Common NICU Tests

Your baby will have a number of different tests during his stay in the neonatal intensive care unit (NICU). These tests help determine what your baby's problems may be and how they should be treated. Tests also help monitor his progress. Your baby's doctor will tell you what tests are recommended and inform you of the results. If your baby needs a major test, the doctor will ask you to sign a consent form before the test is done. These are some of the tests done in the NICU. Your baby may need additional specialized tests, depending on his medical condition.


  • Blood tests: These are among the most common procedures done in the NICU. Blood tests provide important information on how your baby is doing. They alert doctors to potential problems before they become more serious.
  • Echocardiogram: A specialized form of ultrasound examination that is used to study the heart. It can detect structural problems (heart defects) and problems with how the heart works. 
  • Hearing test: Premature and other sick babies are at increased risk of hearing problems. Before your baby goes home he will have a hearing test. It is important to detect hearing problems early, in order to help prevent speech and language problems.
  • Magnetic resonance imaging (MRI): MRI scan’s produce a very detailed picture that may be difficult to see on an X-ray or ultrasound. This test is painless and safe for babies. Your baby will need to be taken to the radiology department for this test. 
  • Newborn screening test: Also called a PKU, this is a test performed by pricking a baby's heel to obtain a few drops of blood on a filter paper. It tests babies for serious hereditary disorders. 
  • Retinopathy of prematurity (ROP) examination: This test usually is done for babies born at or before 32 weeks of gestation or weighing less than 1,500 grams (3 1/3 pounds). The test is generally performed about 4 weeks after birth, or when your baby reaches 31 to 33 weeks. Before the examination, the doctor places drops in your baby’s eyes so the doctor can see her retina and determine whether the blood vessels are developing normally. If your baby has any signs of ROP, the doctor will repeat this test regularly to see if the condition is clearing up on its own, or whether treatment is necessary. 
  • Ultrasound: Ultrasound takes a picture of a baby's organs using sound waves, rather than X-rays. A small hand-held device called a transducer is rubbed back and forth over the area that the doctor wants to see. An ultrasound examination is painless and is usually done in the NICU. 
  • Urine tests: Like blood tests, urine tests can tell a great deal about a baby's overall condition. Urine tests can help determine how well the kidneys are working, and whether your baby has an infection. 
  • Weighing: Your baby is weighed soon after delivery, then at least once a day while he is in the NICU. Don't be alarmed if your baby loses some weight in the first days or weeks after birth. This is normal, especially for very small babies. When a premature baby starts gaining weight at a steady rate, it is an encouraging sign that he is doing well. 
  • X-rays: X-rays provide pictures of your baby's lungs and other internal organs. These pictures help your baby's doctor plan her treatment and monitor her progress.