Pregnant women, especially in their last trimester, need to be very guarded to avoid contracting COVID-19, according to new statewide data collected by a group of obstetricians across several hospital systems in Washington.

Dr. Kristina Adams Waldorf, an obstetrician-gynecologist with the University of Washington School of Medicine, said UW Medicine obstetricians are telling their patients to be particularly careful from the seventh month of pregnancy on because it appears they are more susceptible to severe COVID-19 pneumonia. The finding comes from the Washington state COVID-19 in Pregnancy Collaborative. 

"In Washington state, we have seen one in seven pregnant women hospitalized with COVID-19 and one in eight might have severe COVID-related pneumonia," she said. 

The collaborative also published a report in May which showed COVID-19 raises the risk for women who are pregnant and obese of having a preterm birth.