Can the hepatitis B vaccine be administered during pregnancy?

Hepatitis B Vaccine Can and Should Be Given During Pregnancy to At-Risk Women

Yes, hepatitis B vaccine is safe and recommended during pregnancy for women at risk for HBV infection, and should not be delayed or withheld due to pregnancy status. 1, 2, 3

Who Should Receive Hepatitis B Vaccine During Pregnancy

Pregnant women meeting any of the following high-risk criteria should be vaccinated 1, 2:

• More than one sex partner during the previous 6 months 1, 2
• Evaluation or treatment for a sexually transmitted infection 1, 2
• Recent or current injection-drug use 1, 2
• HBsAg-positive sex partner 1, 2
• Any pregnant patient who requests the vaccine can be offered vaccination, even without documented risk factors 2, 3

Safety Profile in Pregnancy

The vaccine contains noninfectious HBsAg particles that pose no risk to the developing fetus 1, 4:

• No apparent risk of adverse effects to the fetus based on extensive clinical experience 1, 4
• No increased risk of abortion, stillbirth, congenital malformations, or sudden infant death syndrome 4, 5
• Safe throughout all trimesters of pregnancy 4, 6
• Neither pregnancy nor lactation is a contraindication to vaccination 1, 4

Large-scale safety data from the Vaccine Safety Datalink study of over 650,000 pregnancies found no significant associations between HepB exposure during pregnancy and gestational hypertension, gestational diabetes, pre-eclampsia, cesarean delivery, pre-term delivery, low birthweight, or small for gestational age infants 5.

Vaccination Schedule and Administration

Standard 3-dose series (0,1, and 6 months) should be initiated during pregnancy 2, 4:

• An accelerated schedule of 0,1, and 4 months is effective and can be completed during pregnancy 7
• Must be administered intramuscularly in the deltoid muscle—administration in the buttock markedly reduces immunogenicity and must be avoided 1, 4
• If a dose is missed, give it as soon as possible without restarting the series 4

The accelerated schedule achieves 90% seroconversion after three doses and is practical for completion during prenatal care 7.

Critical Distinction: Maternal Protection vs. Neonatal Prophylaxis

The vaccine protects the mother from acquiring HBV during pregnancy—it does NOT prevent infant infection if the mother is already HBsAg-positive 2, 3:

• All pregnant women must be tested for HBsAg during the first trimester of every pregnancy, regardless of vaccination history 1, 2
• Infants born to HBsAg-positive mothers require both HBIG and hepatitis B vaccine within 12 hours of birth to prevent perinatal transmission 1, 2, 3
• Pregnant women at high risk who test HBsAg-negative in the first trimester should undergo repeat testing later in pregnancy 2

Additional Counseling and Prevention

Pregnant women at risk should receive counseling on prevention methods beyond vaccination 1, 2:

• Avoidance of high-risk behaviors and exposure reduction strategies 2
• Safe sex practices and harm reduction for injection drug users 1

Common Pitfalls to Avoid

• Do not postpone vaccination due to unfounded safety concerns—the vaccine is explicitly safe during pregnancy 1, 4
• Do not administer the vaccine in the buttock, as this significantly lowers immunogenicity in adults 1, 4
• Do not assume vaccination eliminates the need for universal HBsAg screening—all pregnant women must still be tested 1, 2
• Do not confuse maternal vaccination with neonatal prophylaxis—infants of HBsAg-positive mothers still require HBIG and vaccine at birth 1, 2, 3
• Do not restart the series if a dose is missed—simply administer the missed dose promptly 4

Implementation in Clinical Practice

Healthcare providers should implement standing orders to identify and vaccinate pregnant women at risk as part of routine prenatal services 1, 2:

• Delivery hospitals should have policies ensuring all pregnant women are tested for HBsAg 1
• Electronic medical record reminders or prompts can facilitate identification of at-risk patients 1