Declarations
Ethics approval and consent to participate This study was approved by the ethics committee of Obstetrics and Gynecology Hospital of Fudan University (No. Kyy-2020-162). Oral informed consent was obtained from the parents of the infants for using the images and data for analysis.
Consent for publication Not applicable.
Availability of data and materials: All data generated or analysed during this study are included in this published article [and its supplementary information files].
Competing interests There is no conflict of interest associated with this manuscript.
Funding This research was funded by financial support from the Shanghai Municipal Health Commission(202040402), Shanghai, China.
Author Contributions JM.W and GN.X proposed the idea of this research and designed the protocol. GN.X performed the LUS. JL.D and XF.W collected clinical data. Y.Y performed the statistics analysis. GN.X and JM.W drafted the article and revising it critically for important intellectual content. F.L, Y.Y, CQ.L, XF.W have been involved in revising the manuscript critically for important intellectual content. All authors read and approved the final manuscript.
Acknowledgement Baoyunlei and Yinjun, the secretaries of our department, must be appreciated because of great efforts to this study