Hindawi Publishing Corporation ISRN Preventive Medicine Volume 2013, Article ID 879493, 8 pages http://dx.doi.org/10.5402/2013/879493 Research Article Influenza Vaccination in Pregnant Women: A Systematic Review Tais F. Galvao, 1,2 Marcus T. Silva, 3 Ivan R. Zimmermann, 1 Luiz Antonio B. Lopes, 4 Eneida F. Bernardo, 4 and Mauricio G. Pereira 1 1 Faculty of Medicine, University of Brasilia, Campus Universitario, Conj 16, Sala 77, 70904-970 Brasilia, DF, Brazil 2 Getulio Vargas University Hospital, Federal University of Amazonas, Rua Apurina 4, Centro, 69020-170 Manaus, AM, Brazil 3 Faculty of Medicine, Federal University of Amazonas, Rua Afonso Pena 1053, Centro, 69020-160 Manaus, AM, Brazil 4 State Health Department, LACEN, Setor de Areas Isoladas Norte, Bloco B, 70086-900 Brasilia, DF, Brazil Correspondence should be addressed to Tais F. Galvao; taisgalvao@gmail.com Received 8 August 2013; Accepted 12 September 2013 Academic Editors: F. Pregliasco, H. Rashid, and S. H. Seo Copyright © 2013 Tais F. Galvao et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Objective. To assess the efects of the inactivated inluenza virus vaccine on inluenza outcomes in pregnant women and their infants. Methods. We performed a systematic review of the literature. We searched for randomized controlled trials and cohort studies in the MEDLINE, Embase, and other relevant databases (inception to September 2013). Two researchers selected studies and extracted the data independently. We used the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach to assess the quality of the evidence. Results. We included eight studies out of 1,967 retrieved records. Inluenza vaccination in pregnant women signiicantly reduced the incidence of inluenza-like illness in mothers and their infants when compared with control groups (high-quality evidence) and reduced the incidence of laboratory-conirmed inluenza in infants (moderate-quality evidence). No diference was found with regard to inluenza-like illness with fever higher than 38 ∘ C (moderate-quality evidence) or upper respiratory infection (very-low-quality evidence) in mothers and infants. Conclusions. Maternal vaccination against inluenza was shown to prevent inluenza-like illness in women and infants; no diferences were found for other outcomes. As the quality of evidence was not high overall, further research is needed to increase conidence and could possibly change these estimates. 1. Introduction Pregnant women and neonates are at greater risk for inf- luenza-related complications than the general population [1, 2]. Most institutions and organizations recommend that all pregnant women receive the trivalent inactivated inluenza virus vaccine [3–8]. Such endorsements rely on the immuno- genic response of the mothers, the lack of teratogenicity, and the contrandication of immunization in children younger than six months [7, 9–11]. Despite the broad recommendation to vaccinate pregnant women against inluenza, coverage is still limited. A survey held by the Centers for Disease Control and Prevention involving women who were pregnant from October 2011 to January 2012 showed that only half of the respondents had been vaccinated and fewer than 10% had received the vaccine before giving birth [12]. Similar patterns were found in previous studies [13]. Although there is clear evidence of the eicacy of the inluenza vaccine for the general population [14], to our knowledge, a systematic approach with regard to the evidence of the therapeutic efects of inluenza vaccination in pregnant women is lacking. Our objective is to review the efects of inluenza vaccination in preventing inluenza-related out- comes in pregnant women and their infants. 2. Methods 2.1. Eligibility Criteria for the Included Studies. We selected randomized controlled trials or cohort studies that assessed the efects of inactivated inluenza vaccine in preventing inluenza-related outcomes in pregnant women and their of- spring compared with placebo, other vaccines, or no vaccines. We excluded studies that assessed monovalent vaccines, such as the H1N1 inluenza vaccine, because they are used for speciic epidemic situations.