COVID vaccine and Pregnancy FAQ

From Dr. Kathleen Watt

23 August 2021:

The following is an update to the blog written on COVID-19 vaccination in pregnancy for Ob/Gyn Affiliates and its division, Women’s Health Care Associates.  This update is being issued because new data and recommendations continue to emerge and because the pandemic and the SARS-COV-2 virus continue to change.

Smiling Pregnant Woman

What are the latest recommendations for vaccination of pregnant women?

The American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine (SMFM), the two leading organizations representing specialists in obstetric care, recommend that ALL PREGNANT INDIVIDUALS BE VACCINATED AGAINST COVID-19. This recommendation was published on July 30, 2021. The president of SMFM has stated that “COVID-19 vaccination is the best method to reduce maternal and fetal complications of COVID-19 infection amount pregnant people”. The CDC estimates that 22% of all pregnant individuals in the U.S. have received one or more doses of the COVID-19 vaccine. ACOG also recommends that all breast-feeding individuals and women contemplating pregnancy in the future be immunized as well.

Why does COVID-19 matter to a pregnant woman?

Because you are at higher risk of adverse health outcomes, such as need for hospitalization, need for ICU admission, need for use of a ventilator, and risk of death. Because your fetus may be at risk for preterm birth if you get a COVID-19 infection during pregnancy. Because COVID-19 is dangerous to the people around you.

If I’ve already had COVID, why should I be vaccinated?

If you’ve already had COVID, data from trials show that COVID vaccines can be safely given to people with prior COVID infections. The CDC recommends waiting until you have recovered from the acute illness and have met the criteria to discontinue isolation. A study published in the CDC’s Morbidity and Mortality Weekly Report shows that people who did not get vaccinated after having had COVID infection were 2.34 times more likely to be reinfected than those who did get vaccinated.

How safe are these vaccines for pregnant women?

As of July 19, 2021, there have been over 136,500 pregnancies reported in CDC’s v-safe post-vaccination health checker. No safety signals have been observed. Among v-safe pregnancy registry outcomes in COVID-19 vaccinated pregnant individuals, the following pregnancy complications have been studied, comparing pregnant vaccinated women with pregnant unvaccinated women: miscarriage, gestational diabetes, preeclampsia or gestational hypertension, eclampsia, intrauterine growth restriction, preterm birth, congenital anomalies, small for gestational age babies, and neonatal death. Outcomes were NO DIFFERENT for all of these conditions.

What about claims linking COVID vaccination to infertility?

ACOG recommends vaccination for all eligible people who are trying to conceive or who may be considering future pregnancy. It is not necessary to delay pregnancy after completing both doses of the COVID-19 vaccine. Claims linking COVID-19 vaccines to infertility are unfounded and have no scientific evidence supporting them. According to the Pfizer-BioNTech website: “There is no scientific evidence to suggest that the vaccine could cause infertility in women. In addition, infertility is not known to occur as a result of natural COVID-19 disease, further demonstrating that immune responses to the virus, whether induced by infection or a vaccine, are not a cause of infertility. Reports on social media have falsely asserted that the vaccine could cause infertility in women and the FDA is concerned that this misinformation may cause women to avoid vaccination to prevent COVID-19, which is a potentially serious and life-threatening disease”. The mRNA vaccines cause the vaccinated person’s cells to make the COVID spike protein. This then triggers the immune system to respond to subsequent viral exposures. “Contrary to false reports on social media, this protein is not the same as any involved in formation of the placenta.” A small study of 45 men in the Journal of the American Medical Association showed there was no decreases in any sperm parameters before vs. after mRNA vaccination.

Why be vaccinated?

The COVID-19 outbreak in the U.S. has exceeded 100,000 new confirmed daily infections in August, the highest rate since the winter surge. This was up from approximately 11,000 cases per day in June. More than 95% of individuals who are hospitalized and/or dying from COVID-19 are unvaccinated. All currently available COVID-19 vaccines have demonstrated high efficacy for preventing laboratory-confirmed illness and/or hospitalizations due to severe COVID illness. Among 4000 individuals in the AZ HEROES study (healthcare, essential, and frontline workers) who received 2 doses of the mRNA vaccines, the vaccines reduced the risk of infection by 90% in real-world settings. Fully vaccinated people are less likely to have asymptomatic infection or transmit SARS-COV-2 to others. Pregnant women who are vaccinated generate higher antibody titers than those who had SARS-COV-2 infection during pregnancy. COVID antibodies are present in the umbilical cord blood of babies and in breastmilk after maternal vaccination.

What about timing of vaccination in pregnancy?

Any trimester of pregnancy is appropriate for vaccination. COVID-19 vaccines may be administered simultaneously with other vaccines, including within 14 days of receipt of another vaccine. This includes vaccines routinely administered during pregnancy, such as influenza and TDaP.

What serious side effects have been linked to vaccination?

Though very rare, the following side effects are significant and are associated with vaccination: Anaphylaxis is a severe allergic response to the vaccine or any of its components. This occurs in less than 1% of the recipients of Pfizer, Moderna, or J&J. Rare cases of cardiac inflammation (myocarditis and pericarditis) have been reported after vaccination. Most of the cases have been reported with the mRNA vaccines (Pfizer and Moderna). Most of the cases were in males. One recent study of over 2 million individuals receiving at least 1 COVID-19 vaccination showed that all 57 patients with cardiac inflammation (that’s less than one person per 20,000 who were vaccinated) with these outcomes recovered or were improving at the time of follow-up, and none died. The J&J vaccine has been linked to Cerebral Venous Sinus Thrombosis (CVST), where blood clots form in various places in the body. This occurs in 8.9 per million doses of J&J, so it is very rare. No cases in the U.S. have been among pregnant women, and pregnant women are not thought to be at increased risk of CVST if they get the J&J vaccine. The J&J vaccine has been linked to Guillain-Barre syndrome, though these cases are also very rare.

What about variants?

According to the CDC, COVID-19 vaccines are effective against severe disease and death from variants of the virus currently circulating in the U.S., including Delta. Delta is a variant of concern and has been shown to have increased transmissibility. It may also cause more severe COVID-19 infection. The CDC recommends that you wear a mask in public in order to reduce the risk of being infected with the Delta variant.

What about breakthrough infections?

According to the CDC, breakthrough infections with COVID-19 illness after vaccination are uncommon, including with Delta. When they do occur, they tend to be mild. However, you can still spread the infection to others. A large study from Massachusetts reported breakthrough infection occurred in 0.18% of the 4.3 million immunized residents in Massachusetts, and 95% of these breakthrough infections did not require hospitalization.

What about boosters?

According to the CDC, protection against infection after vaccination decreases over time. This may be significant for people who are at high risk for disease and for people who were vaccinated early in the pandemic. For this reason, the CDC now recommends: —giving a third dose of coronavirus mRNA vaccines to some significantly immunocompromised individuals, such as people on chemotherapy for cancer or for people on immune-suppressing drugs due to an organ transplant. —giving a third dose of coronavirus mRNA vaccines to all individuals vaccinated more than 8 months after their second dose. Pending further evaluation by the FDA and the recommendation of the CDC’s Advisory Committee on Immunization Practices, this will likely begin the week of September 20th.

Finally, please remember:

If you choose to vaccinate:

This is your choice.

You may be able to have more freedom to do the things you had to stop doing because of the pandemic.

Your baby may benefit from your antibodies.


If you choose NOT to vaccinate:

This is your choice.

You should continue to observe other safety measures to protect yourself and others, such as wearing a mask, social distancing, and avoiding crowds.

You can still get the vaccine after you deliver/when you are breastfeeding.



The American College of Obstetricians and Gynecologists Website:  Practice Advisory:  “COVID-19 Vaccination Considerations for Obstetric Gynecologic Care”.  December 2020 (updated July 30, 2021).


The American College of Obstetricians and Gynecologists Website:  “ACOG and SMFM Recommend COVID-19 Vaccination for Pregnant Individuals”.  July 30, 2021.


Arizona Healthcare, Emergency Response, and Other Essential Workers Surveillance Study (AZ HEROES) in JAMA. 2021;326(6):473. doi:10.1001/jama.2021.12619.


Centers for Disease Control and Prevention Website:  “Joint Statement from HHS Public Health and Medical Experts on COVID-19 Booster Shots”.   August 18, 2021.


Centers for Disease Control and Prevention Website:  “When You’ve Been Fully Vaccinated”.  Updated July 27, 2021.


Centers for Disease Control and Prevention Website:  “Reduced Risk of Reinfection with SARS-CoV-2 after COVID-19 Vaccination — Kentucky, May-June 2021.  MMWR Early Release.  August 13, 2021 / 70(32);1081-1083.


Centers for Disease Control and Prevention Website:  “SARS-CoV-2 Variant Classifications and Definitions”.  Updated August 17, 2021. website “Pfizer-BioNTech COVID-19 Vaccine Frequently Asked Questions “.  Updated August 12, 2021. website (, Massachusetts COVID-19 vaccination data and updates, 2021.


“Myocarditis and Pericarditis After Vaccination for COVID-19” in JAMA. August 4, 2021. doi:10.1001/jama.2021.13443.

“Sperm Parameters Before and After COVID-19 mRNA Vaccination” in JAMA. 2021;326(3):273-274. doi:10.1001/jama.2021.9976.