Zwangere vrouwen kunnen zich volgens het laatste advies RIVM laten vaccineren met de mRNA vaccins van Pfizer en Moderna. Dat geldt niet alleen meer voor vrouwen met onderliggende ziekten (zoals diabetes of hart- en longziekten) maar ook voor gezonde zwangere vrouwen De voordelen van vaccinatie wegen op tegen de mogelijke nadelen.
Het is je eigen keuze of je je laat vaccineren. Het is belangrijk om je goed te informeren over de voor- en nadelen hiervan. We hebben alle informatie voor je op een rij gezet: zo kan je een weloverwogen keuze maken.
Pregnant women are advised by the RIVM to take the covid 19 vaccination when invited. The advice is to have a mRNA vaccination (Pfizer or Moderna). It is up to you if you want to have this vaccination. To make a decision we have listed the links to the right information below.
Op onze website staan links naar de updates van de multidisciplinaire werkgroep 'Covid 19 en zwangerschap' en een uitgebreide samenvatting van de tot nu toe bekende data. On our website you can find links to the updates from the midwifery covid team. Also there is an extensive overview of all the information that we have (in dutch):
De beroepsgroep voor verloskundigen KNOV heeft een keuzehulp gemaakt om te beslissen of je de vaccinatie wil of niet. The KNOV has made a helpfull tool to decide if you want the vaccination:
Er is een videopresentatie gemaakt voor aanstaande moeders over de vaccinatie (kosten €10,-). There is a webinar about the corona vaccination in pregnancy (in dutch, costs €10,-).
Hieronder de laatste data van de John Hopkins Universiteit (VS). Here you find the latest reseach numbers from John Hopkins University (US).
As of May 25, 2021, there are more than 167 million confirmed and probable cases of COVID-19 around the world. The highest number of total cases is still in the U.S. (33 million) followed by India (27 million), Brazil (16 million), France (5.6 million), Turkey (5.2 million), Russia (4.9 million), and the United Kingdom (4.5 million). In our last research update in late March 2021, we shared at that time that there were 66 million cases in the world and 15 million in the U.S. So, the numbers have nearly tripled worldwide but only doubled in the U.S., reflecting the slowdown in U.S. cases.
Research on Receiving the Vaccine during Pregnancy and Lactation
Preliminary findings of mRNA vaccine COVID-19 safety in pregnant people
Since pregnant people were not included in the clinical trials, there are limited safety data for mRNA COVID-19 vaccines during pregnancy. However, many pregnant people in the general population have received these vaccines outside of clinical trials, and researchers can assess safety outcomes in this group. A study published April 21 in the New England Journal of Medicine found no evidence of safety concerns among pregnant people who received the mRNA vaccines (Shimabukuro et al. 2021). The study used data from three U.S. vaccine safety monitoring systems: the “v-safe after vaccination health checker” surveillance system (a voluntary smartphone app, discussed in our March 30 research update), the v-safe pregnancy registry (a telephone-based survey that collects detailed info), and the Vaccine Adverse Event Reporting System (VAERS). Between December 14, 2020 and February 28, 2021, a total of 35,691 v-safe participants identified as pregnant. Most people in the sample (about 75%) identified as non-Hispanic white. Vaccine-related side effects were mostly similar between pregnant and nonpregnant v-safe participants; however, pregnant participants were more likely to report injection site pain and less likely to report headache, myalgia (muscle pain), chills, and fever. Out of nearly 4,000 participants in the v-safe pregnancy registry, 827 had a completed pregnancy (86% had a live birth, 13% had a miscarriage, 0.1% had a stillbirth, and around 1% had an induced abortion or ectopic pregnancy). Most of the participants who had a completed live birth had received their mRNA COVID-19 vaccines in the third trimester. There were no newborn deaths. About 9% of the babies were born preterm and about 3% were small for gestational age. During the study period, the VAERS processed 221 reports of adverse events involving COVID-19 vaccination among pregnant people. About 30% of these adverse events were considered pregnancy or newborn-related. The most frequently reported pregnancy or newborn-related adverse events were miscarriage (37 in the first trimester, 2 in the second trimester, and 7 unknown or not reported), followed by stillbirth, premature rupture of membranes, and vaginal bleeding, with 3 reports for each. No congenital anomalies were reported to the VAERS, a requirement under the vaccine emergency use authorizations (EUAs). Although the researchers couldn’t directly compare vaccinated pregnant people to pregnant people who did not receive the COVID-19 vaccine, the rates of adverse events appear to be similar to the rates in studies of pregnant people before the pandemic. In other words, there is no evidence to date that COVID-19 vaccination during pregnancy increases the risk of any of these adverse events. For example, 13% of pregnant people who received the vaccine experienced a miscarriage (pregnancy loss before 20 weeks of pregnancy). The published rate of miscarriage in studies before the pandemic is 10 to 26% (Dugas and Slane, 2021). Importantly, the v-safe pregnancy registry does not yet include anyone who was vaccinated early in pregnancy and then had a live birth. So, although these preliminary findings are reassuring, there is still very little data on COVID-19 vaccination in the first trimester; follow-up is ongoing.
The impact of the COVID-19 vaccines on the placenta
The first study to examine the impact of the COVID vaccines on the placenta was recently published (Shanes et al. 2021). Growing evidence shows the increased severity of COVID-19 for pregnant people, and a study from May 2020 found the placentas of those who tested positive for the virus to have significantly higher rates of placental injury (abnormal blood flow between mother and baby in utero), compared to a control group (Shanes, Mithal, Otero et al. 2020). This new study in 2021, by many of the same authors, is the first to examine if the risk of placental injury is also elevated for individuals who have taken the COVID-19 vaccine. The study includes 84 vaccinated patients and a control group of 116 unvaccinated patients, all between the ages of 30 and 37, and who gave birth at Prentice Women’s Hospital in Chicago. Most patients had received either Moderna or Pfizer vaccines during their third trimester. Patients’ placentas were examined after birth, especially looking for abnormal blood flow between parent and fetus or for problems with fetal blood flow. The results showed no increased likelihood of placental abnormalities from having taken COVID-19 vaccines in the third trimester. Compared to the increased risk for placental injury from contracting COVID-19, the new data suggest that the vaccine may be protective against this type of risk to the placenta. These results are limited to a non-random sample, with possible baseline differences between the groups of vaccinated and unvaccinated individuals. In the past, some members of our audience have complained that these types of studies that we are reporting are too small. It’s important to point out that biological studies (where biological tissues are studied) often have smaller samples than other types of studies because they’re much more time-consuming and expensive to conduct. So, a biological study of placentas from 84 vaccinated and 116 unvaccinated participants is actually a pretty decent sample size. However, to study a wide range of rarer placental abnormalities, a larger number of participants will be needed. There is still no evidence on the placental impact from COVID-19 vaccination in the first or second trimester of pregnancy.
New research on vaccine response in pregnancy and lactation
On February 5, 2021, the first known case of an infant with antibodies to SARS-CoV-2 after maternal vaccination was posted on a preprint server (Gilbert and Rudnick, 2021). Then, in March, a study published in AJOG provided the first cohort data on maternal antibody response to COVID-19 vaccination. (Gray et al. 2021). We discussed the details of these studies in our research update from March 30, 2021, which you can access here on our COVID-19 resource & pregnancy page. We now have more evidence on vaccine response in pregnancy and lactation. In a study published May 13, 2021, in JAMA, researchers from Beth Israel Deaconess Medical Center studied the immune responses of a cohort of 103 individuals of child-bearing age who received either of the COVID-19 mRNA vaccines (Moderna or Pfizer). Of this group of 103 people, 30 were pregnant and 16 were lactating. The study group also included 28 unvaccinated people with confirmed COVID-19 infection. (Collier et. al, 2021). All vaccinated study participants (both pregnant and non-pregnant) developed immune responses against COVID-19 and SARS-COV-2 variants of concern. Antibodies from the vaccine were present in the cord blood and human milk. Also of significance, the antibody response was more robust in people who had the vaccine than it was in the study participants who were not vaccinated but had previous COVID-19 infection. This research suggests benefit from vaccination in pregnant people. This is significant because, while we know that COVID-19 infection in pregnancy carries an increased risk of morbidity and mortality, thus far pregnant people have been excluded from phase 3 vaccine trials. There are some limitations of this study that should also be considered. First, the sample size is small (although as we mentioned in the above section, studies that include biological samples—such as cord blood—are usually smaller because of the expense and time involved in collecting and testing the samples). Second, this is a convenience sample rather than a randomized, placebo-controlled clinical trial. Third, while the researchers have demonstrated an immune response and the transfer of antibodies from pregnant person to baby via cord blood and human milk, this does not prove or disprove immunity in babies of vaccinated parents. More research needs to be done to make this determination. Per the lead author Ai-ris Y. Collier, MD, “future research should focus on determining the timing of vaccination that optimizes delivery of antibodies through the placenta and breast milk to newborns.”
The Royal College of Obstetricians and Gynecologists (RCOG) in the U.K. has an excellent, recently updated Q&A page on COVID-19 vaccines, pregnancy, and breastfeeding (May 14, 2021). They share the latest advice from the Joint Committee on Vaccination and Immunisation (JCVI) that “COVID-19 vaccines should be offered to pregnant women at the same time as the rest of the population, based on their age and clinical risk group.” The Royal College of Midwives’ page on COVID-19 vaccines and pregnancy also cites the JCVI advice. The U.S. Centers for Disease Control and Prevention (CDC) states that getting vaccinated is a personal choice, and lactating people and pregnant people can receive a COVID-19 vaccine if they desire (May 14, 2021). In the U.S., the American College of Obstetricians and Gynecologists (ACOG) recommends that pregnant individuals have access to COVID-19 vaccines and that lactating individuals be offered the vaccine similar to non-lactating individuals (April 28, 2021). They also state, “Pregnant patients who decline vaccination should be supported in their decision.” On April 29, 2021, the U.S. Society for Maternal Fetal Medicine (SMFM) updated their guidance on “Provider Considerations for Engaging in COVID-19 Vaccine Counseling With Pregnant and Lactating Patients.” They strongly recommend that “pregnant and lactating people have access to the COVID-19 vaccines and that they engage in a discussion about potential benefits and unknown risks with their healthcare providers regarding receipt of the vaccine.” The Society of Obstetricians and Gynecologists of Canada (SOGC) released a statement on COVID-19 vaccination and pregnancy on December 18, 2020 and reaffirmed it on May 4, 2021. They affirm, “Pregnant individuals should be offered vaccination at any time during pregnancy or while breastfeeding if no contraindications exist.” The World Health Organization’s (WHO) Strategic Advisory Group of Experts on Immunization policy recommendations regarding the Pfizer BioNTech COVID-19 vaccine were last updated on April 20, 2021. They say that vaccination can be offered to a lactating person if they are part of a group recommended for vaccination. Regarding pregnancy, the WHO recommends, “Pregnant women may receive the vaccine if the benefit of vaccinating a pregnant woman outweighs the potential vaccine risks. For this reason, pregnant women at high risk of exposure to SARS-CoV-2 (e.g. health workers) or who have comorbidities which add to their risk of severe disease, may be vaccinated in consultation with their health care provider.”
Q & A Section
Question: Do the vaccines have any effect on fertility?
There have been no documented negative effects on fertility or pregnancy from the COVID-19 vaccines to date. Several vaccinated individuals from clinical trials became pregnant through the course of the study, so we know that blanket infertility from the vaccines is not possible. Fertility was not specifically studied in trials; however, no loss of fertility was observed in animal trials, nor has an increase in human infertility been reported in any monitoring and data collection efforts. In the United States, ACOG released a statement stating that “loss of fertility is scientifically unlikely.”
That said, there has been much online debate, questions and concern around this topic, including in parenting groups on social media. The source of most concerns can be traced back to December 2020, when German doctor Wolfgang Wodarg and a former Pfizer employee wrote a letter to the European Medicines Agency. They had noticed genetic sequencing similarities between the SARS-CoV-2 spike protein and another protein (Syncytin-1) that helps keep the placenta attached to the uterus in pregnancy.
They asked to delay the Pfizer/BioNTech approval to be sure the vaccine would not cause the body to attack its own placenta proteins, while targeting the intended spike protein. Other researchers have since confirmed that the SARS-CoV-2 spike protein and Syncytin-1 protein are not similar enough to cause harm. This is further confirmed by results from the study reviewed above (Shanes et al.) that showed no increased likelihood of placental injury after vaccination in late pregnancy.
For those concerned about the small sample size of the Shanes et al. study, the Mayo Clinic also explains that antibodies developed from the vaccine are the same as those from contracting the disease. If these antibodies, meant to target the spike protein, also had a negative impact on the placenta, a rise in miscarriages and infertility would be expected across the population of all those who tested positive for COVID-19 in the last 15 months. Such a rise has not been found.
We hope to see research in the future including individuals who gave birth after developing antibodies (either from natural infection or vaccination) in the preconception period or in early pregnancy. This would confirm the fertility in two groups that have no scientific reasons for concern yet have not been specifically studied.
Question: What did the researchers find in the adolescent trials?
On May 10, the FDA announced in a news release that it has expanded its emergency use authorization of the Pfizer COVID-19 vaccine for adolescents aged 12-15 years. This is an extension of the previous emergency use authorization for teenagers aged 16-17.
The dosing and dosage are the same for adolescents and adults, which is 2 doses given 3 weeks apart. The vaccine should not be given to anyone with a history of a severe allergic reaction to any component of the vaccine.
The on-going safety data to support the emergency use authorization for adolescents comes from a randomized, placebo-controlled clinical trial of 2,600 participants aged 12-15 in the United States. Of this group, about half received the vaccine and half received the placebo. Greater than 50% of the total study population was followed for at least two months post vaccine.
As with adult and older teenage populations who received the vaccine, the most common side effects were pain at the injection site, tiredness, headache, chills, muscle pain, fever, and joint pain.
It’s important to point out that the vaccination of young adolescents raises concerns about equity in global vaccine access. While the U.S. vaccinates its teens, other countries are not able to vaccinate their highest-risk adults. The United States currently has a surplus of vaccine (with some states resorting to hosting cash lotteries to convince more people to get the vaccine), while only 0.3% of all vaccines administered worldwide have gone to low-income countries.
With countries like Nepal now experiencing 50% positivity rates, help is needed to lessen the strain on these fragile medical systems and to stop the spread of new strains of the virus. As infectious disease specialist Dr. Stone put it, “Viruses do not recognize borders. No one is safe until we all are.”
This concludes the research update for May 25, 2021. We hope you found it helpful! We do not have a specific date for our next COVID-19 research update, but we plan on releasing another update in the fall.
If you would like to submit a follow-up question for our consideration to include in upcoming newsletters, you can submit your question here.
The EBB Research Team
Collier AY, McMahan K, Yu J, et al. (2021). Immunogenicity of COVID-19 mRNA Vaccines in Pregnant and Lactating Women. JAMA. Published online May 13, 2021. Click here. Dugas C and Slane VH (2021). Miscarriage. In: StatPearls. Treasure Island, FL: StatPearls Publishing, 2021. Click here. Gilbert P. and Rudnick C. (2021). Newborn antibodies to SARS-CoV-2 detected in cord blood after maternal vaccination. medRxiv [preprint]. Click here. Gray K., Bordt E., Atyeo C., et al. (2021). COVID-19 vaccine response in pregnant and lactating women: a cohort study. AJOG. 2021 Mar 25 [Articles in press]. Click here. Shanes ED, Otero S, Mithal LB, et al. (2021). Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Vaccination in Pregnancy: Measures of Immunity and Placental Histopathology. Obstet Gynecol. 2021 May 11. Click here. Shanes, E. D., Mithal, L. B., Otero, S., Azad, H. A., Miller, E. S., & Goldstein, J. A. (2020). Placental Pathology in COVID-19. American journal of clinical pathology, 154(1), 23–32. Click here. Shimabukuro TT, Kim SY, Myers TR; CDC v-safe COVID-19 Pregnancy Registry Team (2021). Preliminary Findings of mRNA Covid-19 Vaccine Safety in Pregnant Persons. N Engl J Med. 2021 Apr 21. Click here.