RESUMO
OBJECTIVE: To report assisted reproduction technologies (ART) outcome and characterize severe mitochondrial sheath (MS) anomalies in two infertile asthenoteratozoospermic patients. DESIGN: Case reports. SETTING: Private IVF clinic and academic research institution. PATIENT(S): Two infertile men with asthenoteratozoospermia. INTERVENTION(S): Intracytoplasmic sperm injection (ICSI) was performed in both cases. MAIN OUTCOME MEASURE(S): Clinical and laboratory evaluation were performed and spermatozoa studied by epifluorescence microscopy and transmission electron microscopy (TEM). RESULT(S): Patient 1 had sperm with acute bendings at the level of the narrow midpieces. Mitochondria were either scarce or absent. Three ICSI embryos were transferred. A pregnancy was achieved followed by a miscarriage at the end of the first trimester. Patient 2 had sperm with very long MSs. The number of gyres was increased to more than 30. Two ICSI cycles were performed with good fertilization rates and embryo quality, but no pregnancy was achieved. CONCLUSION(S): MS defects were studied by phase-contrast, epifluorescence microscopy, and TEM that afforded a detailed view of the sperm midpiece and the topography of the whole flagellum. The results indicate that midpiece defects, while causing severe asthenozoospermia and lower fertilizing potential, may not necessarily represent negative prognostic factors in ART.