Can pregnant women safely receive the recombinant hepatitis B vaccine?

Hepatitis B Vaccination in Pregnancy

Yes, pregnant women can and should receive the hepatitis B vaccine when indicated—pregnancy is explicitly not a contraindication to hepatitis B vaccination. 1, 2

Safety Profile

The hepatitis B vaccine is safe for both mother and fetus throughout all trimesters of pregnancy. The vaccine contains noninfectious hepatitis B surface antigen (HBsAg) particles that pose no risk to the developing fetus. 1

• Limited but consistent data from multiple studies demonstrate no apparent risk of adverse events to the developing fetus when hepatitis B vaccine is administered to pregnant women. 1
• No evidence exists linking hepatitis B vaccination to increased rates of abortion, stillbirth, congenital malformations, or sudden infant death syndrome. 1, 3
• Research specifically evaluating first-trimester exposure found no congenital abnormalities, with all infants developing normally. 3
• The vaccine is well-tolerated during pregnancy, with injection site discomfort being the most common complaint (10.5% of recipients). 4

Clinical Indications for Vaccination During Pregnancy

Pregnant women at risk for hepatitis B virus infection should be specifically targeted for vaccination. 2, 5

High-Risk Groups Requiring Vaccination:

• Healthcare workers with occupational exposure 3
• Women with multiple sexual partners or a partner with hepatitis B 1
• Injection drug users 1
• Women traveling to endemic areas 3
• Household contacts of persons with chronic hepatitis B infection 1
• Women engaging in high-risk behaviors who should be re-screened at delivery 5

Vaccination Schedule and Administration

The standard three-dose schedule (0,1, and 6 months) can be initiated and completed during pregnancy. 1, 6

• An accelerated schedule of 0,1, and 4 months is effective, practical, and can be completed during the course of pregnancy in high-risk women. 4
• The vaccine should be administered intramuscularly in the deltoid muscle, not the buttock, as buttock administration substantially reduces immunogenicity. 1
• Seroconversion rates after completing the three-dose series during pregnancy reach 90%. 4

Important Timing Considerations:

• The three-dose schedule is highly immunogenic and safe during pregnancy, with higher maternal and neonatal antibody levels compared to two-dose schedules. 6
• If the vaccination series is interrupted, the missing dose should be administered as soon as possible—the series should not be restarted. 1

Immunogenicity Considerations

Pregnant women may exhibit a slightly slower and lower immune response compared to non-pregnant women, though seroconversion rates remain high. 7

• Body mass index is inversely associated with seroconversion rates, though there is no specific BMI threshold above which seroconversion fails to occur. 4
• When post-exposure prophylaxis is indicated, passive-active immunization with hepatitis B immunoglobulin (HBIG) and vaccine can be started safely during pregnancy. 7
• The relatively weaker response in some pregnant women calls for monitoring anti-HBs levels one month after completing the initial vaccination series. 7

Postexposure Prophylaxis

Sexual contacts of patients with acute hepatitis B should receive both HBIG and begin the hepatitis B vaccine series within 14 days, regardless of pregnancy status. 1

• HBIG combined with vaccination is more effective than vaccination alone in preventing infection after exposure. 1
• Pregnancy does not alter the standard postexposure prophylaxis protocol. 1

Breastfeeding

Hepatitis B vaccination is not contraindicated during breastfeeding. 1

Critical Clinical Pitfalls to Avoid

• Do not delay vaccination in pregnant women at risk due to unfounded safety concerns—the vaccine is explicitly safe during pregnancy. 1, 2
• Do not administer the vaccine in the buttock—this significantly reduces immunogenicity in adults. 1
• Do not restart the series if a dose is missed—simply administer the missing dose as soon as possible. 1
• Do not withhold HBIG and vaccine from pregnant women requiring postexposure prophylaxis—the 14-day window is critical. 1