Twins: Identical or Fraternal?

Congratulations! You are pregnant with twins.

Chances are your happy news is quickly met with the question about whether or not your twins are identical or fraternal? And what is the difference? Can doctors know before you give birth whether you have identical or fraternal twins?

Basically identical twins develop from ONE fertilized EGG that splits in two. Identical twins are essentially genetic photocopies of one another. This means that they will look very much alike, and will be the same gender. Identical twins also sometimes share the same placenta and are called monochorionic. Sometimes, during early ultrasounds doctors can look at the placenta and tell if they share a placenta or not. Making things even more difficult is the fact that some identical twins do not share a placenta, even though they originated from one egg. Most often, doctors will not know whether your twins are identical or fraternal until genetic testing is done after delivery.

Fraternal twins do not necessarily look alike and are as genetically similar as any other siblings are. Fraternal twins occur when a woman ovulates more than one egg and both are fertilized. In some instances, this fertilization can occur a few days, or even a week or more apart, depending upon when the eggs were released. Fraternal twins do not share a placenta, and can be two girls, two boys, or a boy and a girl.

In some instances – even after birth, many people will mistake your twins for identical or fraternal based on their appearance. While most identical twins are genetic carbon copies and share the same DNA, your twins can be identical yet still have some aesthetic differences. Additionally, identical twins DO NOT have the same fingerprints which seems to strengthen the idea that there are genetic differences.

And strangely enough, even twins who don’t look alike are often mistaken by others as identical simply because they share a birthdate.

At some point, finding out for sure whether your twins are fraternal or identical is an important piece of information to have. If your twins have any health problems later in life doctors can benefit from knowing whether they are identical or fraternal. Anomalies and birth defects can occur more commonly in identical twins than in fraternal twins, although experts aren’t exactly sure why and believe it has something to do with whether or not they shared a placenta or had their own.

All the way around, having twins is a blessing! While it may make your pregnancy more difficult and you are certainly in for a lot of work and lost sleep once they are born, you are also in store for TWICE THE LOVE!

Written By Stef, Mom of 4 @Momspirational

This information is not intended to replace the advice of a trained medical doctor. Health & Parenting Ltd disclaims any liability for the decisions you make based on this information, which is provided to you on a general information basis only and not as a substitute for personalized medical advice. All contents copyright © Health & Parenting Ltd 2018. All rights reserved.