What are Monoamniotic Twins anyway?

Do you want to know what a monoamniotic twin is? I have written an article so you can see.

What is a Momo twin?

Many people do not know how to define a Monoamniotic twin. Monoamniotic twins “describes twins that are monochorionic and monoamniotic, that is, there is a single chorion and a single amniotic sac. The amniotic sac is the bag of waters that contains the fetus, while the chorion is the outer membrane. These are monozygotic twins that develop from a single egg/sperm combination which splits into two. When the split is delayed, usually a week or so after conception, the process of growing a placenta, chorion and amniotic sac has already begun, and the two embryos will develop within a single, shared sac. Only about 1% of twin pregnancies will occur in this manner.”( Fierro,2013, p.1)  

Monoamniotic twins share the same sac in their mothers stomach, and they develop from a single egg that splits in two. They not only share the same sac, but there is no dividing membrane between them.  They are swimming in the same space, attached to cords that can wrap around each other. That means that they can cut off each other’s blood supply and

compress each other’s umbilical cords. This makes their survival rate drop to about 50%.  Monoamniotic twins are one of the most rare occurrences in twin pregnancies.  It’s one step away from being conjoined twins.

Our Family's Momo Twins

Lucy and Hannah 

We are the first set of Momo twins born from our mom's generation.  The second set belongs to my mother's first cousin, and they are also girls.

In our grandfather's generation, his first cousin had Momo twins, who are girls.  They are about the same age as our mom.  In our great grandfather's generation, his sister had Momo twins.  Back then, the kind of monitoring that is recommended, was not available.  One of the twins died before it was born.  In the next generation, we are still trying to find out the incidence of twins.  But the generation before that, we have a picture of our great-great-great grandfather, who can't be proven to be a Momo twin, but he certainly looks like an identical twin!  He and his brother look like Abraham Lincoln!  Their names are Horace and Horatio.

All of these twins are from one line in our family.  Another interesting picture is of Clyde and Claude, but they are married in to the line, not directly descended from our line.

We would love to find out if anyone else has Momo twins born every generation in one family!

Monoamniotic Twins, trying to find a genetic connection

We (Hannah and Lucy) are Monoamniotic twins.  From all of the research that we have done, we have never found anyone who has studied to see if Monoamniotic (Momo) twins can run in families.  We understand that the chance of having Momo twins is rare, kind of like being struck by lightning. However, in our family, there has been a set of Momo twins born in every generation on one side of our family.  In fact, in our parents' generation, there are two sets of Momo twins born.  We have created this blog in the hopes that someone will be able to help us find out more information.  We also would love to hear your stories and experiences, especially if you have Momo twins that run in your family.  Please leave comments to this post so we can add your stories.