Overview

Definition:
-Vitamin K prophylaxis at birth is the administration of a vitamin K injection to all newborns to prevent hemorrhagic disease of the newborn (HDN)
-Hepatitis B prophylaxis involves administering hepatitis B vaccine and, in some cases, hepatitis B immune globulin (HBIG) to infants born to mothers with hepatitis B infection to prevent vertical transmission and chronic infection.
Epidemiology:
-Hepatitis B infection affects millions worldwide, with significant risk of chronic infection and liver disease in infants born to infected mothers
-HDN, though rare with prophylaxis, can occur in exclusively breastfed infants and those with malabsorption, particularly in the first few months of life.
Clinical Significance:
-These prophylactic measures are critical public health interventions to prevent serious, potentially life-threatening conditions in newborns
-They are standard of care in obstetric and pediatric practice worldwide, including India, and form a core part of pediatric and DNB/NEET SS curriculum.

Vitamin K Prophylaxis

Indications:
-Routine administration to all newborns
-particularly important for preterm infants, infants of mothers on anticonvulsants, and exclusively breastfed infants.
Recommendations:
-Intramuscular (IM) injection of phytonadione (Vitamin K1) within the first hour of life or as soon as possible after birth
-Oral prophylaxis is an alternative but less effective and has lower compliance rates.
Dosage:
-Full-term infants: 0.5-1 mg IM
-Preterm infants (<1.5 kg): 0.2-0.5 mg IM
-Larger doses may be required in specific circumstances such as maternal anticoagulant use
-Oral dose: 2 mg within 6 hours of birth, followed by 1 mg daily for 3 months or duration of breastfeeding.
Adverse Effects:
-IM injection: Minimal local pain or swelling
-Oral: Gastrointestinal upset
-Rare allergic reactions
-Contraindications: None absolute, but caution in severe hepatic impairment.

Hepatitis B Prophylaxis

Indications:
-All infants born to HBsAg-positive mothers require prophylaxis
-Infants born to mothers with unknown HBsAg status should also receive prophylaxis.
Recommendations:
-For infants born to HBsAg-positive mothers: Administer Hepatitis B vaccine and HBIG within 12 hours of birth
-For infants born to HBsAg-negative or unknown status mothers: Administer Hepatitis B vaccine alone within 24 hours of birth.
Vaccine Schedule:
-Infants born to HBsAg-positive mothers: First dose of vaccine (and HBIG) within 12 hours, second dose at 1-2 months, third dose at 6 months
-Infants born to HBsAg-negative/unknown mothers: First dose at birth, second dose at 1-2 months, third dose at 6 months (or according to routine immunization schedule).
Hb Immune Globulin Hbig:
-Administered intramuscularly at a separate site from the vaccine, within 12 hours of birth for infants of HBsAg-positive mothers
-Dosage: 0.5 mL (10 IU/kg).
Follow Up: Infants born to HBsAg-positive mothers require serological testing (HBsAg and anti-HBs) at 9-12 months of age to confirm immunity and assess for infection.

Diagnostic Approach

Maternal Screening:
-HBsAg status of all pregnant women should be determined during antenatal care
-Identification of HBsAg-positive mothers is crucial for timely neonatal prophylaxis.
Infant Assessment: Assessment of gestational age, birth weight, and maternal HBsAg status immediately after birth to determine appropriate prophylactic measures.
Monitoring For Hdn: Observing for signs of bleeding such as bruising, melena, hematemesis, hematuria, and intracranial hemorrhage, especially in the first few days to weeks of life.

Management Of Hdn

Initial Management:
-Immediate cessation of oral feeding if bleeding is suspected
-Intravenous fluid resuscitation if hemodynamically unstable
-Prompt administration of vitamin K (phytonadione) if not already given or if HDN is suspected, even if prophylaxis was administered.
Blood Products:
-Fresh frozen plasma (FFP) or prothrombin complex concentrate (PCC) for coagulopathy
-Packed red blood cells for anemia due to blood loss
-Platelets if thrombocytopenic and bleeding.
Supportive Care:
-Close monitoring of vital signs, neurological status, and urine output
-Investigations to rule out other causes of bleeding.

Complications

Vitamin K Deficiency Bleeding Potential:
-Intracranial hemorrhage (most severe and life-threatening)
-gastrointestinal bleeding (hematemesis, melena)
-umbilical cord bleeding
-epistaxis
-hematuria
-prolonged bleeding from circumcision site.
Hepatitis B Infection Potential:
-Acute hepatitis B infection
-chronic hepatitis B infection (leading to cirrhosis, hepatic failure, and hepatocellular carcinoma in adulthood).
Prophylaxis Failure: Rare instances of breakthrough hepatitis B infection can occur despite prophylaxis, particularly if maternal viral load is extremely high or prophylaxis is delayed.

Key Points

Exam Focus:
-Recall the recommended doses and timing for Vitamin K and Hep B vaccine/HBIG
-Understand the indications for HBIG
-Know the follow-up serology for infants of HBsAg-positive mothers
-Differentiate between IM and oral Vitamin K efficacy.
Clinical Pearls:
-Always ask for maternal HBsAg status at delivery
-Administer Vitamin K and Hepatitis B vaccine/HBIG at separate sites
-Document the administration of all prophylactic agents clearly
-Emphasize the importance of completion of the Hep B vaccine series for infants.
Common Mistakes:
-Delaying prophylaxis beyond the recommended window
-Administering Vitamin K orally when IM is preferred or in cases of significant bleeding
-Forgetting to screen mothers for HBsAg status
-Not performing follow-up serology for infants at risk of chronic Hep B infection.