Asacol is the brand name of a medicine called mesalazine. Ranitin contains ranitidine. Wysolone is the brand name of prednisolone. Azathioprine is the generic name. None of the medicines mentioned above would cause any malformation in the baby if taken during the first trimester (three months) of pregnancy. However azathioprine should be avoided since in some rare cases it may retard the growth of the baby. It should only be taken if the disease is severe and not controlled with other medicines. There is absolutely no reason at all to terminate pregnancy.