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The following references up to March 31, 2023 were used to inform the content for the relevant sections of the Confidence Project infographics for all languages – a pdf of references is also available here. 

Risks Associated With COVID-19 in Pregnancy:  

  1. McClymont E, Albert AY, Alton GD, et al. Association of SARS-CoV-2 Infection During Pregnancy With Maternal and Perinatal Outcomes.?JAMA. 2022;327(20):1983-1991. doi:10.1001/jama.2022.5906 
  2. Smith ER, Oakley E, Grandner GW, et al. Adverse maternal, fetal, and newborn outcomes among pregnant women with SARS-CoV-2 infection: an individual participant data meta-analysis.?BMJ Glob Health. 2023;8(1):e009495. doi:10.1136/bmjgh-2022-009495 
  3. Villar J, Ariff S, Gunier RB, et al. Maternal and Neonatal Morbidity and Mortality Among Pregnant Women With and Without COVID-19 Infection: The INTERCOVID Multinational Cohort Study [published correction appears in JAMA Pediatr. 2022 Jan 1;176(1):104].?JAMA Pediatr. 2021;175(8):817-826. doi:10.1001/jamapediatrics.2021.1050 
  4. Ackerman CM, Nguyen JL, Ambati S, et al. Clinical and Pregnancy Outcomes of Coronavirus Disease 2019 Among Hospitalized Pregnant Women in the United States.?Open Forum Infect Dis. 2021;9(2):ofab429. Published 2021 Sep 3. doi:10.1093/ofid/ofab429 
  5. Kasehagen L, Byers P, Taylor K, et al. COVID-19–Associated Deaths After SARS-CoV-2 Infection During Pregnancy — Mississippi, March 1, 2020–October 6, 2021. MMWR Morb Mortal Wkly Rep 2021;70:1646–1648. doi:? icon 
  6. Metz TD, Clifton RG, Hughes BL, et al. Association of SARS-CoV-2 Infection With Serious Maternal Morbidity and Mortality From Obstetric Complications.?JAMA. 2022;327(8):748-759. doi:10.1001/jama.2022.1190
  7. Mullins E, Hudak ML, Banerjee J, et al. Pregnancy and neonatal outcomes of COVID-19: coreporting of common outcomes from PAN-COVID and?AAP-SONPM registries.?Ultrasound Obstet Gynecol. 2021;57(4):573-581. doi:10.1002/uog.23619 
  8. Allotey J, Stallings E, Bonet M, et al. Clinical manifestations, risk factors, and maternal and perinatal outcomes of coronavirus disease 2019 in pregnancy: living systematic review and meta-analysis.?BMJ. 2020;370:m3320. Published 2020 Sep 1. doi:10.1136/bmj.m3320 
  9. Zambrano LD, Ellington S, Strid P, et al. Update: Characteristics of Symptomatic Women of Reproductive Age with Laboratory-Confirmed SARS-CoV-2 Infection by Pregnancy Status — United States, January 22–October 3, 2020. MMWR Morb Mortal Wkly Rep 2020;69:1641–1647. DOI:? 
  10. Ko JY, DeSisto CL, Simeone RM, et al. Adverse Pregnancy Outcomes, Maternal Complications, and Severe Illness Among US Delivery Hospitalizations With and Without a Coronavirus Disease 2019 (COVID-19) Diagnosis.?Clin Infect Dis. 2021;73(Suppl 1):S24-S31. doi:10.1093/cid/ciab344
  11. Galang RR, Newton SM, Woodworth KR, et al. Risk Factors for Illness Severity Among Pregnant Women With Confirmed Severe Acute Respiratory Syndrome Coronavirus 2 Infection-Surveillance for Emerging Threats to Mothers and Babies Network, 22 State, Local, and Territorial Health Departments, 29 March 2020-5 March 2021.?Clin Infect Dis. 2021;73(Suppl 1):S17-S23. doi:10.1093/cid/ciab432 
  12. Money D. Canadian surveillance of COVID-19 in pregnancy: Epidemiology, maternal and infant outcomes. Report #4: Released June 3rd, 2021. Maternal and infant outcomes (March 1, 2020 to March 31, 2021) from five Canadian provinces.  
  13. Ackerman CM, Nguyen JL, Ambati S, et al. Clinical and Pregnancy Outcomes of Coronavirus Disease 2019 Among Hospitalized Pregnant Women in the United States.?Open Forum Infect Dis. 2021;9(2):ofab429. Published 2021 Sep 3. doi:10.1093/ofid/ofab429 
  14. Lipkind HS, Vazquez-Benitez G, DeSilva M, et al. Receipt of COVID-19 Vaccine During Pregnancy and Preterm or Small-for-Gestational-Age at Birth – Eight Integrated Health Care Organizations, United States, December 15, 2020-July 22, 2021.?MMWR Morb Mortal Wkly Rep. 2022;71(1):26-30. Published 2022 Jan 7. doi:10.15585/mmwr.mm7101e1 
  15. Stock SJ, Carruthers J, Calvert C, et al. SARS-CoV-2 infection and COVID-19 vaccination rates in pregnant women in Scotland [published correction appears in Nat Med. 2022 Feb 4;:].?Nat Med. 2022;28(3):504-512. doi:10.1038/s41591-021-01666-2 
  16. Ellington S, Strid P, Tong VT, et al. Characteristics of Women of Reproductive Age with Laboratory-Confirmed SARS-CoV-2 Infection by Pregnancy Status – United States, January 22-June 7, 2020.?MMWR Morb Mortal Wkly Rep. 2020;69(25):769-775. Published 2020 Jun 26. doi:10.15585/mmwr.mm6925a1

Benefits and Effectiveness of mRNA Vaccines in Pregnancy: 

  1. Carlsen EØ, Magnus MC, Oakley L, et al. Association of COVID-19 Vaccination During Pregnancy With Incidence of SARS-CoV-2 Infection in Infants.?JAMA Intern Med. 2022;182(8):825-831. doi:10.1001/jamainternmed.2022.2442
  2. Dagan N, Barda N, Biron-Shental T, et al. Effectiveness of the BNT162b2 mRNA COVID-19 vaccine in pregnancy.?Nat Med. 2021;27(10):1693-1695. doi:10.1038/s41591-021-01490-8 
  3. Nevo L, Cahen-Peretz A, Vorontsov O, et al. Boosting maternal and neonatal humoral immunity following SARS-CoV-2 infection using a single messenger RNA vaccine dose.?Am J Obstet Gynecol. 2022;227(3):486.e1-486.e10. doi:10.1016/j.ajog.2022.04.010 
  4. Goldshtein I, Nevo D, Steinberg DM, et al. Association Between BNT162b2 Vaccination and Incidence of SARS-CoV-2 Infection in Pregnant Women.?JAMA. 2021;326(8):728-735. doi:10.1001/jama.2021.11035 
  5. Watanabe A, Yasuhara J, Iwagami M, et al. Peripartum Outcomes Associated With COVID-19 Vaccination During Pregnancy: A Systematic Review and Meta-analysis. JAMA Pediatr. 2022;176(11):1098-1106. doi: 10.1001/jamapediatrics.2022.3456. 
  6. Mithal LB, Otero S, Shanes ED, Goldstein JA, Miller ES. Cord blood antibodies following maternal coronavirus disease 2019 vaccination during pregnancy.?Am J Obstet Gynecol. 2021;225(2):192-194. doi:10.1016/j.ajog.2021.03.035 
  7. Kelly JC, Carter EB, Raghuraman N, et al. Anti-severe acute respiratory syndrome coronavirus 2 antibodies induced in breast milk after Pfizer-BioNTech/BNT162b2 vaccination.?Am J Obstet Gynecol. 2021;225(1):101-103. doi:10.1016/j.ajog.2021.03.031 
  8. Nir O, Schwartz A, Toussia-Cohen S, et al. Maternal-neonatal transfer of SARS-CoV-2 immunoglobulin G antibodies among parturient women treated with BNT162b2 messenger RNA vaccine during pregnancy.?Am J Obstet Gynecol MFM. 2022;4(1):100492. doi:10.1016/j.ajogmf.2021.100492 
  9. Prabhu M, Murphy EA, Sukhu AC, et al. Antibody Response to Coronavirus Disease 2019 (COVID-19) Messenger RNA Vaccination in Pregnant Women and Transplacental Passage Into Cord Blood.?Obstet Gynecol. 2021;138(2):278-280. doi:10.1097/AOG.0000000000004438 
  10. Gray KJ, Bordt EA, Atyeo C, et al. Coronavirus disease 2019 vaccine response in pregnant and lactating women: a cohort study.?Am J Obstet Gynecol. 2021;225(3):303.e1-303.e17. doi:10.1016/j.ajog.2021.03.023 
  11. Magnus MC, Örtqvist AK, Dahlqwist E, et al. Association of SARS-CoV-2 Vaccination During Pregnancy With Pregnancy Outcomes.?JAMA. 2022;327(15):1469-1477. doi:10.1001/jama.2022.3271 
  12. Ibroci E, Liu X, Lieb W, et al. Impact of prenatal COVID-19 vaccination on delivery and neonatal outcomes: Results from a New York City cohort.?Vaccine. 2023;41(3):649-656.  
  13. Morgan JA, Biggio JR Jr, Martin JK, et al. Maternal Outcomes After Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection in Vaccinated Compared With Unvaccinated Pregnant Patients.?Obstet Gynecol. 2022;139(1):107-109. doi:10.1097/AOG.0000000000004621 
  14. Rottenstreich M, Sela HY, Rotem R, Kadish E, Wiener-Well Y, Grisaru-Granovsky S. Covid-19 vaccination during the third trimester of pregnancy: rate of vaccination and maternal and neonatal outcomes, a multicentre retrospective cohort study.?BJOG. 2022;129(2):248-255. doi:10.1111/1471-0528.16941 
  15. Blakeway H, Prasad S, Kalafat E, et al. COVID-19 vaccination during pregnancy: coverage and safety.?Am J Obstet Gynecol. 2022;226(2):236.e1-236.e14. doi:10.1016/j.ajog.2021.08.007 
  16. Jorgensen SCJ, Hernandez A, Fell DB, et al. Maternal mRNA covid-19 vaccination during pregnancy and delta or omicron infection or hospital admission in infants: test negative design study. BMJ. 2023;380:e074035. doi:\ 
  17. Jorgensen SCJ, Hernandez A, Fell DB, et al. 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. JAMA Pediatrics. 2023. 
  18. Prasad S, Kalafat E, Blakeway H, et al. Systematic review and meta-analysis of the effectiveness and perinatal outcomes of COVID-19 vaccination in pregnancy.?Nat Commun. 2022;13(1):2414. Published 2022 May 10. doi:10.1038/s41467-022-30052-w 
  19. Theiler RN, Wick M, Mehta R, Weaver AL, Virk A, Swift M. Pregnancy and birth outcomes after SARS-CoV-2 vaccination in pregnancy.?Am J Obstet Gynecol MFM. 2021;3(6):100467. doi:10.1016/j.ajogmf.2021.100467 
  20. Fell DB, Dhinsa T, Alton GD, et al. Association of COVID-19 Vaccination in Pregnancy With Adverse Peripartum Outcomes.?JAMA. 2022;327(15):1478-1487. doi:10.1001/jama.2022.4255 
  21. Morgan JA, Biggio JR, Jr., Martin JK, et al. Pregnancy Outcomes in Patients After Completion of the mRNA Coronavirus Disease 2019 (COVID-19) Vaccination Series Compared With Unvaccinated Patients. Obstet Gynecol. 2023;141(3):555-562. doi: 10.1097/AOG.0000000000005072. 

Safety of COVID-19 Vaccines During Pregnancy: 

  1. Magnus MC, Örtqvist AK, Dahlqwist E, et al. Association of SARS-CoV-2 Vaccination During Pregnancy With Pregnancy Outcomes.?JAMA. 2022;327(15):1469-1477. doi:10.1001/jama.2022.3271 
  2. Goldshtein I, Steinberg DM, Kuint J, et al. Association of BNT162b2 COVID-19 Vaccination During Pregnancy With Neonatal and Early Infant Outcomes.?JAMA Pediatr. 2022;176(5):470-477. doi:10.1001/jamapediatrics.2022.0001 
  3. Shimabukuro TT, Kim SY, Myers TR, et al. Preliminary Findings of mRNA Covid-19 Vaccine Safety in Pregnant Persons [published correction appears in N Engl J Med. 2021 Oct 14;385(16):1536].?N Engl J Med. 2021;384(24):2273-2282. doi:10.1056/NEJMoa2104983 
  4. Zauche LH, Wallace B, Smoots AN, et al. Receipt of mRNA Covid-19 Vaccines and Risk of Spontaneous Abortion.?N Engl J Med. 2021;385(16):1533-1535. doi:10.1056/NEJMc2113891 
  5. Calvert C, Carruthers J, Denny C, et al. A population-based matched cohort study of major congenital anomalies following COVID-19 vaccination and SARS-CoV-2 infection.?Nat Commun. 2023;14(1):107. Published 2023 Jan 6. doi:10.1038/s41467-022-35771-8 

Safety of COVID-19 Vaccines During Breastfeeding: 

  1. Muyldermans J, De Weerdt L, De Brabandere L, Maertens K, Tommelein E. The Effects of COVID-19 Vaccination on Lactating Women: A Systematic Review of the Literature.?Front Immunol. 2022;13:852928. Published 2022 Apr 8. doi:10.3389/fimmu.2022.852928 

Effect COVID-19 Vaccines on Fertility:  

  1. Edelman A, Boniface ER, Benhar E, et al. Association Between Menstrual Cycle Length and Coronavirus Disease 2019 (COVID-19) Vaccination: A U.S. Cohort.?Obstet Gynecol. 2022;139(4):481-489. doi:10.1097/AOG.0000000000004695 
  2. Aharon D, Lederman M, Ghofranian A, et al. In Vitro Fertilization and Early Pregnancy Outcomes After Coronavirus Disease 2019 (COVID-19) Vaccination.?Obstet Gynecol. 2022;139(4):490-497. doi:10.1097/AOG.0000000000004713 
  3. Avraham S, Kedem A, Zur H, Youngster M, Yaakov O, Yerushalmi GM et al.?Coronavirus disease 2019 vaccination and infertility treatment outcomes.?Fertility and Sterility. 2022 Jun;117(6):1291-1299. doi: 10.1016/j.fertnstert.2022.02.025 
  4. Wesselink AK, Hatch EE, Rothman KJ, et al. A Prospective Cohort Study of COVID-19 Vaccination, SARS-CoV-2 Infection, and Fertility.?Am J Epidemiol. 2022;191(8):1383-1395. doi:10.1093/aje/kwac011 
  5. Hillson K, Clemens SC, Madhi SA, et al. Fertility rates and birth outcomes after ChAdOx1 nCoV-19 (AZD1222) vaccination.?Lancet. 2021;398(10312):1683-1684. doi:10.1016/S0140-6736(21)02282-0 

Side Effects / Adverse Outcomes of COVID-19 Vaccines: 

  1. Karlstad Ø, Hovi P, Husby A, et al. SARS-CoV-2 Vaccination and Myocarditis in a Nordic Cohort Study of 23 Million Residents.?JAMA Cardiol. 2022;7(6):600-612. doi:10.1001/jamacardio.2022.0583 
  2. Kharbanda EO, Haapala J, DeSilva M, et al. Spontaneous Abortion Following COVID-19 Vaccination During Pregnancy [published correction appears in JAMA. 2021 Sep 10;:null].?JAMA. 2021;326(16):1629-1631. doi:10.1001/jama.2021.15494 
  3. Muir KL, Kallam A, Koepsell SA, Gundabolu K. Thrombotic Thrombocytopenia after Ad26.COV2.S Vaccination.?N Engl J Med. 2021;384(20):1964-1965. doi:10.1056/NEJMc2105869 
  4. See I, Su JR, Lale A, et al. US Case Reports of Cerebral Venous Sinus Thrombosis With Thrombocytopenia After Ad26.COV2.S Vaccination, March 2 to April 21, 2021.?JAMA. 2021;325(24):2448-2456. doi:10.1001/jama.2021.7517 
  5. Pavord S, Scully M, Hunt BJ, et al. Clinical Features of Vaccine-Induced Immune Thrombocytopenia and Thrombosis.?N Engl J Med. 2021;385(18):1680-1689. doi:10.1056/NEJMoa2109908 
  6. Greinacher A, Thiele T, Warkentin TE, Weisser K, Kyrle PA, Eichinger S. Thrombotic Thrombocytopenia after ChAdOx1 nCov-19 Vaccination.?N Engl J Med. 2021;384(22):2092-2101. doi:10.1056/NEJMoa2104840 
  7. Sangli S, Virani A, Cheronis N, et al. Thrombosis With Thrombocytopenia After the Messenger RNA-1273 Vaccine.?Ann Intern Med. 2021;174(10):1480-1482. doi:10.7326/L21-0244 
  8. Cines DB, Bussel JB. SARS-CoV-2 Vaccine-Induced Immune Thrombotic Thrombocytopenia [published correction appears in N Engl J Med. 2021 Jun 10;384(23):e92].?N Engl J Med. 2021;384(23):2254-2256. doi:10.1056/NEJMe2106315 
  9. Tiede A, Sachs UJ, Czwalinna A, et al. Prothrombotic immune thrombocytopenia after COVID-19 vaccination.?Blood. 2021;138(4):350-353. doi:10.1182/blood.2021011958 
  10. Witberg G, Barda N, Hoss S, et al. Myocarditis after Covid-19 Vaccination in a Large Health Care Organization. New England Journal of Medicine. 2021;385(23):2132-2139. doi: 10.1056/NEJMoa2110737 
  11. Diaz GA, Parsons GT, Gering SK, Meier AR, Hutchinson IV, Robicsek A. Myocarditis and Pericarditis After Vaccination for COVID-19.?JAMA. 2021;326(12):1210-1212. doi:10.1001/jama.2021.13443