Dear Editor,
We read the review by Neef and colleagues with great interest.1 The authors aimed to provide comprehensive information on birth-related data, clinical features, treatment options, and rRT-PCR results from SARS-CoV-2 tests in different samples from neonates and their mothers. We want to congratulate the authors for establishing a timely and informative systematic review of this disease in neonates. However, we would like to draw their attention toward the following issues.
First, we would like to suggest that the authors should present a full electronic search strategy for at least one database, including any limits used, such that it could be repeated according to the PRISMA recommendations.2
Second, in the “Data collection” section, the authors fail to extract the hospital's name and periods of recruitment. Some pregnant women may have been included in multiple publications, as admission dates often overlap for reports from the same hospital. The cases from reference number 29 (Yang et al.3) should be considered duplicates considering the case series from reference number 11 (Chen et al.4) reported in the same hospital with overlapping periods of recruitment. At least one pregnant woman or neonate had identical characteristics (e.g., maternal age, gestational age at delivery, delivery mode, complications, drug treatment, clinical symptoms, gender, Apgar score, and birth weight). Including duplicates may introduce bias into a systematic review and may affect the understanding of the disease and its epidemiology. We suggest that the authors should review the hospital and periods of recruitment. When a hospital publishes their cases more than once, and if the periods of recruitment overlap, only the study with the biggest sample size must be included to minimize the possibility of doubles counting.
Author contributions
JC conceived the design of the comments and made critical revision. MT and HL drafted the manuscript. GL searched the literature and extracted the data. All authors approved the final version for publication.
Declaration of competing interest
The authors have no conflicts of interest to declare.
References
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