What Do We Know about the COVID Vaccine for Pregnant Women?

Pregnancy is usually an exciting, exhilarating event, laced with love. Yet it is often shot through with worry as well. We know that not all pregnancies go smoothly. Even in apparently normal pregnancies, 4% of women can develop pre-eclampsia which is a high blood pressure situation in the mother which may require risky early delivery of the baby. Miscarriages and stillbirths can occur, although at a rate of less than 1 per hundred pregnancies (0.6%), as well as other problems. Fortunately, the chances of these events happening are low and most pregnancies go well.

The COVID-19 viral pandemic has greatly increased those pregnancy concerns. Reports about how the coronavirus disease affects pregnant women have often varied, and reports on the effects of maternal vaccination on the baby have been almost non-existent until recently. Pregnant women have faced an uncertain choice - whether to vaccinate, or not to vaccinate. As a result, the number of pregnant women in America and other countries who have been vaccinated against COVID-19 is significantly lower than the number of vaccinated non-pregnant women in the same age group.

But a body of reliable information is finally emerging as more experience has been gained with COVID-19, and as more studies have been completed on both mothers and babies. With the health of two persons at stake in every pregnancy, it is very important that we take this new information into account in order to decide about pregnancy vaccination.

Making sense of the previous confusion about the effects of COVID-19 disease in pregnancy.

There are three major reasons that this subject has been so confused:

1. At the beginning of the pandemic, 2020, COVID-19 burst on the scene as a totally unknown disease and so available information was limited for everyone.
2. Reliable studies in any medical/scientific situation often take up to a year to be completed and published, so the results of 2020 studies on pregnancy and the COVID-19 disease did not become available until sometime in 2021. Lots of conflicting information was swirling on the internet before those results were available.
3. Perhaps the most important reason for confusion, however, is that the COVID-19 virus has cycled through 3 different variants over the last two years. Each variant has affected pregnant women differently, and study results may have differed. We need to look at this cause in more detail.

The alpha variant, the original COVID-19 disease in 2020, infected pregnant women at the same rate as the rest of the population, most of the infections were mild, the virus was rarely detected in the bloodstream, and the virus seldom infected the placenta or the baby.

But some pregnant women developed severe infections and those with severe infections had a much worse course than the similarly severely-infected but non-pregnant group of women. Pregnant women with severe COVID-19 were:

• three times more likely to require admission to an ICU because of needing ventilation,
• twice as likely to use a heart-lung machine,
• and almost twice as likely to die. (Morbidity and Mortality Weekly Report, Nov. 2020).

The pregnancies of those women severely infected with the COVID-19 alpha variant were affected in several ways:

• Pre-eclampsia developed at twice the normal rate (American Journal of Obstetrics and Gynecology, Sept 2021).
• More preterm (early) births than usual occurred, which means that more babies were put at risk.
• The risk of stillbirths was two times greater than in normal pregnancies.

Although these severe infections occurred more commonly in women who were older (> 35 years), had other medical disorders such as diabetes, heart disease, or hypertension, or had an African-American or Hispanic heritage, younger women could also develop severe symptoms unexpectedly, and underwent the same risks.

But then the COVID-19 delta variant came along in the summer and fall of 2021, and it quickly became obvious that this COVID-19 disease was much worse than the alpha COVID-19 for pregnant women. The disease was more communicable, and it produced more illnesses of the severe type in pregnant women causing more hospitalizations along with the increased risk of pregnancy problems and death. In the U.S. 40 pregnant women died of COVID-19 during the month of August 2021, and 35 pregnant women died in September 2021. Also important, the risk of a stillbirth became 4 times greater than in a normal pregnancy!

This was not because the virus infected the baby. Intense research on the delta variant showed that the delta COVID-19 virus was carried in much larger numbers in the bloodstream (viremia) than was usual in the alpha variant, and it was infecting the placenta (placentitis). This infection caused widespread fibrous thread deposits, tissue breakdown, and extensive inflammation throughout the organ. The problem was that each of these physical changes lowered the amount of oxygen able to pass through the placenta to keep the baby alive, thus leading to an increased number of stillbirths.

Beginning in the fall of 2021 and through the winter of 2022, the COVID-19 Omicron B.1 variant completely displaced the delta variant in the U.S. It was even more communicable than the delta variant but, fortunately, appears to have been less detrimental to all, including pregnant women. The rate of hospitalization for severely ill COVID-19 infected pregnant women began dropping as the omicron B.1 strain displaced the delta strain, although we will probably not have the results from the studies conducted on omicron pregnancy effects for another 3 to 4 months.

Currently, in spring 2022, we now have a different variant of the Omicron strain making its way through the country. The Omicron BA.2 variant strain has been detected in over 50% of current infections in the U.S. Indications from Europe suggest that this strain is even more transmissible than the B.1, but appears to be similar in the mildness of its effect during pregnancy. We do not yet have firm information on this variant.

The point of mentioning these variants is that the studies that were carried out with each variant produced some different risk numbers. It is no wonder that the information about the risks associated with pregnant women contracting COVID-19 disease has been so confusing.

What do we now know about the risks of the COVID-19 disease for pregnant women?

Pregnant women have the same risks of contracting COVID-19 disease as other people.

Most pregnant women have a mild disease course.

However, infected pregnant women are more susceptible to the severe forms of COVID-19 than non-pregnant infected women. This may be associated with the necessary reduction of defenses that take place within the mother’s immune system during pregnancy so that her body can accept the half-foreign baby (combination of tissues from Mom and Dad) without rejecting it.

Pregnant women who are most likely to develop the severe COVID-19 disease are the older age group (>35 years), or those who have other medical disorders such as diabetes or heart disease, BUT it can, and does, involve women of any age and health status.

Each COVID-19 variant has affected pregnant women differently. So far, we have been fortunate to have had two relatively mild variants, but the severity of the delta variant was a warning that future variants could arise which are more dangerous to both mothers and babies.

And FINALLY, and very importantly, the COVID-19 vaccinations currently available have been shown to be safe for pregnant women and their babies, and effective in preventing those severe forms of COVID-19 which can cause disastrous problems in pregnancy.

Why are so many pregnant women hesitant to get the COVID-19 vaccine?

Some of this hesitancy comes from the natural caution of women who realize that they are now responsible for the safety of two lives, but much of it comes from the standard physician approach of limiting the use of most drugs and vaccinations during pregnancy, especially in the first trimester. [Note: - influenza shots and Tdap vaccine (for whooping cough protection of newborn babies) shots are two that are still encouraged during pregnancy].

This drug refusal approach has been the normal state of obstetrical medicine ever since the Thalidomide disasters, which occurred in the late 1950s to early 1960s, and shocked the medical profession to its core. At that time, pregnant women in England and many other countries were freely given a “miracle” anti-nausea/anti-vomiting medicine called thalidomide to help them through the discomforts of the first trimester. It was supposed to be a non-addictive, non-barbiturate sedative that was marketed heavily and advertised as being completely safe.

 During the next few years, uncountable numbers of stillbirths occurred, and over 10,000 babies throughout the world were born with severe birth defects - without one or both arms, or legs, or with facial, auditory, visual, and other deformities. Unfortunately, it was not until 1961 that thalidomide was shown to be the cause of this worldwide disaster. It was immediately withdrawn from use in pregnancy (although it is still used for certain other medical treatments) but an enormous amount of irreversible damage had already been done.

 However, because of the FDA's slower approach the thalidomide drug had not yet been authorized in the USA and so American mothers were saved from incredible heartbreak. Since then, the medical profession has bent over backward to only prescribe for pregnant women those few medicines whose safety has been intensively studied, especially in the first trimester, and which have been found to be non-injurious. Most medicines either have not been studied carefully enough or do not fit that category.

Consequently, a large contributing factor to the slow uptake of the COVID-19 vaccines among pregnant women was the lack of strong, united support from the medical field when the vaccines first became available. After all, the vaccine scientists had chosen not to include pregnant women in the vaccine trials because of standard drug trial ethics, and so there were no authoritative safety and effectiveness findings for the obstetricians to feel confident about until at least 18 months after the pandemic began. This was despite the fact that mRNA vaccines do not even enter the nucleus of the cell (where the genetic instructions for the body are kept) and therefore the vaccine could not cause genetic changes in the baby.

“Medical organizations said that COVID-19 vaccines shouldn’t be withheld due to pregnancy, but a forceful recommendation for vaccination didn’t come until July of 2021.” (Science News Feb. 27, 2022.)

That strong medical endorsement did come later, as the safety of the vaccines was proven by thousands of pregnant women who chose to be vaccinated after carefully weighing up the safety of the vaccines against the risks of getting the disease. According to the CDC, more than 194,000 pregnant women in the U.S. have gotten COVID-19 vaccines without safety problems, as of the end of January 2022.

Obstetricians now strongly, and without reservation, encourage all pregnant, nursing, and even thinking-about-becoming-pregnant women to be vaccinated against COVID-19. The evident benefit to the health of the mother in preventing severe COVID-19 disease (which was discussed at the beginning of this article) was highlighted by a study done in Scotland which was carried on from December 2020 (the end of the first Covid year, when vaccines finally became available) until the end of October 2021 (6 months ago). In this study, there were 4,950 confirmed coronavirus (COVID-19) infections among pregnant women. 77% of the infections occurred in unvaccinated women while 91% of the 823 hospital stays and all but two of the 104 intensive care admissions also occurred in unvaccinated women.

Now, however, obstetricians are also strongly recommending vaccination because recent studies show that maternal vaccination is turning out to be good for the baby as well. 

Here’s what we have recently learned about the effects of maternal COVID-19 Vaccination, both during pregnancy and nursing, on the baby.

It was already known that vaccinations do not cause Small-For-Gestational-Age babies (Morbidity and Mortality Weekly Report, Jan. 7, 2022) and that vaccinations do not cause an increased risk of miscarriage/abortions (Oct 2021 New England Journal of Medicine)

But we have now learned that when mothers are vaccinated, their babies are protected after birth for up to 6 months because the maternal antibodies cross the placenta into the baby. 100% of the cord blood tested from babies of vaccinated mothers revealed the presence of COVID-19 antibodies. Hospitals report a significant decrease in COVID-19 hospitalizations within the vulnerable first 6 months of life for such babies. Maternal vaccinations given in the latter part of pregnancy result in higher levels of antibodies in the baby at birth, but vaccination is strongly encouraged as soon as possible in the pregnancy because of the extra protection against severe COVID-19 illness that it provides for the mother.

We have also learned that babies of vaccinated mothers receive protection against COVID-19 infection through nursing since protective COVID-19 antibodies transfer to the baby through the breast milk in the same way that the mother’s protective antibodies against diarrheal illnesses pass through the milk. If vaccination was not received during pregnancy, doctors encourage vaccination during the nursing period. The only particular-to-nursing side effect that has been noted is a possible 24-hour drop in the milk supply. The supply picks up again the next day.

In summary, even as the possibility of another COVID-19 variant is developing, the uncertainties about COVID-19 vaccinations for pregnant women are disappearing. Clear information is now available about the risks of the COVID-19 disease during pregnancy, and about the benefits of COVID-19 vaccination to both mother (protection from severe COVID-19 disease risks during pregnancy) and baby (protection from COVID-19 infection in the susceptible newborn time when the baby’s immune system is not yet mature).

You can read all of my COVID-19-related articles here on Crosswalk.com.

Photo credit: ©GettyImages/The Good Brigade

Terrill Wade is a retired M.D. and medical educator who completed her medical training in Australia and her Family Practice Residency and Board Certification in the United States. Her years after that were divided between medicine, homeschooling three children, biology teaching, and adjunct lecturing. She is particularly interested in the effects on society of the new genetic technologies that have developed over the last 20 years. The direction that genetic research takes is enormously influenced by society’s answer to one question: “What does it mean to be human?”

Dr. Wade’s aim is to encourage other Christians to make the effort to accurately understand the relevant scientific facts involved in new medical technology, and, just as importantly, to then assess where, or if, this technology/medical treatment fits within a Christian view of the relationship between God and man.

To further this goal, she gives presentations to Christian groups, writes articles, and sporadically maintains two blogs - newmedinfo.com (currently concerning Covid-19 vaccines) and havingchildrentoday.org (dealing with assisted reproduction matters).