Welcome to Newborn Screening Ontario (NSO)! NSO is located at the Children's Hospital of Eastern Ontario (CHEO) in Ottawa, part of the Champlain Local Health Integration Network (LHIN).

Did you know that approximately 140,000 babies are born every year in Ontario? While the vast majority of these babies are healthy, some have rare and potentially life-threatening diseases. When these diseases are detected in the newborn period, treatment can begin immediately. Early treatment may prevent growth problems, health problems, mental retardation, and sudden infant death. NSO currently screens every baby born in Ontario for at least 28 diseases (for a complete list, please click here) to ensure that every baby has the best start in life.

The newborn screen is performed by taking a blood sample from your baby by pricking the baby’s heel. The blood is collected on special filter paper and sent to NSO's laboratory. The newborn screening sample should be taken between one day (24 hours) and seven days after your baby is born. If the initial newborn screening sample is taken before 24 hours of age, your doctor, midwife, or the hospital where you had the baby should arrange a repeat test within five days.

It is important to note that newborn screening does not provide diagnoses for babies. The “screen” itself identifies babies who MAY have a problem. Follow-up diagnostic testing confirms whether or not the problem or disease is truly present.

A “screen negative” result means that a baby is at a greatly reduced risk for the diseases tested for.

A “screen positive” result does not mean that your baby has a disease, it shows they have an increased chance of having a disease and further testing is needed.


For more about Newborn Screening Ontario, click here.
For Frequently Asked Questions, click here.