Seasonal variation in semen quality in China.

In this study, we assessed the effect of seasonal variation on the semen quality in Chinese by using the average highest temperature (AHT) of the ejaculation day for partitioning season periods. A total of 13 635 semen samples were collected and analysed according to the AHT of the ejaculation day. Semen volume, sperm concentration and the percentage of spermatozoa with normal morphology in midsummer (AHT > 30 °C) were significantly lower than those in other periods of the year. Sperm motility with AHT 10-20 °C in winter and spring was significantly higher than that in other seasons. The percentage of head defects spermatozoa with AHT < 10 °C in winter was significantly lower than that in other periods. We observed that there was a significant effect of season on the semen parameters. Highest environment temperature of the day may be a determining factor for the seasonal variations in semen quality.

[A comparative study of sperm morphology evaluation criteria by the fifth and fourth editions of WHO Laboratory Manual].

OBJECTIVE: To compare the criteria of sperm morphology evaluation in the fifth edition of WHO Laboratory Manual for the Examination and Processing of Human Semen and those in the fourth edition, and to know the changes in the criteria of sperm morphology evaluation in the new edition. METHODS: Nine technicians from Zhejiang Human Sperm Bank evaluated the morphology of 1 000 spermatozoa in 96 sperm morphological pictures according to the criteria in the fourth and fifth editions of WHO Laboratory Manual, respectively. RESULTS: The percentage of morphologically normal sperm by the criteria of the fifth edition was (26.50 +/- 5.06)%, significantly higher than (11.39 +/- 3.17)% by the fourth edition (P < 0.05), while the rates of sperm head and tail defects based on the former were (64.26 +/- 7.66)% and (10.92 +/- 2.03)%, significantly lower than (76.11 +/- 8.18)% and (39.89 +/- 3.85)% according to the latter (P < 0.05). There were no significant differences in the rates of sperm midpiece defects and excessive residual cytoplasm by the fifth and fourth editions ([16.46 +/- 3.08]% vs [15.22 +/- 3.51 ]% and [4.24 +/- 1.66]% vs [3.87 +/- 1.68]%, P > 0.05). CONCLUSION: The criteria of sperm morphology evaluation in the fifth edition of WHO Laboratory Manual are less strict than those in the fourth, and the percentage of morphologically normal sperm is higher according to the fifth edition.

[A combined method for weighing human semen volume].

OBJECTIVE: To search for a method for the precise measurement of human semen volume so as to provide reliable evidence for clinical semen analysis. METHODS: The volumes of 492 semen samples collected from 137 donors by Zhejiang Human Sperm Bank were measured respectively by three different methods including electronic balance weighing, volumetric cylinder measuring, and combination of the two methods above. With the combined measuring method, the semen weight was first obtained by electronic balance weighing, then the semen density determined by volumetric cylinder measuring, and lastly the semen volume figured out by a formula. Paired sample t-test was used to compared the combined method with electronic balance weighing and volumetric cylinder measuring. RESULTS: The mean volume of the 492 semen samples obtained by the combined measuring method was (3.46 +/- 1.17) ml, significantly lower than (3.75 +/- 1.21) ml from electronic balance weighing (P < 0.05) and markedly higher than (3.22 +/- 1.16) ml from volumetric cylinder measuring (P < 0.05). The mean semen density of the 492 samples was (1.0928 +/- 0.0761) g/ml, and the mean weight of the residual semen in the container used in volumetric cylinder measuring was (0.269 +/- 0.122) g. CONCLUSION: Semen volume measured by electronic balance weighing is higher while that obtained from volumetric cylinder measuring is lower than the actual value. An accurate semen volume can be achieved by the combined measuring method, which, therefore, deserves to be widely used both clinically and in researches.

[Impact of seasonal variation on pre- and post-thaw donor semen parameters].

OBJECTIVE: To investigate the relationship of seasonal variation with pre- and post-thaw semen parameters as well as the cryosurgical of human spermatozoa. METHODS: A total of 6 414 semen samples were collected from 1 135 donors aged 22 - 32 years by Zhejiang Human Sperm Bank, and divided into spring, summer, autumn and winter groups according to the time of collection. All the samples underwent routine seminal analysis, and the sperm parameters were compared between different seasons. The sperm specimens were cryopreserved in aliquots and analyzed after thawing. RESULTS: The semen volume was (2.92 +/- 1.17) ml in spring, significantly higher than in summer, autumn and winter ([2.71 +/- 1.07 ], [2.74 +/- 1.15] and [2.83 +/- 1.15] ml, P < 0.05). Sperm density was the highest in autumn ([105.60 +/- 39.76] x 10(6)/ml) as compared with the other three seasons ([101.18 +/- 40.16] x 10(6)/ml, [93.54 +/- 35.10] x 10(6)/ml, and [101.29 +/- 38.37] x 10(6)/ml, P < 0.05). The sperm progressive motility was the highest in spring ([58.49 +/- 10.04] %) and the cryosurgical of sperm the lowest in summer, with statistically significant differences from the other groups (P < 0.05). CONCLUSION: Seasonal variations affect human semen quality and cryosurgical of sperm. The semen volume, the percentage of progressive motile sperm, the cryosurgical of sperm, and the post-thaw density of progressive motile sperm are higher in spring than during the rest of the year.

Sperm banking for male reproductive preservation: a 6-year retrospective multi-centre study in China.

Sperm banking can preserve male fertility effectively, but the current conditions of sperm cryopreservation in China have not been investigated. This retrospective investigation was based on data collected at multiple centres in China from January 2003 to December 2008. The collected data included urogenital history, indication for cryopreservation, semen parameters, use rate, type of assisted reproductive technique (ART) treatment and pregnancy outcome. The study population included 1 548 males who had banked their semen during the study period at one of the clinics indicated above. Approximately 1.9% (30/1 548) of the cryopreserved semen samples were collected from cancer patients; about 88.8% (1 374/1 548) of the patients had banked their semen for ART and 8.6% (134/1 548) had a male infertility disease (such as anejaculation, severe oligozoospermia and obstructive azoospermia). The total use rate of cryopreserved semen was 22.7% (352/1 548), with 119 live births. The cancer group use rate was 6.7% (2/30), with one live birth by intracytoplasmic single sperm injection (ICSI). The ART group use rate was 23.2% (319/1 374), with 106 live births. The reproductive disease group use rate was 23.1% (31/134), with 12 live births. The semen parameters in each category varied; the cancer patient and infertility disease groups had poor semen quality. In vitro fertilization (IVF) and ICSI were the most common ART treatments for cryopreserved sperm. Semen cryopreservation as a salvage method is effective, but in many conditions it is underutilized, especially in cancer patients. Lack of awareness, urgency of cancer treatment and financial constraints are the main causes of the low access rate. The concept of fertility preservation should be popularized to make better use of this medical service in China.

[Risk of cross-contamination and its prevention in human sperm cryobanking].

Despite the worldwide application of sperm-freezing technology as a means of preserving male fertility functions, few reports are seen about the transmission of microorganisms to cryopreserved sperm via contaminated liquid nitrogen (LN). Although the risk of cross-contamination between samples stored in liquid nitrogen is "vanishingly small", it must be accepted as a finite risk and all reasonable measures taken to reduce the likelihood of its occurrence. Moreover, all methods employed, including collection, cryopreservation, storage and thawing of human sperm as well as the clinical use of cryobanked human sperm, must reduce the risk of contamination from any source throughout the entire process.

Obesity and benign prostatic enlargement: a large observational study in China.

OBJECTIVES: To investigate the associations of prostate enlargement with obesity and hypertension in Chinese men. METHODS: A total of 649 men from Zhejiang, China were invited to the Family Planning Station of Wenlin to undergo prostate volume measurement with transrectal ultrasonography. Benign prostatic enlargement (BPE) has been defined as a prostate volume larger than 20 cm3. The associations between BPE and prostate volume with body mass index (BMI) and blood pressure were evaluated by multivariate linear and logistic regression analyses. RESULTS: Overweight (BMI of 25 or more but less than 28 kg/m2) and obese (BMI of 28 kg/m2 or more) men experienced a significantly increased age-adjusted risk of BPE compared with men with a lower BMI (odds ratio 1.63, 95% confidence interval 1.16 to 2.30, and odds ratio 2.26, 95% confidence interval 1.11 to 4.59, respectively). Each 0.37-kg/m2 increase (95% confidence interval 0.18 to 0.57, P <0.01) in the BMI was associated with a 1-cm3 increase in prostate volume. No associations were observed between hypertension and BPE. CONCLUSIONS: This is the first study to provide evidence that the BMI is positively associated with prostate volume in the Chinese population. Obese Chinese men are at increased risk of an enlarged prostate compared with nonobese Chinese men.

[Epidemiological study on semen quality of 562 volunteers aged 22-30].

OBJECTIVE: This study is to understand the difference of semen quality among the different areas and the related factors. METHODS: Five hundred and sixty-two people were under from seven provinces. RESULTS: Results showed that the quantity and density of semen, the rate of moving forward semen, livability, percent age of normal formed semen and the total number of semen were statistically different among the seven areas. The difference was ranged as 28.82%, with the highest 2.95 ml in Shanxi province and the lowest 2.29 ml in Henan province. Geometric mean of semen density was found the lowest 36.27 x 10(6)/ml in Guizhou province, next to it was 42.52 x 10(6)/ml in Shandong province and the highest was 74.77 x 10(6)/ml in Hebei province. The percent age with forward progression of semen was seen the lowest 44.40% in Henan province, followed by 51.88% in Hebei province and 52.88% in Zhejiang province and the highest were 76.50% in Shanghai, 75.24% in Shanxi province, with a range of 72.30%. The highest semen viability was 85.89% in Shanghai, while the lowest 72.35% in Henan, with a range of 18.71%. Normal sperm morphology was seen the lowest 68.45% in Hebei province, with the highest 88.06% in Guizhou province, and the range was 28.65%. The geometric mean of total sperm count was seen the highest 204.23 x 10(6)/ml in Hebei province and the lowest 77.69 x 10(6)/ml in Guizhou province. Results showed through analysis of variance that some indexes were different in some provinces. CONCLUSION: The results indicated that the semen quality was different in different regions in China and its influential factors may be region and geography environment.