L.T.
I did a google search for "enlarged fetal kidneys" and found more helpful results, including what I copied below. Good luck to you both!!
"Enlarged kidneys are commonly detected on sonograms before birth. The majority of time, nothing serious is wrong. In a small number of children, there could be an obstruction or problem that will require treatment. The most important thing at this time is whether the amount of amniotic fluid around the baby is normal.
Enlarged kidneys are quite common and are not due to anything mothers have done during pregnancy. Evaluation needs to be done after the child is born, and in most cases the kidney function is fine, and does not require treatment.
However, when there is a problem, the most common causes are:
A cystic kidney may be a sign that that kidney did not develop properly and is usually an isolated problem, meaning typically no other problems may exist.
Also, there may be a problem with the chromosomes, most kids with these findings are otherwise normal."
from http://en.allexperts.com/q/ObGyn-Pregnancy-issues-1007/En...