Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection During Pregnancy In China: A Retrospective Cohort Study

Mingzhu Yin; Lijuan Zhang; Guangtong Deng; Chaofei Han; Minxue Shen; Hongyin Sun; Furong Zeng; Wei Zhang; Lan Chen; Qingqing Luo; Dujuan Yao; Min Wu; Shihuan Yu; Hui Chen; David Baud; Xiang Chen

There were numerous differences in the laboratory findings between pregnant patients and non-pregnant patients. Compared with nonpregnant patients, pregnant patients had more white blood cell and neutrophil counts, shorter prothrombin time and activated partial thromboplastin time, higher level of D-dimer, procalcitonin and aspartate aminotransferase. Moreover, there was no statistical difference in the proportion of abnormal levels of alanine transaminase and serum creatinine between these two groups, while pregnant patients had higher level of alanine transaminase and lower level of serum creatinine than non-pregnant patients. These abnormalities suggested that pregnant patients might have diminished cell-mediated immunity, hypercoagulable state, and increased hepatic injury compared with non-pregnant patients. These abnormalities were not unique between pregnant and non-pregnant patients with COVID-19. Previous studies showed that pregnant patients were more likely to have complications and adverse outcomes such as sepsis and hepatic injury with SARS-CoV and MERS-CoV infection. 30, 31 Monitoring the severity of COVID-19 is imperative for the adjustment of treatment strategies. Though analyzing cytokines in peripheral blood of 123 hospitalized patients with COVID-19, Wan et al. found that IL-6 were higher in severe patients than in mild patients. 23 Another team observed the similar phenomenon and further demonstrated significant decrease of IL-6 after treatment for patients with severe COVID-19. 22 Our study showed that pregnant patients had increased IL-6 level compared with non-pregnant patients, which is consistent with our previous finding that more pregnant patients were diagnosed as severe or critical pneumonia than non-pregnant patients. However, in our study, although the median level of IL-6 was higher in severe/critical group than moderate group, no significant difference was identified between these two groups. NLR and SII are the inflammatory markers which have been reported to be associated with the progress of disease. 32, 33 We found that NLR and SII were positively correlated with the severity of COVID-19. It seems that these two inflammatory indices have a higher sensitivity than IL-6 on evaluating the severity of COVID-19. Besides, unlike IL-6, NLR and SII could be easily calculated from blood standard examination. A large, prospective study is necessary to investigate the value of NLR and SII in monitoring the severity of COVID-19.