The news of becoming a parent indeed brings a lot of joy, as the arrival of a baby is a delightful event. Parents shop for cute clothes and fancy cribs while relatives are off to the gift shops to get their hands on the latest toys for newborns. 

But what if you get to know, you are up for double trouble?

The news of having a twin pregnancy is equally joyous but undoubtedly brings the hassle of having to manage two babies with it. The only thing that makes it easier is that, unlike identical twins, fraternal twins are non-identical, and the parents don’t have to search for ways to differentiate between their twins. 

However, due to non-identical frames of physical traits, the parents themselves would have to spend a lifetime explaining how the different-looking siblings in almost all aspects are twins for real.

Let’s have a look at some of the common facts and characteristics that fraternal twins possess.

How Are Fraternal Twins Formed Embryonically?

In rare cases, two unfertilised eggs can be released in the ovaries simultaneously. If these two different eggs get fertilised by two different sperms simultaneously upon intercourse, both fertilised eggs individually implant in the uterus and grow.

This means that the fraternal twins only share about 50 percent DNA, unlike the monozygotic or identical twins, who share an absolute 100 percent. Hence, fraternal twins are not genetically or physically identical.

While the reason for fraternal twin birth is not precisely known, most often, it runs in the family, and a mother is likely to have fraternal twins if she or someone in the family has had a similar pregnancy before.

Unpopular Facts About Fraternal Twins


picture of twins holding each other's hand


While we have scratched the surface of fraternal twin pregnancy, let’s dive into some of the lesser-known facts about double newborns.

1. They Are The More Common Type Of Twins

When we hear the word twins, most people would imagine two identical humans with identical physical traits. However, that’s not usually the case. As per statistics, a twin pregnancy is more likely to result in fraternal twins. Around 75 percent of all twin pregnancies are fraternal twins.

2. The Fraternal Twins Can Have Different Sexes, Unlike The Identical Twins

A baby’s gender is determined by the chromosome brought by the father’s sperm to the egg for fertilisation. Since two separate sperms fertilise the eggs for fraternal twins, the gender of the babies can be distinct as well. It means that either baby can be a boy or a girl, unlike identical twins who tend to have the same gender.

This usually serves as a fun factor when someone asks the siblings their dates of birth, and the revelation that they are twins is made on people.

3. Fraternal Twins May Have Two Different Fathers

A phenomenon usually seen in movies is pretty accurate in real life too.

Commonly known as superfecundation or bi-paternal twins, fraternal twins may have two fathers and are generally seen in women with hyper-sexual activity.

The woman’s cycle will be interrupted by the release of eggs multiple times (a phenomenon known as hyper-ovulation), and she will be having sex with more than one partner. Hence, leading to the two different eggs being fertilised by sperms coming from two different fathers, making bi-paternal twins a possibility.

4. They May Not Be Born On The Same Day

Yes, you read it right!

Fraternal twins are not necessarily supposed to be born on the same day. They can have a week or even a month gap in their ages. This happens when a woman releases one egg during her cycle, and it gets fertilised, then her cycle gets interrupted.

Now when she experiences another cycle, she releases another egg while already being pregnant. The second egg gets fertilised upon having sex now, as per a phenomenon known as superfetation. 

This leads to the birth of fraternal twins with a week or even a month’s difference. This phenomenon can take place up to 24 days after the first egg’s release.

5. They Have Separate Supporting Structures

When looked upon in-utero, fraternal twins have completely separate in-utero growth and supporting structures. In addition, since fertilisation and implantation are different, twins develop separate amniotic sacs, placentas, and other in-utero supporting structures.

6. They Might Be Polar Opposites

Fraternal twins only share 50 percent of the genetic makeup. This leads to them being sometimes polar opposites in their characteristics and preferences.

While this individuality will undoubtedly be adorable, simultaneously mastering the routines and preferences of two different babies will definitely be a nightmare for the parents. This is because you will be looking after two completely different individuals who are not close to each other, unlike identical twins who have a stronger bond. After all, they share 100 percent of their DNA.

7. Fun Part: They Are Difficult To Differentiate

Fraternal twins tend to look dissimilar enough not to be labelled twins by the general public, who would often be found taken aback by shock when they learn the pair of siblings are twins.

However, often fraternal twins can look identical to a high level as well. For example, they may look like a pair of siblings with 100 percent shared genetic makeup. On the contrary, sometimes, identical twins may not resemble each other so much because of the environmental factors that may lead to slight physical differences. 

The only sure-fire way to confirm if a pair of siblings are twins is the DNA zygosity genetic test. Besides demonstrating the twin status, this test is also responsible and essential for determining the baby’s health.


Twins may be double trouble for the parents, but they are a joyful bliss as they fill the home with positive vibes and laughter. Their dissimilarities make them unique but quite similar at the same time as well.