Vesicoureteric reflux is more common in –
Newborn females
Older girls
Older boys
Only during pregnancy
Clinical manifestations of VUR 

In primary reflux the average age ofpresentation is 2-3 years.
Reflux is more common in females and it is usually detected earlier in females so we can say that reflux is present from birth but it is usually detected at 2-3 years of age but in feinales the age of detection is earlier.

Features are -

In primary reflux the patient usually presents with symptoms of pyelonephritis or cystitis.
In secondary reflux manifestation of primary diseases are usually the presenting symptoms
Reflux is the most common cause of pyelonephritis. It is seen in 30-50% of patients with pyelonephritis.
It is present in over 75% of patients with radiological evidence of chronic pyelonephritis Diagnosis of Vesicoureteric reflux -
The most useful process for conclusive diagnosis of reflux is micturating cystourethrogram.
This will demonstrate the grade of reflux as well as urethral anatomy.
The other useful technique for detecting vesicoureteric reflux is radionuclide imaging.
It is extremaly sensitive at detecting reflux but do not demonstrate the anatomic detail seen with voiding cystourethro gram.
So they are used for follow up after micturating cystourethrogram because they offer less radiation exposure.