Heterogeneous distribution of histone methylation in mature human sperm.

PURPOSE: To analyze the presence of various histone modifications in ejaculated human spermatozoa METHODS: In this prospective study, seminal ejaculates from 39 normozoospermic individuals were evaluated for semen analysis and the presence of histone modifications in isolated nuclei. RESULTS: We observed heterogeneous presence of histone methylation in normal mature human sperm. We observed that 12 to 30 % of the nuclei of normal sperm contain a heterogeneous distribution of the marks H3K4Me1, H3K9Me2, H3K4Me3, H3K79Me2, and H3K36Me3. Moreover, the presence of these marks is higher in the poor motile fraction of the ejaculate, which is associated with poor morphology and functional quality. In contrast, we did not observe histone acetylation (H3K4Ac and H4K5Ac) in normal or abnormal mature human sperm CONCLUSIONS: Defects in the process of spermatogenesis may alter the correct epigenetic programming in mature sperm. Further studies are required to evaluate the impact of these findings in human infertility.

Prediction of reproductive outcomes according to different serum anti-Müllerian hormone levels in females undergoing intracystoplasmic sperm injection.

BACKGROUND AND AIM OF THE STUDY: Serum anti-Müllerian hormone (AMH) is a reliable marker of ovarian reserve, and it has been shown to be correlated with reproductive outcomes in grouped analyses. However, practical data is scarce for the physician and the patients to predict these outcomes in an individual couple according to serum AMH measured prior to assisted reproduction technology (ART) procedures. STUDY DESIGN: To address this question, we performed an analytic observational study including 145 females undergoing intracytoplasmic sperm injection (ICSI) in a single center. Results were analyzed according to serum AMH; subgroup analyses were performed by grouping patients according to patient's age and FSH levels. RESULTS: The risk of cycle cancellation decreased from 64% in patients with serum AMH ≤ 3 pmol/L (0.42 ng/mL) to 21% with AMH ≥ 15 pmol/L (2.10 ng/mL). Cycle cancellation occurred in approximately two-thirds of the patients with AMH ≤ 3 pmol/L irrespective of the FSH level. However, with higher AMH values the risk of cycle cancellation decreased more significantly in patients with normal FSH. The rate of good response increased from almost null in patients with AMH ≤ 3 pmol/L to 61% in those with AMH ≥ 15 pmol/L. The positive correlation between good response and AMH was also significant, but with lower absolute rates, when patients were grouped according to their age or FSH levels. Pregnancy rate increased moderately, but significantly, from 31% with AMH ≤ 3 pmol/L to 35% with AMH ≥ 15 pmol/L. CONCLUSIONS: We provide estimates of reproductive outcomes according to individualized values of serum AMH, in general and in subgroups according to patient's age or serum FSH, which are helpful for the clinician and the couple in their decision making about starting an assisted reproductive treatment.

Use of metaphase I oocytes matured in vitro is associated with embryo multinucleation.

OBJECTIVE: To evaluate the impact of oocyte maturational stage at retrieval on embryo multinucleation. DESIGN: Retrospective study. SETTING: Private institution for assisted reproduction. PATIENT(S): A total of 412 patients undergoing 500 intracytoplasmic sperm injection (ICSI) cycles between August 2006 and September 2010. INTERVENTION(S): Routine ICSI laboratory procedures. MAIN OUTCOME MEASURE(S): Normal and abnormal fertilization; embryo development; arrest at pronuclear stage; failure to undergo first mitotic division; presence of embryo multinucleation; embryo quality; pregnancy, implantation, and miscarriage rates. RESULT(S): A significantly lower percentage of multinucleation was found in embryos originating from metaphase II (MII) oocytes when compared with MI-II- and MI-derived oocytes. Significantly fewer multinucleated cells per embryo were observed in MII-derived oocytes. Clinical pregnancy and implantation rates were significantly higher when only embryos derived from MII oocytes were transferred. CONCLUSION(S): Embryo multinucleation rate increases when in vitro-matured (2-5 hours incubation) MI (MI-II) oocytes are used instead of in vivo-matured oocytes in ICSI. Furthermore, all other ICSI outcome parameters are also compromised. The use of donated gametes does not modify these results.

Superoxide dismutase content in sperm correlates with motility recovery after thawing of cryopreserved human spermatozoa.

OBJECTIVE: To investigate the correlation between sperm superoxide dismutase (SOD) content and motility recovery after thawing of cryopreserved human sperm, based on the rationale that this antioxidant enzyme provides protection against reactive oxygen species-induced damage during cryopreservation. DESIGN: Prospective study. SETTING: Private infertility institute and university-based research laboratory. PATIENT(S): Forty-two consenting normozoospermic patients consulting for infertility. INTERVENTION(S): The SOD content was measured in sperm from unfractionated samples and in sperm recovered from the pellet fraction obtained after discontinuous density gradient centrifugation. MAIN OUTCOME MEASURE(S): Sperm motility was evaluated post-thaw in the two sets of samples and motility recovery was plotted against the sperm SOD content to determine their correlation. RESULT(S): There was a significant positive correlation between motility recovery after thawing and SOD content in sperm from the 90% gradient pellet containing highly purified mature sperm. There was also a significant negative correlation between motility after thawing and SOD content in the unfractionated sample. CONCLUSION(S): The positive correlation between post-thaw motility recovery and SOD content in mature spermatozoa provides a good predictor of post-thaw motility recovery after cryopreservation.

Effect of thawing temperature on the motility recovery of cryopreserved human spermatozoa.

OBJECTIVE: To investigate the effects of thawing temperature on sperm function after cryopreservation. The technical aspects of sperm cryopreservation have significantly improved over the last few decades. However, a standard protocol designed to optimize sperm motility recovery after thawing has not yet been established. DESIGN: Prospective study. SETTING: Private infertility institute and university-based research laboratory. PATIENT(S): Eighty consenting normozoospermic patients consulting for infertility. INTERVENTION(S): Spermatozoa from donor semen samples were thawed at different temperatures. MAIN OUTCOME MEASURE(S): Sperm motility, viability, adenosine-5'-triphosphate (ATP) content, acrosomal status, and DNA integrity were evaluated as a function of thawing temperature in cryopreserved human sperm samples. RESULT(S): Thawing at 40 degrees C resulted in a statistically significant increase in sperm motility recovery compared with thawing at temperatures between 20 degrees C and 37 degrees C. There were no statistically significant differences in sperm viability, acrosomal status, ATP content, and DNA integrity after thawing at 40 degrees C compared with thawing at temperatures between 20 degrees C and 37 degrees C. CONCLUSION(S): Sperm thawing at 40 degrees C could be safely used to improve motility recovery after sperm cryopreservation.

Patients' opinions regarding preimplantation genetic diagnosis in a Latin American fertility clinic.

Patients' opinions concerning the use of preimplantation genetic diagnosis were evaluated in a fertility clinic with a specially designed questionnaire. The results of this study suggest that for couples with fertility problems, an embryo with severe genetic abnormalities has a different moral status than a healthy one.