Hello and welcome to e health forum.
It seems that your unborn baby has been diagnosed with Polycystic kidney disease. This is a condition where multiple cysts grow in the kidneys. As the cysts grow, they can damage the kidney tissue.
Presence of renal cysts in unborn fetuses is less common. Such cysts if remain stable, will not cause any major issues.
PKD or polycystic kidney disease occurs due to genetic mutations. Prenatal testing can identify polycystic kidney disease, via genetic tests and imaging studies like ultrasound.
PKD effects range from mild to severe. After birth, PKD may cause high blood pressure , recurrent urinary infections and with aging can cause renal failure too.
The management of this condition is via regular monitoring with renal function tests and ultrasounds.
You might consult with your doctor for proper tests and further management.