Sperm Concentration and the Fertilization of Human Eggs In Vitro

Abstract

The effect of sperm concentration on the fertilization of preovulatory and immature human eggs was studied in the context of an ongoing in vitro fertilization-embryo transfer (IVF-ET) program. Fertilization success was independent of the follicular recruitment protocol used, and with preovulatory eggs, was inversely related to sperm concentration over the range of 2.5 - 50 X 10(4) motile sperm/ml. Maximum fertilization (80.8%) occurred at a concentration of 2.5 X 10(4) motile sperm/ml. The incidence of polyspermic fertilization was directly related to the sperm concentration, decreasing from 5.5% at 10 X 10(4) to 0% at 1-2.5 X 10(4) motile sperm/ml. Immature eggs cultured in vitro, then inseminated, also demonstrated an inverse relationship between fertilization and sperm concentration with a maximum fertilization rate of 66.6% at 5 X 10(4) motile sperm/ml. The percentage of motile sperm in the inseminating population had no influence on fertilization rates unless the value dropped below 40%. Fertilization success using sperm from oligospermic and polyzoospermic males was also examined. In contrast to males with normal semen parameters, oligospermic males demonstrated highest fertilization success at 50 X 10(4) motile sperm/ml. The IVF of preovulatory eggs using sperm from polyzoospermic males was comparable to that for males with normal semen parameters at equivalent sperm concentrations. The implications of these findings to the application of IVF-ET technology to the infertile couple is discussed.

Comparative evaluation of human embryonic stem cell lines derived from zygotes with normal and abnormal pronuclei

“…Inhibition or delay of second polar body extrusion and formation of two female pronuclei (or possibly one diploid) together with a single sperm pronucleus (monospermic digyny) (Palermo et al, 1995). Polyspermy may be correlated with other factors, including oocyte immaturity and postmaturity (Wentz et al, 1983), sperm concentration (Wolf et al, 1984), inherent defects or fractures of the Fig. 10.…”

Critical Assessment of Sperm Morphology Before and After Double Wash Swim-Up Preparation for in Vitro Fertilization

“…When performing in vitro fertilization (IVF), most centers perform swim-up preparations of the sperm prior to insemination [ l , 8,12,141. Traditionally, the success of the swim-up procedure is judged by changes in the percentage of motile sperm recovered, although improvements in the morphology of the sperm recovered have also been demonstrated.…”

Die Beurteilung der Eizellreifung und frühen Embryonalentwicklung bei der assistierten Reproduktion

“…Neben den beschriebenen Gründen bei der Insemination unreifer bzw. überreifer Oozyten (van der Ven et al 1997) mit einer nicht ausreichenden Ausschüttung kortikaler Granula (Sathananthan et al 1985), führen auch zu hohe Spermienkonzentrationen bei der IVF (Wolf et al 1984) Bei der Beurteilung nach der Insemination werden auch Oozyten mit nur einem Vorkern und einem Polkörperchen beobachtet (Abb. 4 a).…”