American College of Nurse Midwives
http://www.acnm.org/
 
American Congress of Obstetricians and Gynecologists
http://www.acog.org/

Bay Area Birth Information
http://www.bayareabirthinfo.org/
 
Childbirth Connection
 
MGH Center for Women's Mental Health
http://www.womensmentalhealth.org/
 
Organization of Teratology- Information about exposures during pregnancy
 
US Department of Health and Human Services
http://www.womenshealth.gov/