Towards Post-Meiotic Sperm Production: Genetic Insight into Human Infertility from Mouse Models.

Declined quality and quantity of sperm is currently the major cause of patients suffering from infertility. Male germ cell development is spatiotemporally regulated throughout the whole developmental process. While it has been known that exogenous factors, such as environmental exposure, diet and lifestyle, et al, play causative roles in male infertility, recent progress has revealed abundant genetic mutations tightly associated with defective male germline development. In mammals, male germ cells undergo dramatic morphological change (i.e., nuclear condensation) and chromatin remodeling during post-meiotic haploid germline development, a process termed spermiogenesis; However, the molecular machinery players and functional mechanisms have yet to be identified. To date, accumulated evidence suggests that disruption in any step of haploid germline development is likely manifested as fertility issues with low sperm count, poor sperm motility, aberrant sperm morphology or combined. With the continually declined cost of next-generation sequencing and recent progress of CRISPR/Cas9 technology, growing studies have revealed a vast number of disease-causing genetic variants associated with spermiogenic defects in both mice and humans, along with mechanistic insights partially attained and validated through genetically engineered mouse models (GEMMs). In this review, we mainly summarize genes that are functional at post-meiotic stage. Identification and characterization of deleterious genetic variants should aid in our understanding of germline development, and thereby further improve the diagnosis and treatment of male infertility.

FSH therapy for idiopathic male infertility: four schemes are better than one.

OBJECTIVE: The aim of this article is to propose an algorithm that aids the clinician to choose the best therapeutic scheme of follicle-stimulating hormone (FSH) in the treatment of men with idiopathic infertility, based on testicular volume (TV) and serum total testosterone concentrations; highlighting the potential role of additional therapy with hCG in a sequential temporal scheme. MATERIALS AND METHODS: We subdivided patients in four clinical groups: patients with normal TV and serum testosterone concentrations (A); patients with normal TV and reduced serum testosterone concentrations (B); patients with reduced TV and serum testosterone concentration (C); patient with low TV e normal serum testosterone concentrations (D). Then, we administered to each group a specific therapeutic scheme. Group A: treated with FSH alone for at least 3 months; group B: treated with hCG alone twice a week for 3 months and addition of FSH for poor responders (unmodified sperm parameters); group C: treated ab initio with FSH and hCG until the pregnancy was reached; group D: treated with FSH alone for 3 months and addition of hCG for moderate poor responders (increased TV but unmodified sperm parameters) or second cycle of FSH for 3 months for severe poor responders (unmodified TV and sperm parameters). After 6 months we evaluated the therapeutic response in term of sperm parameters normalization rate, spontaneous pregnancy rate, and sperm DNA fragmentation normalization rate. RESULTS: 40% of patients became normozoospermic after treatment, while 30% achieved spontaneous pregnancy. B was the group that best responded to treatment in terms of normalization of seminal parameters; while the highest spontaneous pregnancy rate was obtained from the D group. B group also obtained the highest sperm DNA fragmentation normalization rate. CONCLUSIONS: To date, no reliable predictors of response to treatment with FSH exist, but TV and serum testosterone concentrations can help the clinician to choose the best therapeutic scheme for men with idiopathic infertility. The groups treated with a sequential temporal scheme (B and D groups) showed better clinical results compared with two groups treated with conventional schemes (A and C groups).

Which semen analysis correlates with favorable Intracytoplasmic morphologically selected sperm injection (IMSI) outcomes?

OBJECTIVE: To assess whether a correlation exists between different sperm pathologies and Intracytoplasmic morphologically selected sperm injection (IMSI) outcomes. STUDY DESIGN: A retrospective cohort study which included couples with recurrent implantation failures (2 or more unsuccessful IVF-ICSI cycles) undergoing their first IVF-IMSI cycle in Hebrew-University Hadassah Medical Center between January 2008 and May 2017. RESULTS: A total of 170 couples with at least two IVF failures attempting their first IVF-IMSI cycle were included, of them 56 (32.9%) achieved a clinical pregnancy. No correlation was found between clinical pregnancy and a specific abnormal semen parameter. However, a positive correlation with clinical pregnancy was demonstrated when all three semen parameters were abnormal (OR-3.33, p = 0.015). CONCLUSIONS: Our findings suggest that IMSI procedure may be more efficient in severe compound sperm pathologies than in patients with one abnormal sperm parameter. Future prospective trials are required to reinforce these findings and allow formation of clear indications for IMSI.

Treatment strategies for severe oligoasthenoteratozoospermia (OAT) (<0.1 million/mL) patients.

Intracytoplasmic sperm injection (ICSI) using spermatozoa from patients with severe oligoasthenoteratozoospermia is still a challenge. Although spermatozoa are available, lower fertilisation rates as well as compromised pregnancy rates are observed after ICSI. We aimed at identifying respective parameters in the pre-values of ejaculate samples used for couple counselling. The clinical pre-values of 121 patients and their corresponding 228 ICSI cycles performed between 2002 and 2010 were retrospectively analysed. Patients were divided into three groups: (i) group 1 (G1, n = 51) where all patients showed at least once <0.1 million/mL and ICSI was performed using ejaculate alone; (ii) group 2 (G2, n = 14) patients had once <0.1 Mill/mL or azoospermia and a testicular biopsy before start of ICSI; (iii) group 3 (G3, n = 56) patients were azoospermic and directed immediately to testicular sperm extraction (TESE). The pre-values of G2 differed significantly from G1 in terms of volume and motility. Lutenizing hormone (LH) and follicle-stimulating hormone (FSH) values were equal in G1 and G2, but showed significant differences in comparison to G3. Testis volume was significantly higher in G3. In the corresponding ICSI cycles, the percentage of cancelled embryo transfers was highest in G3. We did not find any correlations of hormonal markers or sperm pre-values with the success rates of ICSI. In our patient cohort, spermatozoa retrieved either from ejaculate or testicular biopsies have nearly identical chances in achieving pregnancies. Patients in need of TESE before ICSI have significantly lower sperm counts. However, it is not possible to calculate threshold values as indicator for TESE.

Intracyplasmic Sperm Injection in Patients with Past History of Failed or Poor Fertilization in Previous IVF - ET Cycles : Comparison with Patients with Severe Male Factor / 대한산부인과학회잡지

OBJECTIVE: The purpose of this study was to determine whether intracytoplasmic sperm injection(ICSI) could overcome the defects of oocytes in IVF-ET patients with previous fertilization failure by conventional fertilization technique. Design: Retrospective study Materials and METHODS: A total of 119 ICSI cycles in 57 IVF-ET patients performed from May, 1995 to December, 1997 was enrolled. Subjects were divided into two groups: FR group included 66 ICSI cycles in 35 patients with normal sperm who underwent ICSI due to past history of failed or poor fertilization in the previous IVF-ET cycles, and OAT group included 53 ICSI cycles in 22 patients with severe oligoasthenoterato- zoospermia(OAT) which was defined as sperm concentration < 20 million/ml, mo#dlity < 30% and normal morphology < 4% by strict morphologic criteria. The outcomes of ICSI were analyzed and compared in both groups. RESULTS: The age of female patients, basal serum FSH level, and the numbers of oocytes retrieved and metaphase II oocytes were all comparable in both groups. The fertilization rate after ICSI was similar in both groups(68.7+/-25.3% vs. 67.7+/-24.5%), as were the cleavage rate of normally fertilized oocytes(93.1+/-21.4% vs. 89.3+/-21.6%), the number of embryos transferred(4,00+/-1.98 vs. 4.64+/-2.10), and cumulative embryo score(CES) indicating the quality of embryos(47.3+/-33.2 vs. 54.1+/-33.2). The implantation rate(4.3+/-10.5% vs. 3.8+/-11.0%) and the clinical pregnancy rate per cycle(15.2% vs. 13.2%) were also comparable in both groups. CONCLUSIONS: Although it has been shown that there is a higher risk of chromosomal abnormalities in oocytes from IVF-ET patients with pevious failed or poor fertilization, higher implantation and clinical pregnancy rates wer#e not observed in patients with OAT following ICSL Therefore, the functional defect of sperm such as loss of capacitation, defect of aaasome reaction, and abnormality of nucleus decondensation should be also considered in patients with previous failed or poor fertilization.