Hepatitis B in Pregnancy

📋 Key Information Summary

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Universal HBsAg screening is recommended for all pregnant women in Australia at first antenatal visit, with repeat testing for high-risk women in the third trimester.
Hepatitis B affects approximately 1% of the Australian population; perinatal transmission remains the most common route of chronic HBV acquisition globally.
All HBsAg-positive pregnant women require HBV DNA quantification and ALT assessment to guide antiviral prophylaxis decisions and determine disease activity.
Tenofovir disoproxil fumarate (TDF) 300 mg daily from 28–32 weeks' gestation is recommended when maternal HBV DNA exceeds 200,000 IU/mL to reduce vertical transmission risk.
Women already receiving antiviral therapy for chronic HBV should continue treatment through pregnancy, with TDF preferred due to its established safety profile in pregnancy.
Entecavir and tenofovir alafenamide (TAF) should be switched to TDF before conception or as soon as pregnancy is confirmed.
All neonates born to HBsAg-positive mothers must receive hepatitis B immunoglobulin (HBIG) 100 IU IM plus monovalent HBV vaccine within 12 hours of birth, regardless of maternal viral load.
The full hepatitis B vaccine schedule (at birth, 2 months, 4 months, 6 months — using hexavalent vaccine) must be completed for all exposed neonates.
Post-vaccination serology (HBsAg and anti-HBs) is mandatory at 9–12 months of age to confirm immune response and exclude breakthrough infection.
Breastfeeding is safe and encouraged for HBsAg-positive mothers provided the infant has received appropriate immunoprophylaxis.
Aboriginal and Torres Strait Islander women have higher HBV prevalence; culturally safe screening programmes and antenatal partnerships are essential.
Vertical transmission rates can be reduced from approximately 90% (without intervention) to below 1% with combined maternal antiviral prophylaxis and neonatal immunoprophylaxis.

Maternal Screening & Antiviral Prophylaxis

Universal HBsAg Screening in Pregnancy

All pregnant women in Australia should be screened for hepatitis B surface antigen (HBsAg) at the first antenatal visit, consistent with the National Perinatal Guidelines and the Australian National Hepatitis B Testing Policy. Universal screening identifies women at risk of perinatal transmission and allows timely initiation of preventive strategies.

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Repeat screening: Women with ongoing risk factors — including new sexual partners, incarceration, injecting drug use, or migration from high-prevalence countries — should be retested in the third trimester, even if first-trimester HBsAg was negative.

Australia has a population prevalence of chronic HBV of approximately 1%, with higher rates among Aboriginal and Torres Strait Islander peoples (estimated 2–6% in some communities), people born in endemic regions (sub-Saharan Africa, East and South-East Asia, the Pacific Islands), and people who inject drugs.

Baseline Assessment for HBsAg-Positive Women

Once HBsAg positivity is confirmed, the following investigations should be performed promptly:

Essential HBV DNA (quantitative PCR) Critical for antiviral prophylaxis decision — threshold >200,000 IU/mL. Available through all Australian pathology laboratories. MBS item 69490.

Essential ALT (alanine aminotransferase) Assesses hepatic inflammation and disease activity. MBS item 66500.

Available HBeAg and anti-HBe Distinguishes e-antigen positive (higher infectivity) from e-negative disease. MBS item 69479.

Available HBV genotype May influence treatment decisions in chronic HBV; not always required in pregnancy solely for prophylaxis decisions.

Essential Hepatitis C antibody, HIV serology Co-infection screening as part of standard antenatal blood-borne virus panel.

Available Liver ultrasound / FibroScan Consider if ALT elevated or clinical suspicion of cirrhosis; avoid if not clinically indicated in pregnancy.

Antiviral Prophylaxis — Tenofovir Disoproxil in the Third Trimester

Maternal antiviral prophylaxis aims to reduce the risk of in-utero and intrapartum HBV transmission by suppressing viral load prior to delivery. The principal indication for prophylactic antiviral therapy in previously untreated women is a maternal HBV DNA level >200,000 IU/mL.

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Tenofovir Disoproxil Fumarate (TDF)

Viread® · Generic · Nucleotide analogue

Adult dose 300 mg orally once daily

Gestational start Commence at 28–32 weeks' gestation (ideally by 28 weeks to allow ≥4 weeks of viral suppression before delivery)

Duration Continue to delivery; for women not previously on long-term therapy, may cease 4–12 weeks postpartum with hepatology monitoring (risk of ALT flare). Women with indications for long-term treatment should continue indefinitely.

Renal adjustment If CrCl <50 mL/min: 300 mg every 48 hours; if CrCl 30–49: 300 mg every 48–72 hours; avoid if CrCl <30 mL/min — switch to entecavir or seek specialist advice

Hepatic adjustment No dose adjustment; safe in compensated cirrhosis. Avoid in decompensated cirrhosis without specialist oversight.

Safety in pregnancy Category B3 (TGA). Extensive safety data from HIV treatment in pregnancy. No demonstrated teratogenicity. WHO-recommended first-line for HBV prophylaxis in pregnancy.

PBS status ✔ PBS General Benefit — Authority required for chronic HBV. Section 100 (remote area) supply available.

Women Already on Antiviral Therapy

Women who are already receiving antiviral treatment for chronic HBV at the time of conception should continue therapy throughout pregnancy. The choice of agent requires review:

TDF (Viread®): Preferred agent — continue unchanged throughout pregnancy.
Entecavir (Baraclude®): Switch to TDF pre-conception or as soon as pregnancy is confirmed; entecavir has less pregnancy safety data.
Tenofovir alafenamide (TAF — Vemlidy®): Switch to TDF pre-conception or at confirmation of pregnancy; insufficient pregnancy safety data.
Lamivudine: May be continued if already established, though TDF is preferred due to superior potency and lower resistance risk.
Interferon-alpha: Contraindicated in pregnancy — must be ceased pre-conception with adequate washout.

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Post-partum ALT flare: Women who discontinue TDF after delivery (in whom long-term therapy is not otherwise indicated) are at risk of severe ALT flares (up to 30–45% of patients). ALT should be monitored monthly for at least 3 months postpartum, with urgent hepatology referral if ALT exceeds 10× ULN.

Effectiveness of Combined Prophylaxis

Strategy	Approximate vertical transmission rate	Notes
No intervention	70–90% (if HBeAg+)	Highest risk with high viral load and HBeAg positivity
Neonatal immunoprophylaxis alone (HBIG + vaccine)	5–15%	Failure rate increases with maternal HBV DNA >200,000 IU/mL
Maternal TDF + neonatal immunoprophylaxis	<1–2%	Current best-practice standard; landmark RCTs (Pan et al., JAMA 2016)

Neonatal Management

Immediate Post-Exposure Prophylaxis (Within 12 Hours of Birth)

All neonates born to HBsAg-positive mothers — regardless of maternal viral load, HBeAg status, or whether the mother received antiviral prophylaxis — must receive dual immunoprophylaxis within 12 hours of birth. This is a critical time-sensitive intervention.

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Time-critical: Both HBIG and the first dose of HBV vaccine must be administered within 12 hours of birth. Delay beyond this window significantly reduces the effectiveness of post-exposure prophylaxis and increases the risk of vertical transmission.

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Hepatitis B Immunoglobulin (HBIG)

Hepatitis B Immunoglobulin-VF® (CSL Behring)

Neonatal dose 100 IU (0.5 mL) intramuscularly

Route IM — anterolateral thigh preferred in neonates

Timing Within 12 hours of birth (ideally as soon as feasible after delivery)

Availability Supplied via the National Blood Authority (NBA) through hospital blood banks. Free of charge for authorised indications. Order via hospital transfusion laboratory.

Storage Store at 2–8°C. Do not freeze. Bring to room temperature before administration.

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Hepatitis B Vaccine (Monovalent)

Engerix-B® (GSK) or HB-Vax II® (Merck Sharp & Dohme)

Neonatal dose (birth dose) 0.5 mL (10 µg Engerix-B® or 5 µg HB-Vax II®) intramuscularly

Route IM — anterolateral thigh. Do NOT give in the same limb as HBIG if possible; use contralateral limb.

Timing Within 12 hours of birth, concurrent with HBIG (separate injection site)

PBS status ✔ PBS General Benefit — Also funded under the National Immunisation Program (NIP) for at-risk neonates.

Complete Vaccine Schedule

Following the birth dose, the infant should complete the standard hepatitis B vaccination schedule as part of the National Immunisation Program (NIP). In Australia, this is delivered via the hexavalent combination vaccine (DTPa-hepB-IPV-Hib).

Dose	Age	Vaccine	Funding
1 (birth)	At birth (≤12 hours)	Monovalent HBV (Engerix-B® 10 µg or HB-Vax II® 5 µg)	NIP funded for at-risk neonates
2	2 months	Hexavalent (Infanrix hexa® or Vaxelis®)	NIP funded — all infants
3	4 months	Hexavalent (Infanrix hexa® or Vaxelis®)	NIP funded — all infants
4	6 months	Hexavalent (Infanrix hexa® or Vaxelis®)	NIP funded — all infants

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Preterm infants (<32 weeks or <2000 g): The birth dose of monovalent HBV vaccine should still be given within 12 hours but may not count towards the schedule if given before 32 weeks' gestational age or before 2000 g. Check current Australian Immunisation Handbook for preterm-specific guidance and ensure all four doses are documented correctly.

Post-Vaccination Serology

Post-vaccination serology is essential to confirm successful immunisation and to exclude breakthrough HBV infection. Testing should be performed at 9–12 months of age (i.e., at least 4 weeks after the final scheduled vaccine dose).

Essential HBsAg (hepatitis B surface antigen) If positive, indicates breakthrough infection despite immunoprophylaxis — refer paediatric hepatology for management of chronic HBV.

Essential Anti-HBs (hepatitis B surface antibody) ≥10 mIU/mL indicates protective immune response. If <10 mIU/mL and HBsAg negative, administer a booster dose (or repeat full course) and re-test in 4–8 weeks.

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Interpretation: If HBsAg is negative and anti-HBs ≥10 mIU/mL at 9–12 months, the infant is considered immune and no further follow-up is required. If HBsAg is positive, the infant has acquired chronic HBV despite prophylaxis — this occurs in <2% with optimal combined prophylaxis and warrants specialist paediatric hepatology referral.

Breastfeeding

Breastfeeding is safe and encouraged for HBsAg-positive mothers. There is no evidence that breastfeeding increases the risk of HBV transmission when the infant has received appropriate immunoprophylaxis (HBIG + vaccine). The WHO, Australian Breastfeeding Association, and Australian Society of Clinical Immunology and Allergy (ASCIA) all support breastfeeding in this context.

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Counselling point: Advise mothers that breastfeeding provides significant immunological and nutritional benefits that outweigh any theoretical risk. Ensure the infant's vaccination schedule is completed. Cracked or bleeding nipples do not contraindicate breastfeeding if immunoprophylaxis has been administered.

Aboriginal and Torres Strait Islander Health Considerations

Aboriginal and Torres Strait Islander Health

Higher prevalence

Chronic HBV prevalence in Aboriginal and Torres Strait Islander communities is estimated at 2–6% in some remote regions, significantly higher than the general Australian population (~1%). This reflects historical patterns of mother-to-child and early childhood transmission prior to universal vaccination programmes.

Screening gaps

Despite universal antenatal screening recommendations, some women in remote communities may not access antenatal care early enough for timely HBsAg testing. Point-of-care HBsAg testing and integration with Aboriginal Community Controlled Health Organisations (ACCHOs) can improve screening rates.

Antenatal care access

Women in remote and very remote areas may have limited access to specialist hepatology or obstetric medicine services. Telehealth consultations for HBV DNA interpretation and antiviral prescribing should be utilised. TDF is available through Section 100 PBS in remote areas.

Cultural safety

Engagement with Aboriginal Health Workers and Liaison Officers is essential. Discussions about HBV status, vertical transmission risk, and antiviral therapy should be delivered in a culturally safe, non-stigmatising manner with appropriate language support. Yarning-based education may improve health literacy and treatment adherence.

Neonatal follow-up

Ensure HBIG and birth-dose vaccine availability at remote birthing facilities. Post-vaccination serology at 9–12 months should be actively tracked through ACCHOs and the Australian Immunisation Register (AIR) to prevent loss to follow-up.

National strategy alignment

These recommendations align with the National Aboriginal and Torres Strait Islander Hepatitis B Strategy (2018–2022, successor frameworks under development) and the Eliminate Hepatitis B Australia partnership, which targets HBV elimination as a public health threat by 2030.

📚 References

1. Pan CQ, Duan Z, Dai E, et al. Tenofovir to prevent hepatitis B transmission in mothers with high viral load. N Engl J Med. 2016;374(24):2324–2334.
2. Jourdain G, Ngo-Giang-Huong N, Harrison L, et al. Tenofovir versus placebo to prevent perinatal transmission of hepatitis B. N Engl J Med. 2018;378(10):911–923.
3. World Health Organization. Guidelines for the prevention, care and treatment of persons with chronic hepatitis B infection. Geneva: WHO; 2015 (updated March 2024).
4. Australian Government Department of Health and Aged Care. Australian National Immunisation Program Schedule. Canberra: Commonwealth of Australia; 2024.
5. The Royal Australian College of General Practitioners (RACGP). Australian Immunisation Handbook — Hepatitis B. Updated 2024. Available at: immunisationhandbook.health.gov.au.
6. Visvanathan K, Dusheiko G, Giles M, et al. Managing HBV in pregnancy. Prevention, prophylaxis, and treatment. J Hepatol. 2016;65(3):562–575.
7. Australian Institute of Health and Welfare (AIHW). Hepatitis B and C in Australia — Annual Surveillance Report 2023. Canberra: AIHW; 2023.
8. National Perinatal Epidemiology and Statistics Unit (NPESU). Antenatal Screening for Infectious Diseases in Australia. Sydney: NPESU, UNSW; 2022.
9. Australian Government. National Aboriginal and Torres Strait Islander Hepatitis B Strategy 2018–2022. Canberra: Commonwealth of Australia; 2018.
10. Dionne-Odom J, Tita ATN, Silverman NS. #38: Hepatitis B in pregnancy screening, treatment, and prevention of vertical transmission. Am J Obstet Gynecol. 2016;214(1):6–14.
11. Yi P, Chen R, Huang Y, Zhou RR, Fan XG. Management of mother-to-child transmission of hepatitis B virus: Propositions and challenges. J Clin Virol. 2016;77:32–39.
12. Terrault NA, Lok ASF, McMahon BJ, et al. Update on prevention, diagnosis, and treatment of chronic hepatitis B: AASLD 2018 hepatitis B guidance. Hepatology. 2018;67(4):1560–1599.