Vitamin K for newborn babies to prevent serious bleeding

All babies are born with low levels of vitamin K in their bodies. Vitamin K is made naturally in the intestine but as newborn babies have very little bacteria in their intestine they don't make enough. As your baby grows they will start to make enough vitamin K.

Breast milk contains vitamin K but in too small an amount to provide protection. Too little vitamin K puts your baby at risk of a rare disease called VKDB (vitamin K deficiency bleeding).

All newborn babies have low levels of vitamin K and so they are at risk of VKDB. VKDB is rare and the chance of babies developing it is small, even if they haven't received extra vitamin K. But, if babies do develop VKDB, it can cause internal bleeding leading to death, or permanent damage to their brain and other organs.

Babies who are at increased risk of VKDB include:

• Babies born to mothers taking certain medicines, eg, some medicines for epilepsy and tuberculosis, and anti-coagulants. If you are on any of these medicines, talk to your healthcare provider or midwife before your baby is born.
• Premature babies (born early).
• Sick babies.
• Babies who haven't received vitamin K at birth.
• Exclusively breastfed babies who have not had vitamin K at birth.

• VKDB can happen in the first day of a baby's life but this is rare – it usually happens to babies of mothers taking certain medicines.
• VKDB happens most often in the first 1 to 7 days of a baby's life.
• VKDB can happen up to about 6 months of age in babies with liver or bowel problems, or exclusively breastfed babies who haven't had vitamin K at birth.

Babies have low levels of vitamin K in their bodies because:

• vitamin K is mainly made by bacteria in the gut and there are few bacteria in a baby's gut at birth
• babies don't get enough vitamin K from their mothers during pregnancy or breastfeeding.

The most reliable way to give babies vitamin K is by an injection into the muscle in the leg (intramuscular injection). One injection given just after birth will protect your baby for many months.

It's possible to give babies vitamin K by mouth (orally). However, this isn't recommended because:

• vitamin K isn't absorbed as well when given by mouth
• the protection doesn't last as long and so 3 doses are required (at birth, at 5 to 7 days and at 6 weeks)
• there may be doubt as to whether the dose has been swallowed
• there is a risk that the later dose may be forgotten
• some babies may have conditions that prevent absorption of vitamin K from the gut.

All babies need vitamin K. This includes babies who are premature, very small or sick, as well as babies having surgery.

Research and practice have shown that giving vitamin K by injection at birth is safe and effective. Babies in Aotearoa New Zealand, and in many other countries, have been given vitamin K injections for many years without problems.

Having the injection doesn't cause any health problems, but some babies have a slight swelling or soreness at the site of the injection for a day or two.

One study in the early 1990s suggested that injections of vitamin K might be linked to 1 type of childhood cancer. Later research has proven that vitamin K is not associated with any kind of childhood cancer, whether it's given by mouth or by injection.

It's your choice whether or not your baby receives vitamin K and whether it's given by injection or by mouth. Giving vitamin K by injection provides the best protection for your baby. Giving vitamin K by mouth (orally) doesn't provide as much protection for your baby and they will need to have 2 more doses over a period of weeks.

Not giving vitamin K at all means that your baby is at risk of getting a severe, preventable health problem and you should watch closely for any warning signs of bleeding.

If you decide against your baby having vitamin K, you need to watch very carefully for symptoms of VKDB (vitamin K deficiency bleeding). You should always see your healthcare provider urgently if your baby has any of the following warning signs:

• Easy bruising increasing.
• Bruising around their head and face.
• Bleeding from their nose, gut or umbilical cord (bleeding and bruising are not normal in the first months of life).
• Irritability, vomiting, paler than usual skin or (for dark skinned babies) pale appearing gums which might be due to internal bleeding.
• Your baby is over 3 weeks of age and there are any signs of worsening jaundice.

Your lead maternity carer (LMC) or doctor can give you more information about vitamin K.