Clinical Characteristic of Pregnant Women with COVID-19: A Nationwide Questionnaire Survey in Japan

Background: The clinical features of coronavirus disease (COVID-19) in pregnant women remain unknown. We describe the clinical characteristics and outcomes of pregnant women with COVID-19 in Japan. Methods: A nationwide survey of pregnant women with COVID-19 was conducted in July 2020. A questionnaire was sent to all institutions offering maternity services in Japan. Information regarding maternal characteristics, epidemiological, clinical, treatment, and perinatal outcomes were extracted. Findings: Responses from 1418 institutions were assessed (65% of all delivery institutions in Japan). Seventy-two pregnant women were reported to be diagnosed with COVID-19 between January and June 2020. The positive rate of the universal screening test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) for asymptomatic pregnant women was 0·03% (2/7428). The most common route of infection was familial (57%). Fifty-eight pregnant women with COVID-19 were symptomatic, of which 5 (8·6%) had a severe infection. There was one death, a tourist. Severe respiratory symptoms, oxygen administration, and pneumonia were frequently reported in the 3rd trimester and postpartum period compared to early pregnancy (22·2% vs. 2·5% (p=0·03), 38·9% vs. 7·5% (p=0·01), and 50·0% vs. 7·5% (p<0·01), respectively). All pregnant women with COVID-19 delivered by cesarean section, regardless of symptoms. There was no SARS-Cov-2 transmission to the newborns. Interpretation: The importance of infection prevention should be emphasized, especially in pregnant women, their families, and their roommates during late pregnancy. Funding Statement: None. Declaration of Interests: The authors declare no competing interests. Ethics Approval Statement: This study was approved by the Japan Association of Obstetricians and Gynecologists (No.294, Sep. 12, 2020). This investigation was conducted according to the principles of the Declaration of Helsinki. Informed consent was not obtained from patients or their families because this study was based on the analysis of institutional forms, and the patient records/information was anonymized prior to the analysis.