FAQs #1

In an effort to complete a post for every day in November for NaBloPoMo, I am running through ideas I have had for posts in the past but never seem to get to.  I will be answering frequently asked questions(FAQs).  These question and answers will pertain to having twins and all that it entails.  I don't have a problem with people asking a lot of questions about the boys when we are out and about but what makes me incredulous is when they ask a question, you answer and they argue with you.  In my head I am thinking, "Hey, I am their mom.  I think I would be the one to know." People mean well but there is a lot of myth and miseducation when it comes to twins. So here it goes, some of the frequently asked questions:

Are your twins identical? 
Yes, our boys are identical.  The technical term is monozygotic.  Abraham and Winston were once a single zygote hence they are monozygotic twins.  In that one zygote was all the genetic information that was needed to form a baby.  That single zygote then split to form two separate embryos.  It's pretty incredible to think about how that zygote split and God made two separate babies with two separate intellects and personalities from it.  Monozygotic twins are not carbon copies of one another however due to the physical expression of their genes, that is their phenotype.  The zygote splitting is not a perfect 50/50 split.  One embryo may gain more copies of a gene than another.  A gene may be "turned off" in one embryo and active in another.  Identical twins often look very similar but have many differences as well.  I know a set of identical twins that look very much alike but one has visibly curly hair while the other twin has straighter hair.  Most people know that monozygotic twins still have different fingerprints from one another.  All that to say, monozygotic twins are unique and are not "identical" in the sense that the term is often used. 

How do you know?
We were told that our twins were monozygotic at one of our earliest ultrasounds due to the presence of only one placenta.  Fraternal twins have two separate placentas (since they are conceived as entirely different embryos) and identical twins almost always have a single placenta.  So the boys each had their own amniotic sac but shared their oxygen and food supply through a single chorion.  These twins are known as diamniotic monochorionic (di-mo) twins.  There are cases of the placenta of fraternal twins fusing and looking like a single placenta. When the boys were born, I asked the doctor if it did indeed look like a single placenta.  All signs pointed to a single placenta and while we never had the genetic test done to absolutely confirm that they are monozygotic, we are almost positive they are.

Hmmm, I thought identical twins were always in the same sac.

Nope.  Monoamniotic monochorionic (mo-mo) twins are very rare and when it does happen there is a very high chance of fatality because with no membrane separating the babies, they can easily tangle up their cords and cut off each other's blood supply.  The membrane between the boys was very apparent even at our first ultrasound.  Sure it may look like the babies are really touching one another but they each have their own sturdy amniotic sac containing them and keeping them safe. 

So do you think our boys look identical?