What do you suggest if my unborn babyboy has unilateral hydronephrosis?

Pediatric urologist: There are lots of causes for this. A pediatric urologist will diagnose and provide treatment. It can be lots of things from bladder reflux, obstruction among others.

Fetal hydronephrosis: Good news as unilateral, means that contralateral kidney is normal & your baby will have overall have normal kidney function. Baby will require abdominal ultrasound after birth, to demonstarte kidney, bladder & ureters, coincident with evaluation by pediatric urologist. Immediately after birth if severe, delay 2 - 4 weeks if mild - moderate. Most cases are mild & resolve spontaneously. Don't worry