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PubMed1990

Cellular and developmental biological aspects of bovine meiotic maturation, fertilization, and preimplantation embryogenesis in vitro.

Cellular aspects of reinitiated meiosis, fertilization, and early preimplantation embryogenesis in the bovine species were examined under in vitro conditions. An analysis of the cytoplasmic distribution of mitochondria, lipid droplets and vesicles in over 5,000 living GV-stage oocytes, with subsequent examination by electron microscopy, indicated that the organization of cytoplasm was pleomorphic and that five distinct cellular phenotypes could be identified. Inspection of oocytes during the resumption of arrested meiosis in vivo and in vitro demonstrated that the subcellular organization of the bovine oocyte cytoplasm remains unchanged during maturation to metaphase II. The influence of culture conditions and media on the frequency of maturation, cytoplasmic organization, fertilizability, and early preimplantation embryogenesis was also determined. The findings indicate that meiotic maturation and fertilization in the bovine species can occur at high frequency under comparatively simple and defined conditions. However, the acquisition of developmental competence for fertilization, and the ability of the egg to develop progressively after fertilization appears to be related to the organization of the cytoplasm at the GV stage. The relationship between cytoplasmic organization and conditions of maturation, fertilization, presence or absence of cumulus cells, and the acquisition of developmental competence is discussed with respect to 1) cell biological aspects of mammalian oocyte maturation, 2) the potential influence of extrinsic factors (e.g., differential intrafollicular biochemistry and morphophysiology) on subcellular organization of the GV-stage oocyte, and 3) the finding that morphologically equivalent bovine embryos derived from the in vitro fertilization of in vitro-matured oocytes may be developmentally heterogeneous. The studies also revealed that nuclear and cytoplasmic aberrations which could preclude normal embryogenesis can develop shortly after fertilization. The significance of this finding with respect to cytoplasmic phenotype of the oocyte and conditions of maturation, fertilization, and early embryo culture is discussed.

Animals↗
PubMed1983

Fertilization of mammalian eggs by sperm injection.

Mammalian sperm normally fertilize eggs in the ampulla of the oviduct after a long trip through the female reproductive tract. During this trip, the sperm become capacitated to fertilize but must overcome substantial barriers in the form of egg investments before reaching the plasma membrane of the egg. Once inside the egg the head of the sperm responds to cytoplasmic factors to decondense and form a pronucleus. All the problems of sperm penetration of the egg and its investments can be circumvented by injecting the sperm into the egg with a micropipette. Such injected sperm can participate normally in the subsequent events, typical of fertilized eggs, that lead to the formation of embryos. Sperm can also be injected into normally fertilized eggs to produce a third pronucleus and a triploid embryo. To avoid the mechanical problems of capturing a swimming sperm with a micropipette, the sperm suspension can be sonicated to break off the sperm tails. The resulting sperm heads can easily be injected into unfertilized eggs to induce the normal events of fertilization. With these injection procedures it is possible to test the fertilizing capacity of foreign sperm, of defective sperm, and even of "dead" sperm. We have found that the phenotype of the sperm does not reflect the genotype in terms of fertilizing ability after microinjection. Immotile and grossly defective sperm of the mouse when injected into the egg produce the same reactions that are produced by fertilization with healthy robust sperm.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Stimulating effect of pyroglutamylglutamylprolineamide, a prostatic, TRH-related tripeptide, on mouse sperm capacitation and fertilizing ability in vitro.

Pyroglutamylglutamylprolineamide, a prostatic tripeptide with structural similarities to thyrotrophin-releasing hormone (TRH), has been found in the seminal plasma of several mammalian species, suggestive of a biological function relating to spermatozoa. Using chlortetracycline (CTC) fluorescence analysis and in vitro fertilization, we have obtained evidence that the tripeptide stimulates mouse sperm capacitation and fertilizing ability in vitro. The tripeptide at concentrations from 5-500 nM was added to sperm suspensions and cells were assessed with CTC after 40 min, insufficient time for complete capacitation by a majority of spermatozoa under standard conditions of incubation. Concentrations of 25 nM and higher significantly promoted capacitation, as evidenced by a decrease in the proportion of acrosome-intact F pattern spermatozoa, characteristic of uncapacitated cells, and an increase in the proportion of acrosome-intact B pattern spermatozoa, characteristic of uncapacitated cells. However, there was no significant stimulation of acrosomal exocytosis. These results suggested that peptide-treated cells would be more fertile than their untreated counterparts. This was confirmed using in vitro fertilization, where the presence of 100 nM peptide during sperm preincubation and gamete coincubation significantly stimulated fertilizing ability (peptide, 56.5% of oocytes fertilized; controls, 26.5%). Comparison of the prostatic tripeptide and TRH effects on capacitation revealed that TRH at a concentration of 250 nM was as effective as the prostatic tripeptide in promoting the F-->B transition but was less effective or ineffective at lower concentrations. In vitro fertilization assessment of the two peptides, at 100 nM, revealed that only the prostatic tripeptide significantly stimulated fertility. Again, this was consistent with the CTC analyses.(ABSTRACT TRUNCATED AT 250 WORDS)

Acrosome↗
PubMed2002

An essential role for functional telomeres in mouse germ cells during fertilization and early development.

Late generations of telomerase-null (TR(-/-)) mice exhibit progressive defects in highly proliferative tissues and organs and decreased fertility, ultimately leading to sterility. To determine effects of telomerase deficiency on germ cells, we investigated the cleavage and preimplantation development of embryos derived from both in vivo and in vitro fertilization of TR(-/-) or wild-type (TR(+/+)) sperm with either TR(-/-) or TR(+/+) oocytes. Consistently, fertilization of TR(-/-) oocytes with either TR(+/+) or TR(-/-) sperm, and TR(-/-) sperm with TR(+/+) oocytes, resulted in aberrant cleavage and development, in contrast to the normal cleavage and development of TR(+/+) oocytes fertilized by TR(+/+) sperm. Many (>50%) of the fertilized TR(-/-) eggs developed only one pronucleus, coincident with increased incidence of cytofragmentation, in contrast to the normal formation of two pronuclei and equal cleavage of wild-type embryos. These results suggest that both TR(-/-) sperm and oocytes contribute to defective fertilization and cleavage. We further found that a subset (7-9%) of telomeres was undetectable at the ends of some metaphase I chromosomes from TR(-/-) spermatocytes and oocytes, indicating that meiotic germ cells lacking telomerase ultimately resulted in telomere shortening and loss. Dysfunction of meiotic telomeres may contribute to aberrant fertilization of gametes and lead to abnormal cleavage of embryos, implying an important role of functional telomeres for germ cells undergoing fertilization and early cleavage development.

Animals↗
PubMedDate not supplied

The murine Rb(6.16) translocation: alterations in the proportion of alternate sperm segregants effecting fertilization in vitro and in vivo.

The segregation products of the mouse Rb-(6.16)24 Lub male translocation carrier were analyzed at first cleavage metaphase to determine whether the proportion of normal, balanced, and unbalanced sperm segregants differ in fertilizations occurring in vivo and in vitro. From 34 males, the sperm genomes in 268 first-cleavage mouse embryos were analyzed cytogenetically: 137 and 131 following in vivo and in vitro fertilization, respectively. Both systems demonstrated a preponderance of alternate (67.2% and 54.2%) as compared to adjacent segregation (10.2% and 13.7% as estimated). A contingency table showed that the distribution of reciprocal alternate segregants differed significantly between the two fertilization environments (chi 2 = 20.64, P < 0.0005). Whereas chromosomally normal sperm were 3.6 times more likely than the balanced reciprocals to fertilize in vivo (78.3% normal: 21.7% balanced), 1:1 ratios were recovered following in vitro fertilization (43.7% normal: 56.3% balanced). The data also showed an excess of Y-bearing sperm with the translocation in both in vivo and in vitro fertilization groups. In the latter these segregants were 3 times more likely than X-bearing ones to effect fertilization. These data suggest a phenotypic disadvantage of translocation-X-bearing sperm, possibly mediated through altered haploid gene expression on chromosome 6 and gene expression on the Y. The results show clear evidence for prezygotic selection in vivo and indicate that the environment in which fertilization occurs significantly affects the transmission frequency of this specific translocation.

Animals↗
PubMed2002

Levels of environmental contaminants in human follicular fluid, serum, and seminal plasma of couples undergoing in vitro fertilization.

Environmental chemicals are thought to adversely affect human reproductive function, however there are no studies that have explored the association between failed fertilization and exposure of both partners to environmental contaminants. Therefore, we collected blood and follicular fluid from the female partner and seminal plasma from the male partner of 21 couples attending an in vitro fertilization (IVF) program, in order to determine the extent of the existence of environmental chemicals in these fluids. Any relationship to the outcome of IVF was also considered. Sera and fluids were analysed for a variety of contaminants, including polychlorinated biphenyls, pesticides, cotinine, and the steroids progesterone and estradiol. Of the couples examined, 18 had fertilizations, three of whom became pregnant. There were no fertilizations in three other couples. The contaminants most frequently found in follicular fluid, more than 50% of the samples tested, were p,p'-DDE, mirex, hexachloroethane, 1,2,4-trichlorobenzene, PCB 49, PCB 153, and PCB 180. Cadmium was detected in eight of 21 (38.1%) samples of follicular fluid whereas cotinine was detected in 18 (85.7%). Residue levels of p,p'-DDE, endosulfan I, PCB 99, PCB 138, PCB 153, PCB 180 were quantified in more than 50% of the sera samples examined. Seminal plasma was relatively free of pollutants with mirex being the most frequently detected contaminant found in seven of 21 (33.3%) samples. Mirex could not be detected in the seminal plasma of the husbands whose partner's oocytes failed to fertilize whereas significant levels of mirex were found in the seminal plasma of all couples who had a pregnancy. Cadmium was also found in the follicular fluid of these pregnant subjects. No relationship was found between follicular fluid cotinine in pregnant and non-pregnant subjects. Where identical contaminants were found in both sera and follicular fluids, the levels were about twofold higher in serum and were positively correlated in both fluids. Fertilization was negatively correlated with serum and follicular fluid p,p'-DDE whereas pregnancy was positively correlated with follicular fluid PCB 49. These data reveal that more than 50% of the population of women attending a fertility program have had exposure to environmental chemicals sufficient to produce detectable concentrations in their serum and ovarian follicular fluid. Of the chemical contaminants detected in the serum and follicular fluid of these women, p,p'-DDE was the most frequently detected, had the highest residue levels, and was associated with failed fertilization.

Adult↗
PubMed1989

An evaluation of the BIOSELF 110 fertility indicator.

The BIOSELF 110 is a hand-held, non-invasive electronic instrument that measures basal body temperature and cycle length, and automatically identifies the fertile and infertile phases of the menstrual cycle with flashing red light and green light signals, respectively. The device was evaluated in 77 cycles from 33 ovulatory women in Kuala Lumpur, Malaysia. Ultrasound monitoring of maximum follicular diameter (MFD) and urinary LH measurements with Ovustick were used as reference methods to estimate the time of ovulation and the fertile period. Based on the MFD day, the BIOSELF correctly identified the entire fertile period, and at least four fertile days, in 89% and 94% of the cycles studied, respectively. The mean duration of the fertile period as determined by the number of flashing red light days was 11.0 days (SD 2.9). The device correctly identified the onset of the postovulatory infertile phase in 94% of cycles, with a mean duration of about 10 (green light) days. The results were similar using the LH peak day as the reference method. The mean interval from the onset of the fertile period (first flashing red light day) to the MFD day was 6.9 days (SD 2.6), and from the MFD day to the end of the fertile period, 3.1 days (SD 2.2). The BIOSELF 110 showed itself to be a reliable device for identifying the fertile and infertile phases of the menstrual cycle and, thus, should be a useful aid for couples seeking pregnancy. Prospective clinical trials are underway to assess the contraceptive effectiveness of the device.

Adult↗
PubMedDate not supplied

An in vivo and in vitro investigation into the effects of alpha- chlorohydrin on sperm motility and correlation with fertility in the Han Wistar rat.

Following a recommendation from the International Conference on Harmonisation, pharmaceutical companies are now monitoring possible drug effects on sperm motility in the rat during preclinical safety studies by assessing sperm motility (velocity). However, it is not known precisely how changes in sperm motility relate to fertility. Therefore, the effects of alpha-chlorohydrin on sperm motility were investigated and related to fertility both in vivo and in vitro. alpha-Chlorohydrin was given orally to male rats using a range of doses: 0, 5, 10, and 20 mg/kg for at least 5 consecutive days. Sperm were than assessed for motility using a standard scoring system (operators' observation of sperm) that graded degree of motility (i.e., 0 = i mmotile to 4 = very motile). The results showed a dose-related decrease in sperm motility. The sperm also appeared to move with a "jerky" action. Surprisingly, when this was correlated to fertility, none of the females mated with treated males became pregnant. A dose-related decrease in pregnancy would perhaps have been expected. There was no effect on sperm morphology, and testicular and epididymal pathology were only seen after doses of 20 mg/kg. When sperm from untreated rats were incubated with alpha-chlorohydrin in vitro at concentrations of 0, 0.5, 1.0, and 1.5 mM, sperm motility and motion were similarly affected as observed in vivo. However, the fertilization capacity (in vitro fertilization) of the treated sperm showed a concentration-related reduction in percentage fertilization, and there was also evidence of abnormal embryo development. These findings suggest that the present standard scoring system used in preclinical safety studies is not a comprehensive indicator of sperm function and/or fertility. A better understanding of sperm movement, therefore, is desirable so effects on sperm motility can be related to fertility.

Administration, Oral↗
PubMed2005

Sperm factors related to in vitro and in vivo porcine fertility.

The prediction of sperm fertilizing ability has great economic importance for breeding herds when artificial insemination is used. Classical methods of semen evaluation generally measure the sperm concentration, progressive motility, percentage of viable cells, and acrosome morphology. These assays are poor in predicting sperm fertility, because only the samples with markedly poor quality can be detected. The development of new sperm tests that measure certain sperm functions is an attempt to solve this problem. On the other hand, the binding and penetration of the zona pellucida is one of the most important barriers the spermatozoa must overcome in the fertilization process. Also, the interaction with the oocyte plasma membrane appears to explain much of the variability in sperm fertilizing potential among fertile boars. Thus, the study of the relationship between sperm factors and in vitro fertility may be a good strategy and assays that include a study of gamete interaction may lead to a better way to predict male fertility than the routine laboratory evaluation of semen. This review will discuss the relationships between sperm factors and fertility in vitro and in vivo (AI trial) with both diluted and frozen-thawed semen. We will also try to analyze the problems and limitations related to the interpretation of boar sperm tests.

Animals↗
PubMed1985

Male factor evaluation in in vitro fertilization: Norfolk experience.

Thirty-three patients from the in vitro fertilization (IVF) program at Norfolk are critically reviewed. A battery of tests was designed and an endocrine investigation was carried out on these patients. The fertilization rate for preovulatory oocytes was lower than in the normal male population (39.6% versus 88.6%). When total concentration of sperm with rapidly progressive motility was less than 6 X 10(5), to fertilize several eggs together the fertilization rate was zero. No fertilization was obtained when the number of sperm with rapidly progressive motility recovered after the separation was less than 1.5 X 10(6). The hamster zona-free oocyte penetration test correlated well with the human IVF system. The other parameters investigated did not show good correlation. When fertilization was achieved, the results of the IVF procedure in the series reviewed rendered a 30.8% pregnancy rate per transfer in 26 transfers. Fifty percent of the pregnancies were normal (either ongoing or delivered). Thirty-seven percent were preclinical miscarriages, and 12.5% were clinical abortions. In the abnormal male population, higher concentrations of sperm per egg should be used for insemination for achievement of optimum fertilization rates. Once fertilization is obtained, the results do not differ substantially from the IVF population at large.

Animals↗
PubMed1994

Confocal scanning laser microscopy of morphometric human sperm parameters: correlation with acrosin profiles and fertilizing capacity.

OBJECTIVES: To develop quantitative criteria for assessing sperm morphology and to determine the correlation between the percentage of morphologically normal spermatozoa and the outcome of the sperm hypo-osmotic swelling test, sperm acrosin profile, and sperm capacity for fertilization. DESIGN: The maximal length and width of the sperm head, the length of the midpiece and principal piece of the sperm tail, and the ratio of the surface of the acrosomal region to the total surface of the head were determined in specimens obtained from a group of infertile men and a group of fertile men using a confocal scanning laser microscope. Group A consisted of 53 infertile men who were participating in an IVF program, and group B consisted of 98 fertile men. The mean +/- 2 SD of the morphometric parameters in group B was established as representing the lowest and highest normal values in both groups. A normal spermatozoon was defined as one with morphometric parameters within normal levels. The lowest percentage of morphologically normal spermatozoa, hypo-osmotic swelling test result, and acrosin activity in group B were also taken as the lowest normal values in group A. SETTING: In vitro fertilization program at the Tottori University School of Medicine, Yonago, Japan. MAIN OUTCOME MEASURES: Sperm morphometric parameters, percentage of morphologically normal spermatozoa, hypo-osmotic swelling test, and acrosin activity. RESULTS: The length of the midpiece, ratio (x 100) of the surface of the acrosomal region to the total surface of the sperm head, percentage of morphologically normal spermatozoa, outcome of hypo-osmotic swelling test, and acrosin activity were significantly higher in group B than in group A. The maximal width of the head was significantly lower in group B than in group A. Strongly positive correlations were observed between percentage of morphologically normal spermatozoa or length of midpiece and the proportion of fertilized oocytes in group A and between ratio (x 100) of the surface of the acrosomal region to the total surface of the head and acrosin activity in groups A and B. Sperm morphology showed high positive and negative predictive values for acrosin activity (normal/abnormal) and fertility potential (present/absent). CONCLUSIONS: Using quantitative strict criteria, we found that sperm morphology was an important predictor of sperm fertilizing capacity. The confocal scanning laser microscope provided useful information about the sperm cytoskeleton and its importance in fertilization.

Acrosin↗
PubMed2003

Effect of reducing sperm concentration during IVF on the ability to distinguish between bulls of high and low field fertility: work in progress.

The objectives of this study were to evaluate the effect of sperm dose and sire on the fertilization rate, cleavage rate and blastocyst yield following insemination in vitro, to examine the relationship between these parameters and field fertility in cattle, and to examine the relationship between blastocyst quality and sire used in IVF. Frozen semen from four bulls with 150-day nonreturn rates ranging from 57 to 78% was used. In Experiment 1, oocytes were inseminated with sperm from one of the four bulls at concentrations ranging from 0.016 to 0.5 x 10(6)sperm/ml. A proportion of presumptive zygotes were fixed at 17 h post-insemination (hpi), while the remainder was transferred to in vitro culture (IVC) in droplets of synthetic oviduct fluid (SOF). Cleavage at 48 hpi and the percentage of oocytes reaching the blastocyst stage by Day 8 were recorded. In Experiment 2, to assess blastocyst quality, after insemination with semen from one of the four bulls, presumptive zygotes were cultured in SOF until Day 7. Blastocysts for each bull were removed and vitrified/warmed and survival was recorded at 24, 48 and 72 h after warming. Regardless of bull used, a concentration of 0.125 x 10(6)sperm/ml or above resulted in higher blastocyst yields than any lower concentration used. Fertilization and cleavage rates were also higher at higher sperm concentrations. The best predictor of field fertility was fertilization rate at a concentration of 0.5 x 10(6)sperm/ml (r=0.94, P<0.0001). There was also a significant correlation between cleavage rate at a concentration of 0.5 x 10(6)sperm/ml and nonreturn rate (r=0.90, P<0.0001). In Experiment 2, blastocysts derived from one bull, HTA, were of superior quality as measured by survival 24h after thawing, although these differences were less significant at the subsequent time points measured. In conclusion, these data show that differences between the field fertility of bulls can be determined at sperm concentrations routinely used in IVF. Lowering the sperm concentration does not increase the likelihood of optimizing the differences in fertility or cleavage rate between bulls of different field fertility. We have also demonstrated that the bull can have a significant effect on the quality of blastocysts produced using IVF techniques.

Animals↗
PubMed1997

Influence of an antiprogestin (onapristone) on in vivo and in vitro fertilization.

The effects of a progesterone antagonist (onapristone) on heat synchronization, luteinizing hormone (LH) surge, ovulation, oocyte maturation and fertilization of superovulated ewes were studied. Its effects on in vitro bovine oocyte maturation and fertilization were also studied. Estrus synchronization and superovulation treatments were applied to 39 adult ewes using an intravaginal sponge with fluorgestone acetate for 9 days with injections of prostaglandin F2 alpha and pregnant mare's serum gonadotrophin given 24 h before sponge withdrawal. The animals were randomly assigned to four different groups; T1 receiving only the synchrony treatment (n = 11); T2 ewes received two injections of onapristone (1 mg kg-1, i.v.) 12 h apart from 3 h after sponge withdrawal (n = 10); T3 ewes received two injections of progesterone 12 h apart from sponge withdrawal (n = 10); and, T4 ewes received both onapristone and progesterone as described (n = 8). Ewes were mated by a fertile male during estrus. Progesterone and LH were measured during the superovulation period in plasma samples taken every 4 h. Uterine flushings for ova recovery were performed at 5 days (n = 25), 48 h (n = 5) and 24 h (n = 5). Non-fertilized oocytes collected at 24 and 48 h were checked for meiosis resumption. The effects of two doses of onapristone (D1 and D2) on in vitro bovine oocyte maturation (control = 100, D1 = 100 and D2 = 100) and fertilization (control = 107, D1 = 40 and D2 = 75) were also studied. The percentage of animals showing heat signs was significantly lower in group T3 (50% vs. 100%). The onset of oestrus (27.6, 24.8, 68.8 and 25.5 h, respectively for T1, T2, T3 and T4) and an LH surge (32.3, 28.8, 76.5 and 30.5 h, respectively for T1, T2, T3 and T4) after sponge withdrawal were significantly delayed in group T3. There were no significant differences in the intervals between estrus and LH surge among groups (4.61 +/- 0.75 h). The response and ovulation rates until 40 h after sponge withdrawal (group T3 excluded) were similar among groups, but the fertilization rates were significantly lower in groups T2 and T4 when compared with T1 (2% and 3% vs. 41%, respectively; P < 0.001) due to sperm arrest in the cervix. Ova recovery rate decreased significantly from 24-48 h to 5 days and was not affected by treatments (76.9% vs. 37.1% respectively). Onapristone did not affect the resumption of meiosis. Fertilization of bovine oocytes in vitro decreased significantly only in group D2 when compared to control (48% vs. 62.6%, respectively). In conclusion, onapristone treatment during the preovulatory period did not interfere with normal synchronization of estrus, ovulation and oocyte maturation but severely compromised fertilization by arresting spermatozoa in the cervix.

Animals↗
PubMed1995

Religion and fertility in the Outer Hebrides.

Estimates of fertility in Protestant Barra and Catholic Harris, islands in the Outer Hebrides, over the period 1856-1985, show that in both islands fertility declined, although marital fertility was generally greater than in Scotland as a whole, and illegitimate fertility was less. However, in Barra during 1966-75 there were pronounced rises in all the indices; illegitimate fertility showed the smallest rise. The publication of the papal encyclical Humanae Vitae may have played a part in this change in fertility, although other, probably local, factors must have been acting, as the first rise in numbers of births occurred before the publication of the encyclical. Other than this transient rise, the religious difference between Harris and Barra had little effect on changes in fertility over the whole period. Indices of proportions married showed declines until after World War 2, followed by steep increases. The marked decline in fertility in both islands may be due in part to this low nuptiality. In addition, a trend of occupation away from traditional crofting and fishing towards more skilled mercantile and professional employment may have played a role.

Adolescent↗
PubMed2005

Embryos produced in vitro from bulls carrying 16;20 and 1;29 Robertsonian translocations: efficiency and kinetics of oocyte fertilization and embryo development.

The present experiments were designed to study the effects of Robertsonian translocations on the efficiency and kinetics of in vitro fertilization and early and advanced embryo development. Spermatozoa from bulls with rob(16;20), rob(1;29) and normal karyotype (A, B and C, respectively) were used. Oocytes were matured, fertilized and cultured by the standard protocol described previously. Twenty-four hours after fertilization, adequate numbers of oocytes were fixed, stained and examined. The development of embryos was evaluated on days 2 (D2), 7 (D7) and 8 (D8) after fertilization. The rate of normally fertilized oocytes was significantly lower (p < or = 0.01) for bull A than for bulls B and C. However, no significant differences in the kinetics of fertilization were found between bulls A, B and C. The D2 cleavage rate of embryos was significantly lower (p < or = 0.01) for bull A than for bulls B and C. Both D7 and D8 blastocyst rates for bull A or bull B were significantly lower (p < or = 0.01 or p < or = 0.05) than those for bull C. The percentages of both D7 advanced blastocysts and D8 expanded blastocysts were significantly lower (p < or = 0.01) for bulls A and B than for bull C. In conclusion, for rob(16;20), the efficiency of fertilization was strongly reduced; it resulted in low early and advanced embryo development. On the other hand, for the rob(1;29), neither fertilization nor early embryo development were affected and only advanced embryo development was decreased. But for both translocations, blastocyst formation was significantly delayed.

Analysis of Variance↗
PubMed1992

The effect of nuptiality status variables on fertility: the Kenyan experience.

"This paper examines the relationship between fertility and nuptiality in Kenya using data from the Kenya Fertility Survey 1977/78. The results show that completed fertility (the cumulative fertility at the end of the reproductive period 15-49) decreases with the rise in age at first marriage. Type of union is also found to affect marital stability, frequency of marriage and consequently completed fertility. Regardless of type of union, women whose first union is still continuing have higher fertility than those women whose first union was dissolved and who married once or several times after. Highest fertility is experienced by women married only once and...in monogamous unions. The results also show that polygamously married older women among the rural populations experience higher fertility than their counterparts in the urban areas regardless of age." (SUMMARY IN AFR)

Africa↗
PubMed2003

Diversity of the inhibitory effects on fertilization by anti-sperm antibodies bound to the surface of ejaculated human sperm.

BACKGROUND: The presence of anti-sperm antibodies (ASA) in males can reduce fecundity. However, it has been shown that there is a diversity of ASA bound to the sperm surface. This study was performed to investigate the inhibitory effects on fertilization by ASA in males. METHODS: ASA were detected using the direct-immunobead test (D-IBT) in 509 semen samples. In some cases, the direct-sperm immobilization test (D-SIT) was carried out. The fertilizing ability of infertile males with ASA was determined as follows; (i) an IVF fertilization rate of >/=50%, (ii) a hemizona index (HZI) of >/=50%, and (iii) pregnancy established without the use of ART. RESULTS: In total, 18 (3.54%) infertile males had ASA on the sperm surface. Except for one male with an absolute indication for ICSI because of severe asthenozoospermia and two males who dropped out of this study, fertilizing ability in 15 males could be determined. Four (26.7%) men did not satisfy the criteria. The existence of sperm immobilizing antibodies on the surface of ejaculated sperm had no impact on fertilization. In four (57.1%) of seven patients who had IB-bound sperm of >/=80%, fertilizing ability was inhibited, while none of the eight patients who had <80% IB-bound sperm had an inhibitory effect on fertilization. There was a significant difference between the two groups (P = 0.01). CONCLUSIONS: Some sperm-bound antibodies are related to the inhibitory effects on fertilization, indicating that a diversity of sperm-bound antibodies exists in males. This result might be one of the reasons for the controversy of the relationship between ASA and male immunological infertility. Based on the present study, a sperm-zona pellucida binding assay should be performed for appropriate decision making in infertile males with ASA.

Adult↗
PubMed1996

Two functional assays of sperm responsiveness to progesterone and their predictive values in in-vitro fertilization.

We have recently reported, in a small cohort of subjects, that acrosome reaction (AR) and intracellular free calcium ([Ca2+]i) increase in response to progesterone were significantly correlated with in-vitro fertilization (IVF) rate. In the present study we extended these results to 90 subjects undergoing IVF. We confirm that both parameters were highly significantly correlated with the fertilization rate (P < 0.001). In particular, significantly lower responses to progesterone were detected in subjects with a fertilization rate < 50%, further enlightening the functional significance of sperm responsiveness to progesterone with respect to the process of fertilization. Moreover, we report here that both tests are highly discriminant of fertilization success, with positive predictive values > 90% for [Ca2+]i values which increase by > 1.2-fold and AR inducibility > 7% (cut-off values). Conversely, AR following challenge with the calcium ionophore A23187 was less significantly correlated with the percentage fertilization rate (P < 0.05), and showed lower predictive values than response to progesterone. All these tests ([Ca2+]i increase in response to progesterone, AR in response to progesterone and to A23187) appear highly sensitive and moderately specific. The positive predictive value may rise to > 95% when the combination of two tests ([Ca2+]i and inducibility of AR in response to progesterone) is considered. No correlation with fertilization rate has been found for spontaneous AR or basal [Ca2+]i. In conclusion, we propose that assessment of human sperm responsiveness to progesterone may be clinically useful in predicting fertilizing ability in vitro.

Acrosome↗