7Polar Body Twins and Heteropaternal Superfecundation
Like fraternal twins, polar body twins also look very similar. It happens when an egg is released from the ovaries and splits into 2 parts. The smaller one is known as a polar body, which consists of all the necessary chromosomes to conceive a baby. However, it does not have sufficient fluid to survive. They may have the same genetic material from the parent. In fact, scientists have not found any cases of polar body twins. There is currently no method to help confirm or identify this type. [7]
Superfecundation happens when sperm fertilizes eggs from different sessions of sexual intercourse. If a woman does not have sex with the same man before ovulating, the twins would have different fathers. This process is also known as heteropaternal superfecundation. While it is quite common in cows, dogs, and cats, this phenomenon is very rare in humans. [8]
