What to Do When Your Baby Has a Urea Cycle Disorder

Ammonia. Even if you don’t know much about it, you know it’s great for cleaning but not so great for ingesting. You… you do know not to ingest it, right? If not: Don’t drink it. Put down the ammonia… please.

Anywho, like so many gloriously toxic substances, we produce ammonia naturally as a waste byproduct when our bodies break down proteins. Normally the liver transforms ammonia into urea, which passes harmlessly out of the body.

When this transformation process (called the urea cycle) malfunctions, ammonia can build up in the blood and result in grave damage. That’s why it’s so important to be aware of the symptoms of a urea cycle disorder.

Sadly, many of the patients most vulnerable to urea cycle disorders are also the ones least able to communicate their discomfort: newborns, infants, and young children. Because urea cycle disorders are caused by the absence of an enzyme needed to change ammonia into urea, symptoms typically appear within a day after birth—although in some cases symptoms don’t until later. The problem is that those symptoms don’t immediately scream “urea cycle disorder.” While vomiting is obviously cause for alarm, it’s difficult to connect the dots from “vomiting” to “urea cycle disorder.” And irritability and excessive tiredness are as essential to infant behavior as eating, sleeping, and diaper filling.

infant in diaper urea cycle disorder
A diaper, seen here in unfilled, happier times. [Source: pixabay.com]
So what are new parents and doctors to do to actually identify the disease? One of the best tools is probably awareness, especially of the genetic component. Infants diagnosed with a urea cycle disorder must inherit a defective gene from both parents, so parents should be tested for these defective genes.

Newborns may also be at risk if their Rh factor—which indicates a type of blood protein—is different from the mother’s. In other words, if the mother is Rh factor positive and the baby is negative (or vice versa), the mother’s immune system may think the infant’s red blood cells are foreign and attack them in utero, causing a release of excessive proteins and ammonia in the baby’s blood. In cases where an incompatibility is suspected, doctors can give the mother Rh immune-globulin injections to prevent her immune system from attacking the fetus.

Regardless of the cause, expectant parents should work with their doctors to know the real risks of urea cycle disorders for their children. The good news is that once a urea cycle disorder is identified, it can be managed with a low-protein diet and treatments that help flush ammonia from the body. That may not completely remove the fear factor of a diagnosis, but it does take away some of the guesswork for new parents and lets them focus on what really matters: Enjoying every moment with their baby.