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🦠 What is Hepatitis B?
Hepatitis B is a viral infection caused by the Hepatitis B virus (HBV) that primarily affects the liver.
Transmission: Blood, sexual contact, perinatally (from mother to baby at birth), sharing needles, etc.
Virus type: DNA virus (Hepadnaviridae family)
Incubation period: 1–4 months
🔁 Modes of Transmission
Route Description
Vertical Mother to child (most common in pregnancy)
Horizontal Blood products, sexual contact, needle use
🔍 Clinical Phases
Acute Hepatitis B
Often asymptomatic
Symptoms (if present): fatigue, nausea, jaundice, dark urine, RUQ pain
May resolve or progress to chronic infection
Chronic Hepatitis B
Persistence of HBsAg 6 months
Risk of cirrhosis, liver failure, and hepatocellular carcinoma (HCC)
🧪 Serology Markers
Marker Interpretation
HBsAg Active infection (acute or chronic)
Anti-HBs Immunity (from vaccine or past infection)
Anti-HBc Exposure to virus (IgM = recent; IgG = past)
HBeAg High infectivity
HBV DNA Viral load – used to guide treatment
🤰 Hepatitis B in Pregnancy
Key Concerns:
Mother-to-child transmission (MTCT) is the most common mode in endemic areas.
Transmission risk:
90% if mother is HBeAg+
10–30% if HBeAg-
Prevention of MTCT:
Screen all pregnant women for HBsAg during first prenatal visit.
If mother is HBsAg positive:
Infant should receive:
HBV vaccine + Hepatitis B immunoglobulin (HBIG) within 12 hours of birth
Continue vaccine series at 1 and 6 months
If mother has high viral load (200,000 IU/mL):
Start antiviral therapy (e.g., Tenofovir) at 28–32 weeks gestation
💊 Treatment Overview
In pregnancy:
Tenofovir disoproxil fumarate (TDF) is preferred – safe and effective
Monitor liver function tests (LFTs) and HBV DNA levels
In non-pregnant adults:
Tenofovir, entecavir, pegylated interferon (not for pregnancy)
🚨 Complications of Chronic Hepatitis B
Liver cirrhosis
Hepatocellular carcinoma
Liver failure
Portal hypertension
Variceal bleeding
✅ Summary
Aspect Key Points
Screening All pregnant women: HBsAg at first prenatal visit
Prevention in baby HBV vaccine + HBIG within 12 hrs of birth
Antivirals in mom Tenofovir if HBV DNA 200,000 IU/mL
Breastfeeding Safe if baby received vaccine + HBIG
Long-term monitoring For chronic HBV: liver function and HCC screening
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