The PulseOx test
Your new-born baby will have a test known as a PulseOx Test. This is a routine test offered to all babies after birth during the new-born examination.
The team looking after you will explain the test before it is done and will answer any questions you have.
Why is your baby having this test?
We are trying to find the small number of babies who have medical problems that can cause their oxygen levels to be lower than usual. Some babies can appear healthy when they are born but have lower oxygen levels than expected.
This test will tell us which babies have lower oxygen levels. We can then consider additional tests and assessments to see if your baby has a condition that needs treatment. This will mean that treatment (if appropriate) can be offered as early as possible.
What happens during the test?
A PulseOx Test is completely harmless and painless and takes less than five minutes. It measures the oxygen levels (sometimes called oxygen saturations) in your baby.
We do this by wrapping a small sensor around your baby’s right hand. This sensor is connected to a device called a pulse oximeter, which measures the oxygen levels by shining a light through your baby’s skin. We will then take a second reading with the sensor – this time wrapped around your baby’s foot. It’s important to get both these readings for the test.
We aim to do a PulseOx Test within the first few hours after your baby is born.
What if my baby’s oxygen levels are normal?
If your baby’s oxygen levels are normal, no further PulseOx Tests are needed at this time. Your baby will have all the usual care before being discharged, including their routine new-born examination.
A normal result is very reassuring, but it doesn’t completely rule out the chance of a problem developing. If you have any concerns about your baby’s colour, breathing, feeding or the way your baby is behaving after the test seek urgent advice.
What if my baby’s test shows lower than normal oxygen levels?
There are two reasons why your baby might be showing lower than normal oxygen levels:
1. About three in every 100 babies (3%) will have slightly low oxygen levels on the first test. We know this might be worrying for you, but the lungs of some babies adapt to being born more slowly than others – this is normal and these babies are healthy. Because we know this, if your baby’s oxygen levels are only slightly lower than normal in the first test and your baby appears healthy, then we will do the test again a second time about one or two hours later. This is called a retest.
2. About three in every 1000 babies (0.3%) will have oxygen levels that are much less than expected. These babies will be seen by a doctor or specialist nurse straight away. They will examine your baby and may do tests to try to find out why their oxygen levels are low.
What happens if my baby needs a retest?
Nine out of every 10 babies who need a retest will have normal oxygen levels at their second test, and no further tests are needed. It is important that your baby’s oxygen levels are normal before they are discharged, so very occasionally the need to do the retest will lead to a slight delay in your discharge.
What will happen next if my baby needs further examination or treatment?
In total (including first tests and retests) about seven in every 1000 babies (0.7%) will need further investigations and these babies will probably be admitted to the Neonatal Unit (sometimes called Baby unit, Neonatal Intensive Care Unit (NICU) or Special Care Baby Unit (SCBU)). This may make you feel worried, but you will be able to see your baby on the unit and the doctors or nurses will tell you what is happening at every stage.
On the Neonatal Unit, your baby may have blood tests and x-rays to try to find out why their oxygen levels are low. Some babies may also have an ultrasound of their heart (called an echocardiogram or echo for short).
Of the babies admitted to the Neonatal Unit:
- two in every 10 will be healthy – these babies are usually in the Neonatal Unit for less than 12 hours
- seven in every 10 will have a breathing problem or infection, and they will benefit from early diagnosis and treatment
- one in every 10 will have a heart problem, and they will benefit from early diagnosis and treatment.