A previous prospective study using matched samples found that sperm with low hypoosmotic swelling (HOS) scores had no adverse effect on fertilization rates but markedly reduced pregnancy and implantation rates. The present study attempted to corroborate or refute the aforementioned study by comparing pregnancy rates in donor-recipient pairs using shared oocytes where the sperm of one of the two males had low HOS scores. The results found no pregnancies from the sperm with low HOS scores versus a 41% live delivered rate for those with normal scores. However, fertilization rates were not affected. This retrospective study thus confirms that sperm with low HOS scores cause implantation defects of the embryos that are formed without affecting fertilization rate, embryo cleavage rate, or embryo quality.

Embryo Implantation↗

PubMedDate not supplied

Do antisperm antibodies cause functional impairment of the sperm membrane as manifested by a low hypoosmotic swelling test score?

Low hypoosmotic swelling (HOS) test scores were found to be associated with lower pregnancy rates. The mechanism seems to be related not so much to impaired fertilization but to inhibition of implantation. The defect may be present in males with normal or subnormal semen specimens. However, anecdotal experience suggested that the subset of males with antisperm antibodies (ASAs) have a higher frequency of low HOS scores. The possibility exists that ASAs may impair the functional integrity of the sperm membrane. The study presented herein, artificially added ASAs to sperm to see if this could lower the HOS score. The study would also determine if chymotrypsin, a protein digestive enzyme, could improve HOS scores, if, in fact, they were lowered by the addition of ASAs. The results did not show a reduction in the HOS scores following the addition of ASAs. Thus, it would appear that there is no cause and effect with the simultaneous presence of low HOS scores and ASAs. Possibly, however, longer exposure or a higher concentration of antibodies is needed to lower HOS scores.

Autoantibodies↗

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A study of to determine if limiting the contact of sperm with zona pellucida reduces the rate of spontaneous abortions.

A recent study suggested that oligoasthenozoospermia may be an etiologic factor for spontaneous abortion (SAB) after in vitro fertilization-embryo transfer (IVF-ET). However, IVF-ET with intracytoplasmic sperm injection (ICSI) did not seem to be associated with an increased SAB rate. The study presented herein compared the rate of SAB in pregnancies achieved by IVF-ET according to the type of oocyte insemination process. The 3 types evaluated were conventional insemination, which exposed the oocyte to 25,000 sperm with prolonged contact (16-24 h), intermediate contact with a short insemination protocol where contact with 25,000 sperm was limited to 2 h, and very limited contact with ICSI, where only 1 sperm was injected into the oocyte thus not exposing the zona pellucida to any sperm. The patients were further subdivided into age groups of < or =39 or > or =40. SAB rates after frozen ET were also evaluated. The clinical pregnancy and SAB rates following fresh or frozen ET for conventional, ICSI, and short insemination techniques for the 2 age groups were comparable. These data question whether oligoasthenozoospermia may be a factor in causing SAB, and whether avoidance of contact with the zona pellucida by using ICSI can negate this effect. A larger study is needed.

Abortion, Spontaneous↗

PubMedDate not supplied

Separation of sperm through a 12-layer percoll column decreases the percentage of sperm staining with quinacrine.

Previous methods of enriching sperm with a higher percentage of Y-bearing sperm have been questioned because the claims that Y enrichment was present were based on quinacrine staining of the Y chromosome, and the enrichment was not confirmed by polymerase chain reaction (PCR) or fluorescent in situ hybridization (FISH) techniques. A technique was evaluated that theoretically could increase the percentage of X-bearing sperm by isolating a fraction of the "heaviest" sperm by passing them through 12 layers of discontinuous Percoll gradient. Initially 12 specimens were checked both before and then after separation with 12 layers of Percoll for percentage of Y sperm. The median for baseline Y percentage was 49% and after processing the percentage of Y dropped to 10%. An additional 19 specimens were checked after separation only. The median was 19%. The sample with the lowest preseparation % of quinacrine staining sperm was 45% and the highest was 54%. After 12-layer Percoll, the lowest percentage was 3% and the highest was 24%. There have been claims that quinacrine staining can falsely increase apparent Y-bearing sperm enrichment following certain separation procedures, e.g.. albumin separation, by nonspecific staining of autosomal chromosomes. If anything, then, it should falsely decrease X-bearing sperm enrichment. Thus, 12-layer Percoll separation may actually enrich for X-bearing sperm or possibly this procedure somehow nonspecifically inhibits the ability of quinacrine to stain the Y chromosome.

Cell Separation↗

PubMedDate not supplied

A randomized study comparing the effect of standard versus short incubation of sperm and oocyte on subsequent pregnancy and implantation rates following in vitro fertilization embryo transfer.

Some data suggest that some sperm are associated with a toxic product that lowers embryo implantation rates when these sperm come in contact with the zona pellucida. The possibility exists that shortening the incubation time could improve pregnancy rates. A randomized prospective study was initiated to evaluate pregnancy and implantation rates with transfer of embryos formed by conventional overnight vs short (2-h) co-incubation of sperm and oocytes. The clinical and viable pregnancy rates were 41 and 29% for conventional co-incubation versus 30 and 30% for short co-incubation. Implantation rates were also similar (17.9 vs 17.8%). Short incubation does not seem to impact any advantage over conventional co-incubation techniques in couples undergoing in vitro fertilization where the male factor is normal.

Embryo Implantation↗

PubMedDate not supplied

ICSI as an effective therapy for male factor with antisperm antibodies.

This study was conducted to evaluate if in vitro fertilization (IVF) with intracytoplasmic sperm injection (ICSI) is an effective treatment for infertility complicated by the presence in the male partner of sperm autoantibodies. Over a 1-year study period comparisons of fertilization, pregnancy, and implantation rates were made in couples where the male partner was negative or weakly positive for sperm autoantibodies (<50%) (gr 1); autoantibodies were strongly positive (>80%) (gr 2); or autoantibodies were moderately positive (50-80%) (gr 3). Only patients having oocytes fertilized by ICSI were included. The fertilization, clinical pregnancy, implantation, and miscarriage rate for group 1 (n = 67) was 56, 43, 21, and 14%. Comparable values for group 2 (n = 20) were 55, 40, 23, and 25%, and for group 3 (n = 6) were 63, 33, 23, and 0%. IVF with ICSI demonstrates comparable fertilization, pregnancy, implantation, and miscarriage rates in female partners of males with and without sperm autoantibodies.

Abortion, Spontaneous↗

PubMedDate not supplied

Increasing sperm concentration to adjust for subnormal sperm morphology did not adversely affect implantation after embryo transfer.

Some sperm specimens contribute to infertility not by impairing the fertilization process but by causing embryo implantation defects. One hypothesis is that a toxic factor attached to the sperm is transferred to the zona pellucida by the supernumerary sperm and then subsequently to the embryo membrane. One abnormality, as manifested by subnormal hypoosmotic swelling test (HOST) scores, causes these problems even with the small number of sperm that attach to the zona pellucida under normal physiologic conditions. This study evaluated whether the technique used to increase the oocyte insemination concentration of sperm to adjust for subnormal morphology values using strict criteria may allow a higher concentration of this purported toxic factor to attach to the zona pellucida, thus resulting in the dissimilitude of normal fertilization rate but low implantation rate. A comparison of the pregnancy and implantation rate of embryos formed by insemination of this adjusted sperm concentration of < or = 200,000 sperm vs. those inseminated with the normal concentration of 25,000 sperm failed to demonstrate any differences. Thus, the technique of increasing sperm concentration to adjust for low sperm morphology to improve fertilization rates does not seem to adversely affect implantation rates as long as the HOST scores are normal.

Embryo Implantation↗

PubMedDate not supplied

Pregnancy/implantation rates as related to age following transfer of frozen embryos produced by ICSI.

A study has suggested that one drawback of ICSI is that if these embryos are cryopreserved they have lower implantation rates after thawing and transfer as compared to other frozen embryos derived from conventional oocyte insemination. Other studies have not shown such adverse effects on pregnancy rates following frozen embryo transfer (ET) of embryos formed by ICSI. The study presented here evaluated the largest number of frozen ET cycles of embryos following ICSI, which were compared to couples having frozen ET with embryos formed by conventional insemination. In women age 39 and younger, the clinical, viable, pregnancy rates and implantation rates were very similar. Similar rates were reached for the older group. These data convincingly demonstrate that fertilization by ICSI does not adversely effect the implanting capacity of frozen-thawed embryos.

Adult↗

PubMedDate not supplied

Treatment of sperm with subnormal host scores with chymotrypsin/viable pregnancy after IUI.

Men with low hypoosmotic swelling test (HOST) scores (<50%) rarely achieve a pregnancy with intercourse or conventional intrauterine insemination (IUI) or even IVF. The defect seems to be related to a toxic factor attached to the sperm that can be transferred to the zona pellucida, which ultimately interferes with implantation. A small case series showed optimistic pregnancy outcome with treatment of the sperm with low HOST scores with chymotrypsin. However, the live pregnancy rate in 90 subsequent IUI cycles in men whose low HOST scores were improved by chymotrypsin was only 3.3%. IVF with ICSI remains the only highly effective treatment of this disorder.

Chymotrypsin↗

PubMedDate not supplied

Reevaluation of the clinical importance of evaluating sperm morphology using strict criteria.

Several studies suggest that sperm with < or =4% normal morphology (NM) using strict criteria are subfertile and IVF with ICSI may be needed. However, not all studies agree on the clinical importance of the use of NM with strict criteria. One study of males with oligozoospermia found a lower pregnancy rate (PR) following intercourse with sperm with NM > 14% compared to specimen with < or = 4%. The study presented herein evaluated the efficacy of intrauterine insemination (IUI) according to NM using strict criteria. The clinical PRs for first IUI cycles were 30% (28/91 ) for 0-4% normal forms, 26% (71/268) for range of 5-14%, and 20% (11/53) for >14%. This study corroborates previous data with intercourse only, suggesting that sperm with NM < or =4%, using strict criteria are not necessarily associated with lower fecundity.

Humans↗

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Cumulative probability of pregnancy following IVF with ICSI and fresh or frozen embryo transfer.

The authors studied the cumulative probability of pregnancy for up to 4 consecutive embryo transfer (ET) cycles with ICSI performed for male factor. Transfers could be either fresh or frozen. The clinical pregnancy rate (PR) for the first 4 cycles were similar [44% (61/366); 31% (44/138); 45% (14/31); 44% (4/9)]. Delivery rates were also similar. There was a lower PR on the second retrieval vs. the first retrieval (47% vs. 29%), but this may be related to most of the second retrievals occurring in the second transfer cycle (67%, 31/55); this may be explained by women who were poor responders and required another retrieval without a frozen ET. The majority of transfers in cycle 1 were fresh, whereas cycles 2-4 used primarily frozen-thawed embryos. These data should be helpful for patients requiring IVF with ICSI in deciding to continue with more IVF cycles or consider other

Cryopreservation↗

PubMedDate not supplied

Prognosis for sperm fertilizability: analysis of different variables in men.

An overview of various sperm tests is presented. The standard semen analysis obtained by most clinicians evaluating infertility usually consists of sperm concentration, percent motility, quality of motility, and sperm morphology. Unfortunately, unless the motile density is extremely low, the count and motility are not good prognosticators of fertility potential. Values above the norm for normal fertile couples unfortunately cannot reliably predict normal fertility potential. It is important to find sperm tests that are easy to perform, are relatively inexpensive, and provide an accurate prognosis. Strict morphology was hoped to be such a tool with initial optimism that it was far superior to standard morphology. Unfortunately, this test also failed to be the ideal inexpensive prognostic test after further evaluation. One test that is inexpensive and highly correlates with fertilizability is the presence of antisperm antibodies since their presence frequently does not alter count, motility, or morphology. This test should be performed as part of the routine semen analysis. Other tests highly correlate with the achievement of pregnancy and are simple and inexpensive to perform, but, interestingly, do not correlate with fertilizability. These include the hypoosmotic swelling test (HOST) and the sperm stress test. Abnormalities in these tests imply a different abnormality of sperm that leads to conception failure and that is the transfer of a toxic factor from the sperm to oocyte to embryo that prevents the embryo from implanting. Certainly, the simple, inexpensive HOST should be performed routinely. Other tests of sperm function, e.g., sperm penetration assay, sperm zona pellucida binding assay, and acrosome reaction, have their definite place in the evaluation of the infertile male. However, because they are expensive and difficulty to perform they lend themselves to certain specific circumstances but not to routine testing.

Acrosome Reaction↗

PubMedDate not supplied

Sperm toxicity evaluated by the overnight sperm survival test.

A subnormal sperm stress test has also been associated with implantation failure despite apparently normal fertilization; however, this test is cumbersome and time-consuming. The overnight sperm survival test has been considered to possibly demonstrate lipid peroxidation abnormalities similar to the sperm stress test. The present study evaluated whether lower overnight survival scores were associated with lower pregnancy and implantation rates following in vitro fertilization-embryo transfer. The results showed no adverse effect of poor overnight survival test scores. Possibly, the overnight survival test, though similar in some respects to the sperm stress test, is not similar for properties of predicting embryo implantation defects. Corroboration that subnormal stress tests predicts implantation disorders is needed.

Adult↗