Researchers are still learning how COVID-19 can affect pregnancy. Getty Images
  • To get a better idea of how the coronavirus impacts pregnancy, researchers looked at close to 600 hospitalized pregnant women diagnosed with COVID-19. 
  • Of the 445 live births evaluated during the study, 12.6 percent were preterm.
  • The researchers hope the findings will raise awareness about the complications COVID-19 can cause in pregnant people.

A new report published by the Centers for Disease Control and Prevention (CDC) suggests that COVID-19 is linked to preterm delivery in pregnant women. 

According to the study, pregnant women have a 25 percent higher risk of preterm delivery compared to the general population. The risk also seems to be about 3 times higher in people with symptoms. 

The researchers also looked at miscarriages and stillbirths and found that while a small percentage of pregnant women experienced stillbirth, the rate of pregnancy loss in people with COVID-19 is likely underestimated. 

A British study published in July found that overall stillbirth rates have increased during the pandemic, likely due to pregnant people avoiding hospitals due to fear of developing COVID-19 and healthcare facilities being understaffed. 

Much more research is needed to confirm and better understand how COVID-19 impacts the pregnant body, but experts suspect the complications may be linked to the widespread association the disease causes. 

“Any systemic illness, particularly one that is associated with pneumonia, systemic inflammation, hypoxic stress, and ramping up of the body’s immune system, will place a great stress on the circulation to the uterus and drive up fetal metabolism. This stress may be enough to kill a compromised pregnancy,” said Dr. Bryan Oshiro, a maternal-fetal medicine specialist and assistant vice-chair of obstetrics & gynecology (OB-GYN) at Riverside University Health System

The risk is low, but some pregnant women with COVID-19 have complications 

To get a better idea of how COVID-19 impacts pregnancy, researchers looked at close to 600 hospitalized pregnant women diagnosed with COVID-19. 

A little more than 20 percent of the women had at least one underlying health condition, most commonly asthma and hypertension. 

Rates of hospitalizations were also higher in Hispanic and Black pregnant women, highlighting the disproportionately higher rates of COVID-19 among these communities. 

More than half of the women — 55 percent — were asymptomatic.

About 16 percent were admitted to the intensive care unit (ICU), 8 percent required mechanical ventilation, and 1 percent (two symptomatic women) died. 

Two percent, both symptomatic and asymptomatic, experienced a pregnancy loss. That number is likely to be underreported, according to the CDC. 

Of the 445 live births evaluated during the study, 12.6 percent were preterm births, which is about 25 percent higher than preterm delivery rates reported in the general population. 

The risk for preterm delivery appeared nearly 3 times higher in pregnant women with symptoms of COVID-19.

“This information really highlights what we already know — infections during pregnancy increase the risk for pregnancy complications and preterm delivery,” said Dr. Katherine Campbell, a maternal-fetal medicine physician and obstetrician at Yale Medicine.

The researchers hope the findings will raise awareness about the complications COVID-19 can cause in pregnant people and help doctors adopt more safety measures to help protect those who are pregnant and their newborns. 

How does COVID-19 impact pregnancy? 

Doctors are still working to understand how COVID-19 impacts pregnant people’s bodies, but experts believe the inflammation the disease causes could trigger complications in pregnancy. 

Past studies suggest the coronavirus isn’t typically passed from mother to fetus en utero, according to Campbell. 

When a person contracts the virus, the immune system turns on to try and fight it.

This immune response oftentimes causes widespread inflammation in the body, and it’s known that inflammation is a risk factor for preterm birth labor and delivery, explains Campbell.

“So, when a person has COVID-19, the systemic inflammation that develops as one’s body fights the infection also becomes a risk factor for preterm labor and birth,” Campbell said. 

There are also challenges in caring for hospitalized pregnant people with severe COVID-19.

While most pregnant people with COVID-19 will be able to recover and go into labor and delivery normally, some may need further medical support. 

“In some infections, especially if a mother has difficulty breathing or maintaining normal vital signs, the fetus may struggle to survive, so a delivery is performed as a lifesaving measure,” Campbell said. 

More research is needed to fully understand the link between COVID-19 and pregnancy complications like stillbirth, as a limited number of pregnant people diagnosed with COVID-19 have been included in studies, according to Oshiro.

“Since stillbirth is a rare event, you need a lot of patients to make a definitive statement about stillbirths and COVID,” Oshiro said. 

Many pregnant people will be asymptomatic 

Keep in mind that many people who are pregnant and develop COVID-19 will be asymptomatic.

Oshiro, who has seen nearly 40 pregnant women with COVID-19, said most were symptomless — two were hospitalized with pneumonia and one in critical condition was admitted to the ICU. Of the group, none experienced stillbirth or preterm delivery. 

“I would not be panicked, but would reassure women that in most of the cases, they and their babies will do fine. However, that does not mean that they should not take every precaution and call their provider or go to the hospital if they should have any concerns,” Oshiro said. 

Campbell, too, wants pregnant women to understand that a small percentage of people develop severe illness. Most will be OK and recover safely. 

“I would offer reassurance as most pregnant women who become infected with COVID-19 are likely to have mild or asymptomatic infection,” she said, noting that it’s still important to practice all the safety precautions

How pregnant people can stay safe

If you’re pregnant, you should continue to social distance, wear face masks, and wash hands frequently. 

Avoid groups of people, and if possible, limit errands. 

Even as the weather gets colder and the holidays arrive, Campbell recommends keeping a distance from others. 

“Pregnant women should be mindful that they may be more susceptible to some of the complications associated with a symptomatic case of COVID-19 and continue to make social distancing and mask wearing a priority throughout the holidays,” Campbell said. 

It’s also crucial to check in with your doctor if you experience difficulty breathing or any symptoms in line with COVID-19. 

The flu shot is a must, too, as it will help cut pregnant people’s chance of an infection and keep their immune system strong.

Partners, family members, and others living with anyone pregnant should also get vaccinated against influenza. 

Oshiro also reminds parents-to-be that hospitals continue to be very safe during the pandemic.

“Hospitals are very safe and due to the safety precautions instituted at hospitals today, there is very little risk of the patient acquiring COVID there,” Oshiro said. 

People are more likely to contract the virus out in their communities or during gatherings, hence the need to continue playing it safe. 

The bottom line

New research from the CDC suggests that COVID-19 is linked to preterm delivery.

Health experts need more data to confirm the link and understand how the disease impacts the pregnant body.

Some suspect the complications may be linked to the widespread inflammation COVID-19 causes, as inflammation is a known risk factor for preterm delivery.

Pregnant people should continue to wear masks, wash their hands, and practice social distancing during the pandemic. 

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