1. Department of Obstetrics and Gynecology Division of Maternal Fetal Medicine Baylor College of Medicine Houston Texas USA
2. Department of Molecular and Human Genetics Baylor College of Medicine Houston Texas USA
3. Northern Ontario School of Medicine Thunder Bay Ontario Canada
4. Centre for Rural and Northern Health Research Lakehead University Thunder Bay Ontario Canada
5. Department of Obstetrics and Gynecology Division of Maternal Fetal Medicine University of Toronto Toronto Ontario Canada
6. Social and Behavioral Research Branch National Human Genome Research Institute National Institutes of Health Bethesda Maryland USA