Sarah McDonald (IMAGE) McMaster University Caption Sarah McDonald, senior author of the study and a professor in the Department of Obstetrics and Gynecology at McMaster University Credit McMaster University Usage Restrictions For use when reporting on this research License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.