SynthesisBMC infectious diseases2019
Pregnancy as a risk factor for severe influenza infection: an individual participant data meta-analysis.
Synthesis in BMC infectious diseases, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 52 papers, 1 of them a synthesis that pooled it.
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
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Who cites it
52 citing papers in PubMed, 1 synthesis or guideline pooled it.
- ECTRIMS/EAN consensus on vaccination in people with multiple sclerosis: Improving immunization strategies in the era of highly active immunotherapeutic drugs.Multiple sclerosis (Houndmills, Basingstoke, England) · 2023Pooled it
- Impact of Influenza Vaccination during Pregnancy on Maternal Influenza Disease Severity in Rural Nepal.The American journal of tropical medicine and hygiene · 2026Trial
- Influenza or Meningococcal Immunization During Pregnancy and Mortality in Women and Infants: A Pooled Analysis of Randomized Controlled Trials.The Pediatric infectious disease journal · 2020Trial
- Influenza.Nature reviews. Disease primers · 2026Review
- Viral threats to pregnancy: Global health risks in the era of pandemics.Advances in virus research · 2026Review
- Clinical practice guidelines for the treatment and prophylaxis of influenza in China (2025 edition).Infectious diseases & immunity · 2026Article
- Association between seasonal influenza vaccination and neonatal outcomes in Shanghai, China.Human vaccines & immunotherapeutics · 2025Article
- Risk Groups for Vaccine-Preventable Respiratory Infections in Children and Adults: An Overview of the Australian Environment.Vaccines · 2025Review
- Pregnant hospitalized COVID-19 patients: disease, delivery, maternal and fetal outcomes.BMC pregnancy and childbirth · 2025Observational
- The Burden of HMPV- and Influenza-Associated Hospitalizations in Adults in New Zealand Before and After the COVID-19 Pandemic, 2012-2023.The Journal of infectious diseases · 2025Article
- Influenza Vaccination During Pregnancy and Infant Influenza in the First 6 Months of Life.Obstetrics and gynecology · 2025Article
- Immune Response and Serum Biomarker Screening in Pregnant Women with Influenza A Virus Infection: Insight into Susceptibility and Disease Severity.Diseases (Basel, Switzerland) · 2025Article
- Pre-Existing Allergic Inflammation Alters Both Innate and Adaptive Immune Responses in Mice Co-Infected with Influenza Virus.International journal of molecular sciences · 2025Article
- High-dimensional single-cell phenotyping unveils persistent differences in immune cell profiles between severe and moderate seasonal influenza.Frontiers in immunology · 2025Article
- The intersection of influenza infection and autoimmunity.Frontiers in immunology · 2025Review
- Research progress in vaccination during pregnancy.Frontiers in immunology · 2025Review
- The Impact of Obesity on Influenza Vaccine Immunogenicity and Antibody Transfer to the Infant During Pregnancy.Vaccines · 2024Article
- Acceptance and uptake of vaccines against tetanus, influenza, pertussis, and COVID-19 among pregnant and postpartum women in low- and middle-income countries: a systematic review and meta-analysis protocol.Systematic reviews · 2024Article
- A Retrospective Cross-Sectional Analysis of Viral SARI in Pregnant Women in Southern Brazil.Microorganisms · 2024Article
- Etiology, clinical characteristics, and risk factors associated with severe influenza-like illnesses in Mexican adults.IJID regions · 2023Article
Corrections and comments
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Authors and funding
6 authors.
Funding
Abstract
backgroundWHO identifies pregnant women to be at increased risk for severe outcomes from influenza virus infections and recommends that they be prioritized for influenza vaccination. The evidence supporting this, however, is inconsistent. Ecologic studies in particular suggest more severe outcomes from influenza infection during pregnancy than studies based on individual patient data. Individual studies however may be underpowered and, as reported in a previous systematic review, confounding factors could not be adjusted for. We therefore conducted an individual participant data meta-analysis to assess the risk for severe outcomes of influenza infection in pregnant women while adjusting for other prognostic factors.
methodsWe contacted authors of studies included in a recently published systematic review. We pooled the individual participant data of women of reproductive age and laboratory confirmation of influenza virus infection. We used a generalized linear mixed model and reported odds ratios (OR) and 95% confidence intervals (CI).
resultsA total of 33 datasets with data on 186,656 individuals were available, including 36,498 eligible women of reproductive age and known pregnancy status. In the multivariable model, pregnancy was associated with a 7 times higher risk of hospital admission (OR 6.80, 95%CI 6.02-7.68), among patients receiving medical care as in- or outpatients, pregnancy was associated with a lower risk of admission to intensive care units (ICU; OR 0.57, 95%CI 0.48-0.69), and was not significantly associated with death (OR 1.00, 95%CI 0.75-1.34).
conclusionsOur study found a higher risk of influenza associated hospitalization among pregnant women as compared to non-pregnant women. We did not find a higher mortality rate or higher likelihood of ICU admission among pregnant women who sought medical care. However, this study did not address whether a true community based cohort of pregnant women is at higher risk of influenza associated complications.
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