[Show abstract][Hide abstract] ABSTRACT: Establishing reference norms for semen parameters in fertile men is important for accurate assessment, counselling and treatment of men with male factor infertility. Identifying temporal or geographic variability in semen quality also requires accurate measurement of semen parameters in well-characterized, defined populations of men. The Study for Future Families (SFF) recruited men who were partners of pregnant women attending prenatal clinics in Los Angeles CA, Minneapolis MN, Columbia MO, New York City NY and Iowa City IA. Semen samples were collected on site from 763 men (73% White, 15% Hispanic/Latino, 7% Black and 5% Asian or other ethnic group) using strict quality control and well-defined protocols. Semen volume (by weight), sperm concentration (hemacytometer) and sperm motility were measured at each centre. Sperm morphology (both WHO, 1999 strict and WHO, 1987) was determined at a central laboratory. Mean abstinence was 3.2 days. Mean (median; 5th-95th percentile) values were: semen volume, 3.9 (3.7; 1.5-6.8) mL; sperm concentration, 60 (67; 12-192) × 10(6) /mL; total sperm count 209 (240; 32-763) × 10(6) ; % motile, 51 (52; 28-67) %; and total motile sperm count, 104 (128; 14-395) × 10(6) respectively. Values for sperm morphology were 11 (10; 3-20) % and 57 (59; 38-72) % normal forms for WHO (1999) (strict) and WHO (1987) criteria respectively. Black men had significantly lower semen volume, sperm concentration and total motile sperm counts than White and Hispanic/Latino men. Semen parameters were marginally higher in men who achieved pregnancy more quickly but differences were small and not statistically significant. The SFF provides robust estimates of semen parameters in fertile men living in five different geographic locations in the US. Fertile men display wide variation in all of the semen parameters traditionally used to assess fertility potential.
[Show abstract][Hide abstract] ABSTRACT: Fetal exposure to caffeine is associated with adverse pregnancy outcomes. Animal and human studies suggest that caffeine may have effects on the developing reproductive system. Here we report on mothers’ smoking, coffee and alcohol use, recorded during pregnancy, and semen quality in sons in the age group of 38–47 years. Subjects were a subset of the Child Health and Development Studies, a pregnancy cohort enrolled between 1959 and 1967 in the Kaiser Foundation Health Plan near Oakland, California. In 2005, adult sons participated in a follow-up study (n = 338) and semen samples were donated by 196 participants. Samples were analyzed for sperm concentration, motility and morphology according to the National Cooperative Reproductive Medicine Network (Fertile Male Study) Protocol. Mean sperm concentration was reduced by approximately 16 million sperms for sons with high prenatal exposure (5 cups of maternal coffee use per day) compared with unexposed sons (P-value for decreasing trend = 0.09), which translates to a proportionate reduction of 25%. Mean percent motile sperm decreased by approximately 7 points (P-value = 0.04), a proportionate decline of 13%, and mean percent sperm with normal morphology decreased by approximately 2 points (P-value = 0.01), a proportionate decline of 25%. Maternal cigarette and alcohol use were not associated with son's semen quality. Adjusting for son's contemporary coffee, alcohol and cigarette use did not explain the maternal associations. Findings for son's coffee intake and father's prenatal coffee, cigarette and alcohol use were non-significant and inconclusive. These results contribute to the evidence that maternal coffee use during pregnancy may impair the reproductive development of the male fetus.
[Show abstract][Hide abstract] ABSTRACT: To describe associations between serum inhibin-b and sperm counts, adjusted for effect of time of blood sampling, in larger cohorts than have been previously reported.
Cross-sectional studies of spermatogenesis markers.
Four European and four US centers.
Fertile men (1,797) were included and examined from October 1996-February 2005.
The study was observational and therefore without any intervention.
Associations between inhibin-b and semen variables controlled for time of blood sampling and other covariates.
Inhibin-b decreased about 2.00% per hour from 8 am-12 pm and then about 3.25% per hour from 12 pm-4 pm. There was a strong positive association between inhibin-b levels less than 150 pg/mL and both sperm concentration and total sperm count (slopes of the regression lines were β=0.011 and β=0.013 for natural logarithm-transformed sperm concentration and total sperm count, respectively). For inhibin-b levels of 150-300 pg/mL the associations were not as steep (β=0.002), but still significant. For inhibin-b levels more than 300 pg/mL there was little association to the sperm counts. Neither sperm motility nor morphology was significantly related to inhibin-b level in any group.
Serum inhibin-b levels decrease nonlinearly during the daytime, and are positively correlated with sperm counts, but the predictive power is best when inhibin-b is low.
Full-text · Article · Feb 2010 · Fertility and sterility
[Show abstract][Hide abstract] ABSTRACT: Accurate semen analysis is critical for decisions about patient care, as well as for studies addressing overall changes in semen quality, contraceptive efficacy and effects of toxicant exposure. The standardization of semen analysis is very difficult for many reasons, including the use of subjective techniques with no standards for comparison, poor technician training, problems with proficiency testing and a reluctance to change techniques. The World Health Organization (WHO) Semen handbook (2010) offers a vastly improved set of standardized procedures, all at a level of detail that will preclude most misinterpretations. However, there is a limit to what can be learned from words and pictures alone. A WHO-produced DVD that offers complete demonstrations of each technique along with quality assurance standards for motility, morphology and concentration assessments would enhance the effectiveness of the manual. However, neither the manual nor a DVD will help unless there is general acknowledgement of the critical need to standardize techniques and rigorously pursue quality control to ensure that laboratories actually perform techniques 'according to WHO' instead of merely reporting that they have done so. Unless improvements are made, patient results will continue to be compromised and comparison between studies and laboratories will have limited merit.
Preview · Article · Jan 2010 · Asian Journal of Andrology
[Show abstract][Hide abstract] ABSTRACT: To examine the association between stressful life events and semen parameters.
Cross-sectional analysis in a pregnancy cohort study.
Prenatal clinics in five U.S. cities.
Fertile men (n = 744) in the Study for Future Families, a cohort study of pregnant women and their partners.
Sperm concentration, percent motile, and percent normal morphology and classification above/below World Health Organization (WHO) cutoffs for semen quality.
After adjusting for confounders, men reporting 2+ recent stressful life events had an increased risk of being classified below WHO thresholds for "normal" defined by concentration, motility, and morphology criteria compared with men reporting <2 stressful life events (odds ratio [OR] = 2.06; 95% confidence interval [CI], 1.18, 3.61; OR = 1.54; 95% CI, 1.04, 2.29; OR = 1.93; 95% CI, 1.02, 3.66 for concentration, motility and morphology, respectively). Men experiencing 2+ stressful life events had lower sperm concentration (log scale, beta = -0.25; 95% CI, -0.38, -0.11) and lower percent motile sperm (beta = -1.95; 95% CI, -3.98, 0.07), but percent normal morphology was less affected.
These results suggest that stressful life events may be associated with decreased semen quality in fertile men. The experience of psychosocial stress may be a modifiable factor in the development of idiopathic infertility.
Full-text · Article · Feb 2009 · Fertility and sterility
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND To look at possible long-term risks from anabolic steroids and other xenobiotics in beef, we examined men's semen quality in relation to their mother's self-reported beef consumption during pregnancy. METHODS: The study was carried out in five US cities between 1999 and 2005. We used regression analyses to examine semen parameters in 387 partners of pregnant women in relation to the amount of beef their mothers reported eating while pregnant. Mothers' beef consumption was also analysed in relation to the son's history of previous subfertility. RESULTS Sperm concentration was inversely related to mothers' beef meals per week (P = 0.041). In sons of "high beef consumers" (>7 beef meals/week), sperm concentration was 24.3% lower (P = 0.014) and the proportion of men with sperm concentration below 20 x 10(6)/ml was three times higher (17.7 versus 5.7%, P = 0.002) than in men whose mothers ate less beef. A history of previous subfertility was also more frequent among sons of "high beef consumers" (P = 0.015). Sperm concentration was not significantly related to mother's consumption of other meat or to the man's consumption of any meat. CONCLUSIONS These data suggest that maternal beef consumption, and possibly xenobiotics in beef, may alter a man's testicular development in utero and adversely affect his reproductive capacity.
Full-text · Article · Jun 2007 · Human Reproduction
[Show abstract][Hide abstract] ABSTRACT: Rigorously standardized laboratory protocols and strict quality control (QC) are essential for meaningful comparisons between semen quality data from multiple sites. We describe our experience with the Study for Future Families (SFF), a multicenter study of semen quality in the United States. Detailed protocols were developed, and technicians from each study site attended a training session at the central laboratory. Technicians received blinded replicates from diluted semen specimens for counting by MicroCell and hemacytometer. Sperm motility was assessed using videotaped recordings for simple percent motility and categorical assessment of individual sperm progression as recommended by the World Health Organization (WHO). The mean intertechnician coefficient of variation for individual specimens was 12.6% for MicroCell counts, 15.2% for hemacytometer counts, and 10.5% for percent motility. Intratechnician coefficients of variation averaged 10.3% for MicroCell counts, 12.5% for hemacytometer counts, and 5.2% for percent motility. The average percent differences between the technicians' values and the central standard for individual specimens were 13.5%, 16.6%, and 11.9% for MicroCell counts, hemacytometer counts, and simple percent motility, respectively. We achieved our goal of maintaining mean intratechnician coefficients of variation and mean percent differences from the standard values of 15% or less for measurements of simple percent motility and sperm concentration by MicroCell. Standardization using the Improved Neubauer hemacytometer chamber proved more difficult. We were not successful in standardizing a method for categorical assessment of individual sperm progression.
Full-text · Article · Jul 2004 · Journal of Andrology
[Show abstract][Hide abstract] ABSTRACT: We previously reported reduced sperm concentration and motility in fertile men in a U.S. agrarian area (Columbia, MO) relative to men from U.S. urban centers (Minneapolis, MN; Los Angeles, CA; New York, NY). In the present study we address the hypothesis that pesticides currently used in agriculture in the Midwest contributed to these differences in semen quality. We selected men in whom all semen parameters (concentration, percentage sperm with normal morphology, and percentage motile sperm) were low (cases) and men in whom all semen parameters were within normal limits (controls) within Missouri and Minnesota (sample sizes of 50 and 36, respectively) and measured metabolites of eight current-use pesticides in urine samples provided at the time of semen collection. All pesticide analyses were conducted blind with respect to center and case-control status. Pesticide metabolite levels were elevated in Missouri cases, compared with controls, for the herbicides alachlor and atrazine and for the insecticide diazinon [2-isopropoxy-4-methyl-pyrimidinol (IMPY)]; for Wilcoxon rank test, p = 0.0007, 0.012, and 0.0004 for alachlor, atrazine, and IMPY, respectively. Men from Missouri with high levels of alachlor or IMPY were significantly more likely to be cases than were men with low levels [odds ratios (ORs) = 30.0 and 16.7 for alachlor and IMPY, respectively], as were men with atrazine levels higher than the limit of detection (OR = 11.3). The herbicides 2,4-D (2,4-dichlorophenoxyacetic acid) and metolachlor were also associated with poor semen quality in some analyses, whereas acetochlor levels were lower in cases than in controls (p = 0.04). No significant associations were seen for any pesticides within Minnesota, where levels of agricultural pesticides were low, or for the insect repellent DEET (N,N-diethyl-m-toluamide) or the malathion metabolite malathion dicarboxylic acid. These associations between current-use pesticides and reduced semen quality suggest that agricultural chemicals may have contributed to the reduction in semen quality in fertile men from mid-Missouri we reported previously.
Full-text · Article · Oct 2003 · Environmental Health Perspectives
[Show abstract][Hide abstract] ABSTRACT: Semen evaluation methodology is complex and difficult to standardize. Rigorously standardized laboratory protocols and strict quality control (QC) are essential for meaningful comparison of data from multiple sites. We describe the methods used for determination of semen volume, sperm concentration, and percent sperm motility in the Study for Future Families, a multicenter study of semen quality in the United States. Each of these 3 semen parameters was assessed using 2 techniques, which provided the opportunity to compare precision and assess suitability for multicenter studies. Detailed protocols were used, and technicians were centrally trained. A total of 509 semen evaluations were performed. Semen volume measured by weight was greater (P <.0001) than that determined by pipetting (3.7 +/- 1.6 mL vs 3.2 +/- 1.6 mL). Sperm concentration determined using hemacytometer chambers was consistently higher (P <.001) than that using disposable MicroCell chambers (81.0 x 10(6)/mL vs 65.9 x 10(6)/mL). Precision was slightly greater for the MicroCell chamber. The percentage of motile sperm was assessed by a simple counting technique as well as by the World Health Organization categorical method that assigns individual motile sperm to "a," "b," and "c" categories on the basis of progression. When these 3 categories were collapsed, the methods provided values that were not statistically different (P >.05), although the collapsed values tended to be higher (58.1% vs 51.6%) and less precise (CV 7.7% vs 4.1%) for the categorical method than for motility determined using the simple method. The data obtained in this study demonstrate the critical need for rigorous standardization of protocols and techniques for multicenter studies.
Full-text · Article · Sep 2003 · Journal of Andrology
[Show abstract][Hide abstract] ABSTRACT: Although geographic variation in semen quality has been reported, this is the first study in the United States to compare semen quality among study centers using standardized methods and strict quality control. We evaluated semen specimens from partners of 512 pregnant women recruited through prenatal clinics in four U.S. cities during 1999-2001; 91% of men provided two specimens. Sperm concentration, semen volume, and motility were determined at the centers, and morphology was assessed at a central laboratory. Study protocols were identical across centers, and quality control was rigorously maintained. Sperm concentration was significantly lower in Columbia, Missouri, than in New York, New York; Minneapolis, Minnesota; and Los Angeles, California. Mean counts were 58.7, 102.9, 98.6, and 80.8 X 10(6)/mL (medians 53.5, 88.5, 81.8, and 64.8 X 10(6)/mL) in Missouri, New York, Minnesota, and California, respectively. The total number of motile sperm was also lower in Missouri than in other centers: 113, 196, 201, and 162 X 10(6) in Missouri, New York, Minnesota, and California, respectively. Semen volume and the percent morphologically normal sperm did not differ appreciably among centers. These between-center differences remained significant in multivariate models that controlled for abstinence time, semen analysis time, age, race, smoking, history of sexually transmitted disease, and recent fever (all p-values < 0.01). Confounding factors and differences in study methods are unlikely to account for the lower semen quality seen in this mid-Missouri population. These data suggest that sperm concentration and motility may be reduced in semirural and agricultural areas relative to more urban and less agriculturally exposed areas.
Full-text · Article · Apr 2003 · Environmental Health Perspectives
[Show abstract][Hide abstract] ABSTRACT: Although geographic variation in semen quality has been reported, this is the first study in the United States to compare semen quality among study centers using standardized methods and strict quality control. We evaluated semen specimens from partners of 512 pregnant women recruited through prenatal clinics in four U.S. cities during 1999-2001; 91% of men provided two specimens. Sperm concentration, semen volume, and motility were determined at the centers, and morphology was assessed at a central laboratory. Study protocols were identical across centers, and quality control was rigorously maintained. Sperm concentration was significantly lower in Columbia, Missouri, than in New York, New York; Minneapolis, Minnesota; and Los Angeles, California. Mean counts were 58.7, 102.9, 98.6, and 80.8 × 106/mL (medians 53.5, 88.5, 81.8, and 64.8 × 106/mL) in Missouri, New York, Minnesota, and California, respectively. The total number of motile sperm was also lower in Missouri than in other centers: 113, 196, 201, and 162 × 106 in Missouri, New York, Minnesota, and California, respectively. Semen volume and the percent morphologically normal sperm did not differ appreciably among centers. These between-center differences remained significant in multivariate models that controlled for abstinence time, semen analysis time, age, race, smoking, history of sexually transmitted disease, and recent fever (all p-values < 0.01). Confounding factors and differences in study methods are unlikely to account for the lower semen quality seen in this mid-Missouri population. These data suggest that sperm concentration and motility may be reduced in semirural and agricultural areas relative to more urban and less agriculturally exposed areas.
No preview · Article · Apr 2003 · Environmental Health Perspectives
[Show abstract][Hide abstract] ABSTRACT: Few empirical data exist on the characteristics of subjects who provide semen specimens in epidemiologic studies. The objective of this investigation was to determine participation rates and potential biases in a contemporary study of human semen quality. Subjects (n = 268) are a subset of the Child Health and Development Studies. Their mothers enrolled between 1960 and 1963 during pregnancy. Archived prenatal serum samples, prenatal and birth records, placental examinations, and follow-up for growth and development through adulthood are available. Sons were aged 36-39 years at the time of this study. Respondents to the initial mailing and nonrespondents, who were subsequently traced and recruited, differed in semen parameters, including sperm concentration (78.3 x 10(6)/ml for respondents vs. 37.2; p = 0.003) and the percentage of normal morphology according to the 1987 criteria of the World Health Organization (58.7% for respondents vs. 53.3%; p = 0.04). The authors conclude that researchers designing population-based studies of semen parameters should expect nonrepresentative samples. Adaptation of the design to anticipate and mitigate bias and to maximize efficiency can yield scientifically sound information. Recommendations for study designs are discussed.
No preview · Article · May 2002 · American Journal of Epidemiology
[Show abstract][Hide abstract] ABSTRACT: Although semen analysis is routinely used to evaluate the male partner in infertile couples, sperm measurements that discriminate between fertile and infertile men are not well defined.
We evaluated two semen specimens from each of the male partners in 765 infertile couples and 696 fertile couples at nine sites. The female partners in the infertile couples had normal results on fertility evaluation. The sperm concentration and motility were determined at the sites; semen smears were stained at the sites and shipped to a central laboratory for an assessment of morphologic features of sperm with the use of strict criteria. We used classification-and-regression-tree analysis to estimate threshold values for subfertility and fertility with respect to the sperm concentration, motility, and morphology. We also used an analysis of receiver-operating-characteristic curves to assess the relative value of these sperm measurements in discriminating between fertile and infertile men.
The subfertile ranges were a sperm concentration of less than 13.5 x 10(6) per milliliter, less than 32 percent of sperm with motility, and less than 9 percent with normal morphologic features. The fertile ranges were a concentration of more than 48.0 x 10(6) per milliliter, greater than 63 percent motility, and greater than 12 percent normal morphologic features. Values between these ranges indicated indeterminate fertility. There was extensive overlap between the fertile and the infertile men within both the subfertile and the fertile ranges for all three measurements. Although each of the sperm measurements helped to distinguish between fertile and infertile men, none was a powerful discriminator. The percentage of sperm with normal morphologic features had the greatest discriminatory power.
Threshold values for sperm concentration, motility, and morphology can be used to classify men as subfertile, of indeterminate fertility, or fertile. None of the measures, however, are diagnostic of infertility.
Full-text · Article · Dec 2001 · New England Journal of Medicine