Why There Are Fewer Preemies Born During the COVID-19 Pandemic?

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About one in 10 births in America is a preterm birth, according to the Centers for Disease Control. A preterm, or premature, birth is one that occurs before the 37th week of pregnancy. Preterm babies have higher rates of death and disability. Disability resulting from preterm birth could include feeding and/or breathing problems, cerebral palsy, developmental delays, hearing problems, or vision problems.

Scientists have identified several factors that increase a pregnant woman’s risk for going into preterm labor. Risk factors include:

Currently, measures to prevent preterm birth are limited because, although many risk factors are clear, it is very difficult to pin down the exact cause of premature labor in many cases. Prevention measures include not smoking, drinking, or using substances during pregnancy, appropriate prenatal care, and waiting at least 18 months after having a baby to get pregnant again. Additionally, some women who have a history of giving birth prematurely are offered progesterone treatment to try to cut their risk of preterm labor.

Measures to prevent preterm birth include:

  • Not smoking during pregnancy
  • No alcohol or substance use during pregnancy
  • Appropriate prenatal care
  • Spacing pregnancies at least 18 months apart
  • Progesterone treatment (for those with history of preterm labor)

Caring for a preterm baby causes significant emotional and financial stress for a family. Preventing the death and/or disability that often accompanies a premature birth would go a long way toward easing these burdens.

COVID-19’s effect on premature birth rates

A recent study from Denmark that was accepted for publication in Archives of Disease in Childhood looked at over 30,000 births over five years between March 2015 and April 2020. Researchers found that, compared to the same months the previous four years, during the time period in 2020 when Denmark was on a nationwide lockdown due to COVID-19 there was a 90% reduction in extremely premature births (defined as occurring at less than 28 weeks gestation). It’s important to note, however, there was no significant decrease in premature births that take place between the 28th and 37th weeks.

What caused the decline in premature birth rate?

The researchers think the decline in the extremely premature birth rate could be a ‘side effect’ of the lockdown to protect citizens of Denmark from SARS-CoV-2 (the virus that causes COVID-19). During the time of the Danish national lockdown four important things happened. First, the researchers noted that decreased physical interaction could have prevented pregnant women from being infected with common viruses (such as, cold or influenza). Additionally, the researchers note that increased attention to hygiene and handwashing prevented the spread of many of those same common illnesses. Because maternal inflammation (often occurring alongside illness) could be a contributing factor to premature labor, pregnant women were protected.

Furthermore, the researchers note that a changed work environment could have offered some protective benefit as well. During the national lockdown, people were not going into the office to work. Instead, they were working from home. This could have provided some pregnant women the benefit of having more rest and less stress.

One other unexpected side effect of the lockdown was that air pollution decreased as a result of decreased travel. The question remains, does a lower quality of the air that pregnant women breathe contribute to the risk of having a preterm birth?

Unexpected positive ‘side effects’ of national lockdown include:

  • Decreased physical interaction
  • Increased hygiene/handwashing
  • Changed work environment
  • Decreased air pollution

Looking at the risk factors and the ‘side effects’ of the Danish national lockdown

It’s easy to see how the unexpected positive ‘side effects’ of the national lockdown may have contributed to preventing extremely premature births. Risk factors like infection/illness and work stress were significantly reduced during the lockdown. This gave pregnant women the benefit of reduced illness that leads to inflammation, and more rest. Reducing these risk factors may indeed merit a closer look when it comes to caring for pregnant women. Furthermore, the question of decreased air quality as a risk factor for preterm labor should be explored.

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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