Twin siblings can either be “identical twins” or “fraternal twins ”, within a matter of days you can discover if you, or your children, are identical or fraternal twins.
So what does identical and fraternal actually mean?
When one egg is fertilised in the womb by one sperm cell, and the egg then divides and separates into two identical cells. This will result into identical twins once they are born. The identical twins DNA will be exactly the same, their physical attributes will also be similar
This is when two eggs are independently fertilised by two different sperm cells, this will result in fraternal twins, the DNA profile for the fraternal twins will not be identical, however their physical appearance may still be similar.
Why is an identical twin DNA test needed?
Its only natural for parents to want to find out as much as they can about their children, if they're twins then their zygosity needs to be examined. Zygosity is the degree of similarity of alleles when examining for twins or identical or nonidentical.
The twins themselves may be curious and want to know what their exact genetic relationship is with their sibling out of pure curiosity. Once they have learned their genetic relationship, they can now answer the question “are you identical?”. Also, in future, if the twins would like to participate in a scientific twin study, then knowledge of their exact DNA makeup will be essential.
How do I know if my twins are identical during pregnancy?
Like most parents you will want to know if you’re having identical twins, If you're pregnant with twins, you could experience complications with the pregnancy.
Monochorionic twins (share the same placenta) are mostly born healthy, however 15% of them experience twin-to-twin transfusion syndrome. This means one twin will receive too much blood and the other will not get enough. If you do have monochorionic twins, you will be going for more regular check ups than normal to monitor progress.
The sonographer will be able to identify your babies and their individual or joined placentas, there are various ways your twins may be found to be in the womb, this includes:
Dichorionic diamniotic (DCDA)
Both babies have their own placentas and their own inner and outer membrane. This is the case for one third of all identical/non identical twins. Therefore DCDA twins may not be identical.
Monochorionic diamniotic (MCDA)
Both babies share one single placenta and one single outer membrane, but have their own inner membrane. This is exactly the case for two thirds of all identical twins, therefore the most common type of identical twins, MCDA are identical twins.
Monochorionic monoamniotic (MCMA)
Once again both babies share a placenta, however they have to also share a single outer/inner membrane. This type of pregnancy is very rare and it only accounts for a miniscule 1% of all identical twins. MCMA will be identical twins.
Once the babies are born you can ask your doctor for a blood sample, he will analyse the placenta and send it away for further tests, if needed. Otherwise you can wait a few years to see how the babies develop, by analysing their features, such as foot, hand and ear shape and pattern of tooth eruption. However if you want to know for sure, the quickest and most definitive solution is an identical twin DNA test.
How is an identical twin DNA test completed?
The most accurate method to determine the DNA of a set of twins is by taking a swab of the cheek cells. The DNA Worldwide identical twin DNA test examines specific genetic markers in order to determine the exact relationship between the twins. This will answer the question, are they identical or fraternal?
This is a quick and easy process and can be done in the comfort of your own home. The swabs will need to be sent back and once the laboratory receives them, you can expect results within the next 3-5 days.