Effect of the number of inseminating sperm and the follicular stimulation protocol on in vitro fertilization of human oocytes in male factor and non-male factor couples

The semenogelin I-derived peptide SgI-52 in seminal plasma participates in sperm selection and clearance by macrophages

BACKGROUND

Macrophages can phagocytose sperm, especially damaged spermatozoa, in the female genital tract. The semenogelin I-derived peptide SgI-52 in seminal plasma exhibits seminal plasma motility inhibitor (SPMI) activity and can inhibit sperm motility. This raises the question of the role played by SPMIs in macrophage-mediated phagocytosis of sperm. We speculated that SgI-52 promotes sperm clearance by macrophages. Therefore, we investigated the phagocytosis of sperm in different states using this peptide.

METHODS

SgI-52 was fluorescently labeled, and its binding site for sperm was observed. The ability of macrophages to phagocytose sperm was observed using fluorescence confocal microscopy. Spermatozoa from different sources were co-cultured with SgI-52 in BWW medium for 4 and 22 h to compare the differences in their phagocytosis by macrophages. Sperm motility, induced acrosome reaction, mitochondrial membrane potential, and ATP content were examined after incubation with SgI-52.

RESULTS

SgI-52 could bind to spermatozoa in different states, mainly to the tail, and then spread to the acrosome. This effect was more pronounced in demembranated spermatozoa. SgI-52 promoted phagocytosis of spermatozoa by macrophages, decreased the mitochondrial membrane potential, and increased the average ATP content of spermatozoa (P < 0.05).

CONCLUSIONS

We found for the first time that SgI-52 can bind to spermatozoa in different states and promote their phagocytosis by macrophages. Therefore, we speculate that SgI-52 is involved in the screening of sperm in the female reproductive tract and has potential value in improving assisted reproductive technology.

Semen amyloids participate in spermatozoa selection and clearance

Unlike other human biological fluids, semen contains multiple types of amyloid fibrils in the absence of disease. These fibrils enhance HIV infection by promoting viral fusion to cellular targets, but their natural function remained unknown. The similarities shared between HIV fusion to host cell and sperm fusion to oocyte led us to examine whether these fibrils promote fertilization. Surprisingly, the fibrils inhibited fertilization by immobilizing sperm. Interestingly, however, this immobilization facilitated uptake and clearance of sperm by macrophages, which are known to infiltrate the female reproductive tract (FRT) following semen exposure. In the presence of semen fibrils, damaged and apoptotic sperm were more rapidly phagocytosed than healthy ones, suggesting that deposition of semen fibrils in the lower FRT facilitates clearance of poor-quality sperm. Our findings suggest that amyloid fibrils in semen may play a role in reproduction by participating in sperm selection and facilitating the rapid removal of sperm antigens.

DOI:http://dx.doi.org/10.7554/eLife.24888.001

Seminal plasma, the fluid portion of semen, helps to transport sperm cells to the egg during sexual reproduction. Seminal plasma contains numerous proteins that help the sperm to survive and, in recent years, researchers discovered that it also harbours protein deposits known as amyloid fibrils.

Such protein deposits are generally associated with neurodegenerative diseases such as Alzheimer's and Parkinson’s disease, where a build-up of fibrils can damage the nervous system. Semen amyloids, however, are present in the absence of disease, but can boost infection by HIV and other sexually transmitted viruses, by shuttling virus particles to their target cells. Despite these damaging effects, some researchers had suggested that amyloids in semen could be beneficial for humans, though it was unclear what these benefits might be.

Roan et al. now set out to assess how semen amyloids affect human sperm activity. The results show that semen amyloids bind to damaged sperm cells and immobilize them, which are then quickly cleared away by immune cells. This could ensure that only the fittest sperm cells reach the egg.

These findings suggest that amyloids can potentially serve beneficial roles for reproduction. A next step will be to investigate how semen amyloids trap unwanted sperm and how immune cells know when to remove it. More research is needed to investigate if problems in these processes could lead to infertility in men.

DOI:http://dx.doi.org/10.7554/eLife.24888.002

[A prospective auto-controlled study to evaluate the interest of selected sperm morphology to inseminate oocytes during IVF]

OBJECTIVES

Since we observed in our laboratory a significant decrease of the fertilization rate in the classical IVF procedure compared to ICSI, we wanted to evaluate a new insemination procedure, using sperm morphology of selected semen as a criterion taken into account to calculate the number of mobile sperm to inseminate.

PATIENTS AND METHODS

Therefore, we designed a prospective autocontrolled study which took place from September 2006 to May 2007. All IVF attempts resulting from infertile couples were included in the study if a previous analysis (lesser than one year) of sperm parameters performed in our laboratory was assessed as normal. The retrieved oocytes were separated into two groups (sibling ovocytes), inseminated randomly either with the usual procedure (control group) or with the tested protocol (tested group). Fertilization rate was the primary end point to evaluate this assay. Polyspermy rates were also compared. Subsequently, embryonic quality and development were assessed to eliminate an oxidative stress impact. Paired Student t-test was applied for statistical analysis.

RESULTS

In all, 130 couples were included. The diploid fertilization rate was significantly increased in the tested group compared to the control group (66.9% vs 61.3%; p=0.017). No statistically significant difference was showed between the polyspermy rate and numbers of (i) good quality embryos and (ii) blastomeres per embryo into the two groups.

DISCUSSION AND CONCLUSION

Compared with the conventional insemination procedure, the fertilization rate benefited from the tested insemination method in our laboratory without damaging embryonic growth. In the limit of our procedure, selected sperm morphology should be used to inseminate an appropriate number of spermatozoa within oocytes, even in case of normal semen values.

Male partner screening before in vitro fertilization: preselecting patients who require intracytoplasmic sperm injection with the sperm penetration assay

OBJECTIVES

To determine the diagnostic accuracy of the sperm penetration assay (SPA) and standard semen parameters for subsequent fertilization in in vitro fertilization-embryo transfer (IVF-ET).

DESIGN

Prospective study.

SETTING

Andrology Laboratory, and university research laboratory.

PATIENTS

Two hundred sixteen couples undergoing male-partner screening before IVF-ET (265 cycles).

INTERVENTION(S)

Male-partner screening (semen analyses [SA] and SPA), standard IVF-ET procedures, follow-up of fertilization in IVF-ET.

MAIN OUTCOME MEASURE(S)

Diagnostic accuracy of SA and SPA for prediction of fertilization in IVF-ET.

RESULT(S)

The SPA predicted IVF fertilization with high negative (84%) and positive (98%) predictive rates, and correct prediction in 88% of cycles. In contrast, sperm concentration, motility, morphology, and complete SA showed poor diagnostic accuracy, with correct prediction of IVF fertilization in 64%, 65%, 45%, and 68% of cycles, respectively.

CONCLUSION(S)

Very low sperm concentration and/or motility were good predictors of poor IVF fertilization, however, low to normal semen parameters were not predictive of successful IVF fertilization. The SPA is a useful screening tool that predicts IVF fertilization with high diagnostic accuracy. The SPA may be useful to discriminate between those couples with a high probability of normal fertilization in IVF and those with a low probability of normal fertilization that may benefit from assisted fertilization by intracytoplasmic sperm injection (ICSI).

Numerical dose-compensated in vitro fertilization inseminations yield high fertilization and pregnancy rates

OBJECTIVE

To evaluate in cases with morphologically abnormal sperm whether fertilization and pregnancy rates are increased by normalizing the number of sperm inseminated and whether biomarkers can identify cases of reduced or failed fertilization.

DESIGN

Prospective studies of sperm morphology and function.

SETTING

University hospital assisted human reproduction program.

PATIENT(S)

Partners of 308 women undergoing IVF.

INTERVENTION(S)

Motile sperm populations were assessed for sperm head morphology, for surface receptors for mannose and progesterone binding, and the ability to undergo a free mannose-induced acrosome reaction. Zinc in seminal plasma was determined by atomic absorption spectroscopy.

MAIN OUTCOME MEASURE(S)

Sperm morphology was associated with fertilization and clinical pregnancy rates. Biomarker analyses were correlated with fertilization rates using Kruskal-Wallis tests, chi2 tests, and Spearman rank order correlations.

RESULT(S)

Fertilization and pregnancy rates after numerical dose compensation inseminations were indistinguishable between men with differing percentages of normal sperm. Biomarker deficits were identified irrespective of sperm head morphology in 96% of cases of reduced or failed fertilization.

CONCLUSION(S)

Fertilization and pregnancy rates in cases of abnormal morphology are optimized by inseminating at least 25,000 sperm/mL with normal acrosomes. Reduced or failed fertilization can be predicted by testing for molecular deficits in mannose receptor expression and mannose-stimulated acrosome loss.

Effect of androgen substrates on the steroidogenic pattern of cumulus cells: correlation with cumulus culture morphology

BACKGROUND

In previous studies, higher progesterone secretion was observed in mature versus immature cumulusoocyte complexes. In mature cumulus mass that become homogeneously spread in culture (type C/D) progesterone secretion was higher than in partially (type B) or totally (type A) aggregated morphology. In sharp contrast, estradiol-17 beta secretion was significantly higher in type A than type C/D cumulus.

PURPOSE

Our purpose was to assess whether the decreased estradiol-17 beta level in type C/D cumulus culture is caused by deficiency of substrates.

METHODS

The different cumulus types were incubated with or without 10(-7) M dehydroepiandrosterone, 4-androstane-3, 17-dione, or testosterone. The levels of estradiol-17 beta, testosterone, and progesterone, were measured after 24 hr of culture.

RESULTS

The addition of dehydroepiandrosterone or 4-androstane-3, 17-dione significantly increased the estradiol-17 beta levels in all types of cumulus cells, whereas the addition of testosterone was less effective. In all types of cumulus cells the testosterone levels increased significantly on adding these androgen substrates. In the type C/D cumulus, the testosterone increased to lower levels compared to type A cumulus cells. In the presence of these androgens progesterone secretion is significantly reduced in type A cumulus cells. In type C/D cumulus cells, however, progesterone levels were significantly higher than in type A. The estradiol-17 beta/ testosterone and progesterone/estradiol-17 beta ratios, which partially resemble the degree of aromatase activity and the degree of selectivity for progesterone secretion, respectively, were higher in type C/D than in type A cumulus cells.

CONCLUSIONS

In type C/D cumulus the significant increase in estradiol-17 beta secretion in the presence of various androgens suggests that, under basal conditions, androgen is less available for estradiol-17 beta biosynthesis compared to type A cumulus. Furthermore, the higher progesterone secretion in type C/D cumulus may suggest that the follicles yielding type C/D cumulus cells are more mature than the follicles yielding type A cumulus.

Correlation between sperm morphology using strict criteria in original semen and swim-up inseminate and human in vitro fertilization

To study the value of sperm morphology using strict criteria in raw semen and in swim-up inseminate of human in vitro fertilization (IVF), 135 cycles of IVF with normal sperm concentration and motility were recruited. At least two mature oocytes were recovered in each cycle. The correlation between the percentages of normal forms and fertilization rates of mature oocytes was analyzed. The results demonstrate that the percentage of normal forms in both the raw semen and swim-up sample of patients with poor fertilization was significantly lower than in those with acceptable fertilization. The percentages of normal forms both in raw semen and in swim-up sample were significantly correlated with fertilization rates in vitro, however, the former seemed to have a better correlation (r = .51 and .19, respectively). Regarding the percentages of normal forms in raw semen, the fertilization rate in patients with normal forms < 4% was 6 +/- 11%, for 4-14% it was 58 +/- 36%, and for > 14% it was 88 +/- 20%. The fertilization rates were significantly different among these three groups of patients. The evaluation of sperm morphology using strict criteria in raw semen before IVF is predictive of fertilization outcome and may also help doctors to choose an optimal method of treatment for patients.

Development of a predictive model for optimal zona pellucida binding using insemination volume and sperm concentration

OBJECTIVE

To develop a predictive model under hemizona assay (HZA) conditions for human spermatozoa concentrations and insemination volume for optimum zona pellucida (ZP) binding.

DESIGN

Analysis of 20 different insemination volumes for zona binding and sperm morphology under HZA conditions.

SETTING

Reproductive biology unit, tertiary medical center.

PATIENTS

Four proven fertile sperm donors.

MAIN OUTCOME MEASURES

5-, 20-, 50-, 80-, and 100-microL droplets were analyzed with four different concentrations of 0.5 x 10(6), 1.0 x 10(6), 2.0 x 10(6), and 4.0 x 10(6) cells/mL to determine the number of sperm bound to each hemizona. Fifteen hemizonae were used for each insemination volume or microdroplet. Response surface regression model with volume and concentration as the regressor variables has been used.

RESULTS

The response surface of binding for the factors concentration and volume showed nonlinear association. A formula, indicating the optimal sperm insemination volume for maximum sperm binding to the ZP, Vmax = -(b1 + b5c)/2b6c, is described. The transformed data indicated 60 microL containing 4 x 10(6) sperm/mL to be optimal. Although morphology of zona spermatozoa is superior compared with seminal and postswim-up samples, no difference among the percentage of the normal morphology in different microdroplets could be demonstrated.

CONCLUSION

Optimal volume for the obtained concentration of spermatozoa from a patient can be calculated and therapeutically used for cases of severe oligozoospermic patients by microvolume inseminations in IVF practice.

Predictive value of morphologically normal sperm concentration in the medium for in-vitro fertilization

Morphological evaluation of spermatozoa using strict criteria (MEUSC) and conventional sperm parameters were studied with respect to in-vitro fertilization and pregnancy outcome before and after a swim-up selection procedure. Recovered oocytes were inseminated with 50,000 progressively motile spermatozoa, and this study assess the influence of the total number of spermatozoa and of the percentage with strictly normal morphology in the insemination sample on the outcome of IVF. The results showed that the percentages of spermatozoa with normal morphology using strict criteria, both in native and in post-swim-up samples, were the best predictors of IVF outcome. Their respective cut-off points were 5% and 8%. The number of morphologically normal spermatozoa inseminated also showed a good correlation with fertilization. However, it was not possible to find a proper cut-off point for this parameter. The patients were categorized on the basis of their native and post-swim-up scores. Category 1, in which both parameters were below their respective cut-off points, showed a 7% fertilization rate and a 0% pregnancy rate. Category 3, in which both parameters were above their cut-off points, showed a 70% fertilization rate and a 23% pregnancy rate. This suggests that sperm morphology can be used as a criterion for patient selection for IVF as an aid to identification of possibly subfertile males.

Different morphology and proliferative ability of cumulus and granulosa cells originating from cystic follicles aspirated from stimulated in vitro fertilization patients

OBJECTIVE

To investigate the morphology and proliferative ability of cumulus and granulosa cells (GCs) originating from cystic follicles and normal-sized follicles after ovarian stimulation.

DESIGN

Granulosa cells, cumulus cells, and follicular fluid (FF) were aspirated from cystic follicles and normal-sized follicles from the same ovary. Morphology and proliferative ability of cumulus and GCs were assessed by Giemsa stain and thymidine incorporation, respectively. Cell proliferation was assessed in medium or FF originating from cystic follicles or normal-sized follicles.

RESULTS

An oocyte was found in 40% of the cystic follicles versus 68% in the normal-sized follicles. Changes in dispersion and adhesion properties were observed in cystic versus normal aspirated corona cumuli complex. Proliferative ability was consistently lower in GCs originating from cystic follicles versus normal-sized follicles. Proliferation of GCs originating from normal-sized follicles or cystic follicles was inhibited or increased when grown in FF from cystic follicles or FF from normal-sized follicles, respectively. Differences in embryo quality were significantly in favor of oocytes originating from normal-sized follicles. Although the fertilization rate of those oocytes appeared to be higher, the difference was not of statistical significance.

CONCLUSIONS

Inhibition of GC proliferation in FF from cystic follicles can be reversed by incubating cells in FF from normal-sized follicles. We conclude that factors in the FF may affect cell proliferation.

Sperm count and motility influence the results of human fertilization in vitro

In order to select sperm characteristics that can predict the outcome of in-vitro fertilization-embryo transfer (IVF-ET), semen samples delivered in conjunction with this treatment were studied carefully. We have analysed these data retrospectively in relation to the outcome of treatment. Ninety-one couples were treated for tubal infertility by IVF-ET. Fifteen women became pregnant. Sperm were isolated from semen using a swim-up technique and in most cases 40-80 x 10(3) (range 20-120 x 10(3)) motile sperm per ovum were used for insemination. The couples were divided into three groups: group A who achieved pregnancies, group B who achieved cleaved ova but no pregnancies, and group C who achieved no ova that were cleaved 48 h after oocyte recovery. Comparisons between these groups showed that some characteristics of the native semen samples and the swim-up preparations were significantly different: the sperm concentration (P = 0.001) and total sperm count (P = 0.003) in the native sample, the number of sperm recovered during 30 min of swim-up (P = 0.001), and the specific progressive motility of sperm in the swim-up preparation, both at the time of insemination and on each day, up to 5 days thereafter (P = 0.002-0.028). No pregnancy was achieved with a sperm concentration below 26 x 10(6) ml-1 in the native sample. Some of the sperm characteristics studied in this paper may be of value in the pretreatment evaluation for IVF treatment.

Treatment of severe male-factor infertility with high concentrations of motile sperm by microinsemination in embryo cryopreservation straws

A microinsemination technique was evaluated for treating our program's most severe cases of male-factor infertility. Oocytes were inseminated with high concentrations of motile sperm (1 to 9 x 10(6)/ml) in 10 to 150 microliters within embryo cryopreservation straws. Fertilization was obtained in 20 of 29 (69%) couples treated by this technique. In the 15 patients in which only embryos generated from the straw technique were transferred, 7 clinical pregnancies resulted (46.7% per transfer). The implantation rate for couples receiving embryos from the straw technique only (12/58; 20.7%) compared favorably to that observed for other cases treated during this same time period with regular insemination techniques (111/766; 14.5%). Clinical pregnancy rates per transfer for IVF-ET, TET, and PROST were 33.0% (1/3), 0% (0/2), and 60.0% (6/10), respectively. The percentage of polyploidic embryos was significantly lower (P less than 0.0001) for male-factor patients treated by the straw technique with high sperm concentrations than for non-male-factor patients treated during this same time period with standard sperm concentrations. Normal births have resulted from straw inseminations with 3.4 x 10(6) and ongoing pregnancies with 5.0 x 10(6) motile sperm/ml. The results of this study suggest that some cases of male-factor infertility can be successfully treated by insemination with high concentrations of motile sperm in embryo cryopreservation straws. A technique of centrifuging sperm in straws was also developed to concentrate the entire fraction of washed sperm into 10 microliters. Further development of this technique may allow treatment of more severe cases of oligo/asthenospermia by microinsemination with high concentrations of motile sperm than is presently possible with standard washing techniques.

Delayed fertilization and poor embryonic development associated with impaired semen quality

Delayed fertilization is common in cycles with immature oocytes. This phenomenon was observed in 42 of 423 with mature oocytes. Of the 42 cycles, 16 were excluded because of the presence of sperm autoantibodies. Sperm parameters of the remaining 26 (6.1%) cycles (group A) were compared with those in cycles with no fertilization at all (group B) and those in the control group (group C). The percentage of normal forms was 15% in group B and 24% in group A compared with 51% in group C. Fertilization rates were 32% in group A compared with 81% in group C. The incidence of poor embryonic morphology was 82% in group A compared with 29% in group C. Delayed fertilization and poor embryonic morphology associated with impaired sperm quality is of clinical and prognostic importance.

Hemizona assay and teratozoospermia: increasing sperm insemination concentrations to enhance zona pellucida binding

This study aimed: (1) to evaluate the zona-binding capacity of patients with abnormal sperm morphology, using standard hemizona assay (HZA) conditions and increasing sperm insemination concentration during the assay and (2) to determine the insemination concentration needed to obtain equality in the number of tightly bound sperm to matching hemizonae, using sperm from teratozoospermic patients versus proven fertile controls. The minimum concentration of motile sperm from fertile controls necessary to validate HZA results was 250,000/mL (35.4 +/- 5.6 tightly bound sperm; mean +/- SE). The "effective number of sperm" (morphologically normal with high motility) was 60,750/mL. Each teratozoospermic patient had a unique, (higher) sperm insemination concentration (range: 0.5 X 10(6) to 2.0 X 10(6) motile sperm/mL) necessary to equal the number of tightly bound sperm representing the lower 95% confidence interval for the control sample (at 0.5 X 10(6) motile sperm/mL) with the matching hemizona. These results suggest that the HZA may be used as an indicator of the sperm insemination concentration during in vitro fertilization in patients with teratozoospermia.

Morphology of seminal and swim-up spermatozoa and the outcome of in vitro fertilization and embryo transfer

Tubal infertility was treated by in vitro fertilization-embryo transfer (IVF-ET) in 112 couples. Twenty-eight pregnancies were obtained in 140 treatment cycles. Couples are accepted for treatment in our IVF-ET programme if previous semen samples fulfil the inclusion criteria: ejaculate volume greater than 1.5 ml, concentration of spermatozoa greater than 15 x 10(6) ml-1, greater than 40% motile spermatozoa, and greater than 25% spermatozoa with normal morphology. In order to determine to which extent IVF-ET treatment results are influenced by sperm morphology, within this selected group of patients, we have retrospectively analysed the data from both original semen samples and swim-up preparations. The sperm morphology was not related to the outcome of treatment in terms of fertilization (ovum cleavage rate), early embryo development, or pregnancy. Nor was any relationship detected between early embryo development or pregnancy and the degree of improvement in morphology resulting from the swim-up procedure. However, if improvement in morphology by swim-up was high, ovum cleavage rate was low. Sperm morphology within the limits set by our inclusion criteria could not predict the outcome of IVF-ET treatment. It is further concluded that the presence of abnormal spermatozoa at the site of fertilization may be without harm if only the number of normal sperms is high enough.

The relationship between sperm parameters and fertilizing capacity in vitro: a predictive role for swim-up migration

The relationship between sperm parameters and fertilizing capacity in vitro was examined retrospectively, with the aim of finding predictive criteria for successful in vitro fertilization. Three hundred thirty semen samples were used to inseminate 1462 oocytes. Conventional parameters of sperm concentration and percentage motility in the ejaculate as well as swim-up migration were analyzed in relation to fertilization rate. It was shown that the probability of fertilizing human oocytes in vitro decreases significantly when (a) the sperm concentration is below 20 x 10(6) spermatozoa/ml ejaculate (P = 0.006), (b) motility is lower than 80% (P = 0.002), or (c) less than 4 x 10(6) motile spermatozoa/ml are concentrated in the swim-up fraction (P less than 0.0001). It was also demonstrated that nonfertilizing sperm could not be distinguished from fertilizing sperm by the conventional criteria but rather by the average concentration of motile spermatozoa in the swim-up fraction [12.5 +/- 1.5 and 22.3 +/- 2.3 x 10(6)/ml for the 0 and the 100% fertilization groups, respectively (mean +/- SE; P less than 0.01)]. Thus, the swim-up migration technique can serve as a predictive test for the in vitro fertilizing capacity of sperm.

Micro-insemination: genetic aspects

Micro-insemination involves sperm deposition directly into oocytes. This can be by transfer of sperm (Micro-Insemination Sperm Transfer, or MIST) or by micro-injection into the ooplasm (Micro-Insemination Micro-Injection into Cytoplasm, or MIMIC). Micro-insemination is indicated in spermatozoa with no or very poor motility, very low density, multiple defects, or inability to penetrate oocyte vestments. There is a 10% incidence of chromosomal abnormalities in spermatozoa from fertile and normal men. However, there is no increase in sperm chromosomal abnormalities in men with normal peripheral karyotypes and highly abnormal sperm parameters. Preliminary results of karyotypes of human oocytes that failed to become fertilized after MIST and mouse morulae and blastocysts produced after MIST reveal that there was no significant increase in aneuploidy or polyploidy. There is evidence that MIMIC may result in increased abnormal sperm karyotypes. Polyspermy is low in the mouse and human after transfer of multiple spermatozoa into the perivitelline space, thus suggesting an oolemmal block. However, blastomere membranes do not fuse with spermatozoa, as observed in a study of MIST into human embryos. Zona drilling with acid is not advised because of disturbances to chromosomal kinetics. The conclusion of this review is that MIST does not result in an increased risk of chromosomal abnormalities, while caution must be exercised with MIMIC.

Relationship between the results of sperm analysis and GIFT

In vitro fertilization (IVF) and GIFT have been proposed as therapeutic approaches in infertile couples where a significant male factor is present. To date, few published data are available relating the success rate of GIFT to the severity of the male factor. In this report the results of the first 172 GIFT cases were analyzed. The overall pregnancy rate was 18.0%. The relationship between the occurrence of pregnancy and sperm count (millions/ml), total sperm count (millions/ejaculate), % motility, motile sperm count (millions/ml) and total motile sperm count (millions/ejaculate) were examined. Significant direct correlations were observed between the clinical pregnancy rate and sperm count, total sperm count, motile sperm count and total motile sperm count. Motile sperm count and total motile sperm count had the best correlations with clinical pregnancy rates, which were over 24.0% in groups with motile sperm counts exceeding 40 X 10(6) cells/ml or total motile sperm counts greater than 100 X 10(6)/ejaculate. The clinical pregnancy rates were 12.5% and 7.7%, respectively, for groups with motile sperm counts under 10 X 10(6)/ml and total motile sperm counts below 25 X 10(6)/ejaculate. No correlation was found between percent motile cells and pregnancy rate. Results of the sperm penetration assay using zona-free hamster eggs were available in a subpopulation of 27 patients. No significant correlation between this sperm penetration assay and pregnancy rate could be demonstrated. The incidence of chemical pregnancy showed a significant negative correlation with the total motile sperm count, indicating a higher incidence of early pregnancy wastage in cases of oligozoospermia.(ABSTRACT TRUNCATED AT 250 WORDS)

Corrective measures and pregnancy outcome in in vitro fertilization in patients with severe sperm morphology abnormalities

Sperm morphology evaluated by new, strict criteria is a good predictor of outcome in in vitro fertilization (IVF). This study aimed (1) to determine whether the fertilization rate of preovulatory oocytes in patients with abnormal morphology can be improved by increasing insemination concentration at the time of IVF and (2) to evaluate the pregnancy outcome in patients with abnormal sperm morphology. Three groups were studied: (1) normal morphology, (2) good prognosis pattern, and (3) poor prognosis pattern. All other sperm parameters were normal. Group 3 had a lower overall fertilization rate, lower pregnancy rate/cycle, and lower ongoing pregnancy rate/cycle. Groups 2 and 3 showed a higher miscarriage rate, although not significantly different from group 1. By increasing insemination concentration from 2- to 10-fold, the fertilization rate in group 3 increased from 14.5% to 62.6%. However, pregnancy outcome did not improve. We conclude that patients with severe sperm head abnormalities have a lower ability to establish successful pregnancies, even though fertilization may be achieved.

The value of oocyte reinsemination in human in vitro fertilization

The value of oocyte reinsemination in human in vitro fertilization (IVF) was evaluated in this study. Two groups of 25 cycles each were studied. In group 1 cycles, insemination of mature/questionably mature oocytes (judged by cumulus and corona cell appearance) at 6.5 hours postcollection yielded a fertilization rate of 42.3%. This value was significantly lower than that obtained with reinsemination (70.8%). In group 2, questionably mature oocytes were treated as immature and inseminated 24 to 30 hours postcollection. The fertilization rate of mature eggs in group 2 was 68.2%, with a reinsemination success rate of 40%. Triploidy rates and cleavage rates of mature eggs, fertilized either at initial insemination or reinsemination and of fertilized immature eggs, were similar within group 1 and group 2 cycles. In group 1, two pregnancies resulted from transfer of embryos arising solely from successful reinsemination, with one infant delivered. These results indicate that reinsemination offers a useful adjunct for IVF in cases where fertilization failure occurs.

The role of gamete intrafallopian transfer (GIFT) in the treatment of oligospermic infertility

Gamete intrafallopian transfer (GIFT) was used to treat 32 couples where the male partner was oligospermic (less than 12 X 10(6) motile spermatozoa per milliliter of semen). Initially, 100,000 motile spermatozoa were transferred per fallopian tube and no pregnancies were achieved in 11 cases. The technique was then modified so that a maximal number of motile spermatozoa were transferred (range, 0.11 to 0.90 X 10(6) spermatozoa) and 6 of 21 (29%) pregnancies resulted, with 325,000 spermatozoa being the lowest number associated with pregnancy. It appears that the modified GIFT technique, whereby an increased number of motile spermatozoa are replaced with the oocytes, is an effective therapy in the treatment of oligospermic infertility.

Evolution of a highly successful in vitro fertilization-embryo transfer program

During the first 2 1/2 years of operation of the University of California at Los Angeles in vitro fertilization-embryo transfer program, 47 clinical pregnancies were achieved in 154 laparoscopies for oocyte aspiration (31%). Two of these pregnancies were achieved through transfer of cryopreserved embryos when ongoing pregnancy did not result from embryo transfer in the stimulated cycle. An increase in clinical implantation was noted with a reduction of transfer volume and proportion of air, with 34% of laparoscopies being followed by clinical pregnancy over the last 18 months. No difference in the rate of clinical pregnancy was noted relative to uterine depth or position. The high rate of multiple implantation (47%) suggested a high level of embryo quality. The success rate was attributed to a strong ovarian, human menopausal gonadotropin stimulation, accurate timing of human chorionic gonadotropin, a high oocyte retrieval rate, meticulous laboratory technique, atraumatic, high-fundal transfer of embryos, and initiation of embryo cryopreservation.

Correlation between in vitro fertilization and human sperm density and motility

The conventional sperm characteristics of density (millions per milliliter) and motility, scored in a semi-subjective way, were correlated with results of an on-going in vitro fertilization and embryo transfer program. No male infertility patients were included in this study. Individual characteristics of the "successful" ejaculates are described. Sperm densities in the original ejaculate of more than 10 X 10(6) spermatozoa/ml did not significantly improve outcome (P less than 0.01). In contrast, sperm motility seemed to play the most important role, since most pregnancies (12/14) occurred using sperm samples with greater than or equal to 60% total motility (P less than 0.001). The incidence of multipronuclear fertilization is also described and discussed. These data, which were collected during 1984 in the in vitro fertilization unit of Professor R. Schoysman and coworkers (Vilvoorde, Brussels), may help to make fertilization in vitro and embryo transfer a viable method in cases of mild male subfertility, and to provide guidance in preparing some couples for the combined use of husband and donor semen if a sufficient number of oocytes are obtained.

Assisted fertilization by zona drilling: a mouse model for correction of oligospermia

A micromanipulation apparatus was used to produce holes in the zonae pellucidae of unfertilized mouse oocytes. A microneedle loaded with acid Tyrode's solution was brought into contact with the zona surface, and positive flow was used in conjunction with mechanical pressure to cause a localized dissolution of the zona. Treated eggs were then fertilized in vitro in comparison with control cells. The zona drilling procedure decreased the sperm count required to achieve fertilization by a factor of approximately 100. The rate of polyspermy in zona-drilled oocytes was not greater than in controls, and oocytes fertilized after drilling, when implanted into pseudopregnant foster females, developed to term at the same rate as controls. The results demonstrate that zona drilling is a safe, effective method of increasing the efficiency of fertilization in vitro and may be useful both in agriculture and medicine for conferring fertility upon males with low sperm counts.

Analysis of deoxyribonucleic acid distribution in noncleaving oocytes from patients undergoing in vitro fertilization

The purpose of this study was to describe the quantity and distribution of deoxyribonucleic acid (DNA) in oocytes that did not fertilize or did fertilize and failed to cleave, from patients who underwent in vitro fertilization. Patients were selected with at least one cleaving egg, so that the sperm population was known to be fertile, and failure of fertilization or cleavage in the remaining oocytes could be attributed to nonspermatozoan factors. The noncleaving oocytes were classified into five categories, the majority of which (71%) lacked a polar body and any morphologically identifiable nucleus or germinal vesicle. Three general defects were found: failure to replicate the DNA properly; failure to package the DNA properly; and failure to organize the nuclear material properly after sperm penetration. It is concluded that either altered stimulation protocols or altered in vitro maturation conditions are needed to increase the average number of normal embryos available for transfer.

Comparison of two brands of clomiphene citrate for stimulation of follicular development in a program for in vitro fertilization

Although clomiphene citrate (CC) is used frequently to stimulate multiple follicular development in in vitro fertilization programs, comparison of the two commercially available types has been limited. Therefore, a comparison was made of Serophene (Serono Laboratories, Inc., Randolph, MA) and Clomid (Merrell Dow Pharmaceuticals, Inc., Cincinnati, OH), using the same dosage regimen of CC (150 mg/day for days 3 to 7 of the cycle). Weights and ages of the two groups were not different. Serum estradiol (E2) levels were significantly elevated in Clomid cycles, but the number of developing follicles was not different between the two brands. The percentages of patients in each group who underwent laparoscopy, oocyte recovery, oocyte fertilization, and embryo transfer were also equivalent. Among patients undergoing laparoscopy, no differences in oocyte recovery, oocyte fertilization, and embryo development were noted. Thus, despite greater elevation of serum E2 levels with Clomid, no difference in stimulation regimen outcome was observed.