NICU Terminology Guide

25 terms — tap any tile to read the explanation

Information sourced from Bliss (bliss.org.uk), NHS (nhs.uk), East Midlands Neonatal ODN and NHS Neonatal Network South East. Always speak to your baby's neonatal care team for advice specific to your baby.

Apnoea

A pause in breathing lasting 20 seconds or more, or a shorter pause accompanied by a drop in heart rate or oxygen levels. Apnoea of prematurity is very common in babies born early, because the part of the brain that controls breathing is not yet fully mature. The monitors on the unit will alarm when an apnoea occurs. Babies usually recover on their own or with gentle stimulation, and most outgrow apnoea as they mature. Medication such as caffeine is sometimes used to help.

Blood Gases

A blood test that measures the levels of oxygen, carbon dioxide and other chemicals in your baby's blood. It gives the medical team information about how well your baby is breathing and how other organs, such as the kidneys, are working. Most blood samples for blood gases are taken by pricking the skin at the back of the hand or heel. The results help the team decide whether to adjust breathing support or other treatments.

Blood Transfusion

When extra blood is given to your baby through a cannula or line. This may be needed if your baby becomes anaemic, meaning their red blood cell count is too low for their body to carry enough oxygen. Premature babies can become anaemic because their red blood cells have a shorter lifespan, and because blood samples taken for monitoring can reduce their blood volume over time. Blood transfusions in premature babies are routine and closely monitored.

Bradycardia (Brady)

When your baby's heart rate temporarily slows down. In premature babies, this often happens alongside a desaturation or apnoea and is part of a condition called apnoea of prematurity. It is common in premature babies and usually resolves as they mature. The care team monitors heart rate continuously and will respond quickly if a brady occurs.

Cannula

A small, thin tube inserted into a vein, usually in the hand, foot or scalp, to allow fluids, medication or nutrition to be given directly into the bloodstream. A cannula is shorter term than a PICC line and may need to be resited regularly. Seeing a cannula in your baby's tiny hand or foot can be alarming, but they are a routine and essential part of neonatal care.

Central Line

A thin tube placed into a large vein, often near the neck, chest or groin, to allow medication, fluids and nutrition to be delivered directly into the bloodstream. Central lines are used when a baby needs intensive support over a period of time and a PICC line or cannula would not be sufficient. They are carefully monitored to reduce the risk of infection.

Corrected Age (Adjusted Age)

Your baby's age calculated from their original due date, rather than from their actual date of birth. Because premature babies are born before their development is complete, corrected age gives a much more accurate picture of where they should be developmentally. For example, a baby who is 4 months old but was born 2 months early has a corrected age of 2 months. Corrected age is used by healthcare professionals in the UK until around 2 years.

CPAP (Continuous Positive Airway Pressure)

A type of breathing support that delivers a gentle, steady flow of air through two small tubes placed in your baby's nostrils, or via a small mask. It slightly raises the air pressure in the airways, which helps keep your baby's lungs inflated between breaths. Your baby breathes on their own and CPAP simply provides support to make breathing easier. It is one of the most common forms of breathing support used on neonatal units in the UK.

Desaturation (Desat)

A drop in the level of oxygen in your baby's blood, measured by a saturation monitor attached to their hand or foot. You may hear the monitor alarm when a desat happens. In premature babies, desats are common and are often brief. The baby's oxygen levels usually recover quickly on their own or with gentle stimulation. The care team will monitor the pattern and frequency and adjust breathing support if needed.

Heel Prick Test

A small sample of blood is taken by pricking the skin of your baby's heel. Most routine blood samples in the NICU are taken this way. The newborn blood spot test, also done via heel prick, is offered to all babies in the UK around 5 days after birth to screen for a range of conditions. In the NICU, heel prick tests are used frequently to check blood sugar, blood gases, infection markers and other values.

Incubator

A clear, enclosed, heated bed that keeps your baby warm and protected. Premature babies cannot yet regulate their own body temperature, so the incubator maintains a carefully controlled warm environment. It also reduces the risk of infection and allows the care team to monitor your baby closely. As your baby grows stronger and is able to maintain their own temperature, they will be moved to an open cot, which is a significant milestone in the NICU journey.

Infection Markers (CRP)

Tests that measure substances in the blood that rise when the body is fighting an infection. The most common are white blood cell counts and C-reactive protein (CRP). CRP is a protein produced by the liver in response to infection or inflammation and higher levels suggest the body is fighting something. These markers help the team identify whether your baby has an infection and how well they are responding to treatment such as antibiotics.

IVH (Intraventricular Haemorrhage)

Bleeding that occurs in or around the fluid-filled spaces (ventricles) in the brain. It is most common in babies born before 32 weeks and is graded from 1 to 4, with grade 1 and 2 being mild and often resolving without long-term effects, and grade 3 and 4 being more significant. IVH is diagnosed by ultrasound scan. The care team will discuss the grade and what it means for your baby. Many babies with mild IVH go on to develop typically.

Jaundice

A common condition in newborn babies where the skin and whites of the eyes appear yellow. It is caused by a build-up of bilirubin, a yellow substance produced when old red blood cells are broken down, which the immature liver cannot process quickly enough. Jaundice is very common in premature babies and is usually treated with phototherapy. In babies with darker skin, jaundice may be easier to see in the whites of the eyes, inside the mouth and on the palms and soles of the feet.

Kangaroo Care (Skin to Skin)

Holding your baby directly against your bare chest, skin to skin. Research consistently shows that skin-to-skin contact has significant benefits for premature babies, including helping to regulate their temperature, heart rate and breathing, supporting brain development, and promoting bonding. It also supports breastfeeding and milk supply. You can usually begin skin to skin as soon as your baby is stable enough, and the care team will support you with this.

Nasal Cannula

A small, soft tube with two short prongs that sit just inside your baby's nostrils to deliver oxygen or air. Standard nasal cannulas deliver low-flow oxygen and are typically used when a baby needs only a small amount of breathing support. They are less intensive than CPAP or Optiflow and are often a sign that your baby's breathing is improving.

NEC (Necrotising Enterocolitis)

A serious condition where tissue in the bowel becomes inflamed and, in some cases, begins to break down. It mainly affects premature babies, particularly those born before 32 weeks or weighing less than 1,500g. Signs can include a swollen tummy, blood in stools, and general signs of being unwell. Treatment usually involves stopping milk feeds, giving antibiotics and providing nutritional support through TPN. Some babies need surgery. Breast milk is associated with a reduced risk of NEC.

NG Tube (Nasogastric Tube)

A thin, soft tube passed through your baby's nose, down the throat and into the stomach to deliver breast milk or formula directly. It is used when a baby is not yet strong enough to feed by mouth. The tube is secured gently to your baby's face with tape. It can look alarming at first, but it is one of the most common and important parts of neonatal care, and your baby will still be able to be held and have skin-to-skin contact while it is in place.

Optiflow (High Flow Nasal Cannula)

A brand name for Heated Humidified High Flow Nasal Cannula (HFNC) therapy. It delivers a flow of warm, moist air, with or without oxygen, through small, soft tubes in your baby's nostrils at a higher flow rate than standard oxygen. It is gentler than CPAP and is often used when a baby needs a little breathing support but not as much as CPAP provides, or when weaning from CPAP.

PDA (Patent Ductus Arteriosus)

Before birth, there is a blood vessel called the ductus arteriosus that connects two major blood vessels near the heart. In full-term babies, this closes shortly after birth. In premature babies it sometimes remains open and this is called a PDA. A PDA can put extra strain on the heart and lungs. Some PDAs close on their own as the baby matures; others are treated with medication or, less commonly, surgery.

Phototherapy

A treatment for jaundice that uses a specific wavelength of blue light to break down the bilirubin in your baby's skin into a form that can be passed out of the body more easily. During phototherapy your baby will be placed under special lights, or on a light-emitting pad, with as much skin exposed as possible. Their eyes will be protected with small shields. It is a safe and effective treatment that is very commonly used on neonatal units.

PICC Line (Peripherally Inserted Central Catheter)

A thin, soft plastic tube inserted into a vein in your baby's arm or leg that sits with its tip near the heart, allowing medication, nutrition (TPN) and other fluids to be delivered directly into the bloodstream. It is more stable than a standard cannula and can remain in place for longer. It is often used when your baby needs nutrition or medication over an extended period.

ROP (Retinopathy of Prematurity)

A condition affecting the eyes that can develop in premature babies, particularly those born before 31 weeks or weighing less than 1,500g. In ROP, the blood vessels in the retina, the light-sensitive layer at the back of the eye, do not develop normally. In most cases it resolves without treatment as the baby grows. More severe cases can be treated to prevent problems with vision. In the UK, babies at risk are routinely screened for ROP.

Sepsis

A serious response to infection where the body's immune system begins to damage its own tissues. In premature babies, whose immune systems are not yet fully developed, infections can spread quickly and sepsis can develop faster than in older children or adults. Signs can include changes in temperature, heart rate, breathing and feeding. Sepsis is treated urgently with antibiotics. Early detection and treatment are key, and the care team monitors for signs of infection closely throughout your baby's time on the unit.

TPN (Total Parenteral Nutrition)

A way of providing all the nutrients your baby needs, including fats, sugars, proteins and vitamins, directly into the bloodstream through a tube, when they are not yet able to tolerate milk feeds. TPN is delivered through a PICC line or central line and is carefully formulated to support your baby's growth. It is commonly used when the bowel needs to rest, for example during NEC treatment.