Does It Still Make Sense to Mask up in Pregnancy to Protect You and Your Fetus from Viral Disease?

Throughout the three-year course of the COVID-19 pandemic, those of us who contribute to The Pulse have been committed to following the science. This can mean many things. When no data, or very few data, are available, following the science can mean acting based on a working hypothesis and following recommendations of experts, based on educated guesses and proposed mechanisms that have a basis in what we know from experience with related issues in science and medicine. As an example, given that people during the first year of the pandemic were dying mostly because of COVID-19 reaching an inflammatory phase, manifesting with what critical care doctors call acute respiratory distress syndrome (ARDS), patients were often treated with corticosteroids, even before there was evidence that these medications could mitigate moderate to severe COVID-19. This was an educated guess. Later, evidence arrived showing that steroid treatment improved survival when given to patients with COVID-19 severe enough to require supplemental oxygen, and also showing that steroids were not helpful, and could even do harm, when given for mild COVID-19. This finding also made sense in terms of mechanisms, since in the early phase you need your immune system fighting against SARS-CoV2 (the virus that causes COVID-19), before the immune system does move into a hyper-inflammatory response that does more harm than good.

On the matter of vaccines, science proved that many of the vaccines developed against SARS-CoV2, such as the mRNA vaccines, were extremely effective in preventing the severe kind of COVID-19. Whereas data initially suggested that the Johnson and Johnson (Janssen) vaccine was also very effective, later studies revealed that it was not as effective as the mRNA vaccines (Pfizer-BioNTech and Moderna). Janssen is one of the viral vector vaccines, the other being the AstraZeneca/Oxford vaccine, and the studies showing Janssen not to be as effective as the mRNA vaccines came out, authorities were already concerned about rare blood clotting complications in premenopausal women.

Now when it comes to masks, things really began with educated guesses, because there were no data. Scientists knew that, worn properly, surgical masks did an excellent job at stopping bacteria from spreading. Thus, for about the past 100 years, surgeons and others working in operating rooms have worn masks. This is primarily to protect patients from bacterial infections that can begin from bacteria from the mouths of others entering through the surgical wound and so masks have been worn, not only by those in the operative field who are scrubbed in, such as surgeons and scrub nurses, but also by others in the operating room, such as anesthesiologists and various technicians and nurses. It’s worth noting that the masks also protect the people who are operating from materials that might otherwise splash into their mouths and noses.

When it comes to stopping virus transmission, things have not been as clear. Certain types of masks, called respirators, including N95s, have been recommended since they have been shown to block the movement of most virus particles, but not 100 percent of them. These were recommended early in the pandemic, even though, to work correctly, they must be fitted perfectly to the wearer. If there is even a slight crack through which air can pass next to the nose, it defeats the purpose of wearing a respirator. Given high numbers of people outside of clinical settings like hospitals being so sloppy with masks to the point of letting them drop below the nose (including N95s below the nose), and also scrunching the masks on their chins, pulling them up and down, I noted on this blog that measures like double masking would make sense, at best, only when done correctly. Other contributors to The Pulse also explained N95s, pointing out that they were not all the same, as many were made in China, and again, with emphasis about the proper fitting.

It’s also important to note something else, while healthcare workers were getting protection from SARS-CoV2 by way of N95 respirators at the time when the messaging about masks was getting out, including before the vaccines entered the market, this was one of multiple layers of protection. Entering a room where there was an infected patient, you needed to don your N95, another mask to cover it, a face shield over that, and other things in a particular order. On the way out, you needed to remove things in a certain order and use sanitizing agents along the way. None of this squared with people out in the world, scrunching their masks on their chins and touching this and that, with no concern about getting exposed to particles from other people that would be on their mask’s outer surface whilst they were fiddling around it.

Also, at one point, I wrote about an observation that a journalist had made that many more people near the entrance of Stanford University were riding bicycles wearing masks without helmets than were riding bicycles with helmets. This was a post about balancing risks and it was in early 2022, by which time the percentage of people vaccinated in the city of Palo Alto, California was extremely high and all Stanford students and faculty were up-to-date on their COVID-19 vaccines, because that was required, in order to be on campus. So as for the point: Being outdoors around Stanford University, not much of a risk of becoming infected with SARS-CoV2 or of infecting others. Suffering traumatic brain injury from falling off a bike without a helmet, also that’s a low risk, but it is notably higher than the risk of a viral infection in open air. This is anecdotal, but, having recently returned from a short visit to Stanford University, I should note that I saw numerous people riding bicycles without helmets.

The purpose of all of this buildup relates to the fact that there are now some more data, really an analysis and review of data from numerous studies, published in what’s called Cochrane Reviews. By reviewing numerous published studies dealing with masks and hand washing and analyzing those data, the authors of this recent Cochrane review found that, at the moment, there aren’t any data supporting the use of masks by the general population to stop the spread of viral infections, including SARS-CoV2. The authors include a caveat that such data could come later, but that available data do not support masking.

We could add numerous other caveats. People do not know how to use masks. Perhaps there can be a study in which viral transmission is compared between people who mask correctly versus those who do not mask. Masking correctly would include being very cognizant about what touches what. To do this correctly, you need to learn the procedures, or you need to be meticulous in figuring them out yourself. This brings up a weak point of the review, namely that among the mask studies that the authors combined were some bad studies —bad in that they had no good way to assure that people who were categorized as wearing a mask actually did wear masks and wore them correctly. This is a big caveat, since by putting bad studies together with good studies in an effort to create a bigger study, it weakens the good studies that were included.

From the Cochrane review, I cannot conclude that there will not be data in the future showing that masking of the public can stop spread of viral disease, but I can say, as I could prior to the recent Cochrane review, that certain mask behaviors are completely futile. Case in point is another thing that I saw on my recent visit to Palo Alto. I was in a restaurant that was not particularly crowded, but nobody was wearing a mask. Except for one couple. Seated at a table near the door, these two people wore procedure masks while waiting for their food. When the food arrived, they removed the masks. I don’t recall what the woman did with her mask, but the man put his on his arm by pulling the elastic bands around the sleeve of his jacket. This caused the part of his mask that goes on the face to rub against the sleeve, which had been resting on the table that had on it who knows what from the table’s previous occupants. Then, when finished eating, the two people redonned their masks and kept them on, until they were given tea, so they took them off to drink the tea, then put them on again. While I am eagerly awaiting more mask studies, based on all that we know to this point, I can tell you with confidence that the two people in the restaurant did not receive any medical benefit from the masks, the way that they used them in the restaurant.

So, what does this all mean for you while you’re pregnant and trying to protect yourself and your baby? First, I would never discourage anyone from wearing a respirator in public, if it is well fitting, tightly on the face with no gaps. It may not help, but maybe it does a little bit under certain circumstances. It does not help, if you are the only person with a mask in a public place and you remove it to eat. There are numerous, interesting questions related to how the protection of a mask/respirator changes with the amount of time in a place full of people and with the concentration of people in that place. Between vaccination and masking, vaccination is by far and without doubt the more important measure.

David Warmflash
Dr. David Warmflash is a science communicator and physician with a research background in astrobiology and space medicine. He has completed research fellowships at NASA Johnson Space Center, the University of Pennsylvania, and Brandeis University. Since 2002, he has been collaborating with The Planetary Society on experiments helping us to understand the effects of deep space radiation on life forms, and since 2011 has worked nearly full time in medical writing and science journalism. His focus area includes the emergence of new biotechnologies and their impact on biomedicine, public health, and society.

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