Do the majority of males with subnormal hypoosmotic test scores have normal vitality?
WHO seems to treat vitality and HOS as equal tests. We disagree and find that structural defects of the sperm membrane are much less common than functional impairment of the sperm membrane. Since a male with an HOS test score < 50% will rarely achieve a pregnancy with intercourse, intrauterine insemination, or IVF with conventional insemination it is important to check for the HOS test not viability because the HOS test can be easily corrected with ICSI.
The cases demonstrate primary morphological signs of a developmental error being expressed in two seemingly separate segments but linked by the hypoglossal artery. It suggests a segmental error related to this embryonic vessel. They also show that few phenotypes are specific for a genotypic disorder and highlight the importance of analysing different etiologies for aneurysm formation and anatomical disposition when taking treatment strategy decisions.