Non-obstructive azoospermia (NOA) is defined as no sperm in the ejaculate due to failure of spermatogenesis and is the most severe form of male infertility. The etiology of NOA is either intrinsic testicular impairment or inadequate gonadotropin production. Chromosomal or genetic abnormalities should be evaluated because there is a relatively high incidence compared with the normal population. Although rare, NOA due to inadequate gonadotropin production is a condition in which fertility can be improved by medical treatment. In contrast, there is no treatment that can restore spermatogenesis in the majority of NOA patients. Consequently, testicular extraction of sperm under an operating microscope (micro-TESE) has been the firstline treatment for these patients. Other treatment options include varicocelectomy for NOA patients with a palpable varicocele and orchidopexy if undescended testes are diagnosed after adulthood, although management of these patients remains controversial. Advances in retrieving spermatozoa more efficiently by micro-TESE have been made during the past decade. In addition, recent advances in biotechnology have raised the possibility of using germ cells produced from stem cells in the future. This review presents current knowledge about the etiology, diagnosis, and treatment of NOA.

Spermatozoa are significantly less likely to be successfully retrieved by micro-TESE in men with idiopathic azoospermia.

The objective of this study was to assess the impact of seminal clusterin level on spermatogenesis in infertile men. This study included 89 men who visited our clinic due to infertility, consisting of 28, 33, and 28 diagnosed with normospermia, oligozoospermia and nonobstructive azoospermia (NOA) respectively. The seminal clusterin concentrations measured by enzyme-linked immunosorbent assay were 47.9, 28.2 and 18.4 ng ml in men with normospermia, oligozoospermia and NOA, respectively, with significant differences among these three groups (P < 0.01). Microdissection testicular sperm extraction (MD-TESE) was performed in the 28 men with NOA, and spermatozoon was successfully retrieved from 9. There was a significant correlation between seminal clusterin level and testicular clusterin protein expression evaluated by immunohistochemical staining in these men with NOA (P = 0.026). Of several parameters available before MD-TESE, the univariate analysis identified serum follicle-stimulating hormone (FSH) level <10 IU ml and seminal clusterin level ≥18 ng ml as significant predictors of sperm retrieval, and of these, only serum FSH level <10 IU ml was shown to be independently associated with sperm retrieval in the multivariate analysis. Accordingly, it might be worthy to further evaluate the significance of seminal clusterin level as a biomarker for the assessment of spermatogenic status in infertile men.

Varicocelectomy may improve the sperm quality and fertility potential in men with severe oligozoospermia, particularly for those with relatively high sperm concentration.

PurposeTo evaluate the effectiveness of high‐dose progesterone supplementation for women who are undergoing a frozen‐thawed embryo transfer (FET).MethodsAmong the 2010 FET cycles that were included in the present study, 1188 were 1200 mg/d of vaginal progesterone, while 822 were 900 mg/d. The dose of progesterone that was used was decided by the treatment period and additional progesterone supplementation was used when the serum progesterone levels were <9 ng/mL on luteal day 5.ResultsThe clinical pregnancy rate was higher in the 1200 mg group than in the 900 mg group. The mean serum progesterone level on luteal day 5 in the 1200 mg and 900 mg groups was 12.6 ng/mL and 13.4 ng/mL, respectively. The rate of additional progesterone supplementation was higher in the 1200 mg group. A logistic regression analysis identified a younger age (≤37 years) and the use of 1200 mg progesterone as independent predictive factors for the clinical pregnancy outcome. The analysis of the infant outcomes revealed no significant difference in the distribution of birth ages and weights.ConclusionHigh‐dose transvaginal progesterone of 1200 mg/d as luteal support contributed to good pregnancy outcomes.