Are Twins Genetic?

Something people always wonder about is, “will I have twins this pregnancy. They run on my side and the fathers.” Which is a good question to ask. The answer is simple.

Identical twins are not genetic, so, if pregnant with identical twins—it is not something that you get pregnant with from genetics. If there are identical twins in your family, you would not account for those when wondering if you’ll be pregnant with twins yourself.

Now. When asked, “do twins run in your family?” Sometimes the answer would be, “they don’t run in mine, but they do run on his.” This doesn’t matter. Let me rephrase that:

The only twins that matter are fraternal twins, but the only person they matter with is the mother- not the father. Example, if a mother is a fraternal twin herself, she has a much higher odds of also having fraternal twins.

The reason this comes about is because when you have fraternal twins it involves two eggs, not one. The father cannot produce another egg, that is up to the mother’s genetics.

I've always found this fact interesting because I always thought that the father’s genetic mattered as well. Every time I see someone talking about the family’s genetics (his and hers) regarding twins, I always think of this fact.

I don’t know if some people already know about this fact, but considering I see genetics talked about a lot between both parents—I would say not. It’s something that everyone assumes is true, because the father’s genetics are involved when making a baby in general.

When talking about identical twins though, these types of twins only happen by chance. The embryo splits in two, but in one fertilized egg—therefore they are not genetic.

In fraternal twins, the mother must hyper ovulate, which would produce two fertilized eggs. For that to happen, the mother must have certain genes—therefore, fraternal twins are genetic. Seeing as the father can’t ovulate, this is why his genetics don’t matter.

Another fun fact regarding this subject: if a mother has fraternal twins, she is three to four times more likely to have another set.

Half of fraternal twins are a boy and girl.

Here are women who are more likely to have twins.

A 35-year-old mother, but after 35 the chances decrease.

If a woman eats poorly, the chances are less likely. If a woman is overweight and tall, her chances are higher.

The twin rate goes up after a previous birth, so if you wanted two kids but got twins your second pregnancy—this is a reason why.

It is easy to make the mistake of thinking that fathers are involved in the making of twins. But, after reading this, you should have a broad idea of how twins work and why the father doesn’t matter within them.

In my family, there are twins on my grandfather’s side, which would mean that I am not “destined” to have twins in any of my pregnancies, because my grandfather’s side doesn’t matter. The other factor of the twins on his side, are that they are identical twins, not fraternal, so they wouldn’t even if the father’s genetics did.

The easiest things to remember this fact by is:

Identical twins are by chance, not genetic.

Men don’t ovulate, so they can’t produce fraternal twins—the mother’s genetics do that.

You could also re-read the list of women who are most likely to get pregnant with twins. That could factor in to why you have/or are having twins yourself.

But, if you have identical twins, do not go thinking that your children are going to have twins themselves. Again, it is not genetic.

I hope these few fun facts about twins cleared some women’s minds about having twins themselves, because like me—twins may only run on the male side of your family, so the fraternal wouldn’t matter.