hi, my first son had enlarged kidneys which was picked up at the 20 weeks ultrasound. we had two more scans during the pregnancy, and he went for a scan at 5 days old while we were leaving the hospital, and the problem was no longer evident at all. two more follow up scans got the all clear, so try not to worry (easier said than done i know) sometimes things sort themselves out without further intervention too. all the best, julie