Registered Nurse Comprehensive Predictor Practice Test

Why are live vaccines avoided during pregnancy?

They are generally recommended during pregnancy to boost immunity

They are generally contraindicated during pregnancy due to potential risk to the fetus; they may be given postpartum

Live vaccines use weakened but replication-competent organisms. During pregnancy, that replication could theoretically infect the fetus or cause maternal viremia that crosses the placenta, raising concerns about fetal harm or congenital infection. Because the exact risk is uncertain and fetal safety takes priority, live vaccines are avoided while pregnant. They’re typically given after delivery to ensure maternal immunity without exposing the fetus, with MMR and varicella examples of vaccines that are contraindicated during pregnancy but given postpartum if needed. Inactivated vaccines, by contrast, are generally safe and recommended during pregnancy to protect both mother and baby.

They provide no benefit to the mother or fetus regardless of timing

They are only given if the pregnancy is at risk for infection