Vitamin K deficiency bleeding (VKDB), formerly known as haemorrhagic disease of the newborn, is a serious but preventable bleeding disorder affecting infants during the first six months of life. This condition occurs when babies have insufficient vitamin K to produce adequate clotting factors essential for normal blood coagulation. Newborns are particularly vulnerable because vitamin K does not cross the placenta efficiently, breast milk contains relatively low concentrations, and the newborn gut lacks bacteria necessary to synthesise this vital nutrient. Since the introduction of routine vitamin K prophylaxis programmes in the UK, VKDB has become rare. Current NICE guidance recommends that all newborns should be offered vitamin K prophylaxis to prevent this potentially life-threatening condition.

What Is Vitamin K Deficiency Bleeding?

Vitamin K deficiency bleeding (VKDB), formerly known as haemorrhagic disease of the newborn, is a serious but preventable bleeding disorder that primarily affects infants. This condition occurs when babies have insufficient vitamin K to produce adequate clotting factors, specifically factors II, VII, IX, and X, which are essential for normal blood coagulation.

Vitamin K is a fat-soluble vitamin that plays a crucial role in the synthesis of clotting proteins in the liver. Newborns are particularly vulnerable to deficiency because:

• Vitamin K does not cross the placenta efficiently during pregnancy

• Breast milk contains relatively low concentrations of vitamin K

• The newborn gut lacks the bacteria necessary to synthesise vitamin K

• The immature liver has limited capacity to store and utilise vitamin K

VKDB is classified into three distinct types based on timing of presentation. Early VKDB occurs within the first 24 hours of life and is often associated with maternal medication use. Classical VKDB presents between days 1 and 7 of life, typically in breastfed infants who have not received vitamin K prophylaxis. Late VKDB develops between 1 week and 6 months of age, with most cases occurring by 12 weeks, and is the most dangerous form, frequently associated with underlying conditions affecting vitamin K absorption.

Without prophylactic vitamin K administration at birth, VKDB affects a significant number of newborns. Since the introduction of routine vitamin K prophylaxis programmes in the UK, the incidence has decreased dramatically, making VKDB a rare condition. Current UK guidance (NICE NG194) recommends that all newborns should be offered vitamin K prophylaxis to prevent this potentially life-threatening condition.

Causes and Risk Factors

The primary cause of VKDB is insufficient vitamin K availability during the critical neonatal period when clotting factor synthesis is essential. Several maternal, neonatal, and environmental factors contribute to this deficiency state.

Maternal factors that increase risk include the use of certain medications during pregnancy that interfere with vitamin K metabolism. These include:

• Enzyme-inducing anticonvulsants (particularly phenytoin, phenobarbital, carbamazepine)

• Anticoagulants (warfarin)

• Some antibiotics with specific structures (those with N-methylthiotetrazole side chains)

Women taking these medications should receive specialist obstetric care, and their infants require careful monitoring for bleeding complications.

Neonatal risk factors are particularly important in identifying vulnerable infants. Exclusively breastfed babies face higher risk because breast milk contains lower amounts of vitamin K compared with infant formula. Premature infants have increased susceptibility due to immature liver function and reduced vitamin K stores. Birth trauma, instrumental delivery, or difficult labour may precipitate bleeding in infants who already have vitamin K deficiency.

Underlying medical conditions significantly elevate VKDB risk, particularly for late-onset disease. Cholestatic liver disease and biliary atresia are the most significant risk factors for late VKDB. Other conditions that may affect vitamin K status include alpha-1 antitrypsin deficiency, and malabsorption syndromes. Prolonged antibiotic therapy disrupts gut flora that contribute to vitamin K synthesis.

The most significant preventable risk factor is failure to receive vitamin K prophylaxis at birth. Parental decline of vitamin K administration, whether due to misinformation or personal preference, substantially increases VKDB risk. Healthcare professionals should provide evidence-based counselling to support informed decision-making regarding this life-saving intervention, in line with NICE guidance.

Signs and Symptoms to Watch For

The clinical presentation of VKDB varies depending on the timing and severity of bleeding. Recognition of warning signs is crucial for prompt intervention and prevention of serious complications, particularly intracranial haemorrhage, which occurs in a significant proportion of late VKDB cases.

Early warning signs in newborns may be subtle but require immediate medical attention:

• Excessive bleeding from the umbilical cord stump that persists beyond normal oozing

• Bruising or petechiae (small red or purple spots) appearing without obvious trauma

• Bleeding from puncture sites (heel prick tests, injection sites) that continues beyond 5–10 minutes

• Blood in vomit (haematemesis) or black, tarry stools (melaena) indicating gastrointestinal bleeding

• Pallor, lethargy, or poor feeding suggesting anaemia from blood loss

Classical VKDB typically presents between days 1 and 7 with bleeding from mucosal surfaces, gastrointestinal tract, or skin. Parents may notice blood-streaked vomit, dark stools, or oozing from the nose or mouth. Circumcision sites may bleed excessively in affected male infants.

Late VKDB presents more dramatically and constitutes a medical emergency. Symptoms include:

• Sudden onset of irritability, high-pitched crying, or altered consciousness

• Bulging fontanelle (soft spot) suggesting raised intracranial pressure

• Seizures or abnormal movements

• Vomiting and refusal to feed

• Unexplained bruising, particularly on the head or trunk

• Pale or mottled skin indicating shock

Intracranial haemorrhage is the most feared complication of late VKDB, carrying significant risk of permanent neurological disability or death. Any infant presenting with neurological symptoms, particularly if exclusively breastfed and without documented vitamin K prophylaxis, requires urgent assessment.

Parents should maintain vigilance during the first six months, especially if vitamin K was declined at birth or if the infant has risk factors such as liver disease (indicated by prolonged jaundice with pale stools and dark urine) or malabsorption. Even minor bleeding manifestations warrant medical evaluation to exclude VKDB.

Diagnosis and Testing

Diagnosis of VKDB requires clinical suspicion combined with laboratory confirmation of coagulopathy and vitamin K deficiency. Prompt investigation is essential when bleeding occurs in at-risk infants, as delayed diagnosis increases morbidity and mortality.

Initial clinical assessment includes detailed history-taking to identify risk factors. Clinicians should enquire about:

• Vitamin K prophylaxis administration at birth (dose, route, timing)

• Feeding method (breast milk, formula, or mixed)

• Maternal medication use during pregnancy

• Family history of bleeding disorders

• Presence of jaundice, pale stools, or dark urine suggesting liver disease

Physical examination focuses on identifying bleeding sites and assessing haemodynamic stability. Careful neurological examination is mandatory to detect signs of intracranial haemorrhage.

Laboratory investigations form the cornerstone of diagnosis. First-line coagulation studies include:

• Prothrombin time (PT)/International Normalised Ratio (INR) – typically markedly prolonged in VKDB

• Activated partial thromboplastin time (APTT) – usually prolonged but less dramatically than PT

• Fibrinogen level – normal in VKDB, helping distinguish it from disseminated intravascular coagulation

• Platelet count – normal in isolated VKDB

• Full blood count – may reveal anaemia if significant blood loss has occurred

The characteristic pattern in VKDB shows prolonged PT and APTT with normal fibrinogen and platelets, reflecting deficiency of vitamin K-dependent clotting factors (II, VII, IX, X). Factor VII has the shortest half-life and is affected earliest, explaining why PT is particularly sensitive.

Specific vitamin K testing includes measurement of plasma vitamin K levels and PIVKA-II (proteins induced by vitamin K absence), though these tests are rarely immediately available in UK practice and should not delay treatment. A dramatic improvement in coagulation parameters following vitamin K administration provides retrospective diagnostic confirmation.

Imaging studies may be necessary when intracranial haemorrhage is suspected. Cranial ultrasound offers a bedside screening tool in young infants, but has limitations for detecting certain types of haemorrhage. CT or MRI scanning provides more definitive assessment of intracranial bleeding. There should be a low threshold for neuroimaging in infants with suspected late VKDB, with decisions guided by specialist paediatric and neurosurgical input.

Treatment and Prevention Strategies

Management of VKDB involves immediate treatment of active bleeding and long-term prevention strategies. The approach differs based on whether the infant presents with established bleeding or requires prophylaxis.

Acute treatment for infants with active bleeding constitutes a medical emergency:

• Vitamin K (phytomenadione) 1mg for term infants, with dose adjustment for premature babies. If given intravenously, it must be administered very slowly to avoid rare anaphylactoid reactions (as per Konakion MM Paediatric SmPC)

• Fresh frozen plasma (FFP) 10–15 ml/kg provides immediate replacement of clotting factors while awaiting vitamin K effect (which takes 4–6 hours)

• Prothrombin complex concentrate (PCC) may be considered in severe cases under specialist haematology advice

• Red blood cell transfusion if significant anaemia or haemodynamic compromise exists

• Neurosurgical consultation for intracranial haemorrhage requiring intervention

Coagulation studies should be repeated 4–6 hours after vitamin K administration to confirm response. Most infants show dramatic improvement in PT within this timeframe. Failure to respond suggests alternative diagnoses such as inherited clotting disorders or severe liver disease.

Prevention strategies are highly effective and form the cornerstone of VKDB management. The UK follows NICE guidance (NG194) recommending:

Routine prophylaxis – All newborns should be offered vitamin K shortly after birth. Two regimens are available:

• Intramuscular route: Single 1mg dose (0.5mg for babies under 1.5kg as per BNFc) provides reliable protection against all forms of VKDB with a single administration

• Oral route: Three doses of 2mg mixed micelles preparation (at birth, 4–7 days, and at 1 month for breastfed infants) for parents declining intramuscular administration. Formula-fed infants may not require the third dose as formula contains vitamin K

The intramuscular route is preferred due to superior efficacy and compliance. Studies demonstrate virtually complete protection against VKDB with intramuscular prophylaxis, whereas oral regimens show slightly higher failure rates, particularly if doses are missed.

Special circumstances require modified approaches:

• Infants of mothers taking enzyme-inducing medications should receive 1mg intramuscular vitamin K at birth

• Babies with cholestatic jaundice or malabsorption require specialist paediatric hepatology/haematology input for ongoing vitamin K supplementation, typically via the intramuscular route due to unreliable oral absorption

• Exclusively breastfed infants whose parents declined prophylaxis should receive urgent vitamin K if any bleeding manifestation occurs

Healthcare professionals should provide evidence-based counselling to parents regarding vitamin K prophylaxis, addressing common concerns about safety while emphasising the serious consequences of VKDB. No good evidence supports a link between vitamin K administration and childhood leukaemia.

Suspected adverse reactions to vitamin K can be reported via the MHRA Yellow Card scheme.

When to Seek Medical Advice

Parents and caregivers must understand when bleeding symptoms require urgent medical evaluation. Early recognition and prompt treatment of VKDB significantly improve outcomes and reduce the risk of permanent neurological damage or death.

Seek immediate emergency care (call 999 or attend A&E) if your baby shows:

• Excessive bleeding from any site that does not stop with gentle pressure after 10 minutes

• Blood in vomit or black, tarry stools indicating gastrointestinal bleeding

• Sudden change in behaviour, excessive irritability, or high-pitched crying

• Unusual drowsiness, difficulty waking, or reduced responsiveness

• Seizures, abnormal movements, or stiffening of the body

• Bulging soft spot (fontanelle) on the head

• Unexplained bruising, particularly on the head, face, or trunk

• Pale or mottled skin suggesting shock or significant blood loss

These symptoms may indicate serious bleeding, including life-threatening intracranial haemorrhage, and require immediate medical assessment.

Contact your GP, health visitor or NHS 111 urgently (same day) if you notice:

• Persistent oozing from the umbilical cord stump beyond normal healing

• Small amounts of blood in nappy or vomit

• Bruising appearing without obvious cause

• Prolonged bleeding from heel prick sites or after vaccinations

• Tiny red or purple spots (petechiae) on the skin

• Pale appearance or reduced feeding

Specific risk groups require heightened vigilance. Parents should be particularly alert if:

• Vitamin K prophylaxis was declined at birth

• Your baby is exclusively breastfed (breast milk contains low vitamin K)

• Your baby has jaundice persisting beyond two weeks, pale stools, or dark urine (suggesting liver problems)

• You took certain medications during pregnancy (anticonvulsants, antibiotics, anticoagulants)

• Your baby has chronic diarrhoea or other signs of malabsorption

Preventive consultations are advisable if you declined vitamin K at birth and wish to reconsider. Vitamin K can be administered at any point during the first few months of life, though earlier administration provides better protection. Discuss with your GP or health visitor if you have concerns about your baby's vitamin K status.

Healthcare professionals should maintain a low threshold for investigating bleeding in young infants, particularly during the first six months of life. Coagulation screening is simple, rapid, and potentially life-saving. Parents should never feel they are "overreacting" when seeking advice about bleeding in their baby – early presentation allows prompt treatment and prevents serious complications.

Frequently Asked Questions