How to obtain evidence of vertical transmission in viral infected pregnant women: Reflection on COVID-19 epidemic

During the COVID-19 epidemic, there have been many misconceptions concerning vertical transmission between the mother and fetus/baby, which has caused much discussion and controversy. However, there is no strong evidence to indicate that this novel coronavirus could be vertically transmitted from infected mothers to their fetuses/infants. Several easily confused concepts are clarified in this paper, including vertical transmission, intrauterine transmission, mother-to-infant transmission, intrapartum or postpartum transmission. Well-designed protocols and a disciplined research team are essential for both basic and clinical research, in order to contribute to obtaining more scientific evidence for better understanding of the characteristics of this novel coronavirus. Proper handling and disposal of the body fluids and tissue are critical for safety. We highlight the significant value of relevant research, and suggest future research directions, such as investigating the impact of COVID-19 in different trimesters. Furthermore, China has the most experience of treating pregnant women exposed to the COVID-19 virus, and it would be a great service to the rest of the world, for all centers in China to collaborate to report this collective experience.