Hello doctors A 21-year-old primi with 20wks pregnancy with vulval swelling with pain, afebrile, no burning micturation, no rash, no blisters, no sores, no other symptoms.CBC,urine RM, VDRL, HIV,HBsAg all normal. No h/o trauma Hvs awaited.

Usg show mildoligohydraminos What could be the diagnosis and line of treatment?