Maria C Magnus1, Anne K Örtqvist2,3, Elisabeth Dahlqwist2, Rickard Ljung4,5, Fredrik Skår6, Laura Oakley1,7, Ferenc Macsali8,9, Björn Pasternak2,10, Håkon K Gjessing1,11, Siri E Håberg1, Olof Stephansson2,12. 1. Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway. 2. Clinical Epidemiology Division, Department of Medicine, Solna, Karolinska Institutet, Stockholm, Sweden. 3. Department of Obstetrics and Gynecology, Visby County Hospital, Visby, Sweden. 4. Swedish Medical Products Agency, Uppsala, Sweden. 5. Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden. 6. Department of Infection Control and Vaccines, Norwegian Institute of Public Health, Oslo, Norway. 7. Department of Non-communicable Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom. 8. Department of Health Registry Research and Development, Norwegian Institute of Public Health, Bergen, Norway. 9. Department of Obstetrics and Gynecology, Haukeland University Hospital, Bergen, Norway. 10. Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark. 11. Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway. 12. Department of Women's Health, Division of Obstetrics, Karolinska University Hospital, Stockholm, Sweden.
Abstract
Importance: Data about the safety of vaccines against SARS-CoV-2 during pregnancy are limited. Objective: To examine the risk of adverse pregnancy outcomes after vaccination against SARS-CoV-2 during pregnancy. Design, Setting, and Participants: This registry-based retrospective cohort study included 157 521 singleton pregnancies ending after 22 gestational weeks from January 1, 2021, until January 12, 2022 (Sweden), or January 15, 2022 (Norway). The Pregnancy Register in Sweden and the Medical Birth Registry of Norway were linked to vaccination and other registries for identification of exposure and background characteristics. Exposures: Data on mRNA vaccines-BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna)-and 1 viral vector vaccine-AZD1222 (AstraZeneca)-were collected from national vaccination registries. Main Outcomes and Measures: The risk of preterm birth and stillbirth was evaluated using Cox regression models, with gestational day as the time metric and vaccination as a time-dependent exposure variable. The risk of small for gestational age, low Apgar score, and neonatal care admission was evaluated using logistic regression. Random-effects meta-analysis was used to combine results between countries. Results: Among the 157 521 singleton births included in the study (103 409 in Sweden and 54 112 in Norway), the mean maternal age at the time of delivery was 31 years, and 28 506 (18%) were vaccinated against SARS-CoV-2 (12.9% with BNT162b2, 4.8% with mRNA-1273, and 0.3% with AZD1222) while pregnant. A total of 0.7%, 8.3%, and 9.1% of individuals delivering were vaccinated during the first, second, and third trimester, respectively. Vaccination against SARS-CoV-2 was not significantly associated with increased risk of preterm birth (6.2 vs 4.9 per 10 000 pregnancy days; adjusted hazard ratio [aHR], 0.98 [95% CI, 0.91 to 1.05]; I2 = 0%; P for heterogeneity = .60), stillbirth (2.1 vs 2.4 per 100 000 pregnancy days; aHR, 0.86 [95% CI, 0.63 to 1.17]), small for gestational age (7.8% vs 8.5%; difference, -0.6% [95% CI, -1.3% to 0.2%]; adjusted OR [aOR], 0.97 [95% CI, 0.90 to 1.04]), low Apgar score (1.5% vs 1.6%; difference, -0.05% [95% CI, -0.3% to 0.1%]; aOR, 0.97 [95% CI, 0.87 to 1.08]), or neonatal care admission (8.5% vs 8.5%; difference, 0.003% [95% CI, -0.9% to 0.9%]; aOR, 0.97 [95% CI, 0.86 to 1.10]). Conclusions and Relevance: In this population-based study conducted in Sweden and Norway, vaccination against SARS-CoV-2 during pregnancy, compared with no SARS-CoV-2 vaccination during pregnancy, was not significantly associated with an increased risk of adverse pregnancy outcomes. The majority of the vaccinations were with mRNA vaccines during the second and third trimesters of pregnancy, which should be considered in interpreting the findings.
Importance: Data about the safety of vaccines against SARS-CoV-2 during pregnancy are limited. Objective: To examine the risk of adverse pregnancy outcomes after vaccination against SARS-CoV-2 during pregnancy. Design, Setting, and Participants: This registry-based retrospective cohort study included 157 521 singleton pregnancies ending after 22 gestational weeks from January 1, 2021, until January 12, 2022 (Sweden), or January 15, 2022 (Norway). The Pregnancy Register in Sweden and the Medical Birth Registry of Norway were linked to vaccination and other registries for identification of exposure and background characteristics. Exposures: Data on mRNA vaccines-BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna)-and 1 viral vector vaccine-AZD1222 (AstraZeneca)-were collected from national vaccination registries. Main Outcomes and Measures: The risk of preterm birth and stillbirth was evaluated using Cox regression models, with gestational day as the time metric and vaccination as a time-dependent exposure variable. The risk of small for gestational age, low Apgar score, and neonatal care admission was evaluated using logistic regression. Random-effects meta-analysis was used to combine results between countries. Results: Among the 157 521 singleton births included in the study (103 409 in Sweden and 54 112 in Norway), the mean maternal age at the time of delivery was 31 years, and 28 506 (18%) were vaccinated against SARS-CoV-2 (12.9% with BNT162b2, 4.8% with mRNA-1273, and 0.3% with AZD1222) while pregnant. A total of 0.7%, 8.3%, and 9.1% of individuals delivering were vaccinated during the first, second, and third trimester, respectively. Vaccination against SARS-CoV-2 was not significantly associated with increased risk of preterm birth (6.2 vs 4.9 per 10 000 pregnancy days; adjusted hazard ratio [aHR], 0.98 [95% CI, 0.91 to 1.05]; I2 = 0%; P for heterogeneity = .60), stillbirth (2.1 vs 2.4 per 100 000 pregnancy days; aHR, 0.86 [95% CI, 0.63 to 1.17]), small for gestational age (7.8% vs 8.5%; difference, -0.6% [95% CI, -1.3% to 0.2%]; adjusted OR [aOR], 0.97 [95% CI, 0.90 to 1.04]), low Apgar score (1.5% vs 1.6%; difference, -0.05% [95% CI, -0.3% to 0.1%]; aOR, 0.97 [95% CI, 0.87 to 1.08]), or neonatal care admission (8.5% vs 8.5%; difference, 0.003% [95% CI, -0.9% to 0.9%]; aOR, 0.97 [95% CI, 0.86 to 1.10]). Conclusions and Relevance: In this population-based study conducted in Sweden and Norway, vaccination against SARS-CoV-2 during pregnancy, compared with no SARS-CoV-2 vaccination during pregnancy, was not significantly associated with an increased risk of adverse pregnancy outcomes. The majority of the vaccinations were with mRNA vaccines during the second and third trimesters of pregnancy, which should be considered in interpreting the findings.
Authors: Edwige Péju; Félicie Belicard; Stein Silva; Sami Hraiech; Benoît Painvin; Toufik Kamel; Arnaud W Thille; Antoine Goury; David Grimaldi; Boris Jung; Michael Piagnerelli; Hadrien Winiszewski; Merce Jourdain; Mathieu Jozwiak Journal: Intensive Care Med Date: 2022-08-17 Impact factor: 41.787
Authors: Deshayne B Fell; Sheryll Dimanlig-Cruz; Annette K Regan; Siri E Håberg; Christopher A Gravel; Laura Oakley; Gillian D Alton; Eszter Török; Tavleen Dhinsa; Prakesh S Shah; Kumanan Wilson; Ann E Sprague; Darine El-Chaâr; Mark C Walker; Jon Barrett; Nannette Okun; Sarah A Buchan; Jeffrey C Kwong; Sarah E Wilson; Sandra I Dunn; Shannon E MacDonald; Shelley D Dougan Journal: BMJ Date: 2022-08-17
Authors: Joe Eid; Mahmoud Abdelwahab; Hayley Williams; Madeleine Caplan; Sema Hajmurad; Kartik K Venkatesh; Maged M Costantine; Kara M Rood Journal: Am J Reprod Immunol Date: 2022-07-15 Impact factor: 3.777