By Mojisola Alaiya
A man had to conduct a DNA test on his twin boys as required for an official documentation to confirm that both he and his wife are the parents of the twins. The test result came with devastating blow. He is not the biological father of one of the twins.
How come?
Some women have a condition known as hyper-ovulation but unfortunately majority of people don’t know about this. This condition is the main reason a woman with multiple sex partners can give birth to twins with different fathers. It is also the major reason behind natural multiple births and fraternal twins (non-identical twins from the same father).
Ovulation increases a woman’s craving for intimacy. Hyperovulation increases it more. It is important for a man to have an idea of the menstrual cycle of his woman.
Hyper-ovulation is a condition whereby a woman’s ovary releases multiple eggs (ova) during a single menstrual cycle. A woman’s reproductive system consists of two ovaries and one uterus. Each ovary releases an egg every 28 days. The discharge of an egg into the oviduct is called ovulation. It usually occurs at the mid-point of a menstrual cycle.
Women that hyper-ovulate are more likely to have fraternal multiple births meaning that the babies developed from different eggs and were fertilized by different sperm cells. This is opposed to identical multiple births whereby a fertilized egg divides to form two or more embryos with identical genetic makeup. Identical twins usually are of the same sex and share the same genetic characteristics unlike fraternal twins.
Hyper-ovulation in itself is not a disease and it is most likely genetic.
Hetero-paternal Superfecundation is a situation whereby a second egg released during the same menstrual cycle is fertilized by the sperm cell of a different man in a separate sexual intercourse that took place in a short period of time after the first one.
The methodology utilized in investigating hetero-paternal superfecundation involve autosomal short tandem repeat (STR), Y-chromosome STR analyses and other gene mapping or genetic profiling technology.
A study conducted by a group of scientist stated that as at 2020, about 19 cases of this condition was reported worldwide (Mogollon et al. 2020 [Twins from different fathers: a heteropaternal superfecundation case report in Colombia Biomedica 40(4):604-608]).
Fraternal twins (dizygotic twins) share the same percentage of chromosomes as any other siblings which is about 50% while twins resulting from Hetero-paternal superfecundation share about 25% chromosomes.
Hetero-paternal superfecundation was thought to be a rare phenomenon because few cases were reported.
This may be due to the fact that paternity disputes have been hitherto unpopular.
However, with the current availability of biomolecular methods and increasing number of paternity disputes more cases of this phenomenon will be detected.