key: cord-0715647-xhcd6vjz
authors: Cai, Jianghui; Lin, Yonghong; Wu, Meng-Jun
title: Letter to editor regarding “Clinical Presentation and Outcomes of Pregnant Women With Coronavirus Disease 2019: A Systematic Review and Meta-analysis”
date: 2021-08-06
journal: Clin Infect Dis
DOI: 10.1093/cid/ciab690
sha: 024d52c6202a9358c38a9b9b08d79befee473cc6
doc_id: 715647
cord_uid: xhcd6vjz

nan

To the Editor-We read with great interest the study by Matar and colleagues [1] . The authors aimed to describe the clinical characteristics and perinatal outcomes of coronavirus disease 2019 (COVID-19) in pregnancy. We want to congratulate the authors for establishing a timely and informative systematic review. Certainly, their findings old significance for obstetricians. However, we would like to draw their attention to the following issue.

The authors did not exclude studies suspected of including duplicate reporting. Some pregnant women with COVID-19 may have been included in multiple publications, as admission dates overlap for reports from the same hospital. The 7 cases from reference 34 (Yang et al [2] ) should be considered a duplicate considering the case series from reference 13 (Chen et al [3] ) reported by the same hospital with the periods of recruitment overlapped. At least 1 pregnant woman or newborns had identical characteristics (eg, maternal age, gravida, gestational age at delivery, complications, delivery mode, indications for cesarean section, chest computed tomography results, birth weight).

Furthermore, we are very surprised to find that the authors included a study (reference 15) that was pooled from all hospitals in China, excluding those in Wuhan [4] . Including duplicates may introduce bias into a systematic review and may affect understanding the disease and its epidemiology [5] . Thus, we suggest that the authors should extract the setting/hospital and periods of recruitment. When a hospital had published their cases more than once, if the periods of recruitment overlapped, only the study with the biggest data was included to minimize the possibility of double counting. 

Clinical presentation and outcomes of pregnant women with coronavirus disease 2019: a systematic review and meta-analysis

Clinical characteristics and risk assessment of newborns born to mothers with COVID-19

Clinical characteristics and intrauterine vertical transmission potential of COVID-19 infection in nine pregnant women: a retrospective review of medical records

Withdrawn: clinical manifestations and outcome of SARS-CoV-2 infection during pregnancy

Editorial concern-possible reporting of the same patients with COVID-19 in different reports