Dr. Barrett holding two babiesDr. Barrett is the Chief of  Maternal Fetal Medicine  at Sunnybrook Health Sciences Centre and a Professor of Obstetrics and Gynecology at the University of Toronto. He is a Senior Scientist at the Sunnybrook research Institute and  the Program Research Director of the Women and Babies Program. He is the medical co-director of Clinical Trial Services at Sunnybrook Health Sciences Centre and holds the Waks Family Research Chair of Maternal Fetal Medicine Research.

He is a World Health Organization advisor on Maternal Health, Vice Chair of the Board of the Society of Obstetricians and Gynaecologists and the International Society of Twin Research, and President of the Canadian Society of Maternal Fetal Medicine. He is the Founder and Chair of the Southern Ontario Obstetrical Network (SOON). He has held more than $20 million  in grants, most prominently in the conduct of randomized controlled trials, wherein he has obtained international recognition in the field of multiple pregnancy.

More recently his research has been channeled to both improving outcomes and preventing the occurrence of preterm birth via population  interventions. His most recent and ongoing initiative has been the formation the Alliance for the prevention of preterm and stillbirth in Ontario, which is enjoying increasing philanthropic and ministry support.