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Dr. Stephen J. Lye

Research Institute
Mount Sinai Hospital
Joseph & Wolf Lebovic Health Complex
6-1004 - 25 Orde St.
Toronto Ontario
M5T 3H7

Tel.: 416-586-4800 ext.8224

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Dr. Stephen J. Lye


In spite of significant medical advances in the past forty years, there has been no reduction in the incidence of preterm birth, even though it is associated with high newborn death and disease rates and with significant cognitive and behavioural problems in children and youth. Moreover, there is now compelling evidence that sub-optimal conditions for early development and preterm birth are linked with risk of type 2 diabetes, hypertension, obesity and depression in adulthood. A better understanding of the complex genetic and environmental factors involved in pregnancy and birth will have a significant impact on Canadian health care by minimizing neonatal death and disability and improving lifelong health.

Dr. Stephen Lye is a recognized leader in the field of women's and infants' health. His research holds promise for a new understanding of preeclampsia, a leading global cause of maternal and infant illness and death. In addition, his lab has conducted pre-clinical trials of a drug to stop uterine contractions, which is now being tested on patients in preterm labour at Mount Sinai Hospital.

He has also developed a diagnostic test, pilot tested and now part of a larger study, to distinguish false labour from preterm labour. Once it meets regulatory approval, this test will have a significant impact on patient care, preventing unnecessary hospitalization costs and negative impact on fetal health, since drugs given to stop labour and mature the fetus in case of pre-term birth can have damaging side effects when, as is often the case, they are not needed.

Dr. Lye has also joined a fascinating Australian study investigating the developmental origins of health and disease. This project recruited 3,000 pregnant women, recorded their birth parameters and has followed their offspring for 20 years, studying a range of factors including growth, physiology, and psychosocial development. Dr. Lye will be genotyping the children and the parents, a process that will reveal important data about the complex interplay of genetic and environmental factors involved in health and susceptibility to illness.

Currently, in collaboration with Dr. Alan Bocking and over a team of 30 clinicians and researchers at Mount Sinai Hospital, Dr. Lye is leading the Ontario Birth Study -  the largest Canadian study of its kind to track the health of women and their babies.

At a Glance

Dr. Stephen Lye uncovers the unknown elements of pre-term birth

Dr. Lye is a recognized leader in the field of women's and infants' health and holds the Mount Sinai Hospital Auxiliary Chair in Women's and Infants' Health Research, as well as the Canada Research Chair in Improvement in Health and Function

He created a blood test to differentiate women who will deliver babies prematurely from those who won't 

He is currently co-leading the Ontario Birth Study,that examines the impact of genetics and a baby's environment inside the womb to understand how these factors lead to major diseases later in life

Major Research Activities

The focus of our laboratory is to understand the mechanisms responsible for the onset of labour. We are investigating whether the change in the myometrium from a dormant state to the contractile state that occurs during labour is caused by the activation of genes. The lab has shown that both mechanical signals (due to stretching of the myometrium) and endocrine signals are required to activate a cassette of genes called "contractile-associated proteins" (e.g. CX-43 and oxytocin receptor) and initiate labour.