In vitro culture facilitates the selection of healthy spermatids for assisted reproduction

OBJECTIVE: To evaluate the potential usefulness of in vitro culture of germ cells for distinguishing between healthy and apoptotic spermatids. DESIGN: Prospective study. SETTING: Private assisted reproduction laboratories and a university department. PATIENT(S): Men with secretory azoospermia who were candidates for assisted reproductive treatment. INTERVENTION(S): Testicular biopsy samples were cultured in the presence of FSH and testosterone for 48 hours. Germ cell apoptosis before and after culture was evaluated by terminal deoxyribonucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling. MAIN OUTCOME MEASURE(S): The percentage of germ cells at different stages of spermatogenesis that showed apoptosis-related DNA damage. RESULT(S): In fresh samples, high levels of apoptosis were detected at those stages of spermatogenesis at which major developmental blocks occurred, with a maximum at the most advanced stage detected. In contrast, apoptotic cells were considerably less well represented at the most advanced stage after culture. CONCLUSION(S): In addition to the previously described facilitation of spermatid recognition and the progression of cytoplasmic maturation, in vitro culture of germ cells is useful to overcome the danger of inadvertent use of apoptotic spermatids for assisted reproduction.