Pandemic Influenza and Pregnant Women: An Overview on Influenza Vaccination during Pregnancy and its Impact on Pregnancy Outcomes

Document Type : Review Article


1 Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.

2 Assistant Professor of Pulmonology, Department of Internal Medicine, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.

3 MSc of Operating Room, Department of Operative Room and Anesthetics, School of Paramedical, Sabzevar University of Medical Sciences, Sabzevar, Iran.

4 Nursing Research Center, Department of Community Health Nursing, Razi School of Nursing and Midwifery, Kerman University of Medical Sciences, Kerman, Iran.

5 Student Research Committee, School of Nursing and Midwifery, Sirjan University of Medical Sciences, Sirjan, Iran.

6 MD, Pediatric Nephrologist, Assistant Professor, Department of Pediatrics, Division of Nephrology, Dr. Sheikh Hospital, Mashhad University of Medical Sciences, Mashhad, Iran.



Background: Evidence of the effectiveness and safety of the influenza vaccine in pregnancy is necessary for the decision-making process of healthcare providers. The present study aims to review the available evidence on the effectiveness and safety of influenza vaccination during pregnancy and its impact on pregnancy outcomes.
Materials and Methods: In this overview, two independent researchers have selected articles reporting on the effectiveness and safety of influenza vaccination for pregnant women and their fetuses in the Scopus, EMBASE, Cochrane Library, Web of Science, CINAHL, Medline databases and Google Scholar search engine, without time restrictions up to January 2023.
Results: Based on the available evidence, pregnant women are at a higher risk of serious illness due to influenza than non-pregnant women. The influenza vaccine is the best way to protect pregnant women and their infants against influenza and to prevent possible influenza-associated pregnancy complications. Vaccination during pregnancy is a safe and cost-effective method and also provides neonatal protection against influenza due to the partial transplacental transfer of protective antibodies. There is no evidence of associations between influenza vaccination administered at any time in pregnancy and adverse pregnancy or fetal outcomes, including premature birth, spontaneous abortion, congenital anomalies, shortened gestation, gestational diabetes, chorioamnionitis or gestational hypertensive disorders, and fetal death. In addition, influenza vaccination during pregnancy reduced pregnant women’s risk of pre-delivery hospitalization with influenza-like illness by approximately 39%.
Conclusion: The administration of an inactivated influenza vaccine during pregnancy is safe for both the mother and the fetus and is recommended for all pregnant women. There is no evidence of associations between influenza vaccination and maternal complications or adverse fetal outcomes.