ArticleCMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne2007
Impact of influenza exposure on rates of hospital admissions and physician visits because of respiratory illness among pregnant women.
Article in CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne, 2007. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT01034254 (Field Trial of Maternal Influenza Immunization in Asia), which is not on this map. Cited by 171 papers, 4 of them syntheses that pooled it.
What it found
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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.
Field Trial of Maternal Influenza Immunization in Asia
Who cites it
171 citing papers in PubMed, 4 syntheses or guidelines pooled it, 460 citations in OpenAlex.
- Pooled it
- Associations of maternal upper respiratory tract infection/influenza during early pregnancy with congenital heart disease in offspring: evidence from a case-control study and meta-analysis.BMC cardiovascular disorders · 2019Pooled it
- Optimal timing of influenza vaccine during pregnancy: A systematic review and meta-analysis.Influenza and other respiratory viruses · 2019Pooled it
- Maternal influenza and birth outcomes: systematic review of comparative studies.BJOG : an international journal of obstetrics and gynaecology · 2017Pooled it
- Immunogenicity and safety of a quadrivalent inactivated influenza vaccine in pregnant women: a randomized, observer-blind trial.Human vaccines & immunotherapeutics · 2020Trial
- Encouraging Influenza Vaccination Among Text4baby Pregnant Women and Mothers.American journal of preventive medicine · 2015Trial
- Designs of two randomized, community-based trials to assess the impact of influenza immunization during pregnancy on respiratory illness among pregnant women and their infants and reproductive outcomes in rural Nepal.BMC pregnancy and childbirth · 2015Trial
- Maternal influenza vaccination: evaluation of a patient-centered pamphlet designed to increase uptake in pregnancy.Maternal and child health journal · 2014Trial
- The comparative clinical course of pregnant and non-pregnant women hospitalised with influenza A(H1N1)pdm09 infection.PloS one · 2012Trial
- Immunogenicity of an inactivated monovalent 2009 H1N1 influenza vaccine in pregnant women.The Journal of infectious diseases · 2011Trial
- Heterogeneity in seasonal influenza vaccination opportunity and disease risk during pregnancy and in infants <6 months.Vaccine · 2025Article
- Electrochemical biosensors based on the 3D immobilization of capture probes for influenza virus detection.RSC advances · 2025Review
- Provider Determinants of Maternal Influenza and Pertussis Vaccination Uptake in South Australia in a Tertiary Healthcare Setting.Journal of clinical medicine · 2025Article
- Preventing Influenza Virus Infection and Severe Influenza Among Pregnant People and Infants.Journal of women's health (2002) · 2024Article
- Gestational influenza A virus infection elicits nonresolving vascular dysfunction and T-cell accumulation in the aorta of mice.American journal of physiology. Heart and circulatory physiology · 2024Article
- Determinants of non-vaccination against seasonal influenza during pregnancy.Canadian journal of public health = Revue canadienne de sante publique · 2024Article
- Review
- Rates of Influenza and Tdap Vaccination in Teaching and Private Obstetrical Practices, and the Influence of Vaccine Hesitancy.Maternal and child health journal · 2023Article
- The COVID-19 Vaccines International Pregnancy Exposure Registry (C-VIPER): Protocol and Methodological Considerations.Drug safety · 2023Article
- Influenza Virus Infection during Pregnancy as a Trigger of Acute and Chronic Complications.Viruses · 2022Review
111 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
7 authors at 3 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundExcess deaths have occurred among pregnant women during influenza pandemics, but the impact of influenza during nonpandemic years is unclear. We evaluated the impact of exposure during nonpandemic influenza seasons on the rates of hospital admissions and physician visits because of respiratory illness among pregnant women.
methodsWe conducted a 13-year (1990-2002) population-based cohort study involving pregnant women in Nova Scotia. We compared rates of hospital admissions and physician office visits because of respiratory illness during the influenza season in each trimester of pregnancy with rates during the influenza season in the year before pregnancy and with rates in non-influenza seasons. Poisson regression analyses were performed to estimate rate ratios and 95% confidence intervals (CIs).
resultsOf 134,188 pregnant women in the study cohort, 510 (0.4%) were admitted to hospital because of a respiratory illness during pregnancy and 33,775 (25.2%) visited their physician for the same reason during pregnancy. During the influenza seasons, the rate ratio of hospital admissions in the third trimester compared with admissions in the year before pregnancy was 7.9 (95% CI 5.0-12.5) among women with comorbidities and 5.1 (95% CI 3.6-7.3) among those without comorbidities. The rate of hospital admissions in the third trimester among women without comorbidities was 7.4 per 10,000 woman-months during the influenza season, compared with 5.4 and 3.1 per 10,000 woman-months during the peri-and non-influenza seasons respectively. Corresponding rates among women with comorbidities were 44.9, 9.3 and 18.9 per 10,000 woman-months. Only 6.7% of women with comorbidities had received influenza immunization.
interpretationOur data support the recommendation that pregnant women with comorbidities should receive influenza vaccination regardless of their stage of pregnancy during the influenza season. Since hospital admissions because of respiratory illness during the influenza season were also increased among pregnant women without comorbidities, all pregnant women are likely to benefit from influenza vaccination.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.