Fraternal Twins Facts

"There are two things in life for which we are never truly prepared: twins." ― Josh Billings

The humorist may have very succinctly put forward a thought that every parent expecting twins has twirling in their head day in and day out, after realizing that they are going to be a parent to not one, but two kids. While it can be a joyful experience, parenthood with two kids of the same age can be quite traumatic.

Whether you are expecting identical twins or fraternal, the fact remains that parenting them can never be an easy task. But putting aside that thought, are you wondering how twins are conceived, and if there is any difference in the conception of identical and fraternal twins? Well then, this post should allay your queries on the matter.

One of the most commonly known facts is that possibility of having twins is ruled by genetics, and that is the reason most parents of twins are asked if they have a twin sibling as well. While the genetic theory is true for fraternal twins, it is not so for identical twins. This is one of the most distinguishing things about identical and fraternal twins.

Genetic research of identical twins has proven that it is sheer chance that leads to their conception. On the other hand, fraternal twins are conceived when the mother hyperovulates, i.e., she ovulates more than one eggs during her cycle, and then different sperms fertilize these different eggs.

After fertilization, two separate zygotes start developing, each has its chorion and amnion. Another reason for the conception of twins is the occurrence of superfetation, which is a situation in which an already pregnant woman ovulates, which is fertilized by a sperm.

This phenomenon can occur only up to 24 days after the first egg is released. In such a case, the twins would have been conceived at different dates but will be delivered on the same day, despite the developmental differences. This is a common occurrence in case of in vitro fertilization. Given here are some interesting facts on fraternal twins.

• Giving birth to fraternal twins is more common than having identical twins. In fact, of all twin pregnancies, two-thirds result in the birth of fraternal twins.

• Chances of parents conceiving twins, especially fraternal twins, is more if the mother has a twin sibling. The possibility of a female fraternal twin giving birth to fraternal twins is one in seventeen.
• Research indicates that there is a high probability of giving birth to twins if parents have undergone fertility treatments, or if mother is over 35 years.

• If you analyze the geographical distribution, it is noticed that Africa has the highest number of fraternal twin births, while Asia has the lowest.

• There are researchers whose studies show that the more number of pregnancies a woman has, the higher is the possibility of her conceiving twins. Though seemingly unbelievable, there are also studies that indicate more possibility of a tall woman having twins, as compared to petite women.

• Fraternal twins share only 50% of genetic makeup. They can look as similar as identical twins or as different as ordinary siblings.
• In case of superfetation, it is possible that a pair of fraternal twins can have different fathers. This is because the two eggs are released at different times, and can be fertilized by different sperms.

• Only the mother of fraternal twins can have an effect on the possibility of conceiving them. As of today, there has been no research that indicates that the father's genetic makeup can increase the possibility of conceiving fraternal twins.

• A common misconception is that conjoined twins can be fraternal or identical. But, as a matter of fact, conjoined twins are always monozygotic and, therefore, identical.

Most twins are believed to share a special bond, which connects them more deeply than normal siblings. They may often have an almost telepathic sense of any harm that their twin may be experiencing. While most people believe this to be true for identical twins, it is also true at some level for fraternal twins.

While there may not be any scientific proof for the same, this is one thing that is being constantly researched and also played out in popular media. Hopefully, this information on fraternal twins has helped you understand the biology behind them.