Chronic neonatal lung disease (CNLD)

Chronic neonatal lung disease (CNLD) is a breathing condition that can develop in premature babies. Premature means your baby was born before 37 weeks of pregnancy.

It usually affects premature babies because they’re born before their lungs have fully developed in the womb.

CNLD is sometimes called chronic lung disease of prematurity or bronchopulmonary dysplasia (BPD).

What does this mean for my baby?

Your child’s lungs get bigger and develop more air sacs called alveoli as they grow. Some children with CNLD may have fewer problems with their breathing as they grow older. But other children may continue to have breathing problems.

Some children grow up to have long-term effects from CNLD.

All children are different. How fast they get better, how much their symptoms improve, and what care they need will vary. It can depend on lots of things like how early your baby is born and how much they weigh when they’re born.

How common is CNLD?

CNLD is the most common complication of premature birth. But the risk of developing CNLD is not the same for all premature babies. It mainly affects babies born under 32 weeks.

The earlier a baby is born, the more likely they are to develop CNLD. Around:

• 8 in 100 babies born at 31 weeks get CNLD
• 39 in 100 babies born at 28 weeks get CNLD
• 89 in 100 babies born at 24 weeks get CNLD – less than 1% of premature babies are born at 24 weeks.

CNLD is becoming more common because more babies are surviving being born very prematurely.

Premature lungs and risk of CNLD

Being born prematurely, especially before 32 weeks of pregnancy, is the biggest risk factor for CNLD. This is because your baby is born before their lungs have finished developing in the womb, so they have fewer air sacs and less surfactant in their lungs.

Surfactant is a substance that helps make sure the air sacs in your lungs do not collapse when you breathe out. It’s produced as babies’ lungs develop in the womb, but premature babies may not have enough surfactant.

If your baby is born early, they’re likely to need breathing support like oxygen therapy and ventilation (support from a breathing machine) as soon as they’re born.

Premature babies’ lungs are more likely to get injured from oxygen therapy and ventilation because their lungs are not fully developed.

Breathing support (oxygen therapy and ventilation)

Your baby may need breathing support like oxygen therapy and ventilation when they’re born.

Sometimes these treatments can cause harmful inflammation in your baby’s lungs. This may cause your baby to develop CNLD.

If your baby needs oxygen or ventilation, healthcare professionals will do all they can to prevent or reduce damage. They will use gentler breathing support if possible.

Babies are not born with CNLD. Healthcare professionals will diagnose your baby with CNLD on the neonatal unit if they still need extra oxygen after they’re 28 days old or after 36 weeks corrected age (the age your baby would’ve been born).

Healthcare professionals may do some tests to confirm the diagnosis and understand more about your baby’s condition, including:

• a chest X-ray to check for CNLD and any damage to your baby’s lungs
• pulse oximetry to monitor your baby’s blood oxygen levels
• a blood gas test to show the levels of oxygen and carbon dioxide in your baby’s blood.

Treatment for CNLD will support your baby to help their lungs grow and develop.

The treatment your baby needs will depend on lots of things, like how serious their CNLD is and any other health conditions they have.

Your baby’s specialists will be able to give you the best advice about your child’s condition, but usually babies need:

• extra oxygen (oxygen therapy) to help them breathe better
• special nutritional support to help them put on weight and grow well.

When your baby is in hospital, they’ll be treated in a neonatal unit until they’re well enough to go home.

The time your baby stays in hospital depends on their condition and what treatment they need.

The neonatal unit is the safest place for your baby to be after they first get diagnosed because specialists can do further tests and monitor how your baby is doing.

If your baby is born before 37 weeks, you should have a follow-up appointment with a specialist healthcare professional within 2 days of leaving hospital to check how you and your baby are doing.

Extra oxygen (oxygen therapy)

If your baby has low blood oxygen levels, they may be given extra oxygen. This is called oxygen therapy. Oxygen can be given either through a tube in your baby’s nose or through the air in their incubator.

Your baby may need home oxygen therapy when they leave hospital. This helps your baby continue their treatment without needing to stay in hospital.

Each baby is different but many babies with CNLD will only need oxygen therapy until they’re one year old.

Other treatments your baby may have for CNLD

Some babies with more serious CNLD, or who get respiratory tract infections like bronchiolitis and pneumonia may need additional treatment and breathing support.

Breathing support

Your baby may have breathing support in hospital with a continuous positive airway pressure (CPAP) or ventilator machine.

CPAP is a type of breathing machine that helps your baby to breathe by keeping their lungs inflated. A ventilator is also a machine that helps your baby to breathe.

Your baby may have needed this treatment after they were born if they had newborn respiratory distress syndrome (NRDS).

Bliss have more information about equipment in the neonatal unit, including CPAP and ventilators breathing machines.

Some babies may continue to need breathing support at home.

Medicines

Some babies may need medicines for their CNLD. These may help, but there’s not lots of evidence about how effective these medicines are for CNLD. Research is still happening to find out more. 

Avoid infections as much as possible

It’s important to help your child avoid infections, especially in the first five years of their life.

This is because they’re at more risk of getting respiratory tract infections (sometimes called chest infections) like flu, respiratory syncytial virus (RSV), bronchiolitis, and pneumonia. They’re also more likely to get seriously ill from these infections.

Bliss have more information about how you can help your baby avoid infection.

There are lots of other things that parents and carers can do to help children with CNLD:

• Agree a plan for what to do when your child is ill with their specialist, including when to seek medical attention - make sure you know the signs that your child needs help for their breathing
• Do not smoke or vape, or let others smoke, around your child – take a look at our information if you’d like support on how to stop smoking
• Try to reduce how much air pollution your child is exposed to
• Make sure your child’s vaccines are up to date and ask your doctor about the flu vaccine
• Keep an eye on your baby’s weight and make sure they have a healthy diet - it’s important your baby gets enough nutrients to grow properly so that their lungs can develop well.  Breathing, fighting infection, and coughing can use up your child’s energy. Their immune system will need plenty of protein and vitamins to fight infection. The NHS website has useful information about feeding young babies.

It’s important for your child to urgently see a healthcare professional if they get ill, especially if they have symptoms of a cold or flu. We know from calls to our helpline that it can be hard to get a GP appointment for your child. Make sure their GP surgery knows that your child has CNLD.

Debby Waddell, Respiratory Nurse Specialist

Some children with CNLD may experience complications. These can develop as a baby or as they grow older and they can affect your child for a few days or weeks (short-term) or weeks, months or years (long-term).

It’s difficult to know exactly why some children develop complications, but some complications may also be related to premature birth.

Your child will be given treatment to help manage any complications. They may need to go back into hospital for more monitoring or treatment.

Infections

Children with CNLD are more at risk of getting respiratory tract infections, especially RSV, and being seriously ill if they do.

This means when your child has a respiratory tract infection, especially during the first few years of their life, they may:

• have serious symptoms like breathing difficulties - it’s important to be aware of symptoms that mean you should get medical help
• take longer to recover than babies without CNLD.

Difficulty feeding and reflux

Babies with severe CNLD may have difficulty feeding or bring up milk during or shortly after feeding (reflux).

This can make it difficult for your baby to gain weight or stay a healthy weight.

Find out more about reflux in babies from the NHS, including the symptoms to look out for and when to get medical help.

Pulmonary hypertension

Children with CNLD have a higher risk of developing a condition called pulmonary hypertension. Pulmonary hypertension happens when there’s high blood pressure in the blood vessels that supply your child’s lungs.

This may happen if their lungs have not developed as expected.

CNLD can increase the risk of developing lung health problems in later life.

Long-term effects of CNLD can include:

• developing asthma
• asthma-like symptoms that do not respond well to asthma treatment including coughing, wheezing (noisy chest sounds), and getting very breathless during exercise
• your lungs not working as well
• developing slower and not reaching childhood milestones when expected and developing conditions like cerebral palsy - it’s important to talk to your health visitor or GP if you’re worried about your child's development or their milestones.

Research is still happening to understand the long-term effects of CNLD. They may be linked to how severe your child’s CNLD is and how early they were born.

Always contact your child’s specialists if you’re worried or have any questions.

We know seeing your baby being treated in hospital can be difficult. It’s important you take time to take care of yourself as well as them.

Find support through:

• calling the Listening Ear service provided by charity Contact for families with disabled children
• talking to a healthcare professional - they can signpost you to counselling and wellbeing services
• the charity Bliss – they have information and resources to support families with babies born premature or sick.