Dr. Ashley Roman: Should Pregnant Women Be Vaccinated?
By Ashley Roman, MD
Director, Division of Maternal Fetal Medicine
Silverman Associate Professor of Obstetrics and Gynecology, Department of Obstetrics and Gynecology at NYU Grossman School of Medicine
One of the more common questions asked since the release of the Covid-19 vaccine is, should pregnant women be vaccinated? The short answer: it’s complicated.
The CDC, American College of Obstetricians and Gynecologists, and the Society for Maternal Fetal Medicine all recommend that pregnant women have accessto the vaccine and make an informed decision whether or not to accept it in conjunction with their obstetrician, which in many ways puts the onus on the pregnant woman to navigate what data exist on Covid infection in pregnancy and the safety of the Covid vaccine. Before one can make this decision for themselves, it is important to understand some of the key factors to consider.
How Does the Covid Vaccine Work?
The Moderna and Pfizer Covid vaccines are both mRNA vaccines. These types of vaccines were developed over 30 years ago and use a piece of genetic material that our cells read to make proteins, which triggers a protective immune response. The mRNA is fragile and degrades naturally in the body within a couple days.
This type of vaccine doesn’t contain ingredients that are known to be unsafe or harmful to pregnant women and their babies, but it is different from some of the other vaccines out there. It is not a live vaccine like other vaccines we avoid during pregnancy. It’s worth knowing that there are some vaccines that we routinely recommend during pregnancy to prevent other illnesses that can have severe consequences for the pregnant woman or their newborn, like the flu and whooping cough. These vaccines are made from inactivated virus or bacteria.
Covid Infection During Pregnancy:
One of the most important considerations is that pregnant women who get Covid are more likely to have severe illness than women who are not pregnant, often needing hospitalization and respiratory support. Large population-based studies have demonstrated these increased risks, and our Maternal Fetal Medicine group participated in a multicenter study that found pregnant women with Covid were at an increased risk for mechanical ventilation and ICU care, especially if they have other pre-existing health conditions.
It is estimated that 1 to 3 percent of pregnant women who contract Covid will need ICU care, so the absolute risk is low, but even healthy pregnant women without preexisting conditions can develop severe disease. Covid infection during pregnancy may also put pregnant women at an increased risk of preterm birth.
Data on the Covid mRNA Vaccine in Pregnancy:
Both the Pfizer and Moderna trials excluded pregnant women from enrollment, although a small number of enrollees (a total of 36) became pregnant during the trials. Moderna investigated the effect of the Covid mRNA vaccine in pregnant rats and there were no adverse effects seen. Studies incorporating pregnant women are ongoing.
What Does this Mean?
If you are particularly at risk of exposure to Covid based on your role at NYU Langone or where you live, or have pre-existing conditions that increase your risk of severe illness, you should take that strongly into account in weighing your options.
That said, the decision to be vaccinated is personal and complicated. Each woman must factor in her individual risks and benefits. I counsel women to weigh some key considerations, which are outlined below, and talk to their healthcare provider. My best advice is to carefully weigh all the risks and benefits.
• Reduced risk of Covid, which is more dangerous for pregnant women. The vaccine prevents 95 percent of cases. If you can’t stay home and avoid contact with people, or are a first responder, the vaccine might help you.
• The vaccine builds antibodies to Covid in the mother, which cross the placenta and, in theory, may protect the baby after birth much like the flu shot.
• There are no clinical trials evaluating safety and efficacy. We don’t know if it’s as effective in expectant mothers.
• Side effects may be expected, including a sore injection site, fatigue, and fever. Fever can pose a risk especially in early pregnancy, and would need to be closely monitored and potentially treated with acetaminophen.
Questions to Ask when Weighing Your Benefits vs. Risks:
• Are you in regular or prolonged contact with people outside your household? Do you and they wear masks? Can you socially distance?
• Do you have children in school? Do childcare providers or other workers come to your home?
• Is your community a “hot zone,” where transmission is occurring at higher rates?
• Do you have risk factors, including being overweight, having diabetes, high blood pressure, or heart disease? Are you immune-suppressed or taking medications?
• Do you smoke?
• Are you a frontline healthcare worker or a first responder? Do you have face-to-face contact with patients?
• Do you have a history of anaphylaxis to vaccines or otherwise?
What about Breast Feeding?
The CDC, American College of Obstetricians and Gynecologists, and Society for Maternal-Fetal Medicine report that the vaccine isn’t believed to affect breastmilk safety.
The most up-to-date guidance we have references the Pfizer and Moderna vaccines. As other vaccines and more data become available the guidance will be updated.
What about Trying to Get Pregnant?
Those trying to become pregnant do not need to avoid pregnancy after receiving the Covid mRNA vaccination. If you conceive in the three to four weeks between doses of the Covid vaccine, you should consider receiving the second dose.
We will continue to accumulate more data on the vaccines’ safety and efficacy and will share more information as it becomes known. In the meantime, please continue to keep current on the latest information by reading Covid Alerts, checking the FAQs on Inside Health, and talking with your doctor.