Pregnancy is a seemingly natural and simple process at the outset. However, it has its own set of complications involved. From the health of the child to that of the mother, there are many variables to consider. Moreover, in some cases, the paternity of the child might be uncertain, warranting a prenatal paternity test. Pertaining to the topic of paternity, it was seen how the test can be done without the father in the previous blog, also answering the question - can twins have two different fathers? The latter will be explored in further detail in this blog.
Two types of fraternal conception.
There is a major difference between identical twins and fraternal twins. In the case of the former, an egg is fertilized by one sperm, but it leads to the formation of two embryos. When this occurs, one can generally expect identical twins. On the other hand, if two eggs from the mother are fertilized by the sperm from the same father, then it leads to fraternal twins. However, fraternal twins can also occur by two other means.
What is homopaternal and heteropaternal superfecundation?
Before exploring the two concepts, it is important to understand the meaning of superfecundation. In essence, superfecundation is defined as the fertilization of two different eggs in the same menstrual cycle, leading to twins that are born together but essentially not conceived together.
Homopaternal Superfecundation
In this case, the two eggs are mated in the same menstrual cycle by the sperm of one biological father. Therefore, it leads to the birth of fraternal twins not conceived at the same time.
Heteropaternal Superfecundation
This is an extremely rare scenario wherein two eggs are mated in the same menstrual cycle by the sperm of two different fathers. This implies that one egg was fertilized by the sperm of one father and the other was fertilized by the second father. Therefore, the fraternal twins in this case would be half-siblings, even if they are born together.
There are very few documented cases of this phenomenon, but it is certainly a possibility, no matter how slim.
To get a prenatal paternity test or a blood test to determine the child’s gender, reach out to us at Prenatal Genetics Lab. Run by research scientists, we have decades of experience in human DNA diagnostics. Affordable and non-invasive, our tests are also highly accurate. To know more about our services, contact us today.
