Choosing to start or grow a family during a pandemic has been a difficult decision for many, and there are few studies focused on how pregnant and nursing women can best protect themselves and their children. With the availability of SARS-CoV-2 vaccines, a pressing question arises: should pregnant and nursing individuals get vaccinated? Four experts in the field of obstetrics and epidemiology provide insight into how they are helping their patients make informed clinical decisions about COVID-19.
What is known about COVID-19 infections during pregnancy?
It remains unclear whether pregnancy alters susceptibility to infection. However, asymptomatic infections appear to be relatively common.1,2 Pregnant women who had symptomatic infections were more likely than nonpregnant women to be transferred to the intensive care unit, require ventilation, and to experience a fatal COVID-19 outcome,3 and they were 3 times more likely to deliver preterm (16% vs 6%),1,4
Prior to the pandemic, stillbirths in the United Kingdom occurred at a rate of 2.4 per 1000 births. During the pandemic, the rate of stillbirths has tripled to 9.3 per 1000 births.1,5 The biological mechanism of this increased rate, whether it be a direct consequence of infection or some other factor brought on by the pandemic, has yet to be determined.1
In addition to complications with delivery, there is also some evidence that virus from an infected mother can reach the placenta. Immunohistochemical examination of placental tissue in a case study of a 23-year-old pregnant woman with COVID-19 revealed a very high placental viral load and markers of inflammation. After birth, the infant tested positive for SARS-CoV-2 and exhibited bilateral gliosis in the brain at 11 days of life.6
Given these potential risks, should pregnant or nursing women undergo vaccination?
“We don’t really know of any risks [from vaccination] because pregnant women are oftentimes, for new medications and vaccines, excluded from the clinical trials. What we’re left with is looking at the benefits of the vaccine versus the potential risks,” stated Sonja Rasmussen, MD, professor in the Departments of Pediatrics and Epidemiology at the University of Florida College of Medicine.
Victoria Male, PhD, professor in the Department of Metabolism, Digestion, and Reproduction at Imperial College London, comments, “For pregnant women who are at high risk, either because they are highly exposed or because of existing health conditions, I think it’s clear that the benefits of vaccination outweigh the risks, and I certainly recommend vaccination in these groups. For pregnant people more generally, the safety data allow us to be increasingly confident that the risks of vaccination are very small.”
Daniele de Luca, MD, PhD, professor of neonatology at the Antoine Béclère Medical Center in France, agreed with Dr Male, stating “getting COVID-19 in pregnancy may lead to more severe forms and also to critical consequences needing ICU admission. Moreover, negative pregnancy outcomes (stillbirths and prematurity) may be increased. Thus, vaccination should be considered by all women that are at high risk of infection. We know that vaccines are generally safe, and if pregnant women have a significant risk to be infected they should take the shot without fear.”
The only pregnancy-specific concern was raised by Dr Rasmussen, who pointed out that some vaccine recipients can develop fever. As fevers should be avoided during the first trimester, women receiving a vaccine early in pregnancy should monitor themselves closely for signs of fever and take acetaminophen promptly to reduce the fever.
Because pregnant women were excluded from clinical trials of the mRNA vaccines and no historical data are available for this new technology, Denise Jamieson, MD, MPH, chair of the Department of Gynecology and Obstetrics at Emory Healthcare, stated that pregnant women hesitant to undergo vaccination may opt for the Johnson and Johnson’s Janssen vaccine. “There’s more known about the adenovirus vector machines. Johnson and Johnson has used the same platform but for a different pathogen and has reported experience with more than 1500 pregnant women vaccinated against Ebola. They did developmental and reproductive toxicology studies and had no safety signals.”
However, Dr Male pointed out that “The Janssen and BioNTech-Pfizer vaccines are now beginning formal clinical trials in pregnant people. Once the outcomes of these trials have been reported, assuming that the safety and efficacy are good in pregnant people, we may prefer to offer the vaccines that have undergone formal clinical testing in pregnancy.”
What are potential barriers to vaccination among pregnant or nursing women?
Despite the apparent consensus from experts, hesitancy to undergo vaccination has been reported. This is not surprising as 34% of Americans surveyed between October and December of 2020 indicated they would not be getting vaccinated.7 Women who are pregnant or want to become pregnant have additional concerns about vaccination affecting their fertility or their developing fetus. Following a blog post from a senior employee at Pfizer that falsely claimed the antibodies from the COVID-19 vaccine could attack the placenta, more than one-quarter of young women in the United Kingdom said they would not be vaccinated due to fears of harmful effects on their fertility.8
Physicians should prepare themselves to counsel patients using the most recent clinical data in order to quell hesitation or misinformation about COVID-19 vaccinations. With the availability of several vaccine products, it is imperative that a sufficient proportion of the population be vaccinated such that herd immunity be reached and normality can return.7 Dr Male asserted, “I would encourage [physicians] to stay up to date with their local and national guidance. I have seen a lot of people either denied the vaccine or told to stop breastfeeding before having it because their provider was working from out-of-date guidance.”
The overwhelming consensus from this panel of experts was that pregnant women and nursing mothers should consider being vaccinated against SARS-CoV-2. Dr Rasmussen concluded by stating, “I think the thing to keep in mind is that if you’re at risk of getting COVID-19, certainly COVID-19 is more of a risk to you and your baby than the vaccine.”
1. Rasmussen SA, Jamieson DJ. Pregnancy, postpartum care, and COVID-19 vaccination in 2021. JAMA. Published online February 8, 2021. doi:10.1001/jama.2021.1683
2.Egerup P, Fich Olsen L, Christiansen AH, et al. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies at delivery in women, partners, and newborns. Obstet Gynecol. 2021;137(1):49-55. doi:10.1097/AOG.0000000000004199
3. Zambrano LD, Ellington S, Strid P, et al; CDC COVID-19 Response Pregnancy and Infant Linked Outcomes Team. 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(44):1641-1647. doi:10.15585/mmwr.mm6944e3
4. Allotey J, Stallings E, Bonet M, et al; on behalf of the PregCOV-19 Living Systematic Review Consortium. Clinical manifestations, risk factors, and maternal and perinatal outcomes of coronavirus disease 2019 in pregnancy. BMJ. 2020;370:m3320. doi:10.1136/bmj.m3320
5. Khalil A, von Dadelszen P, Draycott T, Ugwumadu A, O’Brien P, Magee L. Change in the incidence of stillbirth and preterm delivery during the COVID-19 pandemic. JAMA. 2020;324(7):705-706. doi:10.1001/jama.2020.12746
6. Vivanti AJ, Vauloup-Fllous C, Prevot S, et al. Transplacental transmission of SARS-CoV-2 infection. Nat Commun. 2020;11(1):3572. doi:10.1038/s41467-020-17436-6
7. Wouters OJ, Shadlen KC, Salcher-Konrad M, et al. Challenges in ensuring global access to COVID-19 vaccines: production, affordability, allocation, and deployment. Lancet. 2021;397(10278):1023-1034. doi:10.1016/S0140-6736(21)00306-8
8. Male V. Are COVID-19 vaccines safe in pregnancy? Nat Rev Immunol. 2021;21:1-2. doi:10.1038/s41577-021-00525-y