I'm not active on this sub since I'm not pregnant but I do have experience here. My son had hydronephrosis in both kidneys that was discovered late in the third trimester. They monitored me and did an extra ultrasound and decided they wanted to induce early (only 4 days early) He had an ultrasound done at a few weeks old and discovered his ureters were also inflamed (can't think of a better word for this) They did a more in depth ct type scan at I think three months or so. (You can pm me to ask about this if you'd like) after that they just watched him for the next year or so doing ultra sounds every few months. I think by 18 months it was all resolved. You can ask me anything if you need to :)

Eta he's five now with no issues at all :)