NICU Terms Every Twin Parent Should Know: A Plain-English Guide
Walking into the NICU for the first time can feel like stepping into another world. Monitors beep constantly, nurses and doctors use medical abbreviations you’ve never heard before, and your tiny babies may be connected to equipment that looks overwhelming.
If your twins need time in the Neonatal Intensive Care Unit (NICU), learning a few common terms can help you feel more confident during rounds, ask informed questions, and better understand your babies’ daily progress.
As a registered nurse and twin mom, I know how much medical language can affect the way a situation feels. I understood many of these terms before my twins were born, but I also know that understanding the terminology doesn’t necessarily make it less intimidating when it involves your own babies.
You don’t have to memorize an entire medical dictionary. Learning one term at a time is enough.
Twin Parent Tip
Keep a small notebook or use the Notes app on your phone to write down unfamiliar NICU terms during rounds. It's much easier to ask, "Can you explain what brady means?" than to try to remember every new word later.
NICU Places & Equipment
NICU
NICU stands for Neonatal Intensive Care Unit. It is a specialized hospital unit that cares for premature babies and newborns who need extra monitoring, medical treatment, or specialized support after birth.
Some babies stay for only a few days, while others may remain in the NICU for weeks or months depending on their medical needs.
Isolette
An isolette is a clear enclosed bed designed to help premature and medically fragile babies stay warm while protecting them from excess noise, drafts, and germs.
Although it can look intimidating at first, an isolette actually creates a stable environment that helps babies conserve energy for growth and development.
Incubator
You may hear the words incubator and isolette used interchangeably.
Both refer to the enclosed bed that keeps babies warm and provides a carefully controlled environment while they continue to grow.
Open Crib
An open crib is a regular hospital baby bed.
Moving from an isolette to an open crib is often an exciting milestone because it usually means your baby is able to maintain their body temperature without extra heat.
Radiant Warmer
A radiant warmer is an open bed with a heating unit positioned above the baby.
Unlike an isolette, it allows nurses and doctors easy access during medical procedures while still helping keep the baby warm.
Monitor
Every NICU baby is connected to a bedside monitor.
The monitor continuously tracks important information such as:
Heart rate
Breathing rate
Oxygen saturation
Blood pressure (when applicable)
The alarms can sound stressful, but they are designed to alert the medical team whenever a baby's numbers change. Not every alarm means there is an emergency.
Leads
Leads are the small sticky sensors attached to your baby's chest.
These sensors connect to the bedside monitor and allow it to continuously track your baby's heart rate and breathing.
The stickers are changed regularly to help protect your baby's delicate skin.
Pulse Ox
A pulse oximeter, often called a pulse ox, is a small sensor placed on your baby's hand or foot.
It measures how much oxygen is in your baby's blood and sends that information to the bedside monitor.
IV
An IV (intravenous line) is a small catheter placed into a vein.
It allows your baby's care team to give fluids, medications, antibiotics, or nutrition without repeated needle sticks.
PICC Line
A PICC line stands for Peripherally Inserted Central Catheter.
This longer IV is used when babies need medications or intravenous nutrition for an extended period of time. Because it stays in place longer than a regular IV, it can reduce the need for multiple IV placements.
Umbilical Line (UVC/UAC)
Shortly after birth, some babies have special catheters placed in the blood vessels of the umbilical cord.
These are called:
UVC (Umbilical Venous Catheter)
UAC (Umbilical Arterial Catheter)
These lines allow the NICU team to safely give medications, fluids, nutrition, monitor blood pressure, and obtain blood samples while minimizing repeated needle sticks.
As babies become more stable, umbilical lines are typically removed and replaced with other forms of IV access if needed.
Breathing Terms
CPAP
CPAP stands for Continuous Positive Airway Pressure.
CPAP delivers a gentle flow of air through small prongs in your baby's nose or a soft mask. The air helps keep the tiny air sacs in the lungs open, making it easier for babies to breathe on their own.
Many premature babies need CPAP for a period of time while their lungs continue to mature.
Nasal Cannula
A nasal cannula is a small tube that rests just beneath your baby's nose.
It delivers extra oxygen or airflow to help support breathing. Babies on a nasal cannula are breathing on their own but may still need a little assistance while they continue to grow stronger.
Ventilator
A ventilator is a machine that helps a baby breathe when they are not yet able to breathe effectively on their own.
A breathing tube is placed into the baby's airway and connected to the ventilator, which delivers carefully controlled breaths. Some babies only need a ventilator for a short time, while others require support for longer depending on their condition.
Room Air
You may hear the NICU team say your baby is "on room air."
Room air simply means your baby is breathing normal air without receiving any additional oxygen. Since the air we breathe naturally contains about 21% oxygen, being on room air is often an exciting milestone during a NICU stay.
FiO₂
FiO₂ (pronounced "F-I-O-two") stands for Fraction of Inspired Oxygen.
This refers to the percentage of oxygen your baby is receiving.
For comparison:
Room air contains 21% oxygen
Babies needing breathing support may receive a higher percentage
As babies improve, the medical team gradually decreases the FiO₂ toward 21%
Many NICU parents celebrate as they watch those oxygen numbers slowly come down.
Respiratory Distress Syndrome (RDS)
Respiratory Distress Syndrome (RDS) is a common breathing condition in premature babies.
Because babies born early may not have fully developed lungs, they often don't produce enough surfactant, a substance that helps keep the tiny air sacs in the lungs open.
RDS is one of the most common reasons premature babies need breathing support shortly after birth.
Surfactant
Surfactant is a natural substance produced by the lungs that helps keep the tiny air sacs from collapsing.
Premature babies sometimes don't have enough surfactant yet, making breathing much more difficult.
If needed, doctors can give surfactant through a breathing tube shortly after birth to help improve lung function.
Intubation
Intubation is the process of placing a breathing tube into your baby's airway.
The breathing tube connects to a ventilator, allowing the machine to assist or completely support breathing while your baby's lungs recover or continue developing.
Extubation
Extubation means the breathing tube has been removed.
This is often an exciting milestone because it means your baby is ready to breathe with less support. After extubation, many babies transition to CPAP or a nasal cannula before eventually breathing completely on room air.
Monitor Terms
Brady (Bradycardia)
Brady is short for bradycardia, which means your baby's heart rate briefly dropped lower than expected.
Premature babies commonly experience occasional brady episodes because the part of the nervous system that controls breathing and heart rate is still developing.
Some episodes resolve on their own, while others require gentle stimulation from a nurse. Your baby's care team closely monitors how often these events happen and what may be causing them.
Desat (Oxygen Desaturation)
A desat is short for oxygen desaturation, meaning your baby's oxygen level temporarily dropped lower than the care team would like.
Desats are fairly common in premature babies, especially during feedings or after a brady episode. The NICU team pays attention to how low the oxygen level dropped, how long it lasted, and whether your baby recovered independently.
Apnea
Apnea is a pause in breathing that lasts longer than expected.
Premature babies may experience apnea because the part of the brain that controls breathing is still immature.
As babies grow and their nervous systems develop, apnea episodes usually become less frequent and eventually resolve.
A's & B's
You may hear nurses say your baby had a few "A's and B's" overnight.
This is common NICU shorthand for:
A = Apnea
B = Bradycardia
Sometimes desaturation episodes are included as well because these events often occur together.
Self-Resolved
A self-resolved event means your baby's heart rate or oxygen level returned to normal without anyone needing to intervene.
This is generally reassuring because it shows your baby recovered independently.
Stim
Stim is short for stimulation.
If a baby has a prolonged apnea or brady episode, a nurse may gently rub their back, reposition them, or provide another gentle touch to remind their body to resume normal breathing.
Many premature babies outgrow the need for stimulation as they mature.
Feeding Terms
NG Tube
An NG tube (nasogastric tube) is a small feeding tube that passes through your baby's nose into their stomach.
It allows babies to receive breast milk or formula when they are too premature or medically fragile to safely feed by mouth.
Having an NG tube does not mean your baby won't learn to eat. It simply gives them the nutrition they need while they continue developing their feeding skills.
OG Tube
An OG tube (orogastric tube) works just like an NG tube, except it passes through the mouth instead of the nose.
Some NICUs prefer OG tubes for babies receiving certain types of breathing support because they can be more comfortable or easier to position.
PO Feeding
PO stands for "by mouth."
When the medical team says your baby is taking feeds "PO," they mean your baby is drinking milk by bottle or breastfeeding instead of receiving it through a feeding tube.
Learning to feed by mouth is often one of the biggest milestones before NICU discharge.
Gavage Feeding
Gavage feeding means breast milk or formula is delivered slowly through a feeding tube into your baby's stomach.
Many premature babies receive gavage feeds while they develop the strength and coordination needed to safely suck, swallow, and breathe during feedings.
Fortifier
Fortifier is a nutritional supplement that may be added to breast milk or formula.
Premature babies have higher calorie and nutrient needs than full-term babies. Fortifier provides extra protein, calories, vitamins, and minerals to support healthy growth and development.
Adding fortifier does not mean there is anything wrong with your breast milk. It simply helps meet the unique nutritional needs of premature infants.
TPN
TPN stands for Total Parenteral Nutrition.
TPN provides nutrition through an IV when babies are not yet able to tolerate full milk feedings.
It contains carbohydrates, protein, vitamins, minerals, and other nutrients needed to support growth while the digestive system matures.
As babies gradually tolerate larger milk feedings, the amount of TPN is slowly decreased until it is no longer needed.
Lipids
Lipids are intravenous fats that are often given along with TPN.
They provide important calories and essential fatty acids that help support brain development, growth, and overall nutrition.
Feeding Cues
Feeding cues are signs that your baby may be ready to eat.
Common feeding cues include:
Waking before feeding time
Rooting (turning toward touch near the mouth)
Bringing hands to the mouth
Sucking on fingers or a pacifier
Becoming alert before care times
Rather than feeding strictly by the clock, many NICUs watch for these cues to determine when babies are ready to practice feeding by mouth.
Non-Nutritive Sucking
Non-nutritive sucking means practicing sucking without drinking milk.
This often involves offering a pacifier during tube feedings so babies can begin connecting the feeling of sucking with the feeling of a full stomach.
Non-nutritive sucking helps strengthen oral muscles and prepares babies for breastfeeding or bottle feeding.
Feeder & Grower
You may hear your baby's care team describe your baby as a "feeder and grower."
This usually means your baby no longer needs intensive medical treatment but is staying in the NICU to continue learning how to feed by mouth, gain weight consistently, and grow strong enough to safely go home.
For many families, becoming a feeder and grower is an encouraging milestone because it often means the biggest medical challenges have been overcome.
Common Medical Conditions
Jaundice
Jaundice is a yellow coloring of a baby's skin and eyes caused by a buildup of bilirubin in the blood.
Jaundice is extremely common in newborns, especially premature babies, because their livers are still developing and may not remove bilirubin efficiently.
Most cases improve with treatment and careful monitoring.
Bilirubin
Bilirubin is a yellow pigment produced when red blood cells naturally break down.
Because newborns, especially premature babies, have immature livers, bilirubin can build up in the bloodstream faster than the body can remove it.
The NICU team monitors bilirubin levels with blood tests to determine whether treatment is needed.
Phototherapy
Phototherapy is the blue light treatment commonly used to lower bilirubin levels and treat jaundice.
During phototherapy, babies wear protective eye coverings while lying under special lights that help the body break down and eliminate excess bilirubin.
Although seeing your baby under blue lights can feel surprising at first, phototherapy is a very common and effective treatment.
PDA (Patent Ductus Arteriosus)
A Patent Ductus Arteriosus (PDA) is a blood vessel that normally closes shortly after birth.
In premature babies, it sometimes remains open longer than expected, allowing extra blood to flow between major blood vessels.
Some PDAs close on their own, while others may require medication or, less commonly, a procedure to close them.
Sepsis Rule-Out
You may hear your baby's team mention a "sepsis rule-out."
Because newborns can become seriously ill from infections very quickly, NICU teams often start antibiotics while waiting for blood culture results whenever infection is suspected.
A sepsis rule-out does not necessarily mean your baby has an infection. It means the medical team is taking precautions while they gather more information.
NEC (Necrotizing Enterocolitis)
Necrotizing Enterocolitis (NEC) is a serious intestinal condition that primarily affects premature babies.
Although NEC is uncommon, NICU teams monitor babies closely for early signs because prompt treatment is very important.
Most parents will hear the term during their NICU stay, even if their own baby never develops the condition.
Care Team Terms
Neonatologist
A neonatologist is a pediatrician with advanced training in caring for premature, critically ill, and medically complex newborns.
They oversee your baby's medical care, develop treatment plans, and work closely with the rest of the NICU team.
Neonatal Nurse Practitioner (NNP)
A Neonatal Nurse Practitioner (NNP) is an advanced practice registered nurse who specializes in caring for newborns in the NICU.
NNPs perform exams, order tests, prescribe treatments, and work alongside neonatologists to provide daily medical care.
NICU Nurse
NICU nurses provide around-the-clock care for your baby.
They monitor vital signs, administer medications, perform feedings, comfort your baby, answer questions, and often become one of the biggest sources of support for families throughout their NICU journey.
Respiratory Therapist (RT)
A Respiratory Therapist (RT) specializes in caring for babies who need breathing support.
They help manage oxygen therapy, CPAP, ventilators, breathing treatments, and monitor your baby's lung function as they grow stronger.
Lactation Consultant
A Lactation Consultant helps families with breastfeeding, pumping, milk supply, latching, and feeding plans.
Even if your babies cannot breastfeed right away, a lactation consultant can help you establish and protect your milk supply during your NICU stay.
Occupational Therapist (OT)
An Occupational Therapist (OT) helps babies develop the skills needed for feeding, movement, sensory regulation, and everyday activities.
Depending on your baby's needs, an OT may help with positioning, muscle tone, developmental support, and feeding readiness.
Physical Therapist (PT)
A Physical Therapist (PT) focuses on movement, muscle strength, flexibility, positioning, and motor development.
Early therapy can help support healthy movement patterns and developmental progress throughout your baby's NICU stay.
Speech-Language Pathologist (SLP)
Many parents are surprised to learn that Speech-Language Pathologists (SLPs) work in the NICU.
SLPs help evaluate and support feeding skills, including sucking, swallowing, breathing coordination, and oral motor development. Their goal is to help babies learn to feed safely and efficiently.
Social Worker
A NICU Social Worker helps families navigate the emotional and practical challenges of a NICU stay.
They can connect families with financial resources, counseling services, support groups, lodging assistance, transportation resources, and discharge planning.
Case Manager
A Case Manager helps coordinate your baby's care before discharge.
They assist with insurance questions, medical equipment, home health services, follow-up appointments, and other resources your family may need after leaving the hospital.
Rounds
Rounds are daily meetings when the NICU team reviews each baby's progress and discusses the plan for the day.
Whenever possible, try to be present during rounds. This is an excellent opportunity to hear updates, ask questions, and better understand your babies' care.
Development & Bonding
Kangaroo Care
Kangaroo Care is skin-to-skin contact between a parent and baby.
Research shows that skin-to-skin care can help regulate your baby's temperature, heart rate, breathing, and blood sugar while also promoting bonding and supporting breastfeeding.
Even babies receiving medical support can often participate in kangaroo care with guidance from the NICU team.
Corrected Age
Corrected age is your baby's age based on their original due date rather than their birth date.
For example, if your twins were born eight weeks early and are four months old, their corrected age would be about two months.
Corrected age is often used to evaluate growth and developmental milestones during the first two years of life.
Cue-Based Feeding
Cue-based feeding means feeding your baby based on signs of readiness instead of following a strict schedule alone.
Rather than focusing only on the clock, the NICU team watches for feeding cues such as rooting, sucking, and alertness before offering bottles or breastfeeding.
Cluster Care
Cluster care means grouping several caregiving activities together, such as diaper changes, temperature checks, and feedings.
This allows babies to enjoy longer periods of uninterrupted sleep, which is important for growth, healing, and brain development.
Preparing for Discharge
Car Seat Test
Many premature babies complete a car seat test before going home.
During this test, your baby sits in their car seat while nurses monitor their heart rate, breathing, and oxygen levels to make sure they can safely tolerate riding in the seated position.
Rooming In
Some hospitals offer rooming in, where parents spend a night caring for their baby before discharge while hospital staff remain nearby if assistance is needed.
This gives families an opportunity to build confidence before going home.
Discharge Criteria
Every NICU has its own discharge guidelines, but many babies are ready to go home when they can:
Maintain their body temperature in an open crib
Take all feedings by mouth
Gain weight consistently
Breathe without significant medical support
Remain free of concerning apnea or bradycardia episodes for a specified period of time
Your baby's medical team will determine when it is safe for your family to go home.
NICU Terms A–Z Quick Reference
A's & B's – A common NICU shorthand for apnea and bradycardia episodes.
Apnea – A pause in breathing that is common in many premature babies because their nervous systems are still developing.
Bilirubin – A yellow pigment produced when red blood cells break down. High bilirubin levels can lead to jaundice.
Brady (Bradycardia) – A temporary drop in a baby's heart rate below the expected range.
Car Seat Test – A monitored test completed before discharge to ensure your baby can safely ride in a car seat.
Cluster Care – Grouping diaper changes, feedings, and assessments together so babies can rest longer between care times.
CPAP – Continuous Positive Airway Pressure, a form of breathing support that helps keep the lungs open.
Cue-Based Feeding – Feeding based on your baby's readiness cues rather than following the clock alone.
Desat (Desaturation) – A temporary drop in your baby's oxygen level.
Extubation – Removal of a breathing tube after a baby is ready for less breathing support.
Feeder & Grower – A baby who no longer needs intensive medical treatment but remains in the NICU to improve feeding skills and gain weight.
Feeding Cues – Signs that your baby is ready to eat, such as rooting, sucking, or waking before feeding time.
FiO₂ – The percentage of oxygen your baby is receiving. Room air contains approximately 21% oxygen.
Fortifier – Extra nutrients added to breast milk or formula to help premature babies grow.
Gavage Feeding – Delivering breast milk or formula through a feeding tube into the stomach.
Incubator – Another name for an isolette, an enclosed bed that helps regulate a baby's temperature.
Intubation – Placement of a breathing tube into the airway to assist with breathing.
Isolette – A temperature-controlled enclosed bed that helps premature babies stay warm and protected.
IV – An intravenous line used to provide fluids, medications, or nutrition.
Jaundice – Yellowing of the skin and eyes caused by elevated bilirubin levels.
Kangaroo Care – Skin-to-skin contact between a parent and baby that supports bonding and development.
Leads – Sticky sensors placed on your baby's chest to monitor heart rate and breathing.
Lipids – Intravenous fats given along with TPN to provide calories and support growth.
NEC (Necrotizing Enterocolitis) – A serious intestinal condition that primarily affects premature babies.
Nasal Cannula – Small tubing placed beneath the nose to provide extra oxygen or airflow.
Neonatologist – A physician who specializes in caring for premature and medically fragile newborns.
NG Tube – A feeding tube that passes through the nose into the stomach.
NICU – Neonatal Intensive Care Unit, where newborns receive specialized medical care.
NNP (Neonatal Nurse Practitioner) – An advanced practice nurse specializing in newborn intensive care.
OG Tube – A feeding tube that passes through the mouth into the stomach.
Open Crib – A regular hospital crib used once a baby can maintain their own body temperature.
PDA (Patent Ductus Arteriosus) – A blood vessel that remains open after birth and may require monitoring or treatment.
Phototherapy – Blue light therapy used to treat jaundice.
PICC Line – A long-term intravenous catheter used for medications and nutrition.
PO Feeding – Feeding by mouth through breastfeeding or bottle feeding.
Pulse Ox – A sensor that measures the oxygen level in your baby's blood.
Radiant Warmer – An open bed with a heating unit above it that keeps babies warm while allowing easy access for medical care.
Respiratory Distress Syndrome (RDS) – A breathing condition caused by immature lungs that is common in premature babies.
Respiratory Therapist (RT) – A healthcare professional who manages breathing support and oxygen therapy.
Room Air – Breathing normal air without additional oxygen.
Rooming In – An overnight stay where parents care for their baby before discharge with hospital staff nearby if needed.
Rounds – The daily meeting where the NICU team reviews each baby's progress and care plan.
Sepsis Rule-Out – A precautionary evaluation for infection while waiting for blood culture results.
Self-Resolved – An event, such as a brady or desaturation, that corrected itself without intervention.
Speech-Language Pathologist (SLP) – A specialist who helps babies develop safe feeding and swallowing skills.
Stim (Stimulation) – Gentle rubbing or repositioning used to help a baby recover from an apnea or brady episode.
Surfactant – A substance that helps keep the lungs open. Premature babies sometimes need surfactant medication shortly after birth.
TPN (Total Parenteral Nutrition) – Nutrition delivered through an IV while babies are not yet ready for full milk feedings.
Umbilical Line (UVC/UAC) – A catheter placed in the umbilical cord shortly after birth to provide medications, fluids, nutrition, or blood pressure monitoring.
Ventilator – A machine that helps a baby breathe through a breathing tube.
My RN & Twin Mom Perspective
As a registered nurse, many of these medical terms were already familiar to me before becoming a twin mom. But I also know that understanding medical terminology is very different from hearing it used when someone is talking about your own baby.
Thankfully, my twins did not require a NICU stay, but many twin families do. That’s why I wanted to create this guide in plain English. You shouldn’t have to feel like you’re learning an entirely new language while also trying to understand what’s happening with your babies.
NICU staff don’t expect parents to understand every abbreviation or medical term. If you don’t understand something, ask. If you need someone to explain it again, ask again. Understanding what’s happening can help you feel more informed and confident as part of your babies’ care team.
🗣️ SLP Perspective from Dr. Judy
One of the most common questions families ask is, "Why can't my baby just take a bottle yet?"
Feeding is actually one of the most complex skills newborns learn. Babies must coordinate sucking, swallowing, and breathing at the same time. Premature babies often need additional time for these skills to fully develop.
Speech-language pathologists work with NICU babies to evaluate feeding readiness, strengthen oral motor skills, and help ensure feedings are both safe and successful.
Every baby progresses at their own pace. Taking extra time to develop these skills now helps build a safer foundation for feeding after discharge.
Frequently Asked Questions
Why do NICU staff use so many abbreviations?
Medical teams use abbreviations to communicate quickly and efficiently. If you hear a word or acronym you don't recognize, don't hesitate to ask for an explanation.
Can parents participate in rounds?
In many NICUs, yes. Parents are encouraged to listen during rounds, ask questions, and participate in discussions about their baby's care plan whenever possible.
What does "feeder and grower" mean?
A feeder and grower is a baby who no longer needs intensive medical treatment but is staying in the NICU to improve feeding skills and gain weight before going home.
Is it okay to ask the NICU team to explain something more than once?
Absolutely. NICU staff understand that parents are processing a tremendous amount of information during an emotional time. Asking questions helps you become an informed member of your baby's care team.
What's the difference between actual age and corrected age?
Actual age is how long it has been since your baby was born. Corrected age adjusts for how early your baby was born and is often used when tracking growth and developmental milestones during the first two years.
Related Guides
Hospital Bag Checklist for Twins
Preparing for a Twin NICU Stay
Corrected Age vs. Actual Age
Newborn Twin Feeding Schedule
Breastfeeding Twins: The Complete Guide
References
American Academy of Pediatrics. HealthyChildren.org.
Centers for Disease Control and Prevention. Infant Development.
March of Dimes. Premature Babies and the NICU.
National Institute of Child Health and Human Development.
MedlinePlus. Neonatal Intensive Care.
Medical Disclaimer
This content is for educational and informational purposes only and should not be considered medical advice. Every baby and every NICU journey is unique. Always follow the guidance of your baby's neonatologist and NICU care team regarding your child's diagnosis, treatment, and care.
