These sites have patient information pertaining to high-risk obstetrics, prenatal diagnosis, and obstetrical ultrasound.

• The Fetal Treatment Program at the Hospital of the University of Pennsylvania.
• The Hospital for Sick Children in Toronto

• OB Gyn.Net
  Physician reviewed network offering a home for locating and publishing information globally. Includes related news, events, clinical reference, forums, directories, product vendors and career opportunities.

• Obstetric Ultrasound

• New York Online Access to Health (NOAH)
  General Resource for Pregnancy questions
• Olen Interactive Pregnancy Calendar
  A day-by-day customized calendar detailing the development of a baby from before conception to birth.

• National Organization of Mothers of Twins Club
• The Triplet Connection
  Provides vital information to families who are expecting triplets, quadruplets, quintuplets or more, as well as encouragement, resources, and networking opportunities for families who are parents of larger multiples.

• National Down Syndrome Society

• American College of Obstetrics and Gynecology
• Society for Maternal-Fetal Medicine
• American Institute of Ultrasound in Medicine

• Phoenix Perinatal Associates