{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,3]],"date-time":"2026-09-03T02:13:22Z","timestamp":1788401602975,"version":"build-2803163510"},"reference-count":49,"publisher":"BMJ","issue":"12","license":[{"start":{"date-parts":[[2025,12,22]],"date-time":"2025-12-22T00:00:00Z","timestamp":1766361600000},"content-version":"unspecified","delay-in-days":21,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Canadian Immunization Research Network, Canadian Institutes of Health Research, Public Health Agency of Canada, Fonds de recherche du Qu\u00e9bec research career awards.","award":["450980"],"award-info":[{"award-number":["450980"]}]}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"accepted":{"date-parts":[[2025,11,26]]},"published-print":{"date-parts":[[2025,12]]},"abstract":"<jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>To estimate the association between maternal COVID-19 vaccination during pregnancy and adverse neonatal and maternal outcomes.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Design<\/jats:title>\n                    <jats:p>Population-based retrospective cohort study using a hospitalisation database linked with other health administrative databases.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Setting<\/jats:title>\n                    <jats:p>Province of Quebec, Canada, from 1 May 2021 to 30 June 2023.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Participants<\/jats:title>\n                    <jats:p>All singleton pregnancies resulting in a live birth or stillbirth at \u226520 weeks of gestation, excluding those with a conception date &lt;42 weeks before the end of the study period.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Primary outcome measures<\/jats:title>\n                    <jats:p>We used robust Poisson regression models to estimate adjusted risk ratios (aRRs) for chorioamnionitis, postpartum haemorrhage, caesarean delivery, preterm birth, very preterm birth, small for gestational age (SGA), maternal and neonatal admission to intensive care unit (ICU, NICU) and severe neonatal morbidity. We used a Cox regression model with a time-varying exposure variable to estimate adjusted HRs (aHRs) for stillbirth. Propensity score weighting was used to adjust for potential confounding.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Among 140 073 singleton pregnancies resulting in live birth or stillbirth, 61 282 individuals (43.8%) received at least one dose of messenger RNA COVID-19 vaccine during pregnancy. Vaccination during pregnancy was not associated with an increased risk of chorioamnionitis (aRR 0.99, 95% CI 0.95 to 1.04), postpartum haemorrhage (aRR 1.03, 95%\u2009CI 0.99 to 1.06), very preterm birth (aRR 1.04, 95%\u2009CI 0.89 to 1.21) and stillbirth (aHR 1.14, 95%\u2009CI 0.94 to 1.39). Vaccination during pregnancy was significantly associated with a reduced risk of caesarean delivery (aRR 0.94, 95%\u2009CI 0.92 to 0.96), maternal ICU admission (aRR 0.80, 95%\u2009CI 0.65 to 0.98), SGA (aRR 0.94, 95%\u2009CI 0.91 to 0.98), NICU admission (aRR 0.91, 95%\u2009CI 0.85 to 0.96), preterm birth (aRR 0.94, 95%\u2009CI 0.90 to 0.99) and severe neonatal morbidity (aRR 0.91, 95%\u2009CI 0.85 to 0.98).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Our findings suggest that COVID-19 vaccination during pregnancy was not associated with an increased risk of adverse outcomes. Ongoing surveillance of the safety of maternal COVID-19 vaccination is essential as doses continue to be recommended for this group.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/bmjopen-2025-106494","type":"journal-article","created":{"date-parts":[[2025,12,23]],"date-time":"2025-12-23T11:05:23Z","timestamp":1766487923000},"page":"e106494","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":2,"title":["Safety of COVID-19 vaccines among pregnant individuals in Quebec, Canada: a population-based retrospective cohort study from the Canadian Immunization Research Network"],"prefix":"10.1136","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0235-3630","authenticated-orcid":false,"given":"Marilou","family":"Kiely","sequence":"first","affiliation":[{"name":"M\u00e9decine sociale et pr\u00e9ventive, Universit\u00e9 Laval Facult\u00e9 de M\u00e9decine, Qu\u00e9bec City, Quebec, Canada"},{"name":"Centre de recherche du CHU de Qu\u00e9bec-Universit\u00e9 Laval Site CHUL, Qu\u00e9bec City, Quebec, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ella","family":"Diendere","sequence":"additional","affiliation":[{"name":"Institut national de sant\u00e9 publique du Qu\u00e9bec, Qu\u00e9bec City, Quebec, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Isaora","family":"Dialahy","sequence":"additional","affiliation":[{"name":"Quebec National Institute of Public Health, Quebec City, Quebec, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gentiane","family":"Perrault-Sullivan","sequence":"additional","affiliation":[{"name":"Institut national de sant\u00e9 publique du Qu\u00e9bec, Qu\u00e9bec City, Quebec, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6042-3177","authenticated-orcid":false,"given":"Nicholas","family":"Brousseau","sequence":"additional","affiliation":[{"name":"Centre de recherche du CHU de Qu\u00e9bec-Universit\u00e9 Laval Site CHUL, Qu\u00e9bec City, Quebec, Canada"},{"name":"Institut national de sant\u00e9 publique du Qu\u00e9bec, Qu\u00e9bec City, Quebec, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shu Qin","family":"Wei","sequence":"additional","affiliation":[{"name":"OriginElle Fertility Clinic and Women\u2019s Health Center, Montreal, Quebec, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0431-3314","authenticated-orcid":false,"given":"Denis","family":"Talbot","sequence":"additional","affiliation":[{"name":"M\u00e9decine sociale et pr\u00e9ventive, Universit\u00e9 Laval Facult\u00e9 de M\u00e9decine, Qu\u00e9bec City, Quebec, Canada"},{"name":"Centre de recherche du CHU de Qu\u00e9bec-Universit\u00e9 Laval Site CHUL, Qu\u00e9bec City, Quebec, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Am\u00e9lie","family":"Boutin","sequence":"additional","affiliation":[{"name":"Centre de recherche du CHU de Qu\u00e9bec-Universit\u00e9 Laval Site CHUL, Qu\u00e9bec City, Quebec, Canada"},{"name":"P\u00e9diatrie, Universit\u00e9 Laval, Qu\u00e9bec City, Quebec, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Caroline","family":"Quach","sequence":"additional","affiliation":[{"name":"Department of Epidemiology, Biostatistics and Occupational Health, University of Montreal, Montreal, Quebec, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sarah","family":"Jorgensen","sequence":"additional","affiliation":[{"name":"Marshfield Clinic Research Institute, Marshfield, Wisconsin, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9545-6024","authenticated-orcid":false,"given":"Isabelle","family":"Boucoiran","sequence":"additional","affiliation":[{"name":"CHU Sainte-Justine, Montreal, Quebec, Canada"},{"name":"Universit\u00e9 de Montr\u00e9al, Montreal, Quebec, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2025,12,23]]},"reference":[{"key":"2026010703480847000_15.12.e106494.1","doi-asserted-by":"crossref","DOI":"10.1016\/j.nmni.2023.101135","article-title":"Maternal COVID-19 infection and the fetus: Immunological and neurological perspectives","volume":"53","author":"Falahi","year":"2023","journal-title":"New Microbes New Infect"},{"key":"2026010703480847000_15.12.e106494.2","doi-asserted-by":"crossref","DOI":"10.3390\/nu14122534","article-title":"Immune System and Psychological State of Pregnant Women during COVID-19 Pandemic: Are Micronutrients Able to Support Pregnancy?","volume":"14","author":"Alesci","year":"2022","journal-title":"Nutrients"},{"key":"2026010703480847000_15.12.e106494.3","doi-asserted-by":"crossref","DOI":"10.1136\/bmj.m3320","article-title":"Clinical manifestations, risk factors, and maternal and perinatal outcomes of coronavirus disease 2019 in pregnancy: living systematic review and meta-analysis","volume":"370","author":"Allotey","year":"2020","journal-title":"BMJ"},{"key":"2026010703480847000_15.12.e106494.4","doi-asserted-by":"crossref","DOI":"10.1136\/bmjgh-2022-009495","article-title":"Adverse maternal, fetal, and newborn outcomes among pregnant women with SARS-CoV-2 infection: an individual participant data meta-analysis","volume":"8","author":"Smith","year":"2023","journal-title":"BMJ Glob Health"},{"key":"2026010703480847000_15.12.e106494.5","doi-asserted-by":"publisher","DOI":"10.1503\/cmaj.202604"},{"key":"2026010703480847000_15.12.e106494.6","doi-asserted-by":"publisher","DOI":"10.1002\/ijgo.13816"},{"key":"2026010703480847000_15.12.e106494.7","unstructured":"Public Health Agency o Canada . Immunization in pregnancy and breastfeeding: Canadian immunization guide. 2007. Available: https:\/\/www.canada.ca\/en\/public-health\/services\/publications\/healthy-living\/canadian-immunization-guide-part-3-vaccination-specific-populations\/page-4-immunization-pregnancy-breastfeeding.html"},{"key":"2026010703480847000_15.12.e106494.8","doi-asserted-by":"crossref","first-page":"102239","DOI":"10.1016\/j.jogc.2023.102239","article-title":"A Population-Based Test-Negative Matched Case-Control Analysis of SARS-CoV-2 Vaccine Effectiveness Among Pregnant People in Ontario, Canada","volume":"46","author":"Lapinsky","year":"2024","journal-title":"J Obstet Gynaecol Can"},{"key":"2026010703480847000_15.12.e106494.9","doi-asserted-by":"crossref","first-page":"427","DOI":"10.1001\/jamapediatrics.2022.6134","article-title":"Estimated Effectiveness of Postpartum Maternal Messenger RNA COVID-19 Vaccination Against Delta and Omicron SARS-CoV-2 Infection and Hospitalization in Infants Younger Than 6 Months","volume":"177","author":"Jorgensen","year":"2023","journal-title":"JAMA Pediatr"},{"key":"2026010703480847000_15.12.e106494.10","doi-asserted-by":"crossref","first-page":"236","DOI":"10.1016\/j.ajog.2021.08.007","article-title":"COVID-19 vaccination during pregnancy: coverage and safety","volume":"226","author":"Blakeway","year":"2022","journal-title":"Am J Obstet Gynecol"},{"key":"2026010703480847000_15.12.e106494.11","doi-asserted-by":"crossref","first-page":"504","DOI":"10.1038\/s41591-021-01666-2","article-title":"SARS-CoV-2 infection and COVID-19 vaccination rates in pregnant women in Scotland","volume":"28","author":"Stock","year":"2022","journal-title":"Nat Med"},{"key":"2026010703480847000_15.12.e106494.12","doi-asserted-by":"publisher","DOI":"10.1055\/s-0041-1735878"},{"key":"2026010703480847000_15.12.e106494.13","doi-asserted-by":"crossref","first-page":"100352","DOI":"10.1016\/j.ajogmf.2021.100352","article-title":"Pregnant women\u2019s perspectives on severe acute respiratory syndrome coronavirus 2 vaccine","volume":"3","author":"Carbone","year":"2021","journal-title":"American Journal of Obstetrics & Gynecology MFM"},{"key":"2026010703480847000_15.12.e106494.14","doi-asserted-by":"crossref","first-page":"547","DOI":"10.17269\/s41997-022-00641-9","article-title":"COVID-19 vaccine uptake and intention during pregnancy in Canada","volume":"113","author":"Reifferscheid","year":"2022","journal-title":"Can J Public Health"},{"key":"2026010703480847000_15.12.e106494.15","doi-asserted-by":"crossref","DOI":"10.1186\/s12884-022-04505-5","article-title":"Safety of SARS-CoV-2 vaccination during pregnancy- obstetric outcomes from a large cohort study","volume":"22","author":"Dick","year":"2022","journal-title":"BMC Pregnancy Childbirth"},{"key":"2026010703480847000_15.12.e106494.16","doi-asserted-by":"crossref","DOI":"10.1136\/bmjmed-2023-000632","article-title":"Pregnancy, fetal, and neonatal outcomes after a first booster dose of covid-19 vaccine during pregnancy in Ontario, Canada: population based, retrospective cohort study","volume":"2","author":"Fell","year":"2023","journal-title":"BMJ Med"},{"key":"2026010703480847000_15.12.e106494.17","doi-asserted-by":"publisher","DOI":"10.1001\/jama.2022.4255"},{"key":"2026010703480847000_15.12.e106494.18","doi-asserted-by":"publisher","DOI":"10.1001\/jama.2022.3271"},{"key":"2026010703480847000_15.12.e106494.19","doi-asserted-by":"crossref","DOI":"10.1177\/20420986211021233","article-title":"Vaccine Safety Datalink infrastructure enhancements for evaluating the safety of maternal vaccination","volume":"12","author":"Naleway","year":"2021","journal-title":"Ther Adv Drug Saf"},{"key":"2026010703480847000_15.12.e106494.20","doi-asserted-by":"crossref","first-page":"1553","DOI":"10.1016\/S1473-3099(22)00426-1","article-title":"Safety of COVID-19 vaccines in pregnancy: a Canadian National Vaccine Safety (CANVAS) network cohort study","volume":"22","author":"Sadarangani","year":"2022","journal-title":"Lancet Infect Dis"},{"key":"2026010703480847000_15.12.e106494.21","doi-asserted-by":"crossref","DOI":"10.1371\/journal.pmed.1001885","article-title":"The REporting of studies Conducted using Observational Routinely-collected health Data (RECORD) statement","volume":"12","author":"Benchimol","year":"2015","journal-title":"PLoS Med"},{"key":"2026010703480847000_15.12.e106494.22","doi-asserted-by":"crossref","first-page":"1882","DOI":"10.1016\/j.vaccine.2021.02.070","article-title":"Guidance for design and analysis of observational studies of fetal and newborn outcomes following COVID-19 vaccination during pregnancy","volume":"39","author":"Fell","year":"2021","journal-title":"Vaccine (Auckl)"},{"key":"2026010703480847000_15.12.e106494.23","unstructured":"Institut de la statistique du Qu\u00e9bec . Portrait des enfants du qu\u00e9bec: de la grossesse aux premiers mois de la vie. 2023. Available: https:\/\/statistique.quebec.ca\/fr\/produit\/publication\/portrait-enfants-quebec-grossesse-premiers-mois-vie"},{"key":"2026010703480847000_15.12.e106494.24","doi-asserted-by":"crossref","first-page":"247","DOI":"10.24095\/hpcdp.34.4.06f","article-title":"Le Syst\u00e8me int\u00e9gr\u00e9 de surveillance des maladies chroniques du Qu\u00e9bec (SISMACQ), une approche novatrice","volume":"34","author":"Blais","year":"2014","journal-title":"Maladies Chroniques et Blessures Au Canada"},{"key":"2026010703480847000_15.12.e106494.25","unstructured":"Gamache P , Hamel D , Blaser C . Material and social deprivation index: a summary. INSPQ Website. Available: https:\/\/www.inspq.qc.ca\/en\/publications\/2639 [Accessed 13 Nov 2023]."},{"key":"2026010703480847000_15.12.e106494.26","doi-asserted-by":"publisher","DOI":"10.1093\/ije\/dyaa252"},{"key":"2026010703480847000_15.12.e106494.27","doi-asserted-by":"crossref","DOI":"10.1186\/1471-2288-11-49","article-title":"Methodological challenges when estimating the effects of season and seasonal exposures on birth outcomes","volume":"11","author":"Strand","year":"2011","journal-title":"BMC Med Res Methodol"},{"key":"2026010703480847000_15.12.e106494.28","doi-asserted-by":"publisher","DOI":"10.1093\/aje\/kww043"},{"key":"2026010703480847000_15.12.e106494.29","doi-asserted-by":"crossref","DOI":"10.1038\/s41467-023-40965-9","article-title":"Neonatal and maternal outcomes following SARS-CoV-2 infection and COVID-19 vaccination: a population-based matched cohort study","volume":"14","author":"Lindsay","year":"2023","journal-title":"Nat Commun"},{"key":"2026010703480847000_15.12.e106494.30","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa1612296"},{"key":"2026010703480847000_15.12.e106494.31","unstructured":"World Health Organization (WHO) . COVID-19 vaccines: safety surveillance manual. module on safety surveillance of COVID-19 vaccines in pregnant and breastfeeding women. 2021. Available: https:\/\/iris.who.int\/bitstream\/handle\/10665\/342538\/WHO-MHP-RPQ-PVG-2021.1-eng.pdf?isAllowed=y&sequence=1"},{"key":"2026010703480847000_15.12.e106494.32","doi-asserted-by":"publisher","DOI":"10.1093\/aje\/kwt285"},{"key":"2026010703480847000_15.12.e106494.33","doi-asserted-by":"crossref","DOI":"10.1136\/bmj-2022-071416","article-title":"Risk of preterm birth, small for gestational age at birth, and stillbirth after covid-19 vaccination during pregnancy: population based retrospective cohort study","volume":"378","author":"Fell","year":"2022","journal-title":"BMJ"},{"key":"2026010703480847000_15.12.e106494.34","doi-asserted-by":"crossref","DOI":"10.9778\/cmajo.20200239","article-title":"Obstetric and perinatal health outcomes after pertussis vaccination during pregnancy in Ontario, Canada: a retrospective cohort study","volume":"9","author":"Fakhraei","year":"2021","journal-title":"Cmajo"},{"key":"2026010703480847000_15.12.e106494.35","doi-asserted-by":"publisher","DOI":"10.1007\/s10995-011-0797-6"},{"key":"2026010703480847000_15.12.e106494.36","doi-asserted-by":"publisher","DOI":"10.1002\/sim.6607"},{"key":"2026010703480847000_15.12.e106494.37","doi-asserted-by":"publisher","DOI":"10.1097\/ede.0000000000001544"},{"key":"2026010703480847000_15.12.e106494.38","doi-asserted-by":"publisher","DOI":"10.1093\/biomet\/69.1.239"},{"key":"2026010703480847000_15.12.e106494.39","doi-asserted-by":"crossref","first-page":"1098","DOI":"10.1001\/jamapediatrics.2022.3456","article-title":"Peripartum Outcomes Associated With COVID-19 Vaccination During Pregnancy: A Systematic Review and Meta-analysis","volume":"176","author":"Watanabe","year":"2022","journal-title":"JAMA Pediatr"},{"key":"2026010703480847000_15.12.e106494.40","doi-asserted-by":"crossref","DOI":"10.1016\/j.lanepe.2024.101037","article-title":"COVID-19 diagnosis, vaccination during pregnancy, and adverse pregnancy outcomes of 865,654 women in England and Wales: a population-based cohort study","volume":"45","author":"Raffetti","year":"2024","journal-title":"Lancet Reg Health Eur"},{"key":"2026010703480847000_15.12.e106494.41","doi-asserted-by":"crossref","first-page":"470","DOI":"10.1001\/jamapediatrics.2022.0001","article-title":"Association of BNT162b2 COVID-19 Vaccination During Pregnancy With Neonatal and Early Infant Outcomes","volume":"176","author":"Goldshtein","year":"2022","journal-title":"JAMA Pediatr"},{"key":"2026010703480847000_15.12.e106494.42","doi-asserted-by":"crossref","first-page":"215","DOI":"10.1097\/AOG.0000000000005632","article-title":"Coronavirus Disease 2019 (COVID-19) Vaccination and Stillbirth in the Vaccine Safety Datalink","volume":"144","author":"Denoble","year":"2024","journal-title":"Obstet Gynecol"},{"key":"2026010703480847000_15.12.e106494.43","doi-asserted-by":"crossref","first-page":"6430","DOI":"10.1016\/j.vaccine.2015.08.041","article-title":"Does influenza vaccination improve pregnancy outcome? Methodological issues and research needs","volume":"33","author":"Savitz","year":"2015","journal-title":"Vaccine (Auckl)"},{"key":"2026010703480847000_15.12.e106494.44","doi-asserted-by":"crossref","first-page":"1629","DOI":"10.1001\/jama.2021.15494","article-title":"Spontaneous Abortion Following COVID-19 Vaccination During Pregnancy","volume":"326","author":"Kharbanda","year":"2021","journal-title":"JAMA"},{"key":"2026010703480847000_15.12.e106494.45","doi-asserted-by":"publisher","DOI":"10.1093\/humrep\/dead036"},{"key":"2026010703480847000_15.12.e106494.46","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMc2114466"},{"key":"2026010703480847000_15.12.e106494.47","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa2204399"},{"key":"2026010703480847000_15.12.e106494.48","doi-asserted-by":"crossref","first-page":"649","DOI":"10.1038\/s41577-025-01162-5","article-title":"Vaccination in pregnancy to protect the newborn","volume":"25","author":"Male","year":"2025","journal-title":"Nat Rev Immunol"},{"key":"2026010703480847000_15.12.e106494.49","doi-asserted-by":"publisher","DOI":"10.1097\/EDE.0000000000001562"}],"container-title":["BMJ Open"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bmjopen-2025-106494","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,1,7]],"date-time":"2026-01-07T11:51:02Z","timestamp":1767786662000},"score":1,"resource":{"primary":{"URL":"https:\/\/bmjopen.bmj.com\/lookup\/doi\/10.1136\/bmjopen-2025-106494"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,12]]},"references-count":49,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2025,12,23]]},"published-print":{"date-parts":[[2025,12]]}},"alternative-id":["10.1136\/bmjopen-2025-106494"],"URL":"https:\/\/doi.org\/10.1136\/bmjopen-2025-106494","relation":{},"ISSN":["2044-6055","2044-6055"],"issn-type":[{"value":"2044-6055","type":"print"},{"value":"2044-6055","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,12]]}}}