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Newborn and Infant Care

Ovary cyst in a 6 month old baby



My baby is 6 month and she was born with only one kidney and yesterday in a scan they discover she as cyst in the ovary. She is doing well now, and the question is what kind of risk she has now or we she becomes older.


Missing one kidney at birth, or unilateral renal agenesis, is the most common congenital urinary tract malformation. It occurs in about 1 in 2,900 births and is more common among mothers who are African American and those who have diabetes mellitus or both. The causes are believed to be both a consequence of genetic inheritance as well as environmental factors, most of them yet to be identified.

By this time I would imagine that your daughter has had an evaluation of her single kidney's function. If that is normal, then you can expect that this healthy kidney will enlarge over time and maintain normal renal function for her body. It would be important to protect this one kidney from injury, so contact sports should be avoided as she grows into school age activities.

Ovarian cysts and other genital tract malformations commonly occur with renal agenesis. This is because both the genital or reproductive system and the urinary system develop from a common embryonic tissue called the mesoderm. In fact, the mesonephric ducts that build the urinary system guide the development of the reproductive system. So if there is a problem in the development of the urinary system, it is often reflected in altered development of the reproductive system in both girls and boys. Cysts are common in both girls' ovaries and boys' testes. They occur on the same side as the renal agenesis.

Many  times ovarian cysts are seen even on prenatal ultrasounds. The size of the cyst forecasts best what problems may occur. Ovarian cysts 4 cm in size or smaller are highly likely to disappear over time. Ovarian cysts larger than 4 cm are more likely to require surgical care either because the cyst causes the ovary to twist (torsion) or because the cyst fills with blood from a hemorrhage. Bleeding is twice as likely to be the problem as is torsion. In both cases, your daughter would complain of severe abdominal pain on the affected side but she would not have a fever. As an infant, if she started loud crying and pulling up her legs as if in terrible pain, but she was otherwise well, it would be the best action to take her to a pediatric emergency room for care, telling the staff that she has a cyst on her ovary and only one kidney.

In all likelihood, your daughter will do very well. It is likely, though, that she will have an increased chance of passing this problem on to her children. This can be lowered by helping her to maintain a healthy weight through good nutrition and lots of physical activity to decrease her chances of developing diabetes from being overweight.

I hope this information is helpful and easy to understand. Congratulations on your new baby!


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Response by:

Mary M Gottesman, PhD, RN, CPNP, FAAN Mary M Gottesman, PhD, RN, CPNP, FAAN
Professor of Clinical Nursing
College of Nursing
The Ohio State University