Respiratory functions among pregnant women with COVID-19: A single institutional pilot study

Abstract

 During the COVID-19 pandemic, many pregnant women contracted the virus. In Japan, the severity of COVID-19 is evaluated based on oxygen saturation, respiratory symptoms, and imaging findings. During the fifth wave of the pandemic in 2021, we frequently encountered pregnant women who complained of prolonged shortness of breath after the isolation period was lifted, although the cases were mild to moderate. To quantitatively evaluate the respiratory condition, we conducted pulmonary function tests using a spirometer. Among the 17 pregnant women diagnosed with COVID-19 in the third trimester, 10（58.8％）exhibited restrictive ventilatory impairment immediately after the isolation period was lifted. The percentage predicted vital capacity（％ VC）was significantly lower than in non-COVID-19 pregnant women. At the 1-month postpartum check-up, only one of 13 patients（7.7％）who underwent follow-up pulmonary function tests showed restrictive ventilatory impairment; furthermore, ％ VC had significantly improved. Our findings revealed that restrictive ventilatory impairment is frequent in pregnant women with COVID-19 but usually normalizes by approximately 1 month postpartum. These findings do not support routine respiratory function testing for all pregnant individuals affected by COVID-19. However, if abnormal respiratory function persists beyond the 1-month postpartum checkup, it may serve as a clinical indicator of a potential deviation from the typical natural course of COVID-19 during pregnancy.