Yahoo Inc CEO, Marissa Mayer, announced on Twitter today that gave birth to two identical twin 11 December after which it is expected to resume work after a maternity leave of only two weeks . Mayer, who is married to Silicon Valley investors Zachary Bogue had tweeted, “Zack and I are excited to announce that our identical twin girls were born early this morning. Our whole family is doing very well! “The birth of 40 years, had previously given a baby, MacAllister in September 2012.
The difference between identical and fraternal twins
However, did you know that identical twins occur when a single fertilized egg is following by a single sperm, which is divided into two identical halves? After that, two babies separated with identical DNA are formed. In most cases, identical twins belong to the same sex and share the same placenta. However, in some cases, the twins may be male and female and have separate placentas. It is estimated that the incidence rate of identical twins is about four per million. However, researchers have also identified genetic differences between identical twins .
On the other hand, fraternal twins occur when two fertilized eggs are implanted in the uterine wall at the same time after the mother releases two different eggs are fertilized by separate sperm. These twins have a small chance of having the same profile as individual chromosomes and brothers, who share 50% of their DNA. The twins are more common than identical twins and doctors have found that women over 30 years are more likely to have twins. This is how achieved a twin pregnancy .
Image Source: Shutterstock
This article was originally published on thehealthsite, Read the original article here