<prompt> Virus responsible for non immune hydrops fetalis isCytomegalovirusHerpes simplex virusHepatitis B virusParvovirus  <response>: Hydrops is defined as the accumulation of extracellular fluid in tissues and serous cavities. Hydrops fetalis is more common because of non-immune reasons rather than Rh isoimmunization. Most common cause of non-immune hydrops is due to congenital hea block cardiac causes Most common infection causing non immune hydrops- Parvovirus B19 infections 