Twins

Identical twins come from a single fertilized egg that divides in half.

• Thirty percent of twins are identical.
• Identical twins are the same sex and have the same genetic makeup.
• They may share amniotic sacs and placentas, or be separate.

Fraternal twins come from two eggs fertilized by two sperm.

• Although they are born at the same time, fraternal twins are no more alike than other brothers and sisters born to the same parents.
• Inside the mother, fraternal twins are surrounded by separate sacs. They have separate placentas, although sometimes the placentas may grow together.
• Fraternal twins are more likely to be born to:
  • Women 35 and over
  • Women who have already had twins
  • Women who become pregnant soon after stopping birth control pills
  • Women for whom twins run in the family

Risks from carrying twins

• Preterm delivery due to early labor or early rupture of the membranes
• Preeclampsia (high blood pressure, protein in the urine, and/or swelling)
• Gestational diabetes
• Anemia
• Poor fetal growth
• Increased blood loss with delivery
• Cesarean section, if one of the twins is not coming out headfirst
• Because twin pregnancies are more likely to have complications, you may be more likely to need bedrest or hospitalization.

Birth and beyond

• Breastfeeding is usually possible with twins, and the body adapts by making more milk.
• There are special pillows and techniques for breastfeeding twins.
• Dartmouth-Hitchcock has lactation consultants who can help you with any breastfeeding questions you may have.
• There are local support groups for mothers of twins.

Other resources

• "Having Twins And More: A Parent's Guide to Multiple Pregnancy, Birth, and Early Childhood" by Elizabeth Noble
• National Organization of Mothers of Twins Clubs, Inc.
• Sidelines, a resource for high-risk mothers and their families