Vitamin K for newborn babies: injection, drops and why it is offered

Vitamin K travels poorly across the placenta, so babies start life with small stores. Breast milk is also relatively low in it, and a newborn’s gut has not yet been colonised by the bacteria that later make vitamin K. During the first weeks the liver can therefore struggle to produce enough clotting proteins.

For most babies this causes no problem. For a very small number, bleeding occurs without warning and can be severe, which is why the NHS approach is to offer prevention to all babies rather than try to predict who will be affected.

Trust information describes bleeding that can come from the stomach, the navel, the intestine or, more rarely, the brain. Bleeding in the brain is the outcome that causes permanent injury or death, and it can happen with no earlier sign. Some babies have minor bleeds first, such as from the skin, nose or mouth, which is why those signs matter.

Babies at higher risk include those born early, those who have had a difficult or instrumental delivery, those with liver conditions, and those whose mothers took certain medicines such as some anti-epileptic drugs in pregnancy. Tell the midwife about any of these, because they may influence the advice on the route.

The injection is given once, usually within hours of birth, and one dose protects a baby through the vulnerable period. Rotherham NHS Foundation Trust notes that it is the more effective option for preventing VKDB and that the main downsides are short-lived pain and occasional bruising at the site.

The oral route gives a first dose at birth and later doses. According to the trust guidance, breastfed babies need extra oral doses at intervals in the first month, while formula-fed babies need fewer because formula contains added vitamin K. Your midwife will give the exact timetable for your area, and the doses must be given on time, as a missed one leaves the baby less protected.

If a baby vomits shortly after a drop, tell the midwife or health visitor, because the dose may need repeating.

• Injection: one dose, most effective, brief discomfort.

• Drops: a first dose at birth plus follow-up doses, with the timetable depending on how the baby is fed.

• Either choice is recorded in the baby’s red book (the personal child health record) for your health visitor to see.

In 1992 a study raised the possibility of a link between the injection and childhood leukaemia. Because this worried many families, it was examined again in several countries. The trust leaflet states that many more reports disproved the link and that vitamin K has been shown to be safe. The original concern is still repeated online, so it helps to know it was investigated and not confirmed.

Parents should tell a midwife, health visitor or GP promptly about bleeding from the skin, nose or mouth, or from the navel after the cord has separated, during the first six months. Jaundice that is still present after two weeks, especially with pale stools or dark urine, needs assessment because it can point to a liver or bile duct problem that also affects vitamin K absorption.

Sudden pallor, floppiness, drowsiness, persistent vomiting or a swollen soft spot on the head are emergencies and should be treated as such by calling 999 or going to A&E.

It is possible to change your mind later. Speak to your midwife or health visitor as soon as you can, as the benefit is greatest in the first weeks of life. Home births and midwife-led units offer vitamin K in the same way as hospitals.