Study Design and Participants
Renmin Hospital of Wuhan University, located in Wuhan, Hubei Province, is one of the major teaching hospitals and is responsible for the treatments for COVID-19 assigned by the Chinese government. For this retrospective, single-center, case-controlled study, all patients with COVID-19 were diagnosed according to World Health Organization interim guidance2 and were admitted centrally to the hospital from all of Wuhan without selectivity from Jan 1 to May 7, 2020; final date of follow-up was Jul 8. Thirty-seven pregnant women were infected, and 6 were excluded because they were not matched. One pregnant woman received inducing abortion before admission. Two were diagnosed as ectopic pregnancy and they received surgery soon after hospitalization, while four were excluded because of data missing. Clinical characteristics and outcomes of the remaining 31 pregnant patients were compared with another historical cohort of matched non-pregnant COVID-19 patients over the same study period (ratio: 1:4). They were matched with respect to sex, age, timing of contacting COVID-19, underlying illness and residence in Wuhan. This study was approved by the ethics committee of Renmin Hospital (No. WDRM2020-K141). Written informed consent was waived by the Ethics Commission of Renmin hospital for emerging infectious diseases.