Effects of COVID-19 on the Lungs: Implications During Pregnancy

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Being pregnant in the midst of a pandemic is scary. But there are steps you can take to protect yourself. First and foremost, stay home as much as possible. If you must go out, make sure you wear a face covering and encourage others to do the same. Masks have been shown to reduce the rate of transmission of the novel coronavirus (also known as SARS-CoV-2). Another way to protect yourself is to make sure you maintain social distance of at least six feet away from other people at all times. But why are social distancing and wearing masks effective in reducing transmission of the virus?

The main pathway for infection with SARS-CoV-2, the virus that causes COVID-19, is via the airways. The virus is spread through respiratory droplets that come out when an infected person talks, sneezes, coughs, or even breathes into the air. Those respiratory droplets travel different distances depending on the force with which they have been expelled (for example, respiratory droplets from a sneeze or a cough will travel much farther than those expelled when a person is merely talking). Wearing a mask prevents the respiratory droplets from traveling far from their source. That is one reason why wearing masks in public and maintaining social distance are effective at preventing the spread of the disease.

If we are in the presence of an infected person whose respiratory droplets we happen to inhale, we may become infected with SARS-CoV-2. When a person becomes infected with the novel coronavirus, the first place it attacks is the airways. The virus looks for specific receptors, called angiotensin-converting enzyme 2 (ACE2) receptors, that are abundant in the nose, throat, and lungs, as well as other places throughout the body. The virus has specific proteins that fit like a key into the ACE2 receptors. Having the correct ‘key’ allows the virus to enter the cell. The virus then can go on to use the host cell’s DNA and RNA replicating machinery to create more copies of itself that then go on to infect more cells.

The cells in the tiniest airways of the lungs, or alveoli, are rich in ACE2 receptors, making this a prime spot for the virus to attack. When these cells are attacked, the body responds as it is supposed to: the body mounts an immune response to try and rid itself of the foreign invader. In doing so, however, medical scientists have found that the combination of white blood cells, mucus, pus, and other byproducts of an active immune response builds up in those tiny airways and blocks the oxygen from getting to the capillaries on the other side. (The capillaries take the oxygenated blood and carry it to larger arteries that supply oxygen to the organs of the rest of the body.) In this way, the body is deprived of the oxygen that it needs.

How SARS-CoV-2 Invades the Lungs and Impedes Oxygen Flow:

  • The novel coronavirus is covered in a spiky protein coat
  • Some of those spikes are ‘keys’ that fit precisely into ACE2 receptors on the surface of the cells of the lungs and airways
  • The virus enters the cell and uses the host cell’s machinery to create more copies of itself
  • Copies of virus invade even more cells
  • Body responds by mounting immune response to fight the invading virus
  • Small airways (alveoli) are clogged by byproducts of immune reaction
  • Oxygen can no longer reach capillaries
  • Oxygen-depleted capillaries cannot carry oxygen to large vessels of the body to distribute to muscles and organs

We all know that lack of oxygen can damage every organ in your body; continued lack of oxygen will inevitably lead to death. That is why the very sickest of COVID-19 patients get placed on ventilators—to help push the oxygen into their lungs, out to the capillaries, and on throughout the rest of the body. Keeping the blood oxygenated is of utmost importance.

When you’re pregnant, your oxygen supply does double duty. And you need more of it. Not only do you need that extra oxygen to power your own muscles and organs, you also need it to support the fetus that is growing inside of you. Lack of oxygen can put you at risk of miscarriage and can put your fetus at risk for intrauterine growth restriction (IUGR), a condition in which the fetus does not grow as quickly or as large as it normally would, which could cause a whole host of other problems.

At this time, we do not have all the information we would like to have about how SARS-CoV-2 affects pregnant women. Currently, scientists are studying this. Every day, we are finding out more information about how the novel coronavirus specifically affects pregnant women. Until we find out more, it is important to protect yourself by staying home as much as possible, wearing a face mask in public (and encouraging others to do the same), and maintaining a social distance of at least six feet away from others.

Janette DeFelice
Dr. Janette DeFelice is a writer currently focusing on how the changing environment affects our health. She holds a Doctor of Medicine degree from Chicago Medical School where she taught clinical and diagnostic skills to beginning medical students, and a Master’s degree in Humanities from the University of Chicago. She also has a Bachelor’s degree in Political Science. Her writing can be seen online at BeTheChangeMom, ChicagoNow, and Medium, and she’s very excited to have published her first novel, Delia Rising: A Ballet in Three Acts. She lives in Chicago’s west suburbs with her school-age twins, her husband, and a family cat named Clara Barton.

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