Are you pregnant with twins and wondering if they are identical or fraternal. There is a test known as twin zygosity  test which can be used to find out if your twins are identical or fraternal. This test is offered by DNA diagnostic centers.
 

What is twin zygosity ?

 
This is a  test that compares the twins DNA profiles to check whether they match. An exact match means that they are identical twins.  After delivery of the babies, the doctor will also be able to tell if they are identical or fraternal. This is because the identical ones  share a common placenta while fraternal ones are usually in 2 different placentas.

The twin zygosity test is a simple test. It can be done right after the babies are born even though some parents prefer to wait a while. A cheek swab is collected from each twin.  This is then sent to a fully accredited DNA diagnostic lab. The DNA from the samples are extracted, analyzed and compared. Each sample is analyzed  to ensure 100% accuracy.

Why you need to consider twin zygosity ?

 
Here are some of the reasons you may want to consider twin zygosity .

• birth records may be lost or inaccurate
• the placenta of the twins may be damaged or discarded before the zygosity were determined especially in the case of an emergency or life threatening birthing experience
• twins may start to show different physical traits which may cast doubt on the zygosity determined earlier
• personal curiosity

Identical vs fraternal twins

 
Identical twins come from one fertilized egg known as the zygote. the zygote splits in early development to form 2 embryos – the identical twins.  They have the exact DNA because they come from the same egg and one sperm.

Fraternal twins results when two different eggs  from the mother are fertilized by two different sperms. They do to have the same DNA although like siblings they do share some of the DNA they inherit from both parents.