Thanks for your question.
A distended urinary bladder
along with decrease liquor volume ( that can produce a decrease in expected fundal height
) may indicate that there may be an obstruction in the urinary outflow tract of your baby that is why your doctor has advised you for a second opinion
Only if there is so much obstruction to cause backward load on your baby's kidneys, to the extent of damaging it, should delivery be indicated otherwise only ultrasound
follow up is advised till term.
There is no indication for a cesarean delivery in most of the cases however your gynecologist will discuss all the options with you when a more detailed report is available. Till then hope for the best & don't take tension as most of these problems can be easily & satisfactorily dealt with after birth. Your baby is now mature enough to survive in this world in case an early delivery required.
At present it is difficult to say anything as this could be a normal finding if the baby has not passed urine for sometimes & therefore you should better wait for the more experienced sonologist to see your baby's structure in detail & give her/his expert advise.
Wish you best of luck.