Lesson 2 of 5: “Types of Multiples”

Triplets in Utero (click to enlarge)

Triplets in Utero (click to enlarge)

One of the first questions many people ask is “are they identical or fraternal”? 

The answer to this question may be important for medical reasons, as well as psycho-social reasons later on.

Do you know if you are having dizygotic (di-“two” zygotic-“from zygotes”, so two separate zygotes) or monozygotic (“Identical”) twins? 

If each baby has her own inner AND outer sac, your babies are also referred to as di-amniotic, di-chorionic (“di” meaning “two”).



There – Now you can impress all your friends and family with your new vocabulary!

(Here is the study referenced in the video.)

The diagram below may provide a clearer picture of the different types of twins:


If you are interested in learning more about this, check out this link for some diagrams of twins in-utero.

Natural fraternal or dizygotic twining is thought to be hereditary, passed through the mother’s side of the family, and rates tend to be highest in parts of Africa; it is suspected the diet among the Yoruba people has something to do with their higher than average incidence of multiple births!

As you probably know if you are coming from an assisted reproduction experience, the incidence of fraternal multiples is on the rise in the past decade.  And the media is rife with extraordinary stories of higher-order multiples, not always portrayed in a positive light. (i.e. 2008’s “Octo-mom” in the U.S.)

This is due to a number of factors:  More women are waiting longer to have children. Every year over 35 increases the risk of conceiving twins or more.  It also increases the risk of fertility “issues” which drive a number of couples to seek “help”–this of course also increases the risk of multiples.  So, now we have more twins and triplets than we did in days gone by.

Whether your twins, triplets or more were conceived naturally or with a little help, know that by taking a multiples-specific prenatal course, you are taking an important step towards the prenatal health of mom and babies.