Question:

At my 20 week ultrasound (20w 3d) I was informed that the baby has 2 cysts on the right kidney. My doctor didn`t seem overly concerned and told us that we would have another ultrasound further along in pregnancy. Can the cysts disappear? Should I be concerned?

Answer:

Cysts in the kidney are benign, fluid filled pockets that typically do not require treatment. Depending on the size and number of cysts, further tests may be performed after birth including an ultrasound of the kidneys and bladder of the baby. There are a few rare genetic disorders that can result in particular patterns of cysts on the kidney and may require follow-up after birth, particularly if there is a family history of kidney failure. Another possibility is that the “cysts” are actually “hydronephrosis”, which is a partial blockage of the kidney. This can range from a very mild problem that resolves itself to a major obstruction that requires surgery in the first year of life.

A follow-up ultrasound later in the pregnancy can help distinguish between the two. If the kidney has severe hydronephrosis, a consultation with a pediatric urologist after birth would be necessary to decide if further evaluation and treatment is required. No prenatal intervention is ever performed on the baby if the other kidney is normal. Your obstetrician will perform a follow-up prenatal ultrasound to keep an eye on the kidney during the pregnancy. It’s also helpful to let the your pediatrician know about the issue after birth so that they can determine if subspecialty consultation is necessary.

For more information:

Go to the Urinary and Genital Disorders (Children) health topic.