Semen characteristics and fertility tests required for storage of spermatozoa

Abstract

This review addresses critical issues in the selection of semen donors who are very fertile. Traditional semen parameters have been employed and are still used to assess pre- and post-freeze samples in order to discriminate between donors of high and low fecundity. The most predictive factor is the number of motile spermatozoa per straw and the number of motile spermatozoa inseminated. Nevertheless, no absolute standards for fertile samples can be derived from the basic semen examination. The employment of sperm function testing such as the hamster penetration test or computerized motility analysis has been shown to enhance moderately the prediction of fertility of semen samples however, further studies are necessary to determine if these improvements are clinically useful. The need to determine with a high degree of confidence the fecundity of donor semen is enhanced by limitations in the number of pregnancies allowed per donor. The recent publication of league tables in the UK has put extra pressure in clinics to use highly fertile donors. Spermatozoa are also cryostored for patients prior to cancer treatment. With the development of intracytoplasmic sperm injection every sample produced by cancer patients can be stored irrespective of the quality. However, several factors need to be elucidated to maximize the fertility of those patients. The establishment of regional centres in Europe will be a good starting point to deal with many of the issues raised in this review.

Procedure control and acceptance sampling plans for donor sperm banks: a theoretical study

“…However, if we class the lot as good, we cannot be very sure of this, and it is possible that the spermatozoa from this donor might not survive freezing very well; thus, a future survival test could well produce worse results. This is in agreement with the conclusions of Barrat et al (1998), who found that when donors were given a second chance after an initial survival test produced borderline unacceptable results, they almost always provided another unacceptable result, when a second ejaculate was tested. Theoretically, if we analyse two straws and decide to accept the lot if both straws are good (n = 2; c = 0), we will have a low probability of rejecting good lots (0.10) and a fairly high one of accepting a defective one (0.60).…”

“…This theoretical study enables us to propose various possible explanations for the different findings of other authors concerning semen donor banks, such as the high variability of results (Carrell et al 2002) or the poor results obtained when a second ejaculate was tested for donors given a second chance after an initial survival test produced borderline unacceptable results (Barrat et al 1998). Scheme for the procedure control within a sperm bank (*If a donation or frozen sample does not meet the acceptance sampling requirements, and there is no valid reason for this (such as noncompliance with sexual abstinence, fever, stress, excessive physical exercise, technical problems, etc.…”

Semen quality of 4480 young cancer and systemic disease patients: baseline data and clinical considerations

“…Semen collection failure and azoospermia rates were recorded in order to assess the feasibility of sperm freezing in the various groups of pathologies. To discuss the potential use of the frozen sperm samples through Assisted Reproductive Technologies (ART), patients were stratified according to their pathology and to NMSPS categories, defined by a possibly minimal NMSPS required for each strategy: ≥ 4x10 6 for Intra-Uterine Insemination (IUI) [ 17 ], in the range < 4 × 10 6 and ≥2 × 10 6 for conventional In Vitro Fertilization (IVF) and < 2 × 10 6 for Intra Cytoplasmic Sperm Injection (ICSI).…”

Sperm selection in natural conception: what can we learn from Mother Nature to improve assisted reproduction outcomes?

“…However, there are such differences in the fecundity of men even when ‘reasonable numbers of motile cells’ are present that either the proportion of effective cells in the ejaculate/and or their fecundity is significantly different. Further examples of this relate to donor insemination where fecundity of donors can vary by a factor of 3 even though motile sperm numbers are equal ( Barratt et al , 1998 ).…”