Here's how ob/gyns should counsel their pregnant patients to ensure their pregnancy is not complicated by measles.
In pregnancy, measles is associated with a higher risk of complications, particularly pneumonia, and an increased risk of preterm delivery, intrauterine growth restriction, miscarriage, and fetal demise.1 Avoiding the disease in pregnancy is very important, but unfortunately, the MMR vaccine cannot be given before delivery. Ob/gyns should follow the Centers for Disease Control and Prevention guidelines to determine whether women planning pregnancy are immune to measles. Those who are not should receive MMR vaccination at least 4 weeks before conception. Pregnant women who are known not to be immune to measles should, of course, avoid exposure and receive the MMR postpartum. The vaccine is safe for breastfeeding mothers. It is not yet standard of care to measure measles IgG as part of routine prenatal care, however, because the disease was thought to be eradicated. During a measles outbreak, however, it is certainly reasonable to use history or serology during a prenatal visit to determine whether a mother is immune and then treat her accordingly.
1. ACOG. Practice Advisory: Management of Pregnant and Reproductive-Aged Women during a Measles Outbreak. April 2019. https://www.acog.org/Clinical-Guidance-and-Publications/Practice-Advisories/Management-of-Pregnant-and-Reproductive-Age-Women-during-a-Measles-Outbreak