More than 290 million people worldwide, and almost 2 million people in the United States, are infected with hepatitis B virus (HBV), a vaccine-preventable communicable disease. The estimated prevalence of chronic hepatitis B infection in pregnancy is estimated to be 0.7-0.9% in the United States, with>25,000 infants born annually at risk for chronic infection due to perinatal or vertical transmission. Given the burden of disease associated with chronic hepatitis B infection, recent national guidance has expanded indications for screening for hepatitis B infection and immunity and expanded indications for vaccination. The purpose of this document is to aid clinicians caring for pregnant patients in screening for hepatitis B infection and immunity status, discuss the perinatal risks of hepatitis B infection in pregnancy, determine whether treatment is indicated for maternal or perinatal indications, and recommend hepatitis B vaccination among susceptible patients. The following are Society for Maternal-Fetal Medicine recommendations: (1) we recommend triple panel testing (hepatitis B surface antigen screening, antibody to HBsAg, and total antibody to hepatitis B core antigen) at the initial prenatal visit if not previously documented or known to have been performed (GRADE 1C); (2) we recommend universal hepatitis B surface antigen screening alone at the initial prenatal care visit for all pregnancies where there has been a previously documented negative triple panel test (GRADE 1B); (3) we recommend that individuals with unknown hepatitis B surface antigen screening status should be tested on any presentation for care in pregnancy. We also recommend that those with clinical hepatitis, or those with risk factors for acute hepatitis B infection should be tested at the time of admission to a birthing facility when delivery is anticipated (GRADE 1B); (4) we do not recommend altering routine intrapartum care in individuals chronically infected with hepatitis B. Administration of neonatal immunoprophylaxis is standard of care in these situations (GRADE 1B); (5) we do not recommend cesarean delivery for the sole indication of reducing perinatal hepatitis B virus transmission (GRADE 1B); (6) we recommend that individuals with hepatitis B infection can breastfeed as long as the infant receives immunoprophylaxis at birth (GRADE 1C); (7) we suggest that hepatitis B virus-infected individuals who desire invasive testing may have the procedure performed after an informed discussion on risks and benefits in the context of shared decision-making and in the context of how testing will affect clinical care (GRADE 2C); (8) in individuals with hepatitis viral loads >200,000 IU/mL (>5.3 log 10 IU/mL), we recommend antiretroviral therapy with tenofovir (tenofovir alafenamide at 25 mg daily or tenofovir disoproxil fumarate at 300 mg daily) in the third trimester (initiated at 28-32 weeks of gestation) as an adjunctive strategy to immunoprophylaxis to reduce vertical transmission (GRADE 1B); (9) we recommend administering hepatitis B vaccine and hepatitis B immunoglobin within 12 hours of birth to all newborns of hepatitis B surface antigen-positive pregnant patients or those with unknown or undocumented hepatitis B surface antigen status, regardless of whether antiviral therapy has been given during the pregnancy to the pregnant patient (GRADE 1B); (10) we recommend hepatitis B vaccination in pregnancy for all individuals without serologic evidence of immunity or documented history of vaccination (GRADE 1C).Copyright © 2023. Published by Elsevier Inc.