How can twins be sure of their zygosity i.e. whether they are identical or fraternal twins?
Research has shown that up to one-third of twins may be misinformed or unsure about their zygosity. Learn about why this occurs and why it is important to know your zygosity here
- If you have a boy and a girl it’s easy, they will be non-identical or dizygotic (with very rare exceptions)
- If they are of the same sex and definitely shared one placenta it’s also easy, they are almost always identical or monozygotic
- If they are of the same sex and each had a placenta, or if there is doubt about the type of placenta, then they could be either identical (monozygotic) or fraternal (dizygotic)
The best way to be certain is to do a zygosity test.
Discounted zygosity testing for TRA members
We’ve previously had collaborations with zygosity testing providers to offer discounted rates for TRA members. Unfortunately, we do not have any discounts currently available. We are working on this and hope to provide discounted zygosity testing again soon. Stay tuned!
