Immunization is an essential part of care for adults, including pregnant women. Influenza vaccination for pregnant women is especially important because pregnant women who contract influenza are at greater risk of maternal morbidity and mortality in addition to fetal morbidity, including congenital anomalies, spontaneous abortion, preterm birth, and low birth weight. Other vaccines provide maternal protection from severe morbidity related to specific pathogens such as pneumococcus, meningococcus, and hepatitis for at-risk pregnant women. Obstetrician-gynecologists and other obstetric care providers should routinely assess their pregnant patients' vaccination status. Based on this assessment they should recommend and, when possible, administer needed vaccines to their pregnant patients. There is no evidence of adverse fetal effects from vaccinating pregnant women with inactivated virus, bacterial vaccines, or toxoids, and a growing body of data demonstrate the safety of such use. Women who are or will be pregnant during influenza season should receive an annual influenza vaccine. All pregnant women should receive a tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine during each pregnancy, as early in the 27-36-weeks-of-gestation window as possible.