HI .. I just wanted to say I've read your post, have some kidney issues of my own but don't have an answer for you.. You can try a community search on the top of the right hand screen right above the recent activity and put in some key words such as kidney swelling, neonatal, etc. The sitewide search can be acessed on the very top right hand corner "Search MedHelp".
I hope some info from our archives or health topics area can help you .. try way on top hitting health topics and see if any thing comes up there, too.
Did the doctor suspect any particular condition that they are monitoring for? Two of my kids have kidney reflux, which is a condition where the urine sometimes flows back into the kidney. Each were diagnosed when they were a few months old. Enlarged kidneys are sometimes a symptom of this condition. I'm not saying that this is what your baby has, but perhaps it is one thing they will test for once the baby is born.
If it is kidney reflux, most cases are very treatable (assuming there hasn't been too much kidney damage). Here in the US, mild to moderate cases are often just monitored on a yearly basis and/or treated with daily antibiotics. Many kids outgrow it. In some cases, surgery is eventually need to correct the defect, and is highly successful.
See if your doctor can provide more details about what they saw and please keep us posted.