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  • A new study has found that pregnant people with moderate to severe COVID-19 are more likely to have cesarean delivery, preterm birth, or a fetal or newborn death.
  • Pregnant people who had an asymptomatic or mild infection did not have a significantly greater risk of complications.
  • During pregnancy, the body enters an immunosuppressed state. Lung function is also compromised.

New research has found that pregnant people who develop moderate to severe COVID-19 have a greater risk of developing complications than pregnant people who don’t contract an infection.

The study, which was funded by the National Institutes of Health (NIH) and published in JAMA on Feb. 7, shows that pregnant people diagnosed with moderate to severe COVID-19 are more likely to have a cesarean delivery, preterm birth, a fetal or newborn death.

They also had a greater risk of maternal death, high blood pressure disorders related to pregnancy, and postpartum hemorrhage.

Pregnant people who had asymptomatic or mild infections did not experience these increased pregnancy risks.

Dr. Christian Pettker, a professor of obstetrics, gynecology, and reproductive sciences and associate chief quality officer at Yale Medicine, said the findings contribute important additional knowledge to what we know about the risks of COVID-19 during pregnancy.

“Even outside of the acute COVID-19 infection and its substantial risks in pregnancy, pregnant people who are affected by COVID-19 also have increased risks of severe pregnancy complications like hypertension, hemorrhage (bleeding), and non-COVID-19 infections around the time of childbirth,” Pettker said.

The study evaluated 14,104 pregnant people across 17 hospitals in the United States. Of these participants, 2,352 were diagnosed with COVID-19.

Study participants gave birth between March 1 and Dec. 1, 2020, before COVID-19 vaccines were available.

Over 13 percent of pregnant people who tested positive for COVID-19 developed complications, compared with 9 percent of those who tested negative.

Compared with those who didn’t have a coronavirus infection, pregnant people with a coronavirus infection who developed moderate to severe illness were 40 percent more likely to develop serious pregnancy complications — like high blood pressure, preterm birth, or postpartum hemorrhage — or die during pregnancy.

Pregnant people who had an asymptomatic or mild infection did not have a significantly greater risk of complications, which highlights the role disease severity plays in the risk of complications.

“These poor outcomes noted in conjunction with moderate to severe COVID infection correlate with the extent of bodily damage COVID-19 causes,” Dr. Kecia Gaither, double board certified in OB-GYN and maternal-fetal medicine and director of perinatal services at NYC Health + Hospitals/Lincoln in the Bronx, told Healthline.

“It’s worsened in women with comorbid conditions, particularly with poorly controlled diabetes, hypertensive, HIV positive patients with compromised immune systems,” Gaither added.

Tim Bruckner, an associate professor of public health at the University of California, Irvine, said scientists are still exploring the mechanisms behind why COVID-19 can cause complications in pregnant people.

“Possible pathways involve inflammation during the first or second trimester that affects the placenta and the pregnancy as it progresses toward term, as well as symptoms from the course of COVID-19 infection that adversely affects the birthing person at or around birth,” Bruckner said.

During pregnancy, the body enters an immunosuppressed state to allow the developing fetus to survive and thrive.

Lung function also becomes compromised during pregnancy due to a growing uterus that restricts lung expansion.

“COVID-19 loves immunocompromised states. COVID-19 infection essentially envelopes the lungs in a viscous fluid-impaired oxygen exchange; you drown in secretions. It also impairs other bodily organs and functions,” Gaither explained.

Complications of COVID-19 are more severe in people with comorbidities like obesity, diabetes, high blood pressure, HIV, and already compromised immune systems.

Prior research has shown that COVID-19 can trigger coagulation and high blood pressure, which can contribute to health issues during pregnancy.

Pettker said the COVID-19 vaccine should be seen as a health measure to optimize the health of a pregnancy.

Vaccines can reduce the risk of developing moderate to severe COVID-19, which, in turn, may help reduce the risk of preterm birth and pregnancy complications, said Bruckner.

“Pregnant people should consider the vaccine not just to avoid COVID-19 infection, but also to avoid how that infection affects their pregnancy outcomes,” Pettker said.

Pregnant people who develop moderate to severe COVID-19 have a greater risk of developing complications than pregnant people who don’t contract the coronavirus, according to new research funded by the NIH.

Those with asymptomatic and mild infections did not have a greater risk of pregnancy complications, the study found.

These findings highlight the importance of getting vaccinated against COVID-19 to reduce the risk of moderate to severe disease.