In December 2020, the US Food and Drug Administration’s Emergency Use Authorization of the first COVID-19 vaccine presented us with a new tactic in the war against SARS-COV-2—and a new dilemma for obstetricians. What we had learned about COVID-19 infection in pregnancy by that point was alarming. While the vast majority (>90%) of pregnant women who contract COVID-19 recover without requiring hospitalization, pregnant women are at increased risk for severe illness and mechanical ventilation when compared with their nonpregnant counterparts.1 Vertical transmission to the fetus is a rare event, but the increased risk of preterm birth, miscarriage, and preeclampsia makes the fetus a second victim in many cases.2 Moreover, much is still unknown about the long-term impact of severe illness on maternal and fetal health.
Gaining vaccine approval
The COVID-19 vaccine, with its high efficacy rates in the nonpregnant adult population, presents an opportunity to reduce maternal morbidity related to this devastating illness. But unlike other vaccines, such as the flu shot and TDAP, results from prospective studies on COVID-19 vaccination of expectant women are pending. Under the best of circumstances, gaining acceptance of any vaccine during pregnancy faces barriers such as vaccine hesitancy and a general concern from pregnant women about the effect of medical interventions on the fetus. There is no reason to expect that either the mRNA vaccines or the replication-incompetent adenovirus recombinant vector vaccine could cause harm to the developing fetus, but the fact that currently available COVID-19 vaccines use newer technologies complicates the decision for many women.
Nevertheless, what we do know now is much more than we did in December, particularly when it comes to the mRNA vaccines. To date, observational studies of women who received the mRNA vaccine in pregnancy have shown no increased risk of adverse maternal, fetal, or obstetric outcomes.3 Emerging data also indicate that antibodies to the SARS-CoV-2 spike protein—the target of all 3 vaccines—is present in cord blood, potentially protecting the infant in the first months of life from contracting COVID-19 if the mother receives the vaccine during pregnancy.4,5
Our approach to counseling
How can we best help our patients navigate the risks and benefits of the COVID-19 vaccine? First, by acknowledging the obvious: We are in the midst of a pandemic with high rates of community spread, which makes COVID-19 different from any other vaccine-preventable disease at this time. Providing patients with a structure for making an educated decision is essential, taking into account (1) what we know about COVID-19 infection during pregnancy, (2) what we know about vaccine efficacy and safety to date, and (3) individual factors such as:
- The presence of comorbidities such as obesity, heart disease, respiratory disease, and diabetes.
- Potential exposures—“Do you have children in school or daycare? Do childcare providers or other workers come to your home? What is your occupation?”
- The ability to take precautions (social distancing, wearing a mask, etc)
All things considered, the decision to accept the COVID-19 vaccine or not ultimately belongs to the patient. Given disease prevalence and the latest information on vaccine safety in pregnancy, I have been advising my patients in the second trimester or beyond to receive the vaccine with the caveat that delaying the vaccine until the postpartum period is a completely valid alternative. The most important gift we can offer our patients is to arm them with the necessary information so that they can make the choice best for them and their family as we continue to fight this war on COVID-19.