Pregnancy rates are higher with intracytoplasmic morphologically selected sperm injection than with conventional intracytoplasmic injection.

OBJECTIVE: To verify whether microinjection into retrieved oocytes of motile spermatozoa with morphologically normal nuclei, strictly defined by high power light microscopy (x >6000), improves the IVF/intracytoplasmic sperm injection (ICSI) pregnancy rate in couples with repeated ICSI failures.
DESIGN: Comparative prospective study testing routine IVF/ICSI outcome parameters against those of modified ICSI based on morphological selection of spermatozoa with normal nuclei.
SETTING: Male factor fertility laboratory and IVF center. PATIENT(S): Sixty-two couples, with at least two previous consequent pregnancy failed ICSI cycles, underwent a single ICSI trial preceded by morphological selection of spermatozoa with normal nuclei. Fifty of these couples were matched with couples who underwent a routine ICSI procedure at the same IVF center and exhibited the same number of previous ICSI failures. INTERVENTION(S): Standard ICSI and modified ICSI. MAIN OUTCOME MEASURE(S): ICSI pregnancy rate. RESULT(S): The matching study revealed that pregnancy rate after modified ICSI was significantly higher than that of the routine ICSI procedure (66.0% vs. 30.0%). CONCLUSION(S): Microinjection into retrieved oocytes of selected spermatozoa with strictly defined morphologically normal nuclei improves significantly the incidence of pregnancy in couples with previous ICSI failures.