COVID-19 raises risk for women who are obese and pregnant

Study findings suggest that women who contract the virus face a higher incidence of a severe pneumonia, which could lead to preterm birth.

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The novel coronavirus can severely affect pregnant women who are overweight or obese before becoming pregnant, new research suggests.

Published today by the American Journal of Obstetrics and Gynecology, the findings show that women who contract the virus may have a higher incidence of preterm birth.

“One of the most important study findings is that in nearly all cases of severe COVID-19 disease, women were either overweight or obese prior to pregnancy and had other conditions like asthma and high blood pressure,” said senior author Dr. Kristina Adams Waldorf. "The combination of pregnancy, obesity, asthma and a COVID-19 pneumonia can synergistically increase the burden on her lungs.” 

The research was led by Adams Waldorf, professor of obstetrics and gynecology at the University of Washington School of Medicine. Erica Lokken, an epidemiologist at the UW School of Public Health, was lead author of the paper. 

This is the first study published by the Washington State COVID-19 in Pregnancy Collaborative, a group of obstetricians across hospital systems that facilitate 40% of births in Washington state.  The findings came after the hospitals examined the outcomes of 46 pregnant mothers who contracted COVID-19 between Jan. 21 and April 17.

This study included all known infections of the virus in pregnant women from participating hospitals in Washington state. Patients involved in the study had been screened for COVID-19 because they developed symptoms in this time period.  The group focused on this research because the clinical course of COVID-19 in pregnant women is not well understood, Adams Waldorf said. 

“We want to determine the risks of COVID-19 in pregnancy and which subgroups of pregnant women might be at greatest risk. The next step is to translate this information into public health action so that we can provide information to high-risk pregnant women in communities with higher rates of transmission."

The consortium received funding from the UW Population Health Initiative to expand their study across the state. The researchers found that 1 in 7 pregnant women was hospitalized for respiratory concerns and 1 in 8 had a severe COVID-19 pneumonia. The timing of delivery for 25% of the women was influenced by the effects of COVID-19 on lung function and in one case, resulted in a preterm birth.

Of the women studied, nearly all experienced some symptoms of the disease  (93.5%). About 15% of the women were hospitalized and one was admitted to the ICU. Six of the seven patients hospitalized experienced severe COVID-19 symptoms. Eight deliveries occurred in the group during the study. One preterm birth occurred at 33 weeks, and there was one stillbirth, though it was unknown whether this was caused by the coronavirus. 

“These findings support categorizing pregnant patients as a higher risk group, particularly with obesity and chronic diseases like asthma and high blood pressure,” the report concluded.

“It is encouraging that most pregnant patients with COVID-19 experienced mild disease, but we cannot discount that one in eight pregnant patients were hospitalized for respiratory concerns," said Lokken. “We have a lot more to learn." 

Participating institutions represented 16 hospitals from the Seattle-Tacoma-Bellevue metropolitan area, Bellingham, Spokane and their surrounding areas. Sites included the University of Washington Medical Center (Montlake and Northwest campuses) and Harborview Medical Center; Swedish Medical Center (First Hill, Ballard, Issaquah, and Edmonds campuses); Valley Medical Center, MultiCare Health System (Auburn Medical Center, Covington Medical Center, Tacoma General Hospital, Good Samaritan Hospital, Valley Hospital and Deaconess Hospital); EvergreenHealth Medical Center; and PeaceHealth-St. Joseph’s Medical Center. These sites have 34,000 deliveries annually, which represent 40% of the approximately 86,000 deliveries each year in Washington state.

This work was primarily supported by funding from the University of Washington Department of Obstetrics & Gynecology and UW Medicine Gift Funds. Funding also came from the National Institute of Allergy and Infectious Diseases (AI133976, AI145890, AI144938, AI143265, AI120793). Study data were managed using a REDCap electronic data capture tool hosted by the Institute of Translational Health Sciences at the University of Washington, which was supported by the National Center for Advancing Translational Sciences (UL1TR002319).

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