Twins, Triplets or more​

Chorionicity and Amnionicity:

There are three types of twins:

  • Dichorionic–diamniotic—Twins who have their own chorions and amniotic sacs. They typically do not share a placentaand can be fraternal or identical.
  • Monochorionic–diamniotic—Twins who share a chorion but have separate amniotic sacs. They share a placenta and are identical.
  • Monochorionic–monoamniotic—Twins who share one chorion and one amniotic sac. They share a placenta and are identical.

Monochorionic babies have a higher risk of complications than those with separate placentas.

Twin–twin transfusion syndrome (TTTS): the blood flow between the twins becomes unbalanced. One twin donates blood to the other twin. The donor twin has too little blood, and the recipient twin has too much blood. The earlier TTTS occurs in the pregnancy, the more serious the outcomes for one or both babies.

Although monochorionic–monoamniotic babies are rare, this type of pregnancy is very risky. The most common problem is an umbilical cord complication.


When more than one fetus originates from the same egg, we call them identical. Identical babies will be the same sex and will have the same blood type, however, they will have their own unique fingerprints and not 100% same. Family history plays no role.


When two or more eggs are fertilized by more than one sperm, the resulting babies are fraternal. More common with a family history.

They are genetically different, but will likely resemble each other.

Carrying more than one baby increases the chances of:

  • Pre-eclampsia.
  • Gestational diabetes.
  • Pre-term delivery.
  • Birth defects.
  • Miscarriage
  • Cesarean delivery

​Carrying more than one fetus is harder on your body, visit your OB more frequently and increase fluid intake and reduce unnecessary activities.