hi hun, i found out my lil boy had this at my 20 week scan too! firstly please dont worry yourself!! all it is (as it was explained to me) is the muscles that help us wee arent strong enough/ developed enough in some babies so when they go for a wee a little bit comes back up and into the kidneys hence why theres a small amount of fluid in there which causes the kidneys to become enlarged. i had a rescan at 28 weeks where one kidney had sorted itself out, then i had another scan at 34 weeks where they were both in normal range. as the baby develops more, the muscle gets stronger and usually sorts itself out before bubs is born. when Kye was born he was on antibitics called something like Trimenthropine orally. he had a kidney scan at 6 days old where they said everything was fine but to continue the course of antibitoics just in case, then the consultant wrote to me a few weeks later and discharged kye. i worried myself sick like you but please dont worry, it is very common and it is something that generally sorts itself out. enjoy the rest of your pregnancy, bubs will be fine hun! if you ever wanna chat message me chick, i know exactly how your feeling! my lil man has had no problems with weeing or with his kidneys. keep smiling huni your beautiful baby will be just fine :-D xxx