By Ahizechukwu C. Eke, MD, PhD, MPH
Assistant Professor in Maternal Fetal Medicine, Division of Maternal Fetal Medicine, Department of Gynecology & Obstetrics, Johns Hopkins University School of Medicine, Baltimore
Pregnant patients who received the COVID-19 vaccine had lower rates of severe or critical COVID-19 infections compared to pregnant unvaccinated patients.
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 to unvaccinated pregnant patients. Obstet Gynecol 2021; Oct 13. doi: 10.1097/AOG.0000000000004621. [Online ahead of print].
In December 2019, the world was hit by a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes severe pneumonia among other disease manifestations called coronavirus disease 2019 (COVID-19).1 The United States has 18% of these infections, totaling above 47.5 million cases, with more than 776,083 coronavirus-related deaths as of Nov. 22, 2021.2 Pregnancy has now been demonstrated to be an independent risk factor for COVID-19 infection, with pregnant people experiencing severe COVID-19 disease, increased risk of preterm birth, preeclampsia, stillbirths, and other maternal and fetal adverse pregnancy outcomes.3,4
Recent data have shown that more than 95% of pregnant patients who are hospitalized and/or die from COVID-19 are those who have remained unvaccinated.5 In June 2021, following data on the safety and efficacy of COVID-19 vaccines in reducing severe COVID-19 disease, morbidity, and mortality, the American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal Fetal Medicine (SMFM) recommended COVID-19 vaccination for pregnant people, irrespective of COVID-19 infection status.6 Despite these recommendations, vaccination rates remain low and have lagged behind rates of vaccination in nonpregnant adults. In this study, Morgan and col-leagues evaluated maternal outcomes after severe acute COVID-19 infection in vaccinated compared to unvaccinated pregnant patients.7
This was a retrospective cohort study of all active pregnancies at the Ochsner Health System in New Orleans from June 15, 2021, to Aug. 20, 2021. People were included if they were fully vaccinated two weeks prior to the commencement of the study. People who were partially vaccinated were not excluded, but a secondary analysis was performed. The primary outcome measure was the presence of severe COVID-19 illness (defined as peripheral oxygen saturation [SpO2] less than 94% on room air, partial pressure of oxygen [PaO2]/fraction of inspired oxygen [FiO2] ratio less than 300 mmHg, respiratory rate greater than 30 breaths per minute, or lung infiltrates greater than 50%) or critical COVID-19 (defined as respiratory failure, septic shock, or multiple organ failure) based on the National Institutes of Health (NIH) criteria.7 Secondary outcomes included SARS-CoV-2 infection, supplemental oxygen requirement, intensive care unit (ICU) admission, and use of adjunctive medical therapy.7
A total of 10,092 pregnant patients met inclusion criteria (1,332 vaccinated and 8,760 unvaccinated patients). Women who were vaccinated were likely to be older, have a higher body mass index, and be an active smoker (P < 0.001). Patients who were vaccinated had a lower odds of severe or critical COVID-19 infection (0.08% vs. 0.66%; adjusted odds ratio [aOR], 0.10; 95% confidence interval [CI], 0.01, 0.49) and COVID-19 of any severity (1.1% vs. 3.3%; aOR, 0.31; 95% CI, 0.17, 0.51). Although there was one maternal death as the result of severe COVID-19 and six stillbirths in the unvaccinated group, there were no maternal deaths or stillbirths among vaccinated pregnant women. None of the secondary outcomes were statistically significantly different between vaccinated and unvaccinated patients. However, among vaccinated patients, the use of adjunct medical treatment was rare. No vaccinated patient needed supplemental oxygen or ICU admission. In a secondary analysis of partially and fully vaccinated patients (1,536 patients), there remained a lower odds of severe and critical COVID-19 infection (0.07% vs. 0.68%; aOR, 0.08; 95% CI, 0.004-0.40) and COVID-19 of any severity (1.1% vs. 3.3%; aOR, 0.30; 95% CI, 0.17-0.48).7
This study by Morgan et al demonstrated an overall vaccination rate of 13.2% during pregnancy.7 Vaccinated participants had a lower odds for severe and critical COVID-19 infection, COVID-19 infection of any severity, and lower maternal adverse event rates compared to unvaccinated patients. However, this study did not address a number of lingering questions about outcomes following COVID-19 vaccination during pregnancy. For example, the authors focused mainly on maternal outcomes, and only a few fetal outcomes between vaccinated and unvaccinated patients were discussed. Although Morgan et al evaluated the risk of stillbirth, gestational age at delivery and neonatal outcomes were not evaluated.7 These are important data for pregnant people, since fear of adverse neonatal outcomes (e.g., fear of miscarriages and teratogenicity) have been a major reason why some pregnant women are not getting vaccinated.
Maternal COVID-19 vaccination is an effective means of protecting pregnant patients and their fetuses from vaccine-preventable infections.5 Despite the availability of sufficient safety data to support the use of COVID-19 vaccines during pregnancy, maternal immunization remains an underused method of disease prevention, often because of concerns about vaccine safety from both healthcare providers and pregnant people.5 However, recent data suggest that COVID-19 vaccination does not increase the risk for first trimester miscarriage.8 Although current data regarding COVID-19 vaccines during pregnancy are very reassuring, the Centers for Disease Control and Prevention continues to monitor the safety of COVID-19 vaccines during pregnancy through its Vaccine Adverse Event Reporting System (VAERS), V-safe, and Vaccine Safety Datalink surveillance systems.9
Booster COVID-19 vaccine doses were recommended recently for pregnant women and postpartum women. However, the optimal timing of COVID-19 vaccine boosters during pregnancy remains unknown. Although the current practice is to vaccinate pregnant women at least six months from their last completed COVID-19 dose, the optimal timing to vaccinate pregnant women to aid optimal development of passive fetal immunity remains unknown. Determining the optimal timing of COVID-19 vaccination during pregnancy is critical for fetal protection in the first few months of life.
ACOG and SMFM continue to encourage pregnant and postpartum people to get vaccinated against COVID-19 (irrespective of prior COVID-19 infection status). As nationwide efforts to improve vaccination acceptance continue, it is critical for physicians to continue to educate pregnant and postpartum people on the potential benefits of the COVID-19 vaccine in preventing severe or critical illness.
- Eke UA, Eke AC. Personal protective equipment in the siege of respiratory viral pandemics: Strides made and next steps. Expert Rev Respir Med 2021;15:441-452.
- Reuters. COVID-19 tracker. https://graphics.reuters.com/world-coronavirus-tracker-and-maps/countries-and-territories/united-states/
- Diriba K, Awulachew E, Getu E. The effect of coronavirus infection (SARS-CoV-2, MERS-CoV, and SARS-CoV) during pregnancy and the possibility of vertical maternal-fetal transmission: A systematic review and meta-analysis. Eur J Med Res 2020;25:39.
- Di Mascio D, Khalil A, Saccone G, et al. Outcome of coronavirus spectrum infections (SARS, MERS, COVID-19) during pregnancy: A systematic review and meta-analysis. Am J Obstet Gynecol MFM 2020;2:100107.
- Etti M, Calvert A, Galiza E, et al. Maternal vaccination: A review of current evidence and recommendations. Am J Obstet Gynecol 2021; Nov 11:S0002-9378(21)01228-X. doi: 10.1016/j.ajog.2021.10.041. [Online ahead of print].
- American College of Obstetricians and Gynecologists. ACOG and SMFM recommend COVID-19 vaccination for pregnant individuals. Published July 20, 2021. https://www.acog.org/news/news-releases/2021/07/acog-smfm-recommend-covid-19-vaccination-for-pregnant-individuals
- 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 2021; Oct 13. doi:10.1097/aog.0000000000004621. [Online ahead of print].
- Magnus MC, Gjessing HK, Eide HN, et al. Covid-19 vaccination during pregnancy and first-trimester miscarriage. N Engl J Med 2021;385:2008-2010.
- Moro PL, Panagiotakopoulos L, Oduyebo T, et al. Monitoring the safety of COVID-19 vaccines in pregnancy in the US. Hum Vaccin Immunother 2021; Nov 10:1-9.