Hi,
I have had one remicade baby and she is now 9 months old. She is very healthy and at her last appointment she weighed 22lbs and was almost 30 inches long. So, she is growing just fine:)
I timed my remicade treatments so that I had the last one before birth between 32-34 weeks. Much later then that and then the medicine crosses over into the placenta. I would talk to your GI and your OB. Make sure that they both feel you are healthy enough for pregnancy. They should be in contact through out your pregnancy keeping an eye on you.
Congratulations on starting this new journey!