I was unable to take 6mp while pregnant as it caused me to have severe headaches for some unknown reason. After giving birth to my twins I began taking it again and have been nursing for 11 months. They are healthy and happy in every way possible.
I do know how easy it is to blame our medication. I took asacol while pregnant with my 2nd son and he was born with hydroseal and I asked everyone under the sun if it could have been from asacol. And the answer from all medical experts was NO! My pediatrician laughed at me! He said his son had it and his wife did not take asacol. Ask for reassurance from everyone. I am sure you will find that the 6mp caused absolutely no harm to your baby. You may even find other children who have this problem and most likely their mothers never took 6mp.
It is a natural instinct to blame anything wrong with our children (especially when they are infants) on something we have done.
I hope you find the answers you are looking for and I hope all turns out well with your little one.
Diagnosed with UC in July of 2003 then diagnosed with Crohns in August of 2006.