Effect of incubating human sperm at room temperature on capacitation-related events

Citrate Promotes Nitric Oxide Production during Human Sperm Capacitation

Sperm capacitation is a complex process essential for the spermatozoon to recognize and fertilize the oocyte. For capacitation to occur, human spermatozoa require low levels of reactive oxygen species (ROS), increased protein tyrosine phosphorylation, and sufficient levels of energy metabolites such as citrate. Human spermatozoa are exposed to high concentrations of citrate from the seminal plasma, yet the role of citrate in sperm capacitation is largely unknown. We report that citrate can support capacitation in human spermatozoa incubated with no other energy metabolites in the capacitation medium. Reduced capacitation levels were observed in spermatozoa incubated with inhibitors of mitochondrial citrate transporter (CIC), cytosolic ATP-citrate lyase (ACLY), malic enzyme (ME), and nitric oxide synthase (NOS). The role of citrate metabolism in ROS production was further elucidated as citrate increased NO● production in capacitated spermatozoa, whereas inhibition of ACLY reduced NO● production. This research characterizes a novel metabolic pathway for citrate to produce NO● in the process of human sperm capacitation.

Lipidomics profiles of human spermatozoa: insights into capacitation and acrosome reaction using UPLC-MS-based approach

Introduction

Lipidomics elucidates the roles of lipids in both physiological and pathological processes, intersecting with many diseases and cellular functions. The maintenance of lipid homeostasis, essential for cell health, significantly influences the survival, maturation, and functionality of sperm during fertilization. While capacitation and the acrosome reaction, key processes before fertilization, involve substantial lipidomic alterations, a comprehensive understanding of the changes in human spermatozoa's lipidomic profiles during these processes remains unknown. This study aims to explicate global lipidomic changes during capacitation and the acrosome reaction in human sperm, employing an untargeted lipidomic strategy using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS).

Methods

Twelve semen specimens, exceeding the WHO reference values for semen parameters, were collected. After discontinuous density gradient separation, sperm concentration was adjusted to 2 x 106 cells/ml and divided into three groups: uncapacitated, capacitated, and acrosome-reacted. UPLC-MS analysis was performed after lipid extraction from these groups. Spectral peak alignment and statistical analysis, using unsupervised principal component analysis (PCA), bidirectional orthogonal partial least squares discriminant analysis (O2PLS-DA) analysis, and supervised partial least-squares-latent structure discriminate analysis (PLS-DA), were employed to identify the most discriminative lipids.

Results

The 1176 lipid peaks overlapped across the twelve individuals in the uncapacitated, capacitated, and acrosome-reacted groups: 1180 peaks between the uncapacitated and capacitated groups, 1184 peaks between the uncapacitated and acrosome-reacted groups, and 1178 peaks between the capacitated and acrosome-reacted groups. The count of overlapping peaks varied among individuals, ranging from 739 to 963 across sperm samples. Moreover, 137 lipids had VIP values > 1.0 and twenty-two lipids had VIP > 1.5, based on the O2PLS-DA model. Furthermore, the identified twelve lipids encompassed increases in PI 44:10, LPS 20:4, LPA 20:5, and LPE 20:4, and decreases in 16-phenyl-tetranor-PGE2, PC 40:6, PS 35:4, PA 29:1, 20-carboxy-LTB4, and 2-oxo-4-methylthio-butanoic acid.

Discussion

This study has been the first time to investigate the lipidomics profiles associated with acrosome reaction and capacitation in human sperm, utilizing UPLC-MS in conjunction with multivariate data analysis. These findings corroborate earlier discoveries on lipids during the acrosome reaction and unveil new metabolites. Furthermore, this research highlights the effective utility of UPLC-MS-based lipidomics for exploring diverse physiological states in sperm. This study offers novel insights into lipidomic changes associated with capacitation and the acrosome reaction in human sperm, which are closely related to male reproduction.

Live motile sperm sorting device for enhanced sperm-fertilization competency: comparative analysis with density-gradient centrifugation and microfluidic sperm sorting

PURPOSE

A live motile sperm sorting device (LensHooke® CA0) developed to prevent the deleterious effects of centrifugation was evaluated comparatively with conventional density-gradient centrifugation (DGC) and microfluidic-based device (Zymot) in sperm selection.

METHODS

Semen samples from 239 men were collected. CA0 under different incubation intervals (5, 10, 30, and 60 min) and temperatures (20, 25, and 37℃) was conducted. The sperm quality in CA0-, DGC-, and Zymot-processed samples was then comparatively evaluated. Semen parameters included concentration, motility, morphology, motion kinematics, DNA fragmentation index (DFI), and the rate of acrosome-reacted sperm (AR).

RESULTS

Total motility and motile sperm concentration increased in a time- and temperature-dependent manner and the total motility peaked for 30 min at 37℃. In paired analysis, CA0 showed significantly higher total motility (94.0%), progressive motility (90.8%), rapid progressive motility (83.6%), normal morphology (10.3%), and lower DFI (2.4%) and AR (4.7%) than the other two methods in normozoospermic samples (all p < 0.05). For non-normozoospermic samples, CA0 had significantly better results than the other two methods (total motility 89.2%, progressive motility 80.4%, rapid progressive motility 74.2%, normal morphology 8.5%, DFI 4.0%, and AR 4.0%; all p < 0.05).

CONCLUSION

CA0 yielded spermatozoa with enhanced sperm fertilization potentials; DFI was minimized in samples processed by CA0. CA0 was effective for both normal and abnormal semen samples due to its consistent selection efficiency.

A short versus a long time interval between semen collection and intrauterine insemination: a randomized controlled clinical trial

STUDY QUESTION

Does a short interval (i.e. ≤90 min), compared to a long interval (i.e. ≥180 min), between semen collection and intrauterine insemination (IUI) increase the cumulative chance of an ongoing pregnancy after six IUI cycles?

SUMMARY ANSWER

A long interval between semen collection and IUI resulted in a borderline significant improvement in cumulative ongoing pregnancies and a statistically significant shorter time to pregnancy.

WHAT IS KNOWN ALREADY

Retrospective studies assessing the effect of the time interval between semen collection and IUI on pregnancy outcomes have shown inconclusive results. Some studies have indicated a beneficial effect of a short interval between semen collection and IUI on IUI outcomes, while others have not found any differences. To date, no prospective trials have been published on this subject.

STUDY DESIGN, SIZE, DURATION

The study was performed as a non-blinded, single-center RCT with 297 couples undergoing IUI treatment in a natural or stimulated cycle. The study was conducted between February 2012 and December 2018.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Couples with unexplained or mild male subfertility and an indication for IUI were randomly assigned for up to six IUI cycles into either the control group (long interval, i.e. 180 min or more between semen collection and insemination) or the study group (short interval, i.e. insemination as soon as possible after semen processing and within 90 min of semen collection). The study was carried out in an academic hospital-based IVF center in the Netherlands. The primary endpoint of the study was ongoing pregnancy rate per couple, defined as a viable intrauterine pregnancy at 10 weeks after insemination.

MAIN RESULTS AND THE ROLE OF CHANCE

In the short interval group, 142 couples were analyzed versus 138 couples in the long interval group. In the intention-to-treat (ITT) analysis, the cumulative ongoing pregnancy rate was significantly higher in the long interval group (71/138; 51.4%) compared to that in the short interval group (56/142; 39.4%; relative risks 0.77; 95% CI 0.59-0.99; P = 0.044). The time to pregnancy was significantly shorter in the long interval group (log-rank test, P = 0.012). A Cox regression analysis showed similar results (adjusted hazard ratio 1.528, 95% CI 1.074-2.174, P = 0.019).

LIMITATIONS, REASONS FOR CAUTION

Limitations of our study are the non-blinded design, the long inclusion and follow-up period of nearly seven years and the large number of protocol violations, especially because they predominantly occurred in the short interval group. The non-significant results in the per-protocol (PP) analyses and the weaknesses of the study should be taken into account in the assessment of the borderline significance of the results in the ITT analyses.

WIDER IMPLICATIONS OF THE FINDINGS

Because it is not necessary to perform the IUI immediately after semen processing, there can be more time available to choose the optimum work-flow and clinic occupancy. Clinics and laboratories should find their optimal timing of insemination, considering the time between human chorionic gonadotropin injection and insemination in relation to the sperm preparation techniques used as well as the storage time and conditions until insemination.

STUDY FUNDING/COMPETING INTEREST(S)

There were no external funding and no competing interests to declare.

TRIAL REGISTRATION NUMBER

Dutch trial registry, trial registration number NTR3144.

TRIAL REGISTRATION DATE

14 November 2011.

DATE OF FIRST PATIENT’S ENROLLMENT

5 February 2012.

Effect of incubation and analysis temperatures on sperm kinematics and morphometrics during human semen analysis

INTRODUCTION

Human semen analysis must be performed after the liquefaction of the ejaculate. This takes place about 30min after ejaculation and samples must be maintained in the lab during this time. The temperatures for this incubation and the final analysis of motility are crucial but seldom taken into account. This study aims to examine the effect of these temperatures on various sperm parameters both manually (sperm count, motility, morphology, viability, chromatin condensation and maturation and DNA fragmentation) and CASA (kinematics and morphometrics, using an ISAS®v1 CASA-Mot and CASA-Morph systems, respectively) analyzed.

METHODS

Seminal samples from thirteen donors were incubated for 10min at 37°C followed by additional 20min at either room temperature (RT, 23°C) or 37°C and then examined following WHO 2010 criteria.

RESULTS

The data obtained show that there were no significant differences (P>0.05) in the subjective sperm quality parameters with incubation temperature. On the other hand, the head sperm morphometric parameters were significantly higher after room temperature incubation showing, in addition, lower ellipticity (P<0.05). Furthermore, kinematic parameters were evaluated both at RT and 37°C for the two incubation temperatures. In general, the four temperature combinations showed that kinematic parameters followed this order: RT-RT<RT-37<37-37<37-RT (incubation and analysis temperatures respectively).

CONCLUSIONS

Our results showed that temperature control during both incubation and analysis is needed for accurate semen analysis, recommending the use of 37°C during the entire process.

Thermotaxis of mammalian sperm

Sperm are guided through the female reproductive tract. A temperature difference of about 2 °C exists between the storage site and fertilization site of the mammalian oviduct, leading to the hypothesis that sperm can sense and swim towards the oocyte along a rising temperature gradient, known as thermotaxis. Research over the past two decades has reported that sperm feature a sophisticated thermal detection system to detect and track ambient temperature gradients. More recently, thermotaxis is expected to be added to the microfluidic isolation method based on sperm tactic responses for sperm selection. In this paper, mammalian sperm thermotaxis is discussed, explaining the underlying behavioral mechanisms and molecular basis, according to the latest research. Finally, this paper explores the possible application of sperm thermotaxis in assisted reproductive technologies.

Sperm motility in asthenozoospermic semen samples can be improved by incubation in a continuous single culture medium (CSCM®)

Standard protocols for clinical in vitro fertilization (IVF) laboratories recommend incubating semen at 37°C in 5% CO₂ without strictly specifying which medium should be used or for how long. This study aimed to test the most common different incubation media used in Latin American andrology and micromanipulation laboratories and verify which, if any, is the most appropriate medium to improve asthenozoospermic semen samples' motility in the infertile male population. Ejaculates (136) collected from asthenozoospermic men were divided into two cohorts with similar characteristics (cohort 1; n = 28 and cohort 2; n = 108). Cohort 1 was used to evaluate the optimal incubation time with regard to unprepared asthenozoospermic sample sperm motility. After defining an optimal incubation period of 2 h, cohort 2 was used to evaluate which of the four media commonly used in IVF clinics (continuous single culture medium = CSCM®; SpermRinse medium = SR®; in vitro fertilization medium = G-IVF® and human tubal fluid medium = HTF®) was preferred for semen samples from asthenozoospermic patients. Overall, it was determined that a 2-h incubation in CSCM® medium led to the highest asthenozoospermic sperm motility. Thus, this simple, cost-effective, easily reproducible protocol could prove extremely useful for andrology laboratories working with IVF clinics dealing with asthenozoospermic semen specimens. This is particularly relevant since the incidence of the latter is on the rise as semen quality decreases around the globe.Abbreviations: ANOVA: Analysis of variance; ARTs: Assisted reproductive techniques; BWW: Biggers, Whitten, and Whittingham; CO₂: Carbon dioxide; CPM: counted per minute; CSCM: Continuous Single Culture Medium; DAB: 3.3'- diaminobenzidine; DFI: DNA Fragmentation Index; DMSO: Dimethyl sulfoxide; G-IVF: In Vitro Fertilization Medium; GSH: Glutathione; GPx: glutathione peroxidase; HDS: High DNA Stainability; HSA: Human Serum Albumin; HTF: Human Tubal Fluid; HYP: Hyperactivity; ICSI: Intracytoplasmic sperm injection; IUI: Intrauterine insemination; IVF: in vitro fertilization; LIN: Linearity; ROS: Reactive Oxygen Species-level; SC: Sperm concentration; SCA: Sperm Computer Analysis; SCSA: Sperm Chromatin Structural Assay; SR: SpermRinse medium; SSS: Synthetic Serum Substitute; STR: Straightness; SOD: superoxide dismutase; TNE: Tris-Borate-EDTA; TSC: Total sperm count; VAP: Mean velocity; VCL: Curvilinear velocity; VSL: Linear velocity; WHO: World Health Organization; WOB: Wobble; spz: spermatozoa; AO: antioxidant.

Factors Affecting the Survival of Ram Spermatozoa during Liquid Storage and Options for Improvement

Semen preservation is an essential component of reproductive technologies, as it promotes genetic gain and long-distance semen transport and multiplies the number of ewes able to be inseminated per single ejaculate. However, the reduced temperature during cold storage at 5 or 15 °C inflicts sub-lethal damage to spermatozoa, compromising sperm quality and the success of artificial breeding. New and emerging research in various species has reported the advantages of storing spermatozoa at higher temperatures, such as 23 °C; however, this topic has not been thoroughly investigated for ram spermatozoa. Despite the success of storing spermatozoa at 23 °C, sperm quality can be compromised by the damaging effects of lipid peroxidation, more commonly when metabolism is left unaltered during 23 °C storage. Additionally, given the biosafety concern surrounding the international transport of egg-yolk-containing extenders, further investigation is critical to assess the preservation ability of synthetic extenders and whether pro-survival factors could be supplemented to maximise sperm survival during storage at 23 °C.

Does the time interval from the end of sperm processing to intrauterine insemination (lab-to-uterus time) affect treatment outcome?

BACKGROUND

Intra-uterine insemination is an essential component in the treatment of infertility. Success rates are dependent on clinical factors of the female partner, sperm quality, and preparation technique. The effect of the time interval between the end of sperm preparation in the lab, and its injection into the uterine cavity (lab-to-uterus time) is yet to be determined.

AIM

To investigate the association between the lab-to-uterus time and the pregnancy rate.

MATERIALS AND METHODS

Partner and donor spermatozoa intra-uterine insemination cycles were included. Preparation for intra-uterine insemination of partners' fresh ejaculate or donor thawed spermatozoa was identical. The time interval from the completion of this stage to the actual intra-uterine injection was recorded. The lab-to-uterus intervals were divided into groups A (0-29 min), B (30-59 min), C (60-89 min), and D (90-180 min). Pregnancy was defined as two adequate consecutive doubling levels of hCG and the pregnancy rates were compared between the groups.

RESULTS

A total of 267 female patients (138 partner spermatozoa, 129 donors) who had 470 intra-uterine insemination cycles (218 partner spermatozoa, 252 donors) were included. No significant differences in pregnancy rates per treatment cycle were found between the four lab-to-uterus interval groups: A (n = 96 cycles; 16.7%), B (n = 217; 19.4%), C (n = 121; 16.5%), and D (n = 36; 36.1%). No difference was found in the pregnancy rates between partner and donor spermatozoa. In the case of fresh partner spermatozoa, the pregnancy rates for groups were as follows: A (n = 40 cycles, 20%); B (n = 94; 14.9%), C (n = 70; 17.1%), and D (n = 14; 35.7%) (NS). In the case of thawed donor spermatozoa, the pregnancy rates (per cycle) for groups were as follows: A (n = 56; 14.3%), B (n = 123; 22.8%), C (n = 51; 15.7%), and D (n = 22; 36.4)% (NS).

CONCLUSIONS

The intra-uterine insemination outcome was not affected by the lab-to-uterus time interval. Extended waiting up to 3 h for insemination did not have any detrimental effect on pregnancy rates, regardless if partner or donor spermatozoa was used.

Effect of time intervals from the end of sperm collection to intrauterine insemination on the pregnancy rates in controlled ovarian hyperstimulation-intrauterine insemination cycles

OBJECTIVE

To analyze the effect of time intervals from the end of sperm collection to IUI on the pregnancy rates in couples who treated by COH-IUI cycles with gonadotropin due to unexplained infertility.

METHODS

556 couples who underwent the first COH-IUI treatment with gonadotopin due to unexplained infertility were included. Semen samples were obtained by masturbation in a private room near the laboratory on the day of insemination. For each semen samples, time between the delivery time to the laboratory and starting time of sperm washing procedure was noted as semen collection to sperm washing (SC-SW) interval, the time between the starting time of sperm washing procedure and insemination time was noted as sperm washing to insemination (SW-IUI) interval and the time between the delivery time to the laboratory and insemination was noted as semen collection to insemination (SC-IUI) interval. Clinical pregnancy was defined as positive pregnancy test followed by the presence of an intrauterine gestational sac with fetal cardiac activity by transvaginal ultrasonography at least 4 weeks after IUI.

RESULTS

Among 556 couples, there were 84 cases of succesful clinical pregnancy and pregnancy rate was calculated as 15.1%. Intervals from SW to IUI and SC to IUI were significantly shorter in pregnant women than in non-pregnant (p<0.001 and p=0.007, respectively). SW performed ≤40min after SC resulted in higher clinical pregnancy rates than did SW performed >40min after SC (19.1% vs. 6.3%, respectively) (p<0.001). IUI performed ≤60min after the end of SW had higher pregnancy rates (16.9%) compared to IUI performed >60min after the end of SW (4.0%) (p=0.017). Likewise, IUI performed ≤90min after SC resulted in higher pregnancy rates than did IUI performed >90min after SC (18.9% vs. 12.0%, respectively) (p=0.029).

CONCLUSION

IUI outcome is enhanced by shorter intervals from SC to SW, from SW to IUI, and from SC to IUI in gonadotropin-IUI cycles for unexplained infertile couples.

Techniques used for IUI: is it time for a change?

STUDY QUESTION

Are the guidelines for the technical aspects of IUI (WHO, 2010) still in accordance with the current literature?

SUMMARY ANSWER

In general, the laboratory guidelines of the World Health Organization (WHO) are a suitable protocol, although the evidence is not always conclusive and some changes are advisable.

WHAT IS KNOWN ALREADY

Lack of standardization of the technical procedures required for IUI might result in inter-laboratory variation in pregnancy rates. Most centers still use their own materials and methods even though some guidelines are available.

STUDY DESIGN, SIZE, DURATION

A structural review focusing on the association between pregnancy rates and the procedures of semen collection (e.g. ejaculatory abstinence, collection place), semen processing (e.g. preparation method, temperature during centrifugation/storage), insemination (e.g. timing of IUI, bed rest after IUI) and the equipment used.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A literature search was performed in Medline and the Cochrane library. When no adequate studies of the impact of a parameter on pregnancy results were found, its association with sperm parameters was reviewed.

MAIN RESULTS AND THE ROLE OF CHANCE

For most variables, the literature review revealed a low level of evidence, a limited number of studies and/or an inadequate outcome measure. Moreover, the comparison of procedures (i.e. semen preparation technique, time interval between semen, collection, processing and IUI) revealed no consensus about their results. It was not possible to develop an evidence-based, optimal IUI treatment protocol.

LIMITATIONS, REASONS FOR CAUTION

The included studies exhibited a lack of standardization in inclusion criteria and methods used.

WIDER IMPLICATIONS OF THE FINDINGS

This review emphasizes the need for more knowledge about and standardization of assisted reproduction technologies. Our literature search indicates that some of the recommendations in the laboratory guidelines could be adapted to improve standardization, comfort, quality control and to cut costs.

STUDY FUNDING/COMPETING INTEREST(S)

The Dutch Foundation for Quality Assessment in Medical Laboratories (SKML), Nijmegen, The Netherlands. S.K. and W.N. have no conflicts of interest to disclose. C.B. and A.W. are members of the board of the SKML. With a grant from SKML, L.L. was paid for her time to perform the research and write the publication. D.B. received grants from Merck Serono, Ferring and MSD, outside the submitted work.

REGISTRATION NUMBER

N/A.

Evaluation of sperm motility with CASA-Mot: which factors may influence our measurements?

Computer-aided sperm analysis (CASA) is now routinely used in IVF clinics, animal breeding centres and research laboratories. Although CASA provides a more objective way to evaluate sperm parameters, a significant number of factors can affect these measurements. This paper classifies these factors into four categories: (1) sample and slide (e.g. preincubation time, type of specimen and type of chamber slide); (2) microscope (e.g. light source and microscope stage); (3) hardware and software, including the settings of each system; and (4) user-related factors. We review the effects of the different factors in each category on the measurements made and emphasise the need to take measures to standardise evaluations. The take-home message of the present article is that there are several commercial and useful CASA systems, and all are appropriate for routine analysis. Non-commercial systems may also be good choices when the user needs to adapt the device to specific experimental conditions. In both cases (commercial and non-commercial), it is important that standard protocols are put in place for evaluation, as well as methods to validate the system.

Improvement of motility after culture of testicular spermatozoa: the effects of incubation timing and temperature

Background

Sperm motility is the reliable parameter that roles in success of intracytoplasmic sperm injection (ICSI), especially in azoospermia. Selection of appropriate culture duration, temperature and media for enhancing the sperm motility is an important issue in assisted reproduction program. The aim was to evaluate the sperm motion characteristics after culturing of testicular sperm extraction (TESE) samples at different temperatures and time intervals.

Methods

In this prospective study, 27 TESE samples were collected from young azoospermic patients. The samples were cultured in Ham’s F10+20% HAS, at different temperatures (incubation at 37 vs. 25 °C) and sperm total motility was assessed at different time intervals of 0, 24, 48 and 72 h post testicular biopsy.

Results

In vitro culture at 25 °C changed sperm motility from 13% immediately after biopsy to 76% at 24 h, 43% at 48 h and 15% at 72 h. At 37 °C, the sperm motion feature was changed to 67% at 24 h, 38.40% at 48 h and 12.03% at 72 h. Sperm motility change at 24 h was incremental in both conditions of culturing, but significant at 25 °C (P≤0.05).

Conclusions

The ideal in vitro culture for testicular spermatozoa was at 25 °C after 1 day of culture, which optimized the sperm motility in azoospermic TESE samples.

The single and synergistic effects of the major tea components caffeine, epigallocatechin-3-gallate and L-theanine on rat sperm viability

Caffeine, epigallocatechin-3-gallate (EGCG) and L-theanine are the major components of tea (Camellia sinensis L.) and the main representatives of the classes of methylxanthines, catechins and free amino acids present in this beverage. There are many studies reporting tea's health benefits, however it is not clear if those effects are mediated by a single component or a synergistic action. This study aimed to evaluate the individual and synergistic effects of tea's major components on rat epididymal spermatozoa survival and oxidative profile during 3-day storage at room temperature (RT). For that, spermatozoa were incubated with caffeine (71 μg mL(-1)), EGCG (82 μg mL(-1)), or L-theanine (19 μg mL(-1)), alone or in combination. Spermatozoa viability was assessed by the eosin-nigrosin staining technique. The oxidative profile was established by evaluating the levels of carbonyl groups, protein nitration and lipid peroxidation. Supplementation of sperm storage medium with the three compounds together improved sperm viability, after 24, 48 and 72 h of incubation, relative to the control and the groups incubated with each component individually. However, at the end of the 72 h of incubation, there was an increase in protein oxidation in the group exposed to the three compounds, illustrating that the combined treatment triggers different alterations in sperm proteins during their maturational process in the epididymis. This study highlights the importance of the synergism between tea components for the beneficial effects usually attributed to this beverage, particularly in sperm storage at RT.

The effect of preserving prepared sperm samples at room temperature or at 37 °C before intrauterine insemination (IUI) on clinical pregnancy rate

OBJECTIVE

The comparison of the effect of preserving prepared sperm samples at room temperature or at 37 °C before intrauterine insemination (IUI) on clinical pregnancy rate.

MATERIALS AND METHODS

Retrospective clinical research. University hospital, infertility clinic. Patients with one or two follicles, between the ages of 20 and 40, whose infertility period was less than 6 years and the injected total motile sperm count was more than 10 million. Preserving sperm samples prepared for IUI at 37 ºC or at room temperature before IUI. The clinical pregnancy rate of IUI cycles between 1^st of January 2004 and 1^st of December 2011 in which prepared sperm samples were preserved at 37 ºC and the clinical pregnancy rate of IUI cycles between 1^st of December 2011 and 31^st of May 2014 in which prepared sperm samples preserved at room temperature.

RESULTS

Clinical pregnancy rates were similar in IUI cycles in which prepared sperm samples were preserved at 37 ºC and at room temperature (9.3% vs. 8.9%). Clinical pregnancy rates in IUI cycles with 2 follicles were higher than IUI cycles with 1 follicle (10.8% vs. 7.6%) (p=0.002). Further statistical analysis after splitting data according to the number of the follicles revealed that there was no statistical difference between clinical pregnancy rates after IUI cycles in which prepared sperm samples were preserved at 37 ºC or at room temperature in both one follicle (7.6% vs. 7.6%), and two follicle cycles (11.5% vs. 10.1%).

CONCLUSIONS

Preserving prepared sperm samples at room temperature had no negative effect on clinical pregnancy rates when compared with reserving prepared sperm samples at 37 ºC during IUI cycles.

Semen preparation techniques in intrauterine insemination: A comparison of non-temperature and temperature controlled centrifugation in cases of unexplained infertility

AIM:

The aim of the following study is to compare pregnancy rates between the use of non-temperature and temperature controlled centrifugation on semen preparation technique in intrauterine insemination.

MATERIALS AND METHODS:

The retrospective study was conducted on 671 patients of idiopathic infertility who underwent homologous artificial insemination at Fertility Research Center from the period of January 2007 to September 2012. The couples were randomized into two groups namely, Group A-patients (n = 303) being treated with sperm prepared by using non-temperature controlled centrifuge and Group B-Patients (n = 368) being treated with sperm prepared by temperature (37°C) controlled centrifuge.

RESULTS AND CONCLUSION:

The clinical pregnancy rate Group A was 13.86% and Group B was 12.77%. The clinical pregnancy fetal loss rate between the two groups was 38% and 42% respectively. The delivery rate per transfer was 62% and 58% respectively. No statistically significant difference was found between these two groups.

White tea as a promising antioxidant medium additive for sperm storage at room temperature: a comparative study with green tea

Storage of sperm under refrigeration reduces its viability, due to oxidative unbalance. Unfermented teas present high levels of catechin derivatives, known to reduce oxidative stress. This study investigated the effect of white tea (WTEA) on epididymal spermatozoa survival at room temperature (RT), using green tea (GTEA) for comparative purposes. The chemical profiles of WTEA and GTEA aqueous extracts were evaluated by (1)H NMR. (-)-Epigallocatechin-3-gallate was the most abundant catechin, being twice as abundant in WTEA extract. The antioxidant power of storage media was evaluated. Spermatozoa antioxidant potential, lipid peroxidation, and viability were assessed. The media antioxidant potential increased the most with WTEA supplementation, which was concomitant with the highest increase in sperm antioxidant potential and lipid peroxidation decrease. WTEA supplementation restored spermatozoa viability to values similar to those obtained at collection time. These findings provide evidence that WTEA extract is an excellent media additive for RT sperm storage, to facilitate transport and avoid the deleterious effects of refrigeration.

Temperature controlled centrifugation improves sperm retrieval

Sperm retrieval techniques form an integral part of the assisted reproductive programme. The success of sperm separation is measured by the number of motile sperm retrieved from a given semen sample. The study aimed to evaluate the effect of temperature during sperm preparation events on the number and percentage motile sperm retrieved following a double wash swim-up procedure. Thirty semen samples were obtained from 10 normozoospermic donors. After collection samples were divided into two aliquots, one aliquot was placed in an incubator at 34 °C, while the second aliquot was left at room temperature (25 °C). Sperm motility assessments were recorded with a computer assisted sperm analyser. Motile sperm fractions were retrieved from the semen samples following a double wash swim-up technique. Two tubes were prepared for each experiment. Tubes were placed in two different centrifuges: (i) SpermFuge (Shivani Industries, India) with temperature centrifuge control (34 °C) and (ii) Sigma with no temperature control facilities. Both centrifuges were set at 484 g for 5 min. Following the second wash, sperm pellets were layered with culture medium, and sperm was allowed to swim up. Supernatants were removed and analysed for sperm concentration and motility values. Percentage motile sperm was transformed to ARCSIN values and results of the two centrifugation methods at 34 °C and room temperature were compared with Mann-Whitney test for independent samples. The mean sperm concentration retrieved at 34 °C was 43.8 ± 50 (SpermFuge) and 32.7 ± 21 (Sigma) (P < 0.05), compared to retrieved concentration at room temperature namely, 30.9 ± 33 (SpermFuge) and 30.6 ± 17 (Sigma) (P ≥ 0.05). The mean percentage motile sperm at 34 °C was 64.0 ± 19 (SpermFuge) and 44.2 ± 24 (Sigma) (P = 0.02), while at room temperature the percentage motile sperm was 54.7 ± 17 (SpermFuge) compared to 46.5 ± 14 (Sigma) (P ≥ 0.05). Centrifuge temperature and incubation temperature significantly influenced the percentage retrieved motile sperm. The use of temperature-controlled sperm preparation might have clinical value for men with poor sperm motility values.

On the Origin of Descended Scrotal Testicles: The Activation Hypothesis

Male gonads contained in an unprotected skin sack located outside the body cavity are a peculiar mammalian anomaly. We advance the hypothesis that descended scrotal testicles in humans and many other mammals evolved to provide a situation specific means of activating sperm. As a result of consistent temperature differences between the male and female reproductive tracts (i.e., scrotal temperatures are typically maintained at 2-3°C below body temperature), we propose that the rise to body temperature that accompanies insemination into the vagina serves as one of several triggers for the activation of sperm. We explore some of the features of mammalian reproduction and behavior that are consistent with this hypothesis, make some testable predictions, and examine the psychological and behavioral adaptations that have evolved to protect otherwise vulnerable scrotal testicles from damage.

Enzymatic digestion plus mechanical searching improves testicular sperm retrieval in non-obstructive azoospermia cases

BACKGROUND

In non-obstructive azoospermic patients (NOA) besides the mechanical treatment, vital spermatozoa from the tissue obtained from testes by biopsy can be enzymatically prepared.

OBJECTIVE

To increase the sperm recovery success of testicular sperm extraction (TESE), suitable for ICSI.

STUDY DESIGN

Prospective, clinical study. In 177 consecutive men who presented with clinical and laboratory data indicating NOA, tissue samples were obtained by microdissection TESE method. Initially, mature spermatozoa were searched for by mechanical extraction technique shredding the biopsy fractions. In cases with no spermatozoa was observed after maximum 30 min of initial searching under the inverted microscope, the procedure was then followed by enzymatic digestion using DNAse and collagenase type IV. In cases of at least a mature spermatozoon could be obtained properly, ICSI was performed.

RESULTS

Of 177 cases with NOA, conventional mincing method extended with enzymatic treatment yielded successful sperm recovery for ICSI in 102 (57%). Overall in vitro tissue-processing time for patients with sperm recovery failure after 30 min of mechanical searching, was between 80 and 105 min (mean 96+/-9). Cleavage, embryo transfer and clinical pregnancy rates in mechanical plus enzymatic TESE patients were not significantly different from those of only mechanically TESE performed patients (p>0.05).

CONCLUSION

Combination of conventional TESE and enzymatic digestion is an effective method to recover spermatozoa suitable for ICSI. The benefit of the mincing combined with enzyme to sperm retrieval for NOA is firstly to shorten the mechanical searching time, thus minimizing further cellular damage as well as exposure to external conditions, and secondly to reduce the number of cases with sperm recovery failures.

Optimizing incubation conditions for the preservation of sperm motility in processed semen samples

To determine the optimal conditions to maintain sperm motility and viability for prolonged periods, semen specimens were processed and cultured in different temperature and conditions. We conclude that processing of semen and incubation of sperm in protein-supplemented N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES) human tubal fluid medium at room temperature best preserved viability and motility of sperm.

Intrauterine insemination (IUI) pregnancy outcome is enhanced by shorter intervals from semen collection to sperm wash, from sperm wash to IUI time, and from semen collection to IUI time

OBJECTIVE

To determine whether IUI pregnancy was affected by [1] place of semen collection (home vs. clinic), and [2] intervals from collection to sperm wash (C-SW), from sperm wash to IUI (SW-IUI), and from collection to IUI (C-IUI).

DESIGN

Retrospective study.

SETTING

Infertility clinic.

PATIENT(S)

Sixty-two couples in 132 cycles.

INTERVENTION(S)

Clomiphene citrate (CC) or hMG, plus hCG, and IUI.

MAIN OUTCOME MEASURE(S)

Ultrasonographic detection of fetal heart beat(s).

RESULT(S)

Semen collection at clinic resulted in a higher pregnancy rate than collection at home in hMG-treated (44% vs. 18%; P=.03) but not in CC-treated women (9% vs. 9%; P=.93). Intervals of C-SW, SW-IUI, and C-IUI were shorter in pregnant than in nonpregnant hMG-treated women (27 vs. 41 minutes, 42 vs. 85 minutes, and 99 vs. 156 minutes, respectively; P< or =.01) but not in CC-treated women (28 vs. 38 minutes, 51 vs. 63 minutes, and 109 vs. 131 minutes, respectively; P> or =.19). Semen processed within 30 minutes after collection resulted in a higher pregnancy rate than that processed 31-60 minutes after collection in hMG-treated (48% vs. 18%; P=.02) but not in CC-treated women (10% vs. 8%; P=.81). Intrauterine insemination performed within 90 minutes of collection resulted in a higher pregnancy rate than IUI performed at 91-120 minutes or >120 minutes after collection in hMG-treated (99% vs. 22% and 7%, respectively; P<.0001) but not in CC-treated women (11%, 4%, and 10%, respectively; P> or =.46).

CONCLUSION(S)

For i.u.i. with hMG but not CC, semen collection at the clinic is more effective than, and should be chosen over, collection at home. Delaying semen processing from 30 minutes up to 1 hour and/or delaying IUI from 90 minutes up to 2 hours after collection compromises the pregnancy outcome in hMG-IUI cycles. Semen specimens should be processed as soon as just after liquefaction and within 30 minutes of collection, and IUI performed as soon as just after processing and within 90 minutes of collection.