The aim of the present study was to assess variability in the evaluation of human sperm concentration, motility and vitality. Technicians and biologists from 10 teams involved in multicentre studies on semen quality attended the same laboratory, each team using its own methods and equipment to analyse the same semen samples. Inter-individual variability was assessed from 17 fresh semen samples of varying quality. Intra-individual variability was assessed from pools of frozen samples for sperm concentration and motility and stained smears for vitality with three blind evaluations by sample and smear. The mean inter-individual coefficients of variation were 22.9, 21.8 and 17.5% for sperm concentration, motility and vitality respectively. There was no statistical difference among participants for sperm concentration assessment, but significant differences for both motility and vitality (both P: < 0.05). The mean intra-individual coefficients of variation were 15.8, 26.2 and 13.1% for sperm concentration, motility and vitality respectively, with marked differences between expert and novice participants: concentration 9.8% versus 28.0%; motility 22.8% versus 33.0%; and vitality 10.0% versus 19.3%. The present data confirm the need for external quality control schemes for diagnostic purposes, and indicate their utmost importance in multicentre studies on semen quality.

In this study we sought to evaluate whether psychological factors in males affect semen quality and pregnancy. In 1076 men of infertile couples, psychological factors, i.e. exposure to acute stress, coping with stress, the WHO (five) Well-Being Index and the Zung's Anxiety Scale Inventory scores were assessed by a questionnaire at the time of semen analysis. Relationships between psychological factors and semen quality (sperm concentration, rapid and progressive motility and normal morphology) were assessed. In 353 men with infertility duration of < or =1.5 years, sperm concentration > or =5 x 10(6) sperm/mL and a female partner with a laparoscopically confirmed tubal patency, we looked prospectively for relations between psychological factors and the occurrence of a natural pregnancy at a 6-month follow-up (n = 124), and first-trimester loss (n = 18). Anxiety trait, found in 19% of men, was related to previous in vitro fertilization/intracytoplasmic sperm injection attempts (p = 0.014), cigarette intake (p = 0.006), alcohol intake (p = 0.026) and sexual difficulties (p < 0.001). Regression analyses indicated a significant positive relationship between the level of sperm concentration and the WHO (five) Well-Being Index score, each successive score number accounting for a 7.3% increase in sperm concentration (p = 0.039), whereas no correlation was found between psychological factors and sperm rapid progressive motility and normal morphology. Poorer coping with stress was related to the occurrence of a first-trimester miscarriage (p = 0.016) in the female partner. Possible depression in males is related to decreased sperm concentration, and poor coping with stress is associated with increased occurrence of early miscarriage.

Sperm DNA fragmentation and MMP combined may be superior to standard semen parameters for the prediction of natural conception.

Purpose To investigate the relationship between sperm apoptotic biomarkers and patient clinical characteristics, conventional sperm parameters and fertility potential. Material and methods Sperm analysis, phospholipid asymmetry, mitochondrial membrane potential (MMP) and DNA denaturation were assessed in 142 males of infertile couples. Seventy-three couples were allocated to the natural conception group, and 55 couples underwent IVF or ICSI. Results DNA denaturation correlated positively with age and negatively with testicular volume (TV). MMP correlated negatively with BMI and FSH and positively with TV. Normal viable sperm correlated positively with TV and negatively with age, BMI and FSH. DNA denaturation was associated with a significantly lower natural pregnancy rate (OR 5.4, p00.011). Conclusion Sperm apoptosis is related to male age, BMI, testicular volume and FSH. Among the apoptotic markers, only DNA denaturation has been found to predict natural pregnancy better than conventional sperm parameters.

To elucidate the effects of inflammation on sperm quality, this study analysed classical sperm characteristics, leukocytes and elastase in neat semen, and sperm apoptotic markers, i.e. changes in plasma membrane phospholipid asymmetry, mitochondrial membrane potential (MMP), DNA integrity and intracellular reactive oxygen species (ROS), in semen prepared by density gradient using flow cytometry from 348 men of infertile couples. Increased leukocytes (> or = 0.1 x 10(6)/ml) were associated with a decreased sperm concentration, motility and normal morphology (P < or = 0.001). Sperm necrosis and DNA denaturation were increased (31.3 versus 26.6%, P=0.020; 15.5 versus 11.5%, P = 0.011, respectively), whereas spermatozoa with normal MMP were decreased (64.1 versus 70.0%, P=0.004). High leukocyte levels ((> or = 1 x 10(6)/ml) were not associated with any of the observed sperm parameters. At low elastase concentration (100-290 microg/l), DNA denaturation was higher (16.1 versus 10.5%, P = 0.024) compared with very low elastase concentration (< 100 microg/l). A high elastase concentration (290-1000 microg/l) was associated with higher ROS index compared with low elastase concentration (1.28 versus 1.01, P=0.016). Slightly increased leukocytes and elastase are associated with slightly poorer sperm characteristics and/or increased sperm necrosis, DNA denaturation and intracellular ROS and decreased MMP.