morphology of sperm

MH and I have beein trying to concieve for about a year, we just got test results back that showed his morphology at 54- borderline. He was taking allopurinol for gout up till a month ago - and then stopped based on some reports of infertility. Could this be the reason for the low morphology- if he contiues to stop taking the drug will it go back to normal. We already have 2 kids.