What is constraint of blood groups for couples before marriage?

I have heard that some groups treat other groups as anti bodies while pregnancy. is that true?? if wife is of that particular group, iwill that be a problem?What is constraint of blood groups for couples before marriage?
The risk lies in the mother and foetus, not the father. If mummy is RH- and baby is RH+, mummy will develop antibodies against RH+. The second time mummy carries a RH+ baby, baby gets killed as an foreign particle. To know your RH factor, do a blood test. The +/ - sign following your blood group (A, B, AB, O) will tell you which RH factor you have.What is constraint of blood groups for couples before marriage?
groups matter wen blood if transfused,but in fertilisation, any two groups can mix, n dat is not d problem... but it's what rhesus factor u have, is what matters...like ur positive, or negative as in A+ or A-... d problem arises wen the husband's a +ve and wife's a -ve: causes haemolytic disease of the new born in the second baby...the first comes out fine...but their is cure for that too, u must ask the doctor... there are other diseases like Thalessimia, for which both the parents have to get their blood checked to make sure the baby doesn't get it...it's very rare, but u never know,,,it's better u ask the doctor about all dis, if ur plannin' on a baby that is!!! good luck dude!!
My husband and I went through this I am O- and he is A+ When my kids were born they gave them a shot of some sort and I think that's about it. But you would really have to ask my husband I can't remember to much he knows more about it. but yes there can be problems and yes it is true
Its call the Rh groups of blood --- AB, A, B, and O is universal. They test you and your wife's blood for specific blood types then they usually give the new mom a shot after childbirth so if she gets pregnant again her blood anti-bodies won't attack the second baby because of blood type differences.