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Risk of adverse maternal and foetal outcomes associated with inactivated influenza vaccination in first trimester of pregnancy
Author(s) -
Speake Hollie A.,
Pereira Gavin,
Regan Annette K.
Publication year - 2021
Publication title -
paediatric and perinatal epidemiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.667
H-Index - 88
eISSN - 1365-3016
pISSN - 0269-5022
DOI - 10.1111/ppe.12715
Subject(s) - medicine , pregnancy , obstetrics , relative risk , vaccination , confidence interval , population , cohort study , gynecology , immunology , environmental health , genetics , biology
Background In many countries, influenza vaccination is routinely recommended during any stage of pregnancy, yet uptake remains low, particularly in the first trimester. This is thought to be due to maternal concerns regarding vaccine safety. Objective To evaluate the safety of influenza vaccination in the first trimester of pregnancy. Methods In a 4‐year retrospective cohort study using probabilistic record linkage of administrative health data, we established a population‐based cohort of 2391 women vaccinated in first trimester and 68 447 never vaccinated women with a date of conception between 2012 and 2015 in Western Australia. We estimated the relative risk (RR) of perinatal health outcomes among first trimester vaccinated women as compared to never vaccinated women using log‐binomial logistic regression following a propensity score matched (PSM) analyses (2391 vaccinated women matched with 9564 never vaccinated women). Results First trimester vaccination was not associated with increased risk of stillbirth (RR 1.18, 95% confidence interval [CI] 0.64, 2.19), small for gestational age (RR 0.96, 95% CI 0.83, 1.11) or preeclampsia (RR 0.97, 95% CI 0.74, 1.28). The risk of spontaneous birth at 32‐36 weeks was higher in first trimester vaccinated women compared with never vaccinated women (RR 1.40, 95% CI 1.11, 1.77). Vaccination was associated with a 10‐19% increase in the risk of gestational diabetes (RR 1.18, 95% CI 0.94, 1.49), premature rupture of membranes (RR 1.10, 95% CI 0.82, 1.48), and threatened preterm labour (RR 1.19, 95% CI 0.90, 1.59). Conclusions With exception to spontaneous preterm birth, findings suggest that first trimester vaccination is not associated with adverse maternal and foetal outcomes. Results can be used to support patient and provider‐level vaccine decision making during first trimester.