Last updated September 25, 2023
This Practice Advisory was developed by the American College of Obstetricians and Gynecologists’ Immunization, Infectious Disease, and Public Health Preparedness Expert Work Group in collaboration with Laura E. Riley, MD; Richard Beigi, MD; Denise J. Jamieson, MD, MPH; Brenna L. Hughes, MD, MSc; Geeta Swamy, MD; Linda O’Neal Eckert, MD; Mark Turrentine, MD; and Sarah Carroll, MPH.
Summary of Updates
This Practice Advisory provides an overview of the currently available COVID-19 vaccines and guidance for their use in pregnant, recently pregnant, lactating, and nonpregnant individuals aged 12 years and older. For guidance and recommendations for the use of these vaccines in individuals aged 11 years or younger, please visit the website of the American Academy of Pediatrics. For additional information regarding severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and treatment, see ACOG’s Frequently Asked Questions.
This Practice Advisory has been updated to include the following:
- Recommendations for the use of updated 2023-2024 COVID-19 vaccines.
- Removal of bivalent COVID-19 vaccine recommendations.
- The American College of Obstetricians and Gynecologists (ACOG) recommends that all eligible persons aged 6 months and older, including pregnant and lactating individuals, receive a COVID-19 vaccine or vaccine series.
- A single dose of the 2023-2024 updated COVID-19 vaccine is recommended for all adults, including pregnant and lactating adults, at least two months after their last COVID-19 vaccine dose.
- Vaccination may occur in any trimester, and emphasis should be on vaccine receipt as soon as possible to maximize maternal and fetal health.
- For patients who do not receive any COVID-19 vaccine, the discussion should be documented in the patient’s medical record. During subsequent office visits, obstetrician–gynecologists should address ongoing questions and concerns and offer vaccination again.
- Obstetrician–gynecologists and other health care practitioners should lead by example by being vaccinated and encouraging eligible patients to be vaccinated as well.
- COVID-19 vaccines may be administered simultaneously with other vaccines. This includes vaccines routinely administered during pregnancy, such as influenza and Tdap.
- The Janssen (Johnson & Johnson) COVID-19 vaccine is no longer available in the United States. All government-issued doses expired on May 7, 2023.
- Individuals aged 18 years and older who have received 1 or 2 doses of the Janssen (Johnson & Johnson) COVID-19 vaccine should receive a single dose of 2023-2024 updated COVID-19 vaccine.
COVID-19 Vaccine Information
At the time of this publication, three COVID-19 vaccines are currently approved under a BLA or authorized under an EUA by FDA:
- Pfizer-BioNTech COVID-19 Vaccine/COMIRNATY
- Moderna COVID-19 Vaccine/SPIKEVAX
- Novavax COVID-19 Vaccine, Adjuvanted
For primary vaccination for all populations, an updated 2023-2024 COVID-19 vaccine should be administered.
COVID-19 vaccines are rapidly emerging and additional EUAs and BLA’s are likely to materialize. ACOG will strive to update this guidance as quickly as possible while maintaining accurate, evidence-based information.
mRNA COVID-19 Vaccines (Pfizer-BioNtech and Moderna)
The development and use of mRNA vaccines is relatively new. These vaccines consist of messenger RNA (mRNA) encapsulated by a lipid nanoparticle (LNP) for delivery into the host cells. These vaccines utilize the body’s own cells to generate the coronavirus spike protein (the relevant antigens), which, similar to all other vaccines, stimulates immune cells to create antibodies against COVID-19. The mRNA vaccines are not live virus vaccines, nor do they use an adjuvant to enhance vaccine efficacy. These vaccines do not enter the nucleus and do not alter human DNA in vaccine recipients. As a result, mRNA vaccines cannot cause any genetic changes (CDC, Zhang 2019, Schlake 2012). Based on the mechanism of action of these vaccines and the demonstrated safety and efficacy in Phase II and Phase III clinical trials, it is expected that the safety and efficacy profile of the vaccine for pregnant individuals would be similar to that observed in nonpregnant individuals. Further, a growing body of observational data so far have not identified any safety concerns for COVID-19 vaccination during pregnancy.
Protein Subunit Vaccines (Novavax Inc.)
Protein subunit vaccines contain pieces (proteins) of the virus that causes COVID-19. These virus pieces are the spike protein. The Novavax COVID-19 Vaccine, Adjuvanted (Novavax COVID-19 vaccine), also contains another ingredient called an adjuvant that helps the immune system respond to that spike protein in the future. Once the immune system knows how to respond to the spike protein, the immune system will be able to respond quickly to the actual virus spike protein and protect against COVID-19. Protein subunit COVID-19 vaccines do not use any live virus nor can they cause infection with the virus that causes COVID-19 or other viruses. They do not affect or interact with our DNA. The protein pieces do not enter the nucleus of the cell where our DNA (genetic material) is located, so they cannot change or influence our genes (CDC).
Protein subunit vaccines have been used for more than 30 years. Other examples of protein subunit vaccines include the first licensed hepatitis B vaccine, some influenza vaccines, and acellular pertussis vaccines.
The Novavax COVID-19 vaccine uses an adjuvant known as Matrix M to boost the immune response against the virus that causes COVID-19. Adjuvants have been used in some vaccines for decades, and limited data on the use of aluminum-containing adjuvants in pregnancy are reassuring (Jamieson, 2012, Rasmussen 2021). Matrix M is a novel adjuvant in COVID-19 vaccines that has had limited study in pregnancy. It is made with saponins, which are naturally occurring in the bark of trees. Similar adjuvants have been used in other vaccines that have reassuring safety profiles in clinical trials. ACOG will continue to monitor data regarding the use of Matrix M adjuvant in COVID-19 vaccines.
Efficacy of Available COVID-19 Vaccines
All currently available COVID-19 vaccines have demonstrated high efficacy among their respective clinical trial endpoints. Additionally, a growing body of evidence suggests that fully vaccinated people are less likely to have asymptomatic infection or transmit SARS-CoV-2 to others. Finally, emerging data indicate that while individuals may still become infected with COVID-19, those who are up to date on their COVID-19 vaccines, including boosters, are less likely to experience severe illness and serious adverse outcomes as a result of SARS-CoV-2 infection (Barda 2021).
Based on results from clinical trials, the Pfizer-BioNTech COVID-19 vaccine was 95% effective at preventing laboratory-confirmed COVID-19 illness in people who received two doses who had no evidence of previous infection (CDC).
Based on results from clinical trials, the Moderna vaccine was 94.1% effective at preventing laboratory-confirmed COVID-19 illness in people who received two doses who had no evidence of being previously infected (CDC).
A prospective cohort study from two academic centers found that vaccinated pregnant and lactating women produced comparable immune responses to nonpregnant controls, and generated higher antibody titers than those observed following SARS-CoV-2 infection in pregnancy. Further, vaccine-generated antibodies were present in umbilical cord blood and breast milk after maternal vaccination (Gray 2021, Prabhu 2021, Juncker 2021).
Each of these vaccines appeared to have high efficacy in clinical trials among people of diverse age, sex, race, and ethnicity categories and among persons with underlying medical conditions. Further, during the rollout of COVID-19 vaccines, data continue to demonstrate high vaccine efficacy in preventing hospitalization and death (ACIP Slides).
Protein subunit vaccines
On the basis of the results from clinical trials in the U.S., the Novavax COVID-19 vaccine has been shown to be approximately 90% effective overall and 100% effective at preventing severe COVID-19 illness after two doses (ACIP July 2022).
Safety of Available COVID-19 Vaccines
Expected side effects should be explained during counseling, including that they are a normal part of the body’s reaction to the vaccine and developing antibodies to protect against COVID-19 illness.
Most study participants for both the Pfizer-BioNTech and Moderna vaccines experienced mild side effects similar to influenza-like illness symptoms following vaccination (see Table 1 below). In the Pfizer-BioNTech study subgroup of persons aged 18–55 years, fever greater than 38 °C occurred in 3.7% after the first dose and 15.8% after the second dose (FDA 2020). In the Moderna vaccine trials, fever greater than 38°C was reported in 0.8% of vaccine recipients after the first dose, and 15.6% of vaccine recipients after the second dose (FDA 2020). Most of these symptoms resolved by day 3 after vaccination for both vaccines.
As with other available COVID-19 vaccines, most side effects following the Novavax COVID-19 vaccine were mild. Among study participants aged 18–64 years, less than 1% of individuals receiving a vaccine experienced fever greater than 38 °C following the first dose, and approximately 6% experienced fever following the second dose (FDA 2022). Among study participants aged 65 years or older, less than 0.5% of individuals receiving a vaccine experienced fever greater than 38 °C following the first dose, and 2% experienced fever following the second dose. Overall, the Novavax COVID-19 vaccine may result in fewer systemic side effects than mRNA vaccines (FDA 2022).
Patients should be counseled about more severe side effects and when to seek medical care. For more information and details on side effects, see Local Reactions, Systemic Reactions, Adverse Events, and Serious Adverse Events: Pfizer-BioNTech COVID-19 Vaccine from the CDC.
Allergic Reactions Including Anaphylaxis
Allergic reactions including anaphylaxis have been reported to be rare following COVID-19 vaccination in nonpregnant individuals. Anaphylaxis has been observed in 5 cases per million doses administered for the Pfizer-BioNTech vaccine and 4.9 cases per million doses administered of the Moderna vaccine (ACIP August 2021). No cases of anaphylaxis were reported in Novavax COVID-19 vaccine clinical trials (ACIP July 2022).
If anaphylaxis is suspected in a pregnant individual after receiving a COVID-19 vaccination, anaphylaxis should be managed the same as in nonpregnant individuals (e.g., rapidly assess airway, breathing, circulation, and mental activity; call for emergency medical services; place the patient in a supine position, and administration of epinephrine) (CDC). Similar to nonpregnant individuals, anaphylaxis may recur after the individual begins to recover, and monitoring in a medical facility for at least several hours is advised, even after complete resolution of symptoms and signs.
For more information on the management of anaphylaxis after COVID-19 vaccination, see CDC’s website.
Myocarditis and Pericarditis
Since April 2021, cases of myocarditis (ranging from 1 per 100,000 to 2.13 per 100,000) and pericarditis (1.8 per 100,000) have been reported in the United States after mRNA COVID-19 vaccination (Pfizer-BioNTech and Moderna), particularly in adolescents and young adults (Diaz 2021, Witberg 2021). Additionally, cases of myocarditis and pericarditis have been identified in clinical trials following the receipt of the Novavax COVID-19 vaccine (7 per 100,000 in the vaccine group) (Novavax 2022). Reported cases have occurred predominantly in male adolescents and young adults aged 16 years and older. Onset was typically within several days after mRNA COVID-19 vaccination, and cases have occurred more often after the second dose than the first dose. Surveillance of these cases following mRNA COVID-19 vaccination are ongoing.
Clinicians should consider the diagnoses of myocarditis and pericarditis in adolescents or young adults with acute chest pain, shortness of breath, or palpitations. In this population, coronary events are less likely to be a source of these symptoms. In most cases, patients who presented for medical care have responded well to medications and rest and had prompt improvement of symptoms. Clinicians should report all cases of myocarditis and pericarditis post COVID-19 vaccination to VAERS.
For more information, see CDC and the American Heart Association.
To date there has been no association between mRNA vaccines and Guillain-Barre Syndrome (Abara 2023).
Available Safety Information Related to the Use of COVID-19 Vaccines in Pregnancy
Despite ACOG's persistent advocacy for the inclusion of pregnant individuals in COVID-19 vaccine trials, none of the COVID-19 vaccines approved under EUA have been tested in pregnant individuals. However, studies in pregnant women have since been completed and post-market surveillance is ongoing.
Developmental and Reproductive Toxicity Data
Data from Developmental and Reproductive Toxicity (DART) studies for the Pfizer-BioNTech COVID-19 vaccine have been reported in Europe. According to the report presented to the European Medicines Agency, animal studies using the Pfizer/BioNTech COVID-19 vaccine do not indicate direct or indirect harmful effects with respect to pregnancy, embryo/fetal development, parturition, or postnatal development (EMA).
A combined developmental and perinatal/postnatal reproductive toxicity (DART) study of Moderna’s mRNA-1273 in rats was submitted to FDA on December 4, 2020. FDA review of this study concluded that mRNA1273 given prior to mating and during gestation periods at dose of 100 µg did not have any adverse effects on female reproduction, fetal/embryonal development, or postnatal developmental except for skeletal variations, which are common and typically resolve postnatally without intervention (FDA).
According to the Provider Fact Sheet for the Novavax COVID-19 vaccine, in a developmental toxicity study, 0.1 mL of a vaccine formulation containing the same quantity of SARS-CoV-2 rS protein (5 micrograms), one-fifth the quantity of adjuvant (10 micrograms), and inactive ingredients that comprise the formulation buffer (25 mM sodium phosphate, 300 mM sodium chloride, and 0.01% (w/v) polysorbate 80) contained in a single dose of the Novavax COVID-19 vaccine was administered to female rats by the intramuscular route on four occasions: 27 and 13 days prior to mating, and on gestational days 7 and 15. No vaccine-related adverse effects on female fertility, fetal development, or postnatal development were reported in the study (FDA Fact Sheet).
These DART studies provided the first safety data to help inform the use of the vaccine in pregnancy.
Among participants of Phase II/III COVID-19 vaccine clinical studies in nonpregnant adults, a few inadvertent pregnancies that have occurred are being followed to collect safety outcomes.
Post-Administration Pregnancy Surveillance Data
As of February 14, 2022, there have been over 201,000 pregnancies reported in CDC's v-safe post-vaccination health checker (CDC 2021). Based on limited self-reported information, no specific safety signals have been observed in pregnant people enrolled in v-safe; however longitudinal follow-up is needed.
Shortly following the rollout of COVID-19 vaccines CDC launched a v-safe pregnancy registry to collect additional data on COVID-19 vaccines during pregnancy. At the time the registry closed in May 2023 there were approximately 23,000 pregnant individuals enrolled. Data collected from the v-safe pregnancy registry did not indicate any safety concerns based on the reactogenicity profile and adverse events observed among pregnant individuals. Additionally, side effects were similar in pregnant and nonpregnant populations. Specific neonatal outcomes data published in The New England Journal of Medicine, along with pregnancy complication data from 275 completed pregnancies presented at the March 1, 2021 ACIP meeting are included in Table 1.
No differences have been seen when comparing pregnant individuals participating in the v-safe pregnancy registry with the background rates of adverse pregnancy outcomes. It appears that the spontaneous abortion rate following COVID-19 vaccination during pregnancy is consistent with the background rate; however the ideal denominator has not appeared in published literature (Shimabukuro 2021). Data reported by CDC indicate that the proportion of spontaneous abortions reported after COVID-19 vaccination is consistent with the known background rate of this outcome. However, a risk estimate has not yet been established (Shimabukuro 2021, Zauche 2021).
In addition to data reported from the v-safe pregnancy registry, multiple reports from the Vaccine Safety Datalink (VSD) continue to reinforce the safety of COVID-19 vaccination during pregnancy. A case-control study using data from the VSD found that among women with spontaneous abortions, the odds of COVID-19 vaccine exposure were not increased in the prior 28 days compared with women with ongoing pregnancies (Kharbanda 2021). In a subsequent retrospective cohort of >40,000 pregnant women in the VSD, COVID-19 vaccination during pregnancy was not associated with preterm birth or small-for-gestational age at birth overall, stratified by trimester of vaccination, or number of vaccine doses received during pregnancy, compared with unvaccinated pregnant women (Lipkind 2022).
In a research letter published in April 2022, investigators evaluated the association between COVID-19 vaccination during early pregnancy and risk of major fetal structural anomalies identified on ultrasonography. Of 2622 patients who received at least 1 dose of COVID-19 vaccine, 1149 (43.8%) were vaccinated within the teratogenic window. Results of this analysis found that vaccination within the teratogenic window was not associated with presence of a congenital anomaly identified on ultrasonography (Ruderman 2022).
Pregnancy was an exclusion criterion for the Novavax COVID-19 vaccine. However, 147 pregnancies were reported during the clinical trial. Of these pregnancies, 56 are ongoing and 41 resulted in a live birth. Additionally, 25 spontaneous abortions (17% of pregnancies, a rate consistent with the general population),13 voluntary terminations, and 1 ectopic pregnancy occurred. No stillbirths have been observed. These data do not indicate a potential risk to the pregnant person or fetus (ACIP July 2022).
A recent systematic review and meta-analysis that included 61 clinical and preclinical studies involving pregnant persons (n=17,719,495) found no safety concerns regarding the administration of COVID-19 vaccines to pregnant individuals (Ciapponi 2023).
Table 1. V-safe Pregnancy Registry Outcomes of Interest in mRNA COVID-19-Vaccinated Pregnant Individuals
|Pregnancy Complications*||Background Rate||V-safe Pregnancy Registry Overall|
Preeclampsia or gestational hypertension
Intrauterine growth restriction
|Neonatal Outcomes†||Background Rate||V-safe Pregnancy Registry Overall|
Small for gestational age
*Shimabukuro T. COVID-19 vaccine safety update. Advisory Committee on Immunization Practices (ACIP). Atlanta, GA: Centers for Disease Control and Prevention; 2021. Available at: https://www.cdc.gov/vaccines/acip/meetings/downloads/slides-2021-02/28-03-01/05-covid-Shimabukuro.pdf. Retrieved March 1, 2021.
†Shimabukuro TT, Kim SY, Myers TR, Moro PL, Oduyebo T, Panagiotakopoulos L, et al. Preliminary findings of mRNA Covid-19 vaccine safety in pregnant persons. CDC v-safe COVID-19 Pregnancy Registry Team [published online April 21, 2021]. N Engl J Med. DOI: 10.1056/NEJMoa2104983. Available at: https://www.nejm.org/doi/10.1056/NEJMoa2104983.
General Recommendations and Considerations
ACOG strongly recommends that all eligible persons aged 6 months and older, including pregnant and lactating individuals, receive a COVID-19 vaccine or vaccine series. Obstetrician–gynecologists and other women's health care practitioners should lead by example by being vaccinated and encouraging eligible patients to be vaccinated as well. See CDC for detailed COVID-19 vaccine recommendations by product.
- A single dose of the 2023-2024 updated COVID-19 vaccine is recommended for all adults, including pregnant and lactating adults, at least two months after their last COVID-19 vaccine dose.
- Bivalent COVID-19 vaccines are no longer available in the United States.
- COVID-19 vaccines may be administered simultaneously with other vaccines. This includes vaccines routinely administered during pregnancy, such as influenza and Tdap.
- Precautions should be discussed with any individual who reports a history of any immediate allergic reaction to any other vaccine or injectable therapy (i.e., intramuscular, intravenous, or subcutaneous vaccines or therapies not related to a component of COVID-19 vaccines or polysorbate) (CDC). Locations administering COVID-19 vaccines should adhere to CDC guidance for use of COVID-19 vaccines, including screening recipients for contraindications and precautions, having the necessary supplies available to manage anaphylaxis, implementing the recommended postvaccination observation periods, and immediately treating suspected cases of anaphylaxis with intramuscular injection of epinephrine (CDC).
- Individuals, including those who are pregnant and/or lactating, with a history of SARS-CoV-2 infection should receive a COVID-19 vaccine.
- COVID-19 vaccination should be deferred at least until recovery from acute illness.
- People who recently had SARS-CoV-2 infection may consider delaying vaccination for 3 months from symptom onset (or positive test if infection was asymptomatic.
- Individual factors such as risk of COVID-19 severe disease, COVID-19 community level, or characteristics of the predominant SARS-CoV-2 strain should be taken into account when determining whether to delay getting a COVID-19 vaccination after infection.
- Individuals who receive a COVID-19 vaccine should be educated about and encouraged to participate in CDC’s v-safe program (see below for more information on CDC’s v-safe program).
- Obstetrician–gynecologists are encouraged to assess and document patients' COVID-19 vaccination status in the medical record.
Obstetric Care Recommendations and Considerations
COVID-19 Infection Risk in Pregnancy
Pregnant and recently pregnant patients with COVID-19 are at increased risk of more severe illness compared with nonpregnant peers (Ellington MMWR 2020, Collin 2020, Delahoy MMWR 2020, Khan 2021). Available data indicate an increased risk of ICU admission, need for mechanical ventilation and ventilatory support (ECMO), and death reported in pregnant women with symptomatic COVID-19 infection, when compared with symptomatic nonpregnant women (Zambrano MMWR 2020, Khan 2021). Pregnant and recently pregnant patients with comorbidities such as obesity and diabetes may be at an even higher risk of severe illness consistent with the general population with similar comorbidities (Ellington MMWR 2020, Panagiotakopoulos MMWR 2020, Knight 2020, Zambrano MMWR 2020, Allotey 2020, Metz 2021, Galang 2021).
ACOG strongly recommends that pregnant individuals be vaccinated against COVID-19. As of April 15, 2023, about 71% of pregnant individuals have been fully vaccinated against COVID-19 (CDC COVID Data Tracker). Given the potential for severe illness and death during pregnancy, the importance of completion of the initial COVID-19 vaccination series should be emphasized for this population. A recent study in Scotland found that most cases of SARS-CoV-2 infection during pregnancy were among unvaccinated individuals (Stock 2022). Further, data from the U.S. have indicated that among pregnant people with COVID-19, those who were vaccinated experienced less severe illness (Morgan 2022). Obstetrician–gynecologists and other obstetric care providers should routinely assess their pregnant patients' vaccination status. On the basis of this assessment, they should recommend needed vaccines to their pregnant patients.
There is no evidence of adverse maternal or fetal effects from vaccinating pregnant individuals with COVID-19 vaccine, and a growing body of data demonstrate the safety of such use (Ciapponi 2021, Ciapponi 2023, Wainstock 2021, Kachikis 2021, Magnus 2021, Fu 2021, Ruderman 2022). Therefore, individuals who are or will be pregnant should receive the COVID-19 vaccine. Emerging data indicate that vaccine-induced antibodies cross the placenta, but the degree of protection these antibodies provide to the neonate is unknown (Yang 2022). In a recent case-control study from 20 pediatric hospitals, CDC found that COVID-19 vaccination during pregnancy reduced the risk of infant hospitalization with COVID-19 by 61%, suggesting that COVID-19 vaccination during pregnancy might also help protect babies. These findings emphasize the importance of COVID-19 vaccination during pregnancy to protect pregnant people and their babies from COVID-19 (Halasa 2022). Vaccination may occur in any trimester and emphasis should be on vaccine receipt as soon as possible to maximize maternal and fetal health.
A single dose of the 2023-2024 updated COVID-19 vaccine is recommended for all adults, including pregnant and lactating adults, at least two months after their last COVID-19 vaccine dose.
COVID-19 vaccination may occur in any trimester, and emphasis should be on vaccine receipt as soon as possible to maximize maternal and fetal health.
These recommendations also apply to pregnant and recently pregnant (e.g., up to 6 weeks postpartum) individuals.
COVID-19 Vaccine Counseling
Individuals should have access to available information about the safety and efficacy of the vaccine. A conversation between the patient and their clinical team may assist with decisions regarding COVID-19 vaccination during pregnancy.
When recommending the COVID-19 vaccine, clinicians should review the available data on risks and benefits of vaccination with pregnant patients, including the risks of not getting vaccinated in the context of the individual patient’s current health status and risk of exposure, including the possibility for exposure at work or home and the possibility for exposing high-risk household members. Conversations about risk should take into account the individual patient’s values and perceived risk of various outcomes and should respect and support autonomous decision-making (ACOG 2013).
Any of the currently authorized COVID-19 vaccines can be administered to pregnant, recently pregnant, or lactating people.
Additional Vaccination Considerations for Pregnant Individuals
- Similar to their nonpregnant peers, vaccination of pregnant individuals with a COVID-19 vaccine may occur in any setting authorized to administer these vaccines. This includes any clinical setting and nonclinical community-based vaccination sites such as schools, community centers, and other mass vaccination locations.
- Pregnant individuals who experience fever following vaccination should be counseled to take acetaminophen. Acetaminophen has been proven to be safe for use in pregnancy and does not appear to impact antibody response to COVID-19 vaccines.
- Anti-D immunoglobulin (i.e. Rhogam) should not be withheld from an individual who is planning or has recently received a COVID-19 vaccine as it will not interfere with the immune response to the vaccine.
- For patients who do not receive any COVID-19 vaccine, the discussion should be documented in the patient’s medical record. During subsequent office visits, obstetrician–gynecologists should address ongoing questions and concerns and offer vaccination again. Clinicians should reinforce the importance of other prevention measures such as hand washing, physical distancing, and wearing a mask.
ACOG strongly recommends that lactating individuals be vaccinated against COVID-19. While lactating individuals were not included in most clinical trials, COVID-19 vaccines should not be withheld from lactating individuals who otherwise meet criteria for vaccination. Theoretical concerns regarding the safety of vaccinating lactating individuals do not outweigh the potential benefits of receiving the vaccine, and a growing body of evidence demonstrates that COVID-19 vaccination is safe during lactation (Bertrand 2021, Kachikis 2021). Further, current data demonstrate that lactating people who have received mRNA COVID-19 vaccines have antibodies in their breast milk, suggesting a potential protective effect against infection in the infant, although the degree of clinical benefit is not yet known (Perl 2021, Young 2021). There is no need to avoid initiation or discontinue breastfeeding in patients who receive a COVID-19 vaccine (ABM 2020).
Information for pregnant and lactating patients can be found on ACOG’s patient website: Coronavirus (COVID-19), Pregnancy, and Breastfeeding: A Message for Patients.
Gynecologic Care Recommendations and Considerations
Individuals Contemplating Pregnancy
COVID-19 vaccination is strongly recommended for all individuals aged 6 months and older. Further, ACOG recommends vaccination for individuals who are actively trying to become pregnant or are contemplating pregnancy. Additionally, it is not necessary to delay pregnancy after completing all recommended doses of the COVID-19 vaccine.
Claims linking COVID-19 vaccines to infertility are unfounded and have no scientific evidence supporting them. Given the mechanism of action and the safety profile of the mRNA vaccines in nonpregnant individuals, COVID-19 mRNA vaccines are not a cause of infertility. Because it does not replicate in the cells, the vaccine cannot cause infection or alter the DNA of a vaccine recipient and is also not a cause of infertility (Evans, 2021, Morris 2021). Additionally, a growing body of data demonstrate that COVID-19 vaccines do not negatively impact fertility. In a prospective cohort study of couples trying to conceive, no meaningful association between COVID-19 vaccination in either partner with fecundability was found (Wesselink 2022). Further, a study from the Icahn School of Medicine at Mount Sinai investigated fertility outcomes after COVID-19 vaccination, including egg quality, embryo quality and development, pregnancy rates, and early miscarriage. The study showed no differences in rates of adverse outcomes in vaccinated compared to unvaccinated patients (Aharon 2022). Therefore, ACOG recommends vaccination for all eligible people who may consider future pregnancy.
Finally, routine pregnancy testing is not recommended and should not be required prior to receiving any EUA-authorized or FDA-approved COVID-19 vaccine.
Reports of some patients developing temporary contralateral or ipsilateral lymphadenopathy after a COVID-19 vaccination have raised concerns about the possible effect on interpretation of mammogram screening results. A Radiology Expert Scientific Panel has issued a recommendation that mammograms should be conducted prior to COVID-19 vaccination or postponed, if possible, for 4–6 weeks following the second vaccine dose to avoid uncertainty in interpretation of mammogram results.
Screening mammograms are an essential part of preventive care, so postponing screening should only be considered when it does not unduly delay care. If a mammogram is performed fewer than 4–6 weeks after COVID-19 vaccination, patients should inform the mammogram technologist or radiologist when the vaccine was administered, which vaccine was received, and in which arm to aid in interpretation of screening results.
Reports of Post-Vaccination Menstrual Changes
There have been anecdotal reports of temporary changes in menstruation patterns (e.g., heavier menses, early or late onset, and dysmenorrhea) in individuals who have recently been vaccinated for COVID-19. While environmental stresses can temporarily impact menses, vaccines have not been previously associated with menstrual changes. A prospective study of nearly 4,000 women found a temporary non-clinically significant change in cycle length of less than 1 day, and no change in the length of menstrual bleeding. These temporary small variations in cycle length attenuated quickly within two postvaccine cycles (Edelman 2022). Additionally, a recently published prospective observational study of 9555 individuals (77% receiving the COVID-19 vaccine) found a small increase in the probability of greater total bleeding quantity occurred following the first COVID-19 vaccine dose, which resolved in the cycle after the post-vaccination cycle. The total number of heavy bleeding days did not differ by vaccination status (Darney 2023). These data support that any effect of the COVID-19 vaccines on menstruation is minimal and temporary and should not be a reason for individuals to avoid vaccination. ACOG will continue to monitor and evaluate available evidence on this issue.
Additionally, there is no reason for individuals to schedule their vaccinations based on their menstrual cycles; vaccines can be given to those currently menstruating.
Information for patients can be found on ACOG’s patient website: Coronavirus (COVID-19) and Women’s Health Care: A Message for Patients.
Health Equity Considerations and Communities of Color
Communities of color have been disproportionately affected by the COVID-19 pandemic. Individuals in communities of color are more likely to have severe illness and even die from COVID-19, likely due to a range of social and structural factors including disparities in socioeconomic status, access to care, rates of chronic conditions, occupational exposures, systemic racism, and historic and continued inequities in the health care system. Access to and confidence in COVID-19 vaccines is of critical importance for all communities, but willingness to consider vaccination varies by patient context, in part due to historic and continued injustices and systemic racism that has eroded trust in some communities of color. With time, greater proportions of Black Americans have expressed desire for vaccination such that the majority surveyed affirm their intent for vaccination (Pew Research Center, 2021). Despite intent to obtain vaccination, inequities in vaccine distribution persist. Recent data suggest that, while disparities in access have narrowed over recent months, Black and Latinx populations generally remain vaccinated at lower rates than others, in part related to differential access (Kaiser Family Foundation 2021). With the spread of the more transmissible variants, which most profoundly affect unvaccinated people, equitable vaccine access remains essential.
When discussing COVID-19 vaccines with an individual who expresses concerns, it is critical to:
- Be aware of historical and current injustices perpetuated on communities of color.
- Actively listen to and validate expressed fears and concerns while also addressing misinformation about the vaccine.
- Be knowledgeable of the existing avenues for vaccine access in traditionally underserved communities.
- For patients who do not receive the vaccine, the discussion should be documented in the patient’s medical record. During subsequent office visits, obstetrician–gynecologists should address ongoing questions and concerns and offer vaccination again.
If the patient is amenable to further discussion:
- Inform about the testing process, existing safety data, and continued monitoring of safety and efficacy data on COVID-19 vaccines; there have not been shortcuts with the testing of this vaccine.
- Discuss the increased incidence of infection and severe illness from COVID-19 in communities of color.
- Connect patients to trust-building resources developed by people who may have shared experiences and identities (see below for resource examples).
- Note that individuals from communities of color were included in clinical trials (9.8% of Pfizer-BioNTech overall Phase II/III participants were Black and 26.2% were Hispanic/Latinx; 9.7% of Moderna overall Phase II/III participants were Black and 20% were Hispanic/Latinx; 12% of Novavax overall Phase II/III participants were Black and 20% were Hispanic/Latinx), and the vaccine was equally effective among different demographics, including race and ethnicity.
Additional Health Equity Resources
- American College of Obstetricians and Gynecology. Addressing health equity during the COVID-19 pandemic. Position Statement. Washington, DC: ACOG; 2020. Available at: https://www.acog.org/clinical-information/policy-and-position-statements/position-statements/2020/addressing-health-equity-during-the-covid-19-pandemic. Retrieved December 11, 2020.
- American Medical Association. Prioritizing Equity video series: COVID-19 Vaccine & Equitable Distribution. Available at https://www.ama-assn.org/delivering-care/health-equity/prioritizing-equity-video-series-covid-19-vaccine-equitable. Retrieved March 16, 2021.
- Centers for Disease Control and Prevention. Health Equity. Available at: https://www.cdc.gov/coronavirus/2019-ncov/community/health-equity/index.html. Retrieved January 10, 2022.
- Centers for Disease Control and Prevention. Ensuring Equity in COVID-19 Vaccine Distribution. Available at: https://www.cdc.gov/vaccines/covid-19/planning/health-center-program.html. Retrieved March 16, 2021.
- COVID-19 Vaccine Education and Equity Project. Available at: https://covidvaccineproject.org/. Retrieved March 16, 2021.
- Health Resources and Services Administration. Ensuring Equity in COVID-19 Vaccine Distribution. Available at https://www.hrsa.gov/coronavirus/health-center-program. Retrieved March 16, 2021.
- Joint statement on ensuring racial equity in the development and distribution of a COVID-19 vaccine. Health Leads blog. October 26, 2020. Available at: https://healthleadsusa.org/communications-center/blog/joint-statement-on-covid19-vaccine-equity/ . Retrieved December 11, 2020.
- Kaiser Family Foundation. Greater than COVID. Available at: https://www.greaterthancovid.org/. Retrieved March 16, 2021.
- Kaiser Family Foundation. KFF COVID-19 Vaccine Monitor. Available at: https://www.kff.org/coronavirus-covid-19/dashboard/kff-covid-19-vaccine-monitor-dashboard/. Retrieved July 28, 2021.
- The Colorado Health Foundation. Heartwired: COVID-19 Vaccine Messaging Guide. Available at: https://coloradohealth.org/reports/heartwired-covid-19-vaccine-messaging-guide. Retrieved September 30, 2021.
Vaccine hesitancy, particularly around COVID-19 vaccines, exists among all populations. When communicating with patients, it is extremely important to underscore the general safety of vaccines and emphasize the fact that no steps were skipped in the development and evaluation of COVID-19 vaccines. This can be done by briefly highlighting the safety requirements of vaccines, and ongoing safety monitoring even after vaccines are made available.
The following are some messages to consider using when discussing COVID-19 vaccines with patients:
- Vaccines are one of the greatest public health achievements of the 20th century. Before the widespread use of vaccines, people routinely died from infectious diseases, several of which have since been eradicated thanks to robust immunization programs.
- All available COVID-19 vaccines are highly effective. Individuals can be confident in the ability of each of the vaccines to provide a high level of protection from COVID-19 illness.
- Several vaccines have safely been given to pregnant and lactating individuals for decades.
- To date, safety data on COVID-19 vaccines administered during pregnancy do not reveal any safety concerns.
- The rigor of COVID-19 vaccine clinical trials with regards to monitoring safety and efficacy meet the same high standards and requirements as with a typical vaccine approval process.
- While there has been a worldwide attempt to develop COVID-19 vaccines rapidly, this does not mean that any safety standards have been relaxed. In fact, there are additional safety monitoring systems to track and monitor these vaccines, including real-time assessment.
- Side effects such as influenza-like illness can be expected with these vaccines; however, this is a normal reaction as the body develops antibodies to protect itself against COVID-19. COVID-19 vaccines cannot cause COVID-19 infection. It is important not to be dissuaded by these side effects, because in order to get the maximum protection against COVID-19, patients need two doses of the vaccine.
- Safety monitoring continues well beyond the EUA administration.
- COVID-19 Vaccine Monitoring Systems for Pregnant People
- CDC V-Safe COVID-19 Vaccine Pregnancy Registry: A registry to collect additional health information from v-safe participants who report being pregnant at the time of vaccination or a positive pregnancy test after vaccination. This information helps CDC monitor the safety of COVID-19 vaccines in people who are pregnant. V-safe is a new smartphone-based, after-vaccination health checker for people who receive COVID-19 vaccines. V-safe uses text messaging and web surveys from CDC to check in with vaccine recipients following COVID-19 vaccination. V-safe also provides second vaccine dose reminders if needed, and telephone follow-up for anyone who reports a symptom or health condition for which they seek medical attention.
- CDC’s V-Safe: A new active surveillance smartphone-based after-vaccination health checker for people who receive COVID-19 vaccines. V-safe will use text messaging and web surveys from CDC to check in with vaccine recipients for health problems following COVID-19 vaccination. Information on pregnancy status at the time of vaccination and at subsequent follow-up time points will also be collected. The system will provide telephone follow-up to anyone who reports medically significant (important) adverse events or exposure to COVID-19 vaccines during pregnancy or periconception period. As of February 14, 2022, there have been over 201,000 pregnancies reported in CDC’s v-safe after-vaccination health checker.
- Vaccine Adverse Event Reporting System (VAERS): A national early warning system to detect possible safety problems in U.S.-licensed vaccines. VAERS is co-managed by the CDC and the FDA. Healthcare professionals are encouraged to report any clinically significant adverse events following vaccination to VAERS, even if they are not sure if vaccination caused the event. In addition, we are anticipating that the following adverse events will be required to be reported to VAERS for COVID-19 vaccines administered under an EUA:
- Vaccine administration errors (whether associated with an adverse event or not)
- Serious adverse events (irrespective of attribution to vaccination) (such as death, life-threatening adverse event, inpatient hospitalization)
- Multisystem inflammatory syndrome (MIS) in children (if vaccine is authorized in children) or adults
- Cases of COVID-19 that result in hospitalization or death
- CDC’s National Healthcare Safety Network (NHSN): An acute-care and long-term care facility monitoring system with reporting to VAERS
- Vaccines and Medications in Pregnancy Surveillance System (VAMPSS): A national surveillance system designed to monitor the use and safety of vaccines and asthma medications during pregnancy
- FDA is working with large insurer/payer databases on a system of administrative and claims-based data for surveillance and research
- Additional safety monitoring information can be found at https://www.cdc.gov/coronavirus/2019-ncov/vaccines/safety.html.
- ACOG COVID-19 Patient Education Materials. https://www.acog.org/womens-health/covid-19
- CDC Vaccination Considerations for People who are Pregnant or Breastfeeding. https://www.cdc.gov/coronavirus/2019-ncov/vaccines/recommendations/pregnancy.html
- Baystate Health & University of Massachusetts Medical School COVID-19 Vaccine Decision Tool. https://foamcast.org/covidvacpregnancy/?fbclid=IwAR35gMR8Tdx-qEC2CBGAfNYiTMeRhw7W-x0eGjABEh8eqODTujv49bkuzwE
- Frequently Asked Questions about COVID-19 Vaccination. https://www.cdc.gov/coronavirus/2019-ncov/vaccines/faq.html
- CDC’s Talking to Recipients about COVID-19 Vaccines. https://www.cdc.gov/vaccines/covid-19/hcp/index.html
- CDC’s Interim Considerations: Preparing for the Potential Management of Anaphylaxis at COVID-19 Vaccination Sites. https://www.cdc.gov/vaccines/covid-19/info-by-product/pfizer/anaphylaxis-management.html