Pregnant & Breastfeeding Women and COVID-19 Vaccines

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Last reviewed
July 19, 2021

Pregnant & Breastfeeding Women and COVID-19 Vaccines

In the United States, Europe, and globally, health agencies have published various COVID-19 vaccine recommendations for women who may become pregnant, pregnant women, and women breastfeeding their children.

The US Centers for Disease Control and Prevention (CDC) and the European Medicines Agency (EMA) say COVID-19 vaccines can be administered to pregnant women after consulting with their healthcare provider.

On June 7, 2021, the CDC stated 'there is currently no evidence that any vaccines, including COVID-19 vaccines, cause fertility problems. However, data are limited about the safety of COVID-19 vaccines for women who are pregnant. Clinical trials for the COVID-19 vaccines currently authorized for use in the USA did not include breastfeeding people. Because the vaccines have not been studied on lactating people, there are no data available.'

'Taken together, while there’s no need to panic about COVID-19 infection during pregnancy, it’s still a good idea for pregnant women and their loved ones to take extra precautions to protect their health,' stated Dr. Francis S. Collins, Director, NIH, on June 1, 2021.

As of July 19, 2021, there were 38 countries recommending COVID-19 vaccination for pregnant women, and 93 allow vaccinations in some cases, according to the COVID-19 Maternal Immunization Tracker from Johns Hopkins University.

US Centers for Disease Control and Prevention

On June 14, 2021, the CDC stated, 'There is currently no quantified evidence that antibodies formed following COVID-19 vaccination cause problems with pregnancy, including the development of the placenta. However, data are limited about the safety of COVID-19 vaccines for people who are pregnant.' The CDC established the V-Safe COVID-19 Vaccine Pregnancy Registry to learn more about side effect issues.

However, there is currently limited data on the safety of COVID-19 vaccines in pregnant women says the CDC. If you have questions about getting vaccinated, talking with your healthcare professional might help, but it is not required, said the CDC on June 10, 2021.

The CDC reported (113) pregnant women with COVID-19 died between January 2020 and July 12, 2021.

Pregnant & Breastfeeding Women COVID-19 Vaccine Research-Based News

July 16, 2021 - A UC San Fransico study found 'Messenger RNA vaccines against COVID-19 were not detected in human milk, providing early evidence that the vaccine mRNA is not transferred to the infant.'

July 12, 2021 - A retrospective cohort study of pregnant women, the BioNTech - Pfizer (Comirnaty, BNT162b2) vaccine, was significantly lower risk SARS-CoV-2 infection with no vaccination.

July 8, 2021 - The UK's NHS affirmed, 'If you're pregnant and have not had a COVID-19 vaccine yet, you should have the Pfizer/BioNTech or Moderna vaccine. And if you've already had the Oxford/AstraZeneca vaccine for your 1st dose and did not have any serious side effects, you should have it again for your 2nd dose. Furthermore, there's no evidence the COVID-19 vaccines have any effect on your chances of becoming pregnant.'

July 6, 2021 - The JAMA Pediatrics published a new study: Evaluation of mRNA From COVID-19 BTN162b2 and mRNA-1273 Vaccines in Human Milk. Results: Postvaccination milk samples were collected 4 to 48 hours after administering the BNT162b2 (n = 5) or mRNA-1273 (n = 2) vaccines. Analysis of 13 human milk samples collected 24 hours after vaccination, including multiple time points (4 to 48 hours) from a single participant, revealed that none of the samples showed detectable levels of vaccine mRNA in any component of the milk. However, clinical data from larger populations are needed better to estimate the effect of these vaccines on lactation outcomes.

July 2, 2021 - The India Health Ministry announced that pregnant women are now eligible for Covid-19 vaccination at any time of the pregnancy. The Ministry has said that although most infected pregnant women (>90%) recover without the need for hospitalization, “rapid deterioration in health may occur in a few.” However, it adds that most newborns (95%) of Covid-positive mothers have been in good condition at birth.

June 29, 2021 - The U.S. CDC website stated, 'Based on how these vaccines work in the body, experts believe they are unlikely to pose a risk for people who are pregnant. However, there is currently limited data on the safety of COVID-19 vaccines in pregnant people. Human clinical trials that study the safety of COVID-19 vaccines and how well they work in pregnant people are underway or planned.

June 23, 2021 - A new observational study named MOMI-VAX has begun to evaluate the immune responses generated by COVID-19 vaccines administered to 750 pregnant or 250 postpartum women, announced by the National Institutes of Health.

June 23, 2021 - The Nature journal published: COVID vaccines and breastfeeding.

June 17, 2021 - The NEJM journal published a new study: Preliminary Findings of mRNA Covid-19 Vaccine Safety in Pregnant Persons. CONCLUSIONS: Preliminary findings did not show obvious safety signals among pregnant persons who received mRNA Covid-19 vaccines. However, more longitudinal follow-up, including follow-up of large numbers of women vaccinated earlier in pregnancy, is necessary to inform maternally, pregnancy and infant outcomes.

June 15, 2021 - The U.S. CDC posted 'COVID-19 Vaccination Coverage Among Pregnant Women During Pregnancy — Eight Integrated Health Care Organizations, United States, December 14, 2020–May 8, 2021.' As of May 8, 2021, 16.3% of pregnant women identified in CDC’s Vaccine Safety Datalink had received ≥1 dose of a COVID-19 vaccine during pregnancy in the United States. Vaccination was lowest among women aged 18–24 years (5.5%) and highest among women aged 35–49 years (22.7%).

June 4, 2021 - The first Covid-19 vaccine study for pregnant women has been launched across the UK. The study, which involves the University of Edinburgh’s MRC Centre for Reproductive Health, occurs across 11 sites, including the Royal Infirmary of Edinburgh, with more than 200 UK participants. Participants will initially receive two doses of the Pfizer-BioNTech vaccine or a placebo with a gap of 21 days between them.

May 28, 2021 - Canada's National Advisory Committee on Immunization preferentially recommends that a complete two-dose vaccine series with an mRNA COVID-19 vaccine (Pfizer-BioNTech, Moderna) be offered to women who are pregnant or breastfeeding. If they cannot receive an mRNA vaccine, another authorized COVID-19 vaccine should be offered because of an allergy.

May 28, 2021 - The Royal College of Obstetricians and Gynaecologists updated its FAQs to include: The latest advice from the Joint Committee on Vaccination and Immunisation (JCVI) is that COVID-19 vaccines should be offered to pregnant women. Women may wish to discuss the benefits and risks of having the vaccine with healthcare professionals and reach a joint decision based on individual circumstances. And mothers should not stop breastfeeding to be vaccinated against COVID-19. Women trying to become pregnant do not need to avoid pregnancy after vaccination, and there is no evidence to suggest that COVID-19 vaccines will affect fertility.

May 24, 2021 - A new study found during March 29, 2020–March 5, 2021, underlying medical conditions were associated with an increased risk of moderate-to-severe or critical COVID-19 illness among pregnant women. Among 7,950 pregnant women with a SARS-CoV-2 virus infection (42.0% were Hispanic, and 54.5% had Medicaid), moderate-to-severe or critical COVID-19 illness was associated with age 25 years and older, healthcare occupation, pre-pregnancy obesity (28.2%), chronic lung disease, chronic hypertension (10%), and pregestational diabetes mellitus (10%). The risk of moderate-to-severe or critical illness increased with the number of underlying medical or pregnancy-related conditions. Two health conditions were associated with a 59% increased risk, and three or more conditions were associated with more than twice the risk compared to women without any reported conditions. This study did not disclose any related mother or infant fatalities.

May 13, 2021 - The Lancet published an exploratory analysis of a convenience sample, receipt of a COVID-19 messenger RNA vaccine was immunogenic in pregnant women, and vaccine-elicited antibodies were transported to infant cord blood and breast milk. Pregnant and nonpregnant women who were vaccinated developed cross-reactive antibody responses and T-cell responses against SARS-CoV-2 variants of concern.

May 11, 2021 - A limited study by researchers at Northwestern Medical in Chicago of vaccinated pregnant patients reported no observed increase in the incidence of findings characteristic of SARS-CoV-2 infection in pregnancy and no evidence of a vaccine-triggered breakdown in maternal immunologic tolerance of the fetus.

May 11, 2021 - Study: In-Hospital Mortality in a Cohort of Hospitalized Pregnant and Nonpregnant Patients With COVID-19. Overall and within multiple subgroups, we found a substantially lower in-hospital mortality rate in pregnant patients than nonpregnant patients hospitalized with COVID-19 and viral pneumonia, according to a new study by researchers with The University of Texas Health Science Center at Houston and the University of Maryland School of Medicine.

April 29, 2021 - Infants born to women with COVID-19 have a low chance of contracting the disease from their mothers, according to a study published in JAMA. "Our study suggests that mother and baby can be cared for together and that nursing can be recommended without danger to the baby's health," concluded first study author Mikael Norman, MD, in a Karolinska Institutet press release.

April 23, 2021 - A new study published in JAMA Network Open, physician-researchers from Beth Israel Deaconess Medical Center, Brigham and Women's Hospital, Boston Children's Hospital, and Massachusetts General Hospital reveal mother-to-newborn transmission of the coronavirus is rare. Out of the 255 neonates studied, 88.2 percent were tested for SARS-CoV-2, and only 2.2 percent had positive results. 

April 21, 2021 - The NEJM Original Article: Preliminary Findings of mRNA Covid-19 Vaccine Safety in Pregnant Persons. CONCLUSIONS: Preliminary findings did not show obvious safety signals among pregnant persons who received mRNA Covid-19 vaccines. However, more longitudinal follow-up, including follow-up of large numbers of women vaccinated earlier in pregnancy, is necessary to inform maternal pregnancy and infant outcomes.

April 12, 2021 - JAMA published a Research Letter that found robust secretion of SARS-CoV-2 specific IgA and IgG antibodies in breast milk for 6 weeks after vaccination. IgA secretion was evident as early as 2 weeks after vaccination, followed by a spike in IgG after 4 weeks (a week after the second vaccine).

March 24, 2021 - This Practice Advisory was developed by the American College of Obstetricians and Gynecologists’ Immunization, Infectious Disease, and Public Health Preparedness Expert Work Group. Information and recommendations will evolve as more data are collected about these vaccines and guidance for their use in pregnant and lactating patients.

March 12, 2021 - A non-peer-reviewed study's findings highlight that vaccination of pregnant women may provide maternal and neonatal protection from SARS-CoV-2 infection.

February 10, 2021 - Dr. Aya Mohr-Sasson, Sheba Medical Center, Israel, launched a clinical study with 200 women using the mRNA vaccines, evaluating their influence on the ovarian reserve.

February 9, 2021 - mBio published a study: Characterization of SARS-CoV-2 RNA, Antibodies, and Neutralizing Capacity in Milk Produced by Women with COVID-19. 'Our data do not support mother-to-infant transmission of SARS-CoV-2 via milk. Importantly, milk produced by infected mothers is a beneficial source of anti-SARS-CoV-2 IgA and IgG and neutralizes SARS-CoV-2 activity. These results support recommendations to continue breastfeeding during mild-to-moderate maternal COVID-19 illness.'

February 9, 2021 - Emer Cooke, EMA Executive Director and Chair of the International Coalition of Medicines Regulatory Authorities, published a Pregnancy and Lactation Workshop.

February 2, 2021 - Pregnant and recently pregnant women with covid-19 attending or admitted to the hospitals for any reason are less likely to manifest COVID-19 symptoms and are more likely to be admitted to the intensive care unit. Pre-existing co-morbidities, non-white ethnicity, chronic hypertension, pre-existing diabetes, high maternal age, and high body mass index are risk factors for severe covid-19 in pregnancy. 

May 22, 2020 - A limited study published by researchers at Northwestern University COVID-19 reported placentas showed an increased prevalence of decidual arteriopathy and other features of MVM, a pattern of placental injury reflecting abnormalities in oxygenation within the intervillous space associated with adverse perinatal outcomes. These changes may reflect a systemic inflammatory or hypercoagulable state influencing placental physiology.

Note: This information has been aggregated from the US CDC, US FDA, WHO, EMA, and other research-based organizations.