COVID-19 Vaccination Before, During, and After Pregnancy
If being pregnant during a global pandemic were not stressful enough, pregnant women now must wrestle with the decision whether to be vaccinated against COVID-19.
As of this writing, two COVID-19 vaccines, from Pfizer-BioNtech and Moderna are approved in the United States. (More approvals are expected shortly.) Neither has been studied in pregnant and lactating women.
Because of the lack of data, major medical organizations have issued conflicting recommendations for pregnant women. In the U.S. the Centers for Disease Control (CDC), the American College for Obstetricians and Gynecologists and The Society for Maternal Fetal Medicine all say that pregnant women may choose to get the vaccine when a group to which they belong, such as healthcare workers or teachers, becomes eligible.
The World Health Organization, on the other hand, only recommends vaccination for pregnant women who belong to a group at high risk of exposure, such as healthcare workers.
The disagreement among medical experts and lack of studies has opened the door for a firestorm of misinformation targeting pregnant and breastfeeding and reproductive age women, claiming falsely, for example, that these vaccines impair fertility.
Online fear mongering about the vaccine’s unknowns can obscure the threat COVID-19 poses to pregnant women, who are at higher risk of severe illness than women of the same age.
Yuri Edelsen, a Health Minister in Israel, where they recently began vaccinating pregnant women, recently told the Jerusalem Post, “I would say, not being a medical doctor, that when I look at these terrible cases of a number of pregnant women who are in serious condition with the coronavirus, I say to myself, probably it is worse to take the little risk of taking the vaccine instead of finding yourself in a terrible situation in the hospital.”
To make an informed decision, potentially in conjunction with a trusted healthcare provider, women need accurate information on both the risk of vaccination and the risk of COVID-19.
What do we know about the safety of the Pfizer and Moderna COVID-19 vaccines in pregnant women?
To date, no studies have been done in pregnant women. Moderna and Pfizer-BioNtech both excluded pregnant and lactating women from their clinical trials—a common drug company practice for testing novel treatments.
However, Pfizer-BioNtech and Moderna’s trials did include some pregnant women, who did not realize they were pregnant when they enrolled or who became pregnant during the trial. Reassuringly, no harmful effects were seen in these women.
Moderna also tested their reproductive and developmental toxicity vaccine in rats prior to and during pregnancy and found no adverse effects–but animal studies do not always generalize to humans.
There are also biological reasons to believe these vaccines are safe during pregnancy: They do not contain live virus, only so-called messenger RNA (mRNA), so they cannot cause an infection. Nor mRNA does enter the part of the cell that contains its DNA, so these vaccines cannot cause genetic changes.
In short, “based on how mRNA vaccines work, experts believe they are unlikely to pose a specific risk for people who are pregnant,” according to the Centers for Disease Control, (CDC).
We have a long history of safely vaccinating women during pregnancy. Pregnant women routinely receive the flu vaccine—because they are at higher risk of severe illness from the flu—and the tetanus, diphtheria, and pertussis (Tdap) vaccine, in order to pass on protective antibodies against pertussis (whooping cough) to their babies.
What are the current recommendations regarding COVID-19 vaccination for women who are lactating or trying to conceive?
For women who are lactating and those actively trying to conceive, ACOG strongly recommends vaccination when they become eligible.
What are the risks of COVID-19 for pregnant women?
The latest CDC data suggests that relative to other women of the same age, pregnant women are at higher risk of severe COVID-19, including for hospitalization, admission to the ICU (intensive care unit), ventilation and respiratory support, and death.
Fortunately, these risks, although elevated compared to women who are not pregnant, remain low. Approximately 1 in every 100 pregnant women with symptomatic COVID-19 are admitted to an ICU and 3 in 1000 received invasive ventilation. The rates may be higher for pregnant women with other conditions that raise the risk of severe COVID-19, such as obesity, cardiovascular disease, and Type 2 Diabetes.
What are the risks of COVID-19 for fetuses and newborns?
The good news is that the vast majority of newborns born to women with COVID-19 test negative for SARS-COV-2, the virus that causes COVID-19. Among the few that test positive for SARS-COV-2, most have no or only mild symptoms; a few have been admitted to the NICU. Among those who tested positive, it remains unclear whether these babies contracted COVID-19 from their mother during pregnancy or after delivery.
We do know, however, that COVID-19 can spread from the mother to the placenta. A recent study of pregnancy outcomes following maternal infection (the majority of which were asymptomatic) found increased inflammation or impaired blood flow across the placenta in over 20% of pregnancies.
COVID-19 infection also appears to raise the risk of preterm delivery (before 37 weeks). Pregnant women with COVID-19 appear to have an elevated risk of preterm delivery (12.9% of those with COVID-19 delivered early versus 10.9% of those without COVID-19).
Not everyone will read these risks and unknowns the same way. Women will have to weigh their risks of exposure, their risks for severe disease, chance of transmitting the infection, and concerns about the lack of safety data during pregnancy to make the right choice for themselves.