My dd has hydronephrosis of one of her kidneys. It was detected at the 20 week scan (she is now 18mo) and she had a pyloplasty at 3 months and a couple of cystoscopies since.
I am now 17 weeks pg and getting nervous about forthcoming 20 week scan, as that is when dd's was picked up.
If you have one child with hydronephrosis I am interested to know did your other children have it too? On the plus side at least we know now it is curable and the ops, while horrible to go through, are not as major as some problems some kids have.