What prenatal screening tests are currently available in Ontario?
Updated November 2018
*Additional serum-only screening options vary by region for those patients with no access to certified NT ultrasound. Please contact your local screening laboratory for more information.
*It is important to remember that no test can detect every type of congenital anomaly.
When is prenatal screening available?
Options for prenatal screening vary by region and are gestational age-dependent. While some screening tests are available throughout pregnancy, ordering them as early as possible allows for timely prenatal care.
Points to consider when offering prenatal screening:
1. How far along is your patient?
- Enhanced First Trimester Screening (eFTS) is available to those patients who present to care <14 weeks
- Maternal Serum Screen (MSS)-Quad is available to those patients who present >14 weeks
- Non-invasive Prenatal Testing (NIPT) is available to those ≥10 weeks’ gestation (some private labs do offer testing ≥9 weeks), and is only covered by OHIP if certain criteria are met. (More information on NIPT for health care providers can be found here)
2. Does your patient have access to an accredited ultrasound lab offering nuchal translucency (NT) ultrasound?
- eFTS incorporates both NT ultrasound and maternal blood work
- Serum-only screening is available for those without access to NT-accredited ultrasound clinics. For further information on regional options, please contact your local screening lab
This prenatal screening pathway can be used as a guide for offering timely prenatal screening to patients.
Be sure to check out our point of care tools to help support your discussions with patients about screening choices.
What has changed in Ontario?
- Because prenatal screening is moving towards results available earlier in pregnancy (using enhanced first trimester screening – eFTS), allowing couples more time for decision making and access to additional services, integrated prenatal screening (IPS) is no longer available in Ontario.
- In keeping with the 2017 joint SOGC-CCMG guidelines stating “Second trimester serum alpha fetoprotein screening to rule out open neural tube defects is no longer necessary unless there is a barrier to good quality ultrasound examination”, screening for open neural tube defects using second trimester MS-AFP has been discontinued. The primary screening test for the detection of fetal structural abnormalities, including neural tube defects, is a second trimester anatomical ultrasound with detailed fetal cranial and spinal imaging and assessment. This second trimester anatomical ultrasound is recommended for all pregnant persons at about 18-20 weeks of pregnancy to look at the baby’s growth and anatomy, regardless of prenatal screening results. While most babies are born healthy, 1 in 25 babies in Canada will be born with a difference that may require medical intervention
What is available for twin & higher order multiple pregnancies?
If your patient is expecting twins, prenatal screening is available but in general is not as sensitive as in a singleton pregnancy. At this time, both eFTS and MSS-Quad are available in twin pregnancies. Higher order multiples can be offered nuchal translucency ultrasound and a second trimester anatomical ultrasound, however, serum screening for Down syndrome and trisomy 18 is not currently available for these patients.