American College of Obstetricians and Gynecologists
http://www.acog.org/

Center for Prenatal Pediatrics
http://www.prenatalpediatrics.org/

Centers for Disease Control and Prevention, Reproductive Health
http://www.cdc.gov/reproductivehealth/

La Leche League
http://www.lalecheleague.org/

March of Dimes
http://www.modimes.org/

Maternity Center Association
http://www.maternitywise.org/home.html

The National Parenting Center
http://www.tnpc.com

Society for Maternal-Fetal Medicine
http://www.smfm.org/

The What to Expect Foundation
http://www.whattoexpect.org/