The impact of histones linked to sperm chromatin on embryo development and ART outcome.

The purpose of this study was to investigate the relationship between the proportion of sperm chromatin linked to remaining histone and assisted reproductive technology (ART) outcome. A prospective cohort study was performed on couples undergoing ART process at the Department of Reproduction Medicine (HFME, Bron, France). The histone-to-protamine ratio (HPR) was measured using the method described by Wykes & Krawetz (2003) J Biol Chem 278, 29471. The correlations with sperm DFI, blastocyst formation, pregnancy rate, and delivery rate were investigated. A total of 291 ART cycles were included (42 c-IVF and 249 ICSI procedures): 3870 oocytes were punctured and 2211 embryos were obtained, among which 507 were transferred and 336 frozen. The mean HPR was 18.9%. A significant negative correlation was found between HPR and DFI (r = -0.12, p < 0.05). Regarding the type of ART procedure (c-IVF or ICSI), the same kind of relationship between HPR and ART parameters was observed. Regardless of the type of ART procedure used, when the HPR was within the range [6%; 26%], the blastocyst formation rate was higher: 87.8% vs. 71.2% (HPR<6%; p < 0.01) and 74.6% (HPR >26%; p < 0.01). The highest delivery rate (DR; 24.5%) was obtained for HPR within the range [6%; 26%]; DR was 21.9% for HPR<6% and 18.3% for HPR>26%; however, the differences were not statistically significant. The procedure described in this study seems to be a reliable evaluation of the HPR. The HPR parameter seems to be correlated to embryonic development up to the blastocyst stage, but its involvement in clinical pregnancy/delivery could not be confirmed. HPR should be further investigated for confirming the relationship with blastocyst formation. After this, the next step will be to investigate the etiologies of HPR alterations for improving the sperm nucleus quality for increasing the chance of pregnancy.

[Medical optimisation of sperm retrieval in non obstructive azoospermia]. / Optimisation médicale du recueil de spermatozoïdes dans les azoospermies non obstructives.

Medical optimisation of sperm retrieval in non-obstructive azoospermia is reviewed. Gonadotropin treatment of hypogonadotropic hypogonadism allows obtaining sperms in the ejaculate in about 90% of cases provided the duration of treatment was long enough. TESE is indicated in case of persistent azoospermia at 2 years of continuous treatment. Some publications reported a possible effect of hormonal treatments (FSH, hCG, anti-estrogens, aromatase inhibitors) in primary spermatogenic failure, but mainly in cases selected for their favourable histology and normal hormonal levels. The effect on unselected cases remains doubtful. Conversely, the effect of the treatment of varicoceles is significant. Other medical treatments or advises need further investigations.

Screening for Chlamydia trachomatis and Ureaplasma urealyticum infection in semen from asymptomatic male partners of infertile couples prior to in vitro fertilization.

In a prospective study, the prevalence of infection with Chlamydia trachomatis and Ureaplasma urealyticum was evaluated in the semen of 92 asymptomatic male partners of infertile couples using polymerase chain reaction and culture, respectively. The results were compared with the detection of serologically specific antibodies. U. urealyticum and C. trachomatis were detected in 12 (13%) and 10 (10.8%) of the tested ejaculates, respectively. One mixed infection was detected. No correlation was found between detection of the pathogens in ejaculates and the presence of specific antibodies in serum. This study therefore confirms the limited diagnostic value of serological analysis to ascertain infection with C. trachomatis or U. urealyticum. The high frequency of detection of these pathogens among asymptomatic male partners of infertile couples emphasizes their potential role in the impairment of male fertility, and the need for sensitive and specific detection methods to prevent infection of the early embryo when using new reproductive techniques such as zona pellucida hatching or intracytoplasmic microinjection.