1. Department of Health Promotion and Policy, School of Public Health and Health Sciences University of Massachusetts Amherst Amherst MA USA
2. Midwifery Services at Cooley Dickinson ObGyn & Midwifery Cooley Dickinson Medical Group Northampton MA USA
3. Department of Public Health Sciences, College of Medicine Penn State University Hershey PA USA
4. Department of Obstetrics and Gynecology College of Medicine Hershey PA USA