When many people hear the word “twins” they automatically think of identical twins. But fraternal twins are actually much more common, making up approximately 75% of the twin population.
For a quick refresher, fraternal twins occur when two separate eggs are released and fertilized by two different sperm.
Though fraternal twins are much more common than identical twins, many people don’t know much about them. Here are some facts about fraternal twins that may surprise you.
Fraternal twins generally are conceived one of two ways – when the mother releases more than one egg during her cycle or when the mother experiences another cycle and releases an egg after she is already pregnant, which can occur up to 24 days after the release of the first egg. For this reason, fraternal twins can be conceived a few weeks apart, though they generally will be born at the same time.
Because fraternal twins are conceived by two separate eggs being fertilized by two different sperm, sometimes days or even weeks apart, it is possible for fraternal twins to be fathered by sperm from two different men.
Scientifically speaking, fraternal twins are no different than any other pair of siblings, sharing 50% of their genes. But sometimes fraternal twins of the same gender can look remarkably alike, leading people to assume that they are identical twins.
Fraternal twins only share about 50% of the same genetic makeup so they are less likely to have the same hunger and sleep needs during each development phase. Fear not, there are sleep apps and resources available for you to work with your duo and help them both get to the Land of Nod.
It is believed by many scientists that a predisposition to release more than one egg can be genetically inherited, which is why many people will notice a family history of fraternal twins. In fact, female fraternal twins have a 1 in 17 chance of conceiving fraternal twins themselves. Also, once a woman has given birth to one set of fraternal twins she is three times more likely to conceive a second set.
About the Author Mariam Barnes is a Former Ad Executive, turned SAHM of twin girls. After 4 months of staying home Mariam started Twinmom.com as a place for great content, resources, and advice for twin moms. Twinmom.com has also partnered with TwinLoveConcierge to provide twin parenting classes in person and online. The site has grown at an AMAZING speed proving that there is a need for a twin mom community that can laugh, and cry together.