Hepatitis B during pregnancy

By trimester

Weeks 1–13

1st trimester

HBsAg screening is recommended in every pregnancy, even after prior vaccination or earlier negative testing. A positive result should trigger confirmatory evaluation, liver tests, HBV DNA measurement, specialist coordination, and referral to the perinatal hepatitis B program.

Weeks 14–27

2nd trimester

Clarify whether results show current infection, past resolved infection, immunity from vaccination, or susceptibility. Build a delivery and newborn plan early, and repeat HBV DNA when the specialist needs it for late-pregnancy antiviral decisions.

Weeks 28–birth

3rd trimester

For HBV DNA above 200,000 IU/mL, SMFM recommends tenofovir disoproxil fumarate or tenofovir alafenamide beginning at 28 to 32 weeks. Ensure the birth facility can give the newborn vaccine and HBIG within 12 hours.

What does the evidence show for hepatitis B?

• CDC recommends HBsAg screening during every pregnancy and HBV DNA testing for every HBsAg-positive pregnant patient. Current infection also triggers referral to the jurisdiction's perinatal hepatitis B program and specialist medical care. 1
• The hepatitis B triple panel separates current infection, past infection, vaccine-associated immunity, and susceptibility: HBsAg indicates current infection, anti-HBs indicates immunity, and total anti-HBc indicates previous or ongoing exposure rather than vaccination alone. 2
• SMFM recommends tenofovir disoproxil fumarate or tenofovir alafenamide at 28 to 32 weeks for HBV DNA above 200,000 IU/mL. It does not recommend cesarean birth solely for hepatitis B, and breastfeeding is acceptable after the infant receives prophylaxis. 3
• In a randomized trial of 200 HBeAg-positive pregnant patients with HBV DNA above 200,000 IU/mL, adding maternal tenofovir to infant prophylaxis lowered perinatal transmission compared with infant prophylaxis alone. The narrow high-risk population and trial regimen limit broader application. 4
• For an infant born to an HBsAg-positive parent, CDC calls for single-antigen hepatitis B vaccine and HBIG in separate limbs within 12 hours of birth, completion of the vaccine series, and serologic testing at 9 to 12 months. 5

When should I call my provider about hepatitis B?

Seek urgent care for yellow skin or eyes with confusion, severe right-upper-abdominal pain, repeated vomiting with inability to keep fluids down, fainting, unusual bleeding, or severe weakness. Call the hepatitis and maternity teams promptly for dark urine, new jaundice, medication side effects, or any plan to stop antiviral medicine. Trust your read on your own body. If something feels off beyond the list above, please consult your healthcare provider rather than waiting it out.