1. Obstetrics and gynecology, Mount Sinai Hospital University of Toronto, Toronto, Canada
2. Sidney Liswood Health Sciences Library, Mount Sinai Hospital Sidney Liswood Health Sciences Library, Toronto, Canada
3. Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Canada
4. Department of Pediatrics, Hospital for Sick Children, Toronto, Canada
5. Prenatal Diagnosis and Medical Genetics Program, Mount Sinai Hospital Sidney Liswood Health Sciences Library, Toronto, Canada