Home

Vaccination During Pregnancy

The Advisory Committee on Immunization Practices (ACIP) and the American College of Obstetricians and Gynecologists (ACOG) recommend1, 2 that women who will be in any stage of pregnancy during flu season (October through April-May) receive an inactivated influenza immunization.  Healthy pregnant women are considered a high risk group3 because they experience higher mortality during influenza pandemics, and are at increased risk of cardiopulmonary hospitalizations during any flu season. 

Despite this recommendation, only 12.8 percent of healthy pregnant women receive an annual flu shot, compared with 24 – 65 percent of people in other high-risk categories4. 

A study5 by Neuzil, Reed, Mitchell, et al, showed that women in any stage of pregnancy are at increased risk of serious influenza-related morbidity (hospitalizations for or death from selected acute cardiopulmonary conditions), but women in their third trimester of pregnancy were at the highest risk.

This study points out that, despite the ACIP/ACOG recommendations for vaccination, controversy still exists about the “routine use” of influenza vaccine in pregnancy.  This may be due to vaccine manufacturers cautioning against routine use of the vaccine during pregnancy.  The study summarizes, “…By the third trimester, the influenza-attributable risk for acute cardiopulmonary hospitalizations is similar to the risk in non-pregnant medically high-risk women for whom vaccination is currently recommended.”  This study shows that pregnant women have about a five times higher risk of dying from influenza-related complications, than non-pregnant women.

It is also important to vaccinate postpartum women against diseases like influenza (if they were not previously immunized) and pertussis.  Vaccinating new mothers against both of these diseases is critical, because they can spread these illnesses to their infants that are not fully protected.  Infants, particularly those under age six months, are at the highest risk of experiencing severe symptoms and death due to pertussis.6   Women should get a tetanus, diphtheria, and pertussis (Tdap) vaccination in the immediate postpartum period.  One dose of Tdap, should replace a single Tetanus-diphtheria (Td) booster. 

Guidelines for Vaccination during Pregnancy Resource

References:

  1. Harper SA, Fukuda K, Uyeki TM, et al. Prevention and control of influenza: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep 2005;54(RR-8):1–40.
  2. ACOG Committee on Obstetric Practice. ACOG committee opinion number 305, November 2004. Influenza vaccination
  3. National Guidelines Clearinghouse, www.guidelines.gov  Prevention and control of influenza: recommendation of the Advisory Committee on Immunization Practices (ACIP). Interim influenza vaccination recommendations – 2004-2005 influenza season. (See pgs 2-4 including pregnant women in any stage as a high priority group for immunization.)
    This recent local study by Lindsay, Jackson, Savitz et al  done in Seattle(4) showed that influenza-like illness episodes increased as the pregnancy progressed, with odds ratios for strength of association between influenza exposure and illness being: 1st trimester 1.12; 2nd trimester 1.30 and 3rd, 1.84, and were even greater during the postpartum period at 2.28.  It indicates that postpartum women would also benefit from the immunization.  In contrast to prior studies, this one estimated that only 23-40 women would need to be vaccinated to prevent one influenza-like illness, emphasizing the value and importance of providing flu shots to this high-risk population or your practice.
  4. Lisa Lindsay, Lisa A. Jackson, David A. Seitz, David J. Weber, Gary G. Koch, Lan Kong, and Harry A. Guess. Community Influenza Activity and Risk of Acute Influenza-like Illness Episodes among Healthy Unvaccinated Pregnant and Postpartum Women. American Journal of Epidemiology Advance Access published March 22, 2006; DOI: 10.1093/aje/kwj095
  5. Neuzil KM, Reed GW, Mitchel EF, et al. Impact of influenza on acute cardiopulmonary hospitalizations in pregnant women. Am J Epidemiology 1998;148:1094–102.
    It states, “While influenza-associated excess mortality among pregnant women was documented during the 1918-1919 and 1957-1958 pandemics, is has not been documented during interpandemic periods.  Case reports and papers in small case series published since that time have described women in the third trimester and early puerperium who died form influenza-related complications, but have not quantified risk.
  6. Centers for Disease Control and Prevention.  Epidemiology of Vaccine-Preventable Diseases.  Atkinson W, Hamborsky J, McIntyre L, Wolfe S, eds.  9th ed.  Washington DC:  Public Health Foundation, 2006.  (See pgs 79-96).