be discovered during the 11-14 week (NT) and 18-22 week ultrasounds.	Only above conditions are tested. A 11-14 week (NT) and 18-22 week ultrasounds are recommended for extra information about the baby's health.
Is it funded by public funds?	Yes	Yes, in certain situations. For example: you are 40 years old at the time of birth or you have a "screen positive" eFTS result. Private-pay is an option if the test cannot be publicly-funded.
What is the chance that the test will fail to give a result?	eFTS is only rarely not able to give a result	Sometimes NIPT fails to give a result or gives a result that is not typical
How accurate is it?	Detects most pregnancies with trisomy 21 and trisomy 18. eFTS is less accurate than NIPT	Detects most pregnancies with trisomy 21 and trisomy 18. NIPT is more accurate than eFTS

Source

The results presented in this visual are based on the sensitivity and specificity of eFTS and NIPT from actual Ontario pregnancies with an estimated date of delivery between September 2016 and March 2023 that underwent prenatal screening (twins were excluded). The incidence of trisomy 21 in this group was 1 in 394. The figures were applied to this fictitious population of 50,000 people. View more details about the performance of prenatal screening tests.

Accessible version of above visual (text only)

More about accuracy

Screening tests can give false positive or false negative results.

False positive

A false positive is when a pregnant individual gets a "screen positive" or "high risk" result but the baby does not actually have trisomy 21. Both screens have false positives. However, there are more false positives through eFTS than NIPT.

False negative

A false negative is when a pregnant individual gets a "screen negative" or "low risk" result but the baby actually has trisomy 21 (missed case). Both screens have few false negatives. However, there are more false negatives through eFTS than NIPT.

To help you understand the accuracy of eFTS and NIPT, view the type of results that 50,000 people can get if they choose prenatal screening.

Results of 50,000 people who have eFTS or NIPT

Type of Result	eFTS	NIPT
False Positive	3,162 people (6.3%) get a "screen positive" result, but the baby does not actually have trisomy 21. The bottom line is that most "screen positive" results are false positives.	35 people (less than 0.1%) get a "high risk" result, but the baby does not actually have trisomy 21.
True Positive	111 people (0.2%) get a "screen positive" result, and the baby does have trisomy 21.	124 people (0.2%) get a "screen positive" result, and the baby does have trisomy 21. The bottom line is that most people who get a "high risk result" do have a baby with trisomy 21, but there are some false positives.
False Negative	14 people (less than 0.1%) get a "screen negative" result, and the baby does have trisomy 21.	1 person (less than 0.1%) gets a "low risk" result, and the baby does have trisomy 21.
True Negative	46,713 people (93.4%) get a "screen negative" result, and the baby does not have trisomy 21.The bottom line is that most people who get a "screen negative" result do not have a baby with trisomy 21, but there are some false negatives (missed cases).	49,840 people (99.7%) get a "low risk" result, and the baby does not have trisomy 21.The bottom line is that most people who get a "low risk" result do not have a baby with trisomy 21.

Frequently Asked Questions

I got pregnant through In-Vitro Fertilization and had Preimplantation Genetic Testing (PGT-A) during this process. Can I still have prenatal genetic screening?

PGT-A involves screening embryos for chromosome differences to help decide which embryos to transfer into the womb. eFTS is not recommended for pregnancies that had PGT-A, since PGT-A is a better screen for trisomy 21, trisomy 18 and other chromosome differences. You can speak to a genetic counsellor about the benefits and limitations of having Non-Invasive Prenatal Testing (NIPT) in your situation.