c. What tests might a baby have in the NICU

NICU staff do tests to find out about your baby’s conditions so they know what treatment your baby needs. For example, providers may do a blood test to check your baby for anemia. Or they may take an X-ray to check for a lung infection.

Your baby’s provider tells you what tests your baby needs and lets you know the results. Before providers can do certain tests, they need your consent. This means they’ll ask you to read and sign a consent form. Sign the form only when you understand the test and why your baby needs it. Be sure to ask the NICU staff any questions before signing the form. This section explains a lot of common tests babies get in the NICU. If your baby needs a test that’s not described here, ask the NICU staff about it. 

blood tests — Tests a baby’s blood for certain health conditions. Blood tests are the most common tests done in the NICU. They give providers important information about how a baby is doing. They also help providers find possible problems before they become serious. Here are some conditions that blood tests can find:

  • Anemia (low number of red blood cells)
  • High levels of bilirubin (a yellowish waste product formed when red blood cells break down) which may mean the baby has jaundice.
  • Low blood sugar (hypoglycemia)
  • Salt or water levels that are out of balance
  • Infection (an illness caused by some viruses, bacteria or other germs)
  • Low oxygen or high carbon dioxide levels (blood gases)

Blood tests can be done through a heel stick, an umbilical catheter (a thin tube that goes into a baby’s umbilical cord and into the belly button), a central line (a small, plastic tube that is placed in a large blood vessel), or from a needle in a blood vessel.

cardiac catheterization (KAR-dee-ak kath-uh-tur-i-ZA-shuhn) — A medical procedure used to find and treat some heart conditions. A long, thin tube called a catheter goes into a blood vessel in the baby’s arm, upper thigh or neck all the way through to her heart. Once the catheter is in place, a provider can test and treat the baby’s heart.

computed tomography (kuhm-PYOO-ted toh-MOG-ruh-fee) — Also called CAT or CT scan. A test that takes pictures of the inside of the body. It is like an X-ray, but gives a clearer, 3D view. This test is painless and safe for the baby. The baby goes to the radiology department for the scan. She may need medicine to keep her still during the test. 

echocardiogram (ek-oh-KAR-dee-oh-gram) — A special kind of ultrasound that takes pictures of the heart. The ultrasound uses sound waves to take the pictures. Providers use it to help find heart defects (a problem with the heart that is present at birth) and other heart problems.

electrocardiogram (e-lek-tro-KAR-deo-gram) — Also called an EKG or ECG. A simple, painless test that records the heart’s electrical activity. An EKG can show how fast a baby’s heart is beating and if the rhythm of the heartbeat is irregular.

hearing test — A test called a brainstem  auditory evoked response test (also called BAER) that checks a baby’s hearing. A tiny earphone is placed in the baby’s ear so he can hear certain sounds. Small sensors are taped to his head. These sensors send information to a machine that measures the baby’s response to the sounds A hearing test is done on all babies as part of newborn screening.

magnetic resonance imaging (mag-NET-ik REZ-uh-nuhns IM-ij-eeng) — Also called MRI. Strong magnets and radio waves take pictures of the inside of the body. An MRI gives a more detailed view than a CT scan, X-ray or ultrasound. This test is painless and safe for a baby and doesn’t use X-rays. The baby may need medicine to keep her still during the test.

newborn screening test — Checks for serious but rare and mostly treatable conditions at birth. It includes blood, hearing and heart screening.

retinopathy of prematurity exam (ret-in-OP-uh-thee of pree-muh-CHOOR-uh-tee eg-ZAM) — Also called ROP exam or eye exam. This test is used most often for babies born before 30 weeks of pregnancy or babies who weigh less than 3 1/3 pounds. An eye doctor, also called an ophthalmologist, checks to see if the blood vessels in a baby’s eyes are developing the right way. If there are signs of problems, the  doctor keeps checking the baby’s eyes over time to see if the condition gets better or needs treatment.

ultrasound (UHL-truh-sound) — A test that uses sound waves to make pictures of the inside of the body. The technician puts a special jelly on the baby’s skin. Then she rolls a small device shaped like a microphone over the area of the baby’s body that she wants to check. Providers often use ultrasound to check for bleeding in the baby’s brain. This test is painless for the baby.

urine tests — Tests a baby’s urine (a liquid the body makes by filtering waste and extra water through the kidneys) for certain health conditions. Urine tests are common in the NICU. They can tell providers a lot about a baby’s overall condition. A urinary catheter (a thin tube that is put in the opening where urine passes out of the body) is used to collect the urine. Urine tests can help find out if:

  • The baby is getting enough fluid
  • The baby’s kidneys (an organ that removes waste products and excess fluid from the body) are working well
  • The baby has an infection (an illness caused by some viruses, bacteria or other germs)

weighing — Measuring a baby’s weight at birth and as he grows and develops. Providers weigh a baby soon after birth and at least once a day in the NICU. It is normal for premature babies (born before 37 weeks of pregnancy) to lose some weight in the first days or weeks after birth. It’s a good sign when babies start to gain weight at a steady rate.

X-ray — A test that uses small amounts of radiation to take pictures of the inside of the body. X-rays provide pictures of a baby’s lungs and other organs. These pictures help a baby’s doctor plan her treatment and check how well she is doing. A baby may need several lung X-rays each day if she has serious breathing problems. She is exposed to a little radiation from these X-rays, but the amount is so low that it doesn’t affect her health now or in the future.