Does the Presence of Nuclear Vacuoles in Human Sperm Selected for ICSI Affect Pregnancy Outcome?

Background: To verify whether or not microinjection of sperm with a normal nuclear shape but large vacuoles affects IVF-ICSI pregnancy outcome.

Methods: A comparative study testing IVF outcome parameters of IVF-ICSI, based on morphological selection of spermatozoa with normal nuclei against those based on microinjection of sperm with a normal nuclear shape but large vacuoles. An experimental group, including 28 IVF-ICSI cycles, where only embryos obtained from microinjection of spermatozoa with a normal nuclear shape but large vacuoles were transferred, was matched with a control group, including 28 IVF-ICSI cycles, where only embryos obtained from microinjection of spermatozoa with a strictly defined morphologically normal nuclear shape and content were transferred. The main outcome was IVF-ICSI pregnancy rate.

Results: The experimental group exhibited a significantly lower pregnancy rate per cycle and significantly higher abortion rate per pregnancy compared to the control group (18 versus 50%, and 80 versus 7%, respectively, P=0.01).

Conclusion: Microinjection of vacuolated sperm appears to reduce the pregnancy rate and appears to be associated with early abortion.