Computer-assisted sperm analysis (CASA): capabilities and potential developments.

Diagnosis and treatment of infertility in men: AUA/ASRM guideline part I

We demonstrate a compact and lightweight platform to conduct automated semen analysis using a lensfree on-chip microscope. This holographic on-chip imaging platform weighs ∼46 g, measures ∼4.2 × 4.2 × 5.8 cm, and does not require any lenses, lasers or other bulky optical components to achieve phase and amplitude imaging of sperms over ∼24 mm(2) field-of-view with an effective numerical aperture of ∼0.2. Using this wide-field lensfree on-chip microscope, semen samples are imaged for ∼10 s, capturing a total of ∼20 holographic frames. Digital subtraction of these consecutive lensfree frames, followed by appropriate processing of the reconstructed images, enables automated quantification of the count, the speed and the dynamic trajectories of motile sperms, while summation of the same frames permits counting of immotile sperms. Such a compact and lightweight automated semen analysis platform running on a wide-field lensfree on-chip microscope could be especially important for fertility clinics, personal male fertility tests, as well as for field use in veterinary medicine such as in stud farming and animal breeding applications.

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Compact and light-weight automated semen analysis platform using lensfree on-chip microscopy.

Computer-aided sperm analysis (CASA) system has been accepted and used commonly as a routine semen analysis instrument in hospital clinical laboratories worldwide. However, technicians in clinical laboratories have little informed knowledge about the principles of CASA system and the sources of analysis errors. In this review, we focus on the concept of CASA, the development course of CASA technology, the clinical application of CASA systems and the factors influencing the accuracies of results, such as frame rate, sperm counting chambers affiliated to the CASA system, algorithms and sperm concentration. These factors and lack of internal quality control may result in huge errors of the CASA between systems and laboratories. It is therefore necessary to perform the standardisation and quality control for CASA.

Computer‐aided sperm analysis: past, present and future

Summary
Cryoinjury is a consequence of cryopreservation and may have a negative impact on sperm quality regarding motility, morphology, and viability. This study was designed to identify potential proteomic changes in human sperm cells throughout the cryopreservation process. Comparisons made within this study included the detection of the sperm proteomic changes induced by incubation of the sperm cells with a protein-free cryoprotectant (with and without CryoSperm), and the proteomic changes induced by freezing, thawing, and subsequent after-thawing incubation at two different temperatures (0 °C vs. 23 °C). Tandem Mass Tag (TMT) peptide labeling coupled with LC-MS/MS was used for protein quantification. LC-MS/MS resulted in the identification of 769 quantifiable proteins. The abundance of 105 proteins was altered upon CryoSperm incubation. Freezing and thawing also induced substantial protein changes. However, fewer changes were observed when semen was thawed and then maintained after-thawing at approximately 0 °C than when it was maintained after-thawing at 23 °C, with 60 and 99 differential proteins detected, respectively, as compared to unfrozen semen incubated in CryoSperm. Collectively, these differences indicate that substantial changes occur in the sperm proteome at every stage of the cryopreservation process which may ultimately impair the sperm fertilizing capability. This is the first study to compare protein levels in fresh and cryopreserved semen using the TMT technology coupled to LC-MS/MS.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/andr.12279

Identification of protein changes in human spermatozoa throughout the cryopreservation process.

Validation of a novel computer-assisted sperm analysis (CASA) system using multitarget-tracking algorithms.

Summary

Are all patients undergoing chemotherapy for long-term sperm banking at risk of permanent sterility? Male fertility is generally lower in men with cancer and all patient groups are at risk of azoospermia. Careful management is required to ensure that samples are not stored for excessively long periods should they not be required. A retrospective analysis of 1688 patient records and prospective recall of patients for semen testing were perfomed. Pre-therapy fertility was compared with a group of pre-vasectomy patients as a comparator. Those who fail to bank spermatozoa, rates of disposal of samples and the utilization in assisted reproduction were also examined. Sperm quality was poorest in testicular cancer (TC) patients followed by those with Hodgkin's lymphoma (HL) prior to treatment. Post-therapy data were available in 376 patients (42%). Sperm number was lowest (and azoospermia highest at 77%) in patients with HL treated with regimens other than adriamycin, bleomycin, vinblastine and dacarbazine (ABVD). Non-HL NHL and leukaemic patients had similarly high rates of azoospermia at 46 and 55%. HL patients treated with ABVD (11%) and TC patients (9.7%) had the lowest rates of azoospermia. Azoospermia was seen in every treatment group except for TC patients receiving carboplatin. Only 45 patients used their samples in ART (4.5%) in 10 years. Little is known about the fertility status of the patients not coming forward for follow-up testing, those conceiving naturally, those with no intention of conceiving and some which may have psychological reasons for not attending. In conclusion, virtually all patients undergoing chemotherapy are potentially at risk of temporary or permanent infertility. However, as uptake and utilization of stored material remain low, sperm banks should be carefully managed to ensure that resources are targeted to the patients most in need.

Review and follow-up of patients using a regional sperm cryopreservation service: ensuring that resources are targeted to those patients most in need

The marked decline in the number of sperm donors recruited in the UK has been largely attributed to changes in regulations and in particular those related to the removal of anonymity. After a 5-year period of inactivity, the sperm donor bank in Nottingham was provided with limited resources to try and recruit donors who were willing to be identified on the HFEA register. Marketing was sporadic and at first low cost and the enquiry rate only increased significantly when the centre's website became operational and higher cost advertising was used. Over a 4-year period, a total of 151 enquiries gave rise to 14 useable donors at a cost of approximately £5,500 each. Donor sperm was generally of high quality having been density gradient prepared prior to cryopreservation and provided an overall ongoing pregnancy rate of 21.6% and 45.6% by IUI and IVF, respectively. The overall exercise demonstrated that identifiable donors were coming forward but in lower numbers compared to those observed before 2005. At current treatment prices, centres should be aware that recouping the costs of donor recruitment and processing may be difficult and that the cost of both donor sperm and donor insemination are likely to rise significantly.

Sperm donor recruitment within an NHS fertility service since the removal of anonymity.

An increase in the reliance on imported donor samples has been the consequence of a continued shortage of UK donors. Disputes can arise between suppliers and purchasers if the sperm quality is not as expected, yet there appears to be no requirement for the standardization of methods for sperm processing or analysis. Following analysis of 102 donor intrauterine insemination cycles, this study demonstrates that the motile sperm concentration is significantly (P < 0.05) reduced after the necessary removal of cryoprotectant before insemination. Suppliers of donor spermatozoa should therefore provide information on standards used for sperm assessment and whether analysis is performed before or after washing in order that purchasers are better informed about the quality of the end product they are committed to buying.

https://www.rbmojournal.com/article/S1472-6483(16)30031-1/pdf

Standards in reporting cryopreserved donor sperm characteristics: should they be reported post-thaw or post-wash?

The increasingly stringent laboratory-approach to diagnosing azoospermia for post-vasectomy semen analysis (PVSA) continues to be at odds with the simpler approach desired by clinicians. This study describes the analysis of 10 years of PVSA and discusses the outcome in relation to risk, cost and assesses whether more stringent procedures are required. PVSA was performed on 4788 patients initially using a 2-test strategy (16 and 20 weeks post-surgery), moving to 1 test during 2013-2014. Azoospermia was confirmed by the analysis of 10 µl of semen followed by 10 µl of centrifuged pellet. In total, there were 9260 tests with a median of 1.93 tests/patient and 18.7 weeks to clearance. Surgical failure occurred in 1.75%, falling to 1.1% between 2011 and 2016. There were no cases of unwanted pregnancy, recanalization or complaints although misdiagnosis was detected in 1 case as a result of failure to confirm patient identification. Azoospermia performed according to World Health Organization (WHO) guidelines is sufficiently robust to confirm success/failure of vasectomy. With uncertainty surrounding the diagnosis, efforts to improve detection of occasional non-motile sperm are futile, cost more and fail to reduce risk of inappropriate clearance. Misdiagnosis is more likely from patient identification error and mitigation may include reverting to the safety net of a 2-test strategy.

Karen Pooley

Papers

Validation of a novel computer-assisted sperm analysis (CASA) system using multitarget-tracking algorithms.

Review and follow-up of patients using a regional sperm cryopreservation service: ensuring that resources are targeted to those patients most in need

Sperm donor recruitment within an NHS fertility service since the removal of anonymity.

Standards in reporting cryopreserved donor sperm characteristics: should they be reported post-thaw or post-wash?

Is azoospermia the appropriate standard for post-vasectomy semen analysis? Or an unachievable goal of best practice laboratory guidelines.