The objective of this retrospective study was to determine whether clinical outcomes (clinical pregnancy, implantation, live births and miscarriage) were affected by the application of IVF or ICSI insemination with different sperm concentrations in ejaculate in unselected population of infertility patients.
Data of 786 in vitro fertilization (IVF) and 1268 intracytoplasmic sperm injection (ICSI) cycles were retrieved and analyzed according the stratification of the cycles as follows: Group with low (0-19.9), normal (20-99.9), above normal (100-150) and high (> 150 M/ml) spermatozoa concentration in ejaculate.
The concentration of spermatozoa in ejaculate negatively affected clinical outcomes including clinical pregnancy (P < 0.01), implantation (P < 0.03), live births (P < 0.02) and miscarriage rate (P < 0.01) in ICSI treatment. In contrary, such an effect was not observed in the IVF cycles. However, comparing IVF and ICSI subgroups, the profound negative effect on clinical outcome was evident in ICSI patients when the concentration of spermatozoa in semen was > 100 M/ml and > 150 M/ml (P < 0.05 to P < 0.001 range).
Our results demonstrate the negative effects of ICSI on embryos implantation, clinical pregnancy, live births, and miscarriage rate when semen had above normal to very high concentrations of spermatozoa in ejaculate. However, such an effect was not observed in the IVF treated patients.