[In vitro fertilization: a comparison with results of the hamster ova penetration test (HOPT)].
The hamster ova penetration test (HOPT) was performed in 82 patients simultaneously with in vitro fertilization of homologous oocytes (IVF). A penetration rate of greater than 20% of inseminated ova was considered to represent a positive test result. The results of HOPT correlated completely with the IVF in all couples with male factor sterility. In couples with female sterility only and in couples with a combination of female and male factors HOPT was falsely negative in 22 and 20% respectively. Despite a negative HOPT in vitro fertilization with formation of two pronuclei 12 to 18 hours after insemination occurred in these patients. Obviously, the interpretation of HOPT is dependent upon the definition of the cut-off point (in our case 20%). Our results support the opinion that there should be no exclusion from an IVF programme based only on a negative HOPT. It appears that any penetration rate greater than 0% should be considered as a sign of potential fertility.