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N. Nomal

Bio: N. Nomal is an academic researcher. The author has contributed to research in topics: Sperm motility & Semen quality. The author has an hindex of 1, co-authored 1 publications receiving 156 citations.
Topics: Sperm motility, Semen quality, Vitality, Sperm

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TL;DR: 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.
Abstract: 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.

177 citations


Cited by
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Journal ArticleDOI
TL;DR: DFI can be used as an independent predictor of fertility in couples undergoing IUI and all infertile men should be tested with SCSA as a supplement to the standard semen analysis, when DFI exceeds 30%, ICSI should be the method of choice.
Abstract: BACKGROUND: The sperm chromatin structure assay (SCSA) has been suggested as a predictor of fertility in vivo as well as in vitro. The available data however, have been based on limited numbers of treatments. We aimed to define the clinical role of SCSA in assisted reproduction. METHODS: A total of 998 cycles [387 intrauterine insemination (IUI), 388 IVF and 223 ICSI] from 637 couples were included. SCSA results were expressed as DNA fragmentation index (DFI) and high DNA stainable (HDS) cell fractions. Outcome parameters were biochemical pregnancy (BP), clinical pregnancy (CP) and delivery (D). RESULTS: For IUI, the odds ratios (ORs) for BP, CP and D were significantly lower for couples with DFI >30% as compared with those with DFI £30%. No statistical difference between the outcomes of ICSI versus IVF in the group with DFI £30% was seen. In the DFI >30% group, the results of ICSI were significantly better than those of IVF. CONCLUSIONS: DFI can be used as an independent predictor of fertility in couples undergoing IUI. As a result, we propose that all infertile men should be tested with SCSA as a supplement to the standard semen analysis. When DFI exceeds 30%, ICSI should be the method of choice.

615 citations

Journal ArticleDOI
TL;DR: Overweight and obesity were associated with an increased prevalence of azoospermia or oligozoospermia, and whether weight normalization could improve sperm parameters should be evaluated further.
Abstract: BACKGROUND The global obesity epidemic has paralleled a decrease in semen quality. Yet, the association between obesity and sperm parameters remains controversial. The purpose of this report was to update the evidence on the association between BMI and sperm count through a systematic review with meta-analysis. METHODS A systematic review of available literature (with no language restriction) was performed to investigate the impact of BMI on sperm count. Relevant studies published until June 2012 were identified from a Pubmed and EMBASE search. We also included unpublished data (n = 717 men) obtained from the Infertility Center of Bondy, France. Abstracts of relevant articles were examined and studies that could be included in this review were retrieved. Authors of relevant studies for the meta-analysis were contacted by email and asked to provide standardized data. RESULTS A total of 21 studies were included in the meta-analysis, resulting in a sample of 13 077 men from the general population and attending fertility clinics. Data were stratified according to the total sperm count as normozoospermia, oligozoospermia and azoospermia. Standardized weighted mean differences in sperm concentration did not differ significantly across BMI categories. There was a J-shaped relationship between BMI categories and risk of oligozoospermia or azoospermia. Compared with men of normal weight, the odds ratio (95% confidence interval) for oligozoospermia or azoospermia was 1.15 (0.93-1.43) for underweight, 1.11 (1.01-1.21) for overweight, 1.28 (1.06-1.55) for obese and 2.04 (1.59-2.62) for morbidly obese men. CONCLUSIONS Overweight and obesity were associated with an increased prevalence of azoospermia or oligozoospermia. The main limitation of this report is that studied populations varied, with men recruited from both the general population and infertile couples. Whether weight normalization could improve sperm parameters should be evaluated further.

476 citations

Journal ArticleDOI
TL;DR: Findings corroborate earlier findings that overweight and obese men have a markedly changed sex hormone profile in serum, whereas reduction of semen quality, if any, was marginal and below the detection limit of this large study.

255 citations

Journal ArticleDOI
TL;DR: It would be sensible to advise men to abstain from smoking to avoid decreased fecundity, and a positive dose-response relationship between smoking and testosterone, LH and the LH/free testosterone ratios is found.
Abstract: BACKGROUND: Previous studies suggest a deleterious effect of cigarette smoking on semen quality, but their results have not been consistent. We studied the association between current smoking and semen characteristics and hormonal levels in a large group of healthy men. METHODS: From 1987 to 2004, seven separate occupational or environmental semen quality studies were co-ordinated by our department. A total of 2562 men participated, each providing semen and blood sample and answering a questionnaire about lifestyle and factors related to health. Appropriate semen and smoking data were available for 2542 men. RESULTS: Adjusting for study, age and other covariates, we observed an inverse dose–response relation between smoking and semen volume, total sperm count and percentage motile sperm. Heavy smokers had a 19% lower sperm concentration than non-smokers. We found a positive dose–response relationship between smoking and testosterone, LH and the LH/free testosterone ratios. CONCLUSION: Current smoking in adult life moderately impairs the semen quality. It is well known that semen quality is associated to fecundity. Therefore, it would be sensible to advise men to abstain from smoking to avoid decreased fecundity.

253 citations

Journal ArticleDOI
TL;DR: The authors' RCT provided level 1b evidence of the superiority of varicocelectomy over observation in infertile men with palpable varicoCEles and impaired semen quality, with increased odds of spontaneous pregnancy and improvements in semen characteristics within 1-yr of follow-up.

204 citations