Hello,
Thanks for posting your query.
Please do not worry. Marriage between rh incompatible couples is common and though there is a chance of incompatibility in the baby it can be easily prevented and treated nowadays. Let me explain,
First of all there is no abnormality in having any blood group type wether B Rh positive or O Rh negative , it's just a normal trait and varies with person to person.
Next , there is no problem in fertility or conceiving a baby in O negative mothers especially if there is no other illness or medical problems .
Further, there is not likely to be any problem in the first born child of a O negative mother even if the baby acquires the fathers blood group ( say baby is B +).
The problem like newborn jaundice or hemolysis or Rh incompatibility syndrome ( hemolysis ) might occur in second child if the mothers body produces antibodies against such Rh antigens recognized after first delivery. This too is preventable nowadays by giving anti D injections to the mother during the pregnancy so that the baby doesn't face the above problems .
In case the baby develops such problems , still it can be treated unless severe.

So to sum it up , there is no such hazard in marrying a O Rh negative female and it just needs future vigilance and appropriate check up by the couples gynaecologist during pregnancy . You can absolutely have healthy babies like any other couple if both of you have no fertility issues.

Hope I have answered your query.
Kindly accept my answer in case you have no further queries.
Wishing you all the best.
Regards

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