Twin Zygosity Test Cost, Accuracy & Directions for Using

The use of a twin zygosity test can aid in identifying whether your twins are monozygotic or dizygotic. This test can help determine if your twins shared a placenta, thus determining if they are fraternal or identical.

These things can’t always be determined at birth, so a twin zygosity test helps parents who want to know. Of course, the test can also be used on adults if you’re a twin but aren’t 100% sure if you are identical to your sibling or not.

How much does a twin zygosity test cost? Prices vary, so you can expect to pay anywhere from $100-$500 to obtain a twin zygosity test. The type of test you want as well as whom you order it from will play a role in how much you’ll pay. Fortunately, there is usually a choice that will fit your budget if you really want to purchase one.

Twin zygosity tests can give you important information about your twins. They can also clear up any confusion about what type of twins you have since that can’t always be determined by ultrasound or even at birth.

Twin Zygosity Test

DNA tests are all the rage, and twin zygosity tests fall into that category. Twin zygosity tests are specifically designed to compare the DNA of twins to determine how much they share.

Twin Zygosity Test Cost: Examples

Test NameCost
Affinity DNAUnder $150
My Forever DNAUnder $200
GenovateBetween $150-$400
Easy DNA Under $150

What Does a Twin Zygosity Reveal?

 A twin zygosity test can reveal if your twins are fraternal or identical. This information is important for a variety of reasons.

First of all, fraternal twins run in families, but identical twins do not. That’s because fraternal twins are a result of hyperovulation, and that can be passed down in families.

If you want to know if the conception of your twins was due to hyperovulation, then you need to know for sure what type they are. 

Identical twins also share almost identical DNA. Fraternal twins only share half of their DNA, which is the same as non-twin siblings.

Knowing your twins have nearly identical DNA can help you decide how to move forward if there are ever health concerns with one of the twins.

How Does a Twin Zygosity Work?

Most twin zygosity tests depend on cheek cell samples, meaning you will only need to use the swab provided in the test to collect a sample from each twin. You will then follow the directions for sending the samples in so they can be tested.

The lab will then look at DNA markers to determine if they match. If enough markers match, then it will be determined that your twins are identical.

It’s possible to talk to your doctor about other methods for testing that involve blood samples and take place in the office. If you need your results for legal reasons, you may be required to use a specific kind of test.

How Accurate Are Twin Zygosity Tests?

Twin zygosity tests are generally considered to be very accurate. If enough DNA markers match on a twin zygosity test, then it’s 99 percent likely that your twins are identical.

There are different types of tests with different levels of depth, so choosing the ones that measure the most markers will increase the chances of accuracy.

Adorable baby twin brothers lying on a animal-themed blanket.

How Much DNA Do Twins Share?

How much DNA twins share depends on if they are fraternal or identical. That’s why twin zygosity testing works so well.

Even though identical twins can have gene mutations that make their DNA not exactly identical, it’s close enough for a twin zygosity test to recognize that they are identical.

Fraternal twins come from two separate eggs fertilized by two separate sperm. Fraternal twins share about 50 percent of their DNA, and that’s the same as any non-twin siblings.

Other Ways To Determine if Twins Are Identical or Fraternal

Twin zygosity tests are only one way to determine if your twins are identical or fraternal.

Doctors can sometimes tell through an ultrasound how many placentas are in the womb. They can also sometimes see if the babies have their own chorions and amniotic sacs. This can help them determine the type of twins you’re having. 

Similarities Between Identical and Fraternal Twins

Both fraternal and identical twins grow together and are born at the same time. They have the unique experience of sharing the womb with a sibling.

They will also probably live their lives with people commenting on them being twins or asking them about it.

Differences Between Identical and Fraternal Twins

Identical twins share the same DNA. If a pair of identical twins marry another pair of identical twins and they have children, their kids would be genetically more like siblings as opposed to cousins. 

However, fraternal twins share the same amount of DNA as non-twin siblings because they come from two separate eggs fertilized by two separate sperm. Identical twins come from one fertilized egg that splits.

Fun Facts About Twins

Twins are fascinating, and there are so many fun facts about them that most people don’t know.

  1. Twins don’t have the same fingerprints, even if they are identical.
  2. Fraternal twins can have different fathers.
  3. Twin moms live longer, and so do twins.
  4. Not all twins have the same birthday. 
  5. Women who have twins are more likely to have another set of twins.

Related Questions:

Can a DNA Test Tell Which Twin Is the Father?

If you have a child with a man who has an identical twin, DNA testing can get very tricky. Since identical twins have almost the exact same DNA, a DNA test won’t tell you which man is the father as DNA tests can’t tell identical twins apart.

What Is the Rarest Type of Twin?

The rarest type of twins are monoamniotic-monochorionic twins. These twins share a placenta, a chorion, and an amniotic sac. All of this sharing makes this type of pregnancy extremely risky. These twins only make up 1 in every 10,000 births.

Final Thoughts

A twin zygosity test can tell you more about your twins and how much DNA they have in common.

If you’re unsure if your twins are fraternal or identical or if you yourself are a twin and want to know what kind, a twin zygosity test can provide you with clear answers.