what is this all about wife having a negative bloodgroup while husband is with an opposite group?

Answer 1

It shouldnt be a matter of concern now.It was earlier a worry at the time of childbirth about the child's blood group not matching with the mother's ,negatives being rare.Now u have anticoagulating injections to prevent complications arising.

Answer 2

You need some very basic physiology knowledge.

It is like hair color. Can't a man with brown hair marry a woman with red hair. Actually this is kindergaten explaination.

Look up blood tyes on the internet and learn about it.