But back then our fore father's don't have time to check all this things and there were happily married and giving birth to numerous healthy children is it that things have changed since then or what's wrong your opinions is recommended
Nothing has really changed, this genotype of a thing is mostly done by people who have acquired some certain level of education in the society and they think it's necessary for them to do this genotype. If you check through the African society today many people are still getting married without any genotype testing and yet they are producing healthy children. For me as an educated person I did went for genotype test with my partner for us to be sure of things so we can avoid certain things that may happen in the future.
Information they said is power and it brings positive changes, and for those that are not informed of course they are deformed it only takes luck and chances for couples to produce healthy children as you said without the examination of a genotype test but however, for those of that are educated it is very much to be very sure about this to avoid ignorantly doing things that we will regret later, I have seen couple passing ignorantly passing through a lot as a result of this, they can even go to the extend of saying that their problems is witchcrafts when it is not, honestly it is good that we do the needful because it is necessary or to be seen as a necessity.