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PubMed2004

In vitro sperm penetration speed and its relationship with in vivo bull fertility.

The in vitro tests utilized to evaluate sperm quality represent an interesting and important approach to evaluate ejaculated fecundant capacity. In the present work, the oocyte-penetrating ability of sperm from two bulls with low and two with high in vivo fertility rate was investigated. Sperm-quality parameters, such as sperm concentration, total and progressive motility, acrosome and total sperm anomalies, proximal cytoplasmic drops and live : dead sperm ratio were assessed and batches of sperm homologues in these parameters were selected. In expt 1, a sperm : oocyte ratio of 3000 was used and the oocytes were fixed 5, 10, 15 and 18 h post-insemination (hpi). In expt 2, the sperm : oocyte ratio was reduced to 1000 and the eggs were fixed at 8 and 10 hpi. The results, analysed by chi-square test, showed significant differences (p <0.001) among bulls at 15 hpi in expt 1 and 8 hpi in expt 2; nevertheless, no accordance was found between sperm penetration rate and in vivo fertility. At 18 hpi, the low-fertility bulls exceeded the two high-fertility bulls, supporting previous reports that suggest an opposite correlation between in vivo and in vitro fertility rate at low doses of heparin. Furthermore, a more efficient zona binding ability of one high-fertility bull was pointed out in expt 2 after the reduction of sperm : oocyte ratio, as it reached the highest percentage of penetration when compared with all the others.

Acrosome↗
PubMed1990

Fertility adaptation of Turkish and Moroccan women in the Netherlands.

"After a short overview of fertility trends among Turkish and Moroccan immigrants in the Netherlands, based upon population and vital registration data, determinants of these trends are analysed using survey data on cumulative fertility as well as on desired fertility." The author concludes that although "a long time series of data is not yet available due to the fairly recent history of the migration of Turkish and Moroccan women to the Netherlands, it appears that their fertility level is declining. Migrant fertility levels are lower than in the countries of origin.... Factors in the decline of overall immigrant fertility are variables related to the country of destination: work and education, insofar as this education was received in the Netherlands." (SUMMARY IN FRE AND SPA)

Africa↗
PubMedDate not supplied

Platelet-activating factor production from in vitro and in vivo fertilized murine embryos is similar.

PROBLEM: This study measured platelet-activating factor (PAF) production of in vitro and in vivo fertilized murine embryos to ascertain whether site of fertilization impacted subsequent embryonic PAF production. METHOD: Oocytes and embryo were collected from stimulated B6D2F1 mice. PAF production throughout the preimplantation phase from the two-celled stage through expanded blastocysts was measured and compared among normally developing embryos with the only difference being site of fertilization. RESULTS: A striking increase in PAF production was noted for both in vivo and in vitro fertilized embryos over the four days of culture. Significantly higher (P < .001) levels of PAF production were noted with development from the two-celled stage (47.22 +/- 4.13; 44.30 +/- 2.43) to expanded blastocysts (254.31 +/- 24.01; 255.11 +/- 5.35 ng/embryo/24 h) for both in vitro and in vivo fertilized embryos, respectively. There was no significant difference (P > .05) in PAF production between the two groups of embryos. CONCLUSIONS: Embryonic PAF production in the mouse increases in a stage-specific manner, and specifically the site of fertilization in vitro versus in vivo does not affect PAF production in normally developing embryos.

Animals↗
PubMed1975

Effect of 4-chloromethyl-2-methyl-2-pentyl- 1,3-dioxolane (AY-22,352) on the fertilizing ability of hamster epididymal spermatozoa.

Fertile male hamsters were injected subcutaneously with AY-22,352 to determine the minimal antifertility dose, the site of action and the onset and duration of infertility. Fertility tests showed that 37 mg AY-22,352/kg/day induced sterility within 4 days. None of the males became infertile within the first 2 days but marked loss of sperm fertilizing ability had occurred by 24 hr from the second injection; all males were sterile after the fourth dose. Comparable daily treatment procuded the same antifertility effect subsequent to bilateral ligation of the corpus epididymidis and fertilization did not occur after artificial insemination with spermatozoa from the cauda epididymidis of such animals. The prompt recovery of fertilizing ability of spermatozoa in males which receoved four daily doses of AY-22,352 (37 mg/kg) and had ligated ductuli efferentes shows that transport of epididymal spermatozoa and their acquisition of fertilizing ability are not influenced by the drug.

Animals↗
PubMed1986

Sperm factors related to failure of human in-vitro fertilization.

Two groups of men were retrospectively selected according to their observed success in in-vitro fertilization. Seminal and post-migration sperm samples from a low fertilization rate group (less than or equal to 33% cleaved embryos) have been compared to results obtained from a high fertilization rate group (greater than or equal to 66%). It was found that a low mean value of the amplitude of lateral sperm head displacement and an increased percentage of abnormal acrosomes were related to in-vitro fertilization failure. None of the individual sperm factors studied was found to determine in-vitro fertilization success with certainty; only when they were considered in combination was it possible to predict the likelihood of successful in-vitro fertilization of human oocytes.

Acrosome↗
PubMed1992

Insulin and insulin-like growth factor I in follicular fluid after induction of ovulation in women undergoing in vitro fertilization.

This study was undertaken to evaluate the relationship between concentrations of insulin and insulin-like growth factor I (IGF-I) in follicular fluid and fertilization and cleavage of human oocytes fertilized in vitro. The concentration of oestradiol, progesterone, luteinizing hormone, follicle-stimulating hormone, testosterone, insulin and IGF-I was determined in 36 follicular fluids, free of visible blood contamination and containing mature oocyte-corona-cumulus complexes, obtained from 12 women undergoing in vitro fertilization. Follicular development was induced by clomiphene citrate and human menopausal gonadotrophin, and follicular aspiration was performed 35 h after an ovulatory dose of human chorionic gonadotrophin. Concentrations of IGF-I were significantly higher in follicular fluids associated with mature oocytes that fertilized and cleaved, than in follicular fluid associated with mature oocytes that did not fertilize (P < 0.001). There was no difference in the concentration of insulin between follicular fluids from which fertilized oocytes were obtained and those with oocytes that remained unfertilized. No significant correlations were found between rates of embryo cleavage, concentrations of insulin and IGF-I. Multiple linear regression analysis demonstrated that the concentrations of IGF-I in follicular fluid were predicted statistically by a negative regression coefficient for the concentration of testosterone, and by a positive regression coefficient for the concentration of progesterone in follicular fluid. No candidate variable was included in the model to predict concentrations of insulin. These data suggest an important role for IGF-I in the mature follicle.

Adult↗
PubMedDate not supplied

Influence of male sexual rest and oocyte aging on parthenogenesis frequency in mice: cytogenetic analysis after in vitro fertilization.

This study was conducted to evaluate the influence of male sexual rest and oocyte aging on fertilization rate and parthenogenesis frequency after in vitro fertilization of mouse oocytes. We used a comparison between cleavage rates and fertilization rates according to chromosomal analysis of oocytes to estimate the parthenogenesis frequency. Fertilization rate was not impaired by male sexual rest. Parthenogenesis frequency was increased by male sexual rest. This effect was enhanced by a concomitant moderate oocyte aging. It is concluded that cleavage rate could not be considered as a reliable test of fertilization after attempted in vitro fertilization in such conditions.

Age Factors↗
PubMed2006

Characterization of Holstein heifer fertility in the United States.

The overall object of this research was to characterize US Holstein (virgin) heifer fertility. This included investigation of factors influencing heifer fertility and estimation of heritability, as well as correlations with cow fertility and first-lactation milk yield. A secondary objective was to compare linear and logistic model estimates of fixed effects and linear and threshold model estimates of heritability. Data consisted of Holstein heifers, which were artificially inseminated, with their first breeding between March 2003 and August 2005. Herds were required to have at least 60 breedings across the 3 yr of data and an overall mean conception rate (CR) between 20 and 80%. After edits there were 537,938 breedings of 362,512 heifers in 2,668 herds from 41 states used for analysis. After edits, the overall mean CR for US Holstein heifers was 57%. Linear and logistic model estimates for all factors were nearly identical. Year of breeding accounted for the most variation in heifer CR, with heifer age and month of breeding being the next most important factors. Conception rate in heifers is maximal at an intermediate age of 15 to 16 mo. Heifers at 26 mo of age and older have roughly a 10% lower CR than heifers bred at younger ages. Although month of breeding affected heifer CR, effects are less than for cows. In contrast to cow fertility, heifer CR is nearly as good in the hotter summer months as in cooler months. Approximately 88% of US herds had a 40 to 70% heifer CR. Heritability estimates of heifer CR on first service were 0.5% from the linear model and 1.0% from the threshold model. Genetic correlation estimates of heifer CR on first service with cow CR on first service and with first-lactation milk yield were 0.39 and -0.19, respectively. Results indicated that selection on either the currently available US daughter pregnancy rate evaluations for cow fertility or on cow CR will also improve heifer fertility. Furthermore, heritability of heifer CR is lower than for cow CR and reporting of heifer breedings is currently less complete than for cow breedings. Thus, there are currently no immediate plans to implement a US genetic evaluation for heifer CR.

Animals↗
PubMedDate not supplied

Accessory sperm as an indication of fertilizing ability of rabbit spermatozoa frozen in egg yolk-acetamide with detergent.

Many factors besides initial semen quality affect fertilization rates as sperm interact with the environment of the female reproductive tract. One of these factors is sperm transport, which can be evaluated by accessory sperm counts. Dutch rabbits were used to test the effects on sperm transport, fertilization, and production of young when sodium and triethanolamine lauryl sulfate (STLS) detergent was added to a medium for sperm cryopreservation. When STLS was added in 10 concentrations ranging from 0% to 2.0% (vol/vol) to an egg yolk-acetamide semen extender, optimal post-thaw motility of rabbit sperm occurred when 0.2% to 0.7% STLS was included. However, when 0%, 0.2%, and 0.7% STLS was included to cryopreserve sperm used for insemination, the fertilization rates were 95%, 68%, and 75%, and the corresponding mean numbers of accessory sperm per embryo were 13.1, 1.7, and 0.4 (P < .05). In another experiment, increasing the acetamide concentration from 0.75 M to 1.25 M decreased fertilization rates from 66% to 35%, and was associated with 4.5 and 0.6 accessory sperm per embryo (P < .05). In the final experiment, 48 does inseminated with sperm cryopreserved with 0%, 0.35%, and 0.70% STLS were allowed to produce young. Corresponding pregnancy rates were 56%, 56%, and 31% (P < .05), and litter sizes were 5.6, 4.1, and 4.2 (P > .05). In these studies, low concentrations of STLS improved motility of frozen-thawed sperm, but fertilization and pregnancy rates were reduced. Sperm transport was correspondingly reduced, and the accessory sperm count provided a reliable measure of the effect of STLS on fertility in contrast to the assessment of the percentage of motile sperm.

Acetamides↗
PubMed2000

Fertility in second unions in Austria: findings from the Austrian FFS.

The simultaneity of decreasing fertility and changing family structures in many European countries has led to a growing interest in fertility behavior in its relation to different family structures. The growing prevalence of higher-order unions (and the consequences for parity progression arising therefrom) is one example of an ongoing change in fertility behavior. Childbearing is not restricted to a single union but may extend over several partnerships. Fertility behavior in higher-order unions is becoming more and more important for determining completed fertility. Motivated by the work of Vikat et al. 1999, the authors investigate fertility behavior in second unions in Austria, focusing on whether and how it is influenced by the number of pre-union children of either partner.

Austria↗
PubMed1986

Fertility and adaptation: Indochinese refugees in the United States.

"Levels of fertility among Indochinese refugees in the United States are explored in the context of a highly compressed demographic transition implicit in the move from high-fertility Southeast Asian societies to a low-fertility resettlement region. A theoretical model is developed to explain the effect on refugee fertility of social background characteristics, migration history and patterns of adaptation to a different economic and cultural environment controlling for marital history and length of residence in the U.S." The chief source for the data and analyses is the Indochinese Health and Adaptation Research Project (IHARP), San Diego State University. "Multiple regression techniques are used to test the model which was found to account for nearly half of the variation in refugee fertility levels in the United States. Fertility is much higher for all Indochinese ethnic groups than it is for American women; the number of children in refugee families is in turn a major determinant of welfare dependency. Adjustments for rates of natural increase indicate a total 1985 Indochinese population of over one million, making it one of the largest Asian-origin populations in the United States."

Acculturation↗
PubMed1993

Recent trends in fertility differentials in Australia.

"The aim of this paper is not to examine broad trends in Australian fertility but to analyse the extent to which fertility patterns vary from one group to another within Australian society.... In general, differences between groups have been converging as fertility overall has declined." Aspects considered include aboriginal fertility, immigrant fertility, and fertility by socioeconomic group.

Australia↗
PubMed1989

Fertility on the US-Mexico border.

Using Bongaarts' model, the relative importance of the proximate determinants of fertility is explored in five populations on the US-Mexico border. For the groups closest to natural fertility (the two Mexican groups), lactation, use of contraception, and marriage all were moderately important in terms of their direct effect on fertility. For the group with lowest fertility (Anglo-American), contraceptive use was an important factor inhibiting fertility; marriage was important but not nearly as important as contraceptive use. For the two US Mexican-American groups, contraceptive use was an important intermediate variable, not as important as for Anglo-Americans, but more important than it was for the two populations in Mexico. The proportion married was a moderately important factor for the Mexican-American groups. For these five populations the principal differences in fertility rates result from substantial differences in the use of effective contraception. Bongaarts' model proved very useful as an analytical framework in this study.

Adolescent↗
PubMedDate not supplied

Taiwan's transition from high fertility to below-replacement levels.

This article compares the fertility experience of Taiwanese in the eight years since the total fertility rate reached 2.1 with that before fertility reached replacement levels. During the earlier period, two-thirds of the fertility decline resulted from falling marital fertility and one-third from higher age at marriage. The changing age distribution retarded this decline. Since 1983, the further decline to 1.7-1.8 has been entirely the result of the trend toward later marriage. Older age distributions now facilitate the decline. Births postponed by those marrying later make the conventional TFR misleading. Computation based on parity-progression ratios raise TFRs from 1.7 to 2.0, a number less alarming to policymakers. Contraceptive prevalence is at saturation levels in all major populations strata. The "KAP-GAP" has disappeared. What would have happened without Taiwan's effective family planning program is impossible to determine, but clearly, contraceptive services supplied by the program were the major proximate cause of Taiwan's fertility decline.

Adolescent↗
PubMed1994

[Sperm motility and fertilization].

Sperm motility is a key function in the process of fertilization. Significant gaps in the knowledge of the mechanisms of control and modulation of sperm motility still remain. It is well known that the percentage of motile sperm is correlated with fertility in vivo but the recent development of assisted reproductive technologies and the extensive use of objective methods to assess sperm movement in vitro indicate that the quality of sperm movement is important too for fertilization. However, the exact pattern of motility characteristics to fulfill fertilization in vitro and in vivo are not clearly established essentially because of the lack of multiparametric and controlled studies in vitro and prospective studies in vivo. There is also presently no evidence for an improvement of fertility when using different pharmacological approaches to increase sperm motility in vitro. Therefore, further efforts are required to improve our basic knowledge of the relations between sperm motility and fertility with the aim to adapt and apply it to the problem of male infertility.

Clinical Trials as Topic↗
PubMed1993

[New methods for predicting sperm fertilizing ability].

There is no reliable method for screening for the fertilizing ability of sperm. 3 new methods are presented: the freezing test (FT), hypoosmotic swelling test (HOST) and migration-sedimentation test (MST). The first 2, test the functional integrity and stability of the sperm membrane under certain osmotic conditions. The MST determines ability to separate high quality sperm. All tests were performed using either fresh semen of husbands, or thawed semen of donors used for fertilization in the IVF unit. Results of the FT were not correlated with the fertilizing ability of sperm in IVF, but HOST results with fresh, but not thawed semen, were correlated. Fertilization of oocytes in IVF was significantly better when HOST value of fresh semen was 45% or more. Motility and morphological normality of sperm separated by MST were better in ejaculates that fertilized ova under in vitro conditions, than in those that did not. Sperm separation by MST of 25% or more of motile sperm, or of more than 1.5 million motile sperm in the sample, indicated statistically significant ability for oocyte fertilization in an IVF system.

Cell Membrane↗
PubMed1993

Human sperm hyperactivation and acrosome reaction and their relationships to human in vitro fertilization.

OBJECTIVE: To determine the relationships between human sperm hyperactivation (HA) and acrosome reaction with fertilization of human oocytes in vitro. DESIGN: Prospective analysis of infertile patients undergoing IVF. SETTING: Tertiary center for infertility and assisted reproductive technology. PATIENTS: Fifty-two couples who underwent IVF or GIFT were studied. The male partners had normal semen parameters on routine analyses. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Sperm HA in seminal fluid and after 1 and 6 hours incubation in capacitation media; sperm acrosome reaction after 0, 6, and 24 hours' incubation in capacitation media; and fertilization rate of human oocytes. RESULTS: The percent spermatozoa with transitional HA after 6 hours of incubation correlated significantly with the fertilization rate of human oocytes. Multivariate discriminant analyses selected six sperm HA and acrosome reaction variables of predictive value in classifying semen samples that achieved fertilization rates above and below 70% threshold. Combination of the selected sperm HA and acrosome reaction variables in seminal fluid and after different times of incubation in capacitation medium classified the samples achieving good or poor fertilization rate with > 80% accuracy. CONCLUSIONS: Assessment of sperm HA and acrosome reaction may be of prognostic value in prediction of human oocyte fertilization rates.

Acrosome↗
PubMed1998

[Clinical aspects of fertility in stallions].

The studies described in this thesis investigated the factors that can affect the fertility of stallions. The introduction describes the male gamete and the processes that occur during maturation of sperm and fertilization. Methods to evaluate the quality of sperm and ova are then discussed. Fertility can be expressed in various ways and is also affected by many factors such as the stallion, the mare and management factors. The fertility of stallions is usually assessed a good year after they have served mares, because then the number of foals is known. However, it would be preferable to be able to predict a stallion's fertility before he is put to stud. To this end, it was investigated whether there is a relationship between a number of sperm parameters and the percentage of non-return after the first cycle. The endocrine control of reproduction is briefly described because hormonal factors can also influence the reproductive potential of stallions. The venereal diseases that are important for regulations concerning the international trade in sperm are also described. The relevance of this diseases to reproduction deserves further investigation. The minimum requirement for a stud stallion is that the stallion should produce sperm of adequate quality and should be able to fertilize mares.

Animals↗