Blog categories: Evidenced-Based Science

By BirthWorks International

By Cathy Daub, PT, Founder of BirthWorks International and Horatio Daub MD, MPH Pregnant persons and persons of childbearing age are finding themselves in a state of confusion not knowing whether or not they should get the Covid-19 vaccine, and thus are worried and anxious not knowing what to do. Consider these two real-life scenarios:
  • I’m not getting the vaccine because I’m getting married soon and have read on the internet that it can cause problems with conceiving or affect the health of my baby.
  • I am a physician and was with an unvaccinated pregnant woman who contracted Covid-19 and she and her baby died from the virus.
These fears are real in the mind of pregnant persons and those of childbearing age.  The concerns of infertility, miscarriage, or still birth are fears of almost every person who is pregnant or preparing for pregnancy.  But are they backed up by scientific evidence in relation to the decision of whether to get a Covid-19 vaccine? As in any medical procedure there is a risk/benefit ratio.  Pregnant persons and those of childbearing age should always ask themselves if the risks of accepting an intervention is greater than the risks of declining it.  It is always wise to choose the path of least risk in your specific situation when making such decisions, and to consult with your healthcare professionals and family members. 

The guiding principle:  Always ask yourself, “Are the risks of accepting this intervention greater than the risks without it?”

To make decisions, it is helpful to have reputable sources of information.  Here is what we know to date from two sources:  The New England Journal of Medicine’s publication “Preliminary Finding of mRNA Covid-19 vaccine Safety in Pregnant Persons” published April 21, 2021 and also the CDC (Centers for Disease Control) “Covid-19 Vaccines While Pregnant or Breastfeeding,” updated August 11, 2021. New England Journal of Medicine - April 21,2021 This preliminary study involving a total of 35,691 pregnant persons compared pregnancy outcomes during the Covid-19 pandemic, to outcomes before the Covid-19 pandemic.  Pregnant participants ages 16-54 who had been vaccinated with mRNA technology using the Moderna or Phizer vaccines were included in the study.  Therefore these findings concern only participants who were vaccinated with either of these these two vaccines and who were already pregnant.  They concluded, “Although not directly comparable, calculated proportions of adverse pregnancy and neonatal outcomes in persons vaccinated against Covid-19 who had a completed pregnancy were similar to incidences reported in studies involving pregnant women that were conducted before the Covid-19 pandemic.” (1)  This means that no significant difference in effects or outcomes were found between the vaccinated and unvaccinated groups.   Below are the data comparing the two in terms of pregnancy loss and neonatal outcomes. The Data Specifically for Pregnancy Loss:
  • Spontaneous abortion less than 20 weeks gestation (miscarriage): Pre-Covid : 10% to 20%  ~ After receiving the Covid vaccine:  12.6%  (in 104 of 827  of completed pregnancies)
  • Stillbirth greater than 20 weeks gestation: Pre-Covid:  Less than 1% ~ After receiving the Covid vaccine:  0.1% (1 out of 725)
 The Data Specifically for Neonatal Outcomes Among Live-born infants
  • For neonatal outcomes among live-birth infants: Pre-Covid:  8%-15% ~ After receiving the Covid vaccine:  9.4%  (60 out of 636 (for preterm births less than 37 weeks and persons vaccinated before 37 weeks)
  • Small  size for gestational age: 23 out of 724 (3.2% vs 3.5% pre Covid-19, major Pre-Covid: 3.5%) ~ After receiving the Covid vaccine:  3.2% (23 out of 724)
  • Major congenital anomalies: Pre-Covid:  3% ~ After receiving the Covid vaccine 2.2% (16 out of 724) 
  • Neonatal death (in the first 28 days after delivery): Pre-Covid: greater than 1% ~ After receiving the Covid vaccine: 0%  (0 out of 724)
Centers for Disease Control (CDC) - August 2021 Updated information from the CDC updated August 11, 2021 is summarized here in terms of what they believe pregnant women need to know.

Evidence about the safety and effectiveness of COVID-19 vaccination during pregnancy has been growing.  These data suggest that the benefits of receiving a COVID-19 vaccine outweigh any known or potential risks of vaccination during pregnancy.(2)

  • COVID-19 vaccination is recommended for all people 12 years and older, including people who are pregnant, breastfeeding, trying to get pregnant now, or might become pregnant in the future.
  • Evidence about the safety and effectiveness of COVID-19 vaccination during pregnancy has been growing.  These data suggest that the benefits of receiving a COVID-19 vaccine outweigh any known or potential risks of vaccination during pregnancy.
  • There is currently no evidence that any vaccines, including COVID-19 vaccines, cause fertility problems in women or men.
  • Pregnant and recently pregnant people are more likely to get severely ill with COVID-19 compared with non-pregnant people.
  • Getting a COVID-19 vaccine can protect you from severe illness from COVID-19.
Therefore, at this time, research is showing from two different reputable sources, that pregnant persons contracting Covid-19 have an increased risk for severe illness requiring ICU care...mechanical ventilation and higher death rates compared to nonpregnant persons of reproductive age contracting Covid-19. (3) The risk/benefit ratio is becoming clear.  The ACOG (American College of Obstetrics and Gynecology), CDC (Centers for Disease Control), and the American Academy of Pediatrics have issued guidance that “the mRNA vaccines should not be withheld from pregnant persons.” (4) How Safe is the Vaccine for People Who Are Breastfeeding? Because clinical trials for vaccines currently used in the USA today did not include people who are breastfeeding, there is limited data available.  However, what we do know is that the Covid-19 vaccines do not appear to cause infection in anyone, including the mother or her baby. The vaccines are effective at preventing Covid-19 in people who are breastfeeding.  In fact, we know that breastfeeding persons who have received the mRNA Covid-19 vaccines have antibodies in their breastmilk which could help protect their babies.  However, more data is needed to determine the degree of this protection. Even though information is here, working with the emotions of people is more difficult.  This is because most of us make decisions based on our gut feeling about what to do and that is an emotional encounter.  It is best you discuss this with your health care providers and understand how this scientific research may affect your personal and specific situation. More studies and long-term follow-up need to be done to see if there are other long-term adverse or protective benefits of the vaccine occurring beyond the three and one-half month study period of the New England Journal of Medicine article, or the current recommendations of the CDC which is current as of August 2021. There are ongoing studies currently active to determine any adverse effects or protective benefits of these two vaccines as well as others. References:
  1. Shimabukuro, Tom T et al, “Preliminary Findings of mRNA Covid-19 Vaccine Safety in Pregnant persons” N Engl J Med, June 2021, 384(24); 2273-2282.  Doi: 10.1056/NEJMoa2104983. Epub 2021 Apr 21.
  2. Centers for Disease Control (CDC): https://www.cdc.gov/coronavirus/2019-ncov/vaccines/recommendations/pregnancy.html
  3. Zambrano LD, Ellington S, Strid P, et al.  Update: characteristics of symptomatic women of reproductive age with laboratory confirmed SARS-COV-2 infection by pregnancy status ---United States, January 22-october 3, 2020, MMWR Morb Mortal Wkly Rep 2020; 69: 6-41-1647.
  4. Shimabukuro, Tom et al, “Preliminary Findings of mRNA Covid-19 Vaccine Safety in Pregnant Persons” N Engl J Med, June 2021, 384(24), 2273-2282.rem