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At least 19 recordsLinked to original sources
PubMed1992

Increased fertilization and pregnancy rate in polypronuclear fertilization cycles in in vitro fertilization-embryo transfer.

OBJECTIVE: To compare fertilization and pregnancy rates between cycles with polypronuclear fertilizations and cycles with normal fertilizations. DESIGN: In vitro fertilization-embryo transfer (IVF-ET) cycles in which oocytes were retrieved were divided into two groups according to the nature of fertilization. PATIENTS: All patients were participants of our IVF-ET program. RESULTS: A significantly higher fertilization rate was found in the polypronuclear fertilization cycles (61% versus 36.6%) and also an improved pregnancy rate (47.5% versus 19.6%) and per embryo transfers (53% versus 28.8%). The vast majority of polypronuclear fertilizations occurred in mature oocytes. CONCLUSION: We believe that the increased receptability of the oocytes improves fertilization and conception rates. The polypronuclear fertilization is an extreme expression of such improved receptibility and should be considered as an encouraging sign for conception.

Embryo Transfer↗
PubMed1994

The effect of varicocele ligation on oocyte fertilization and pregnancy after failure of fertilization in in vitro fertilization-embryo transfer.

Although varicocelectomy is generally believed to improve semen quality and the hamster egg penetration assay, these parameters do not correlate well with in vitro fertilization (IVF) success. The effect of varicocelectomy on IVF of human oocytes was examined on thirteen couples with normal female fertility, but severe oligozoospermia and the presence varicocele in the males with failure of fertilization preoperatively in in vitro fertilization-embryo of transfer (IVF-ET) attempts. The couples were readmitted for the IVF-ET procedure following varicocelectomy. A 31% pregnancy rate was achieved after the operation, while no pregnancies occurred before surgery. Sperm density and motility improved significantly after operation, resulting in a coinciding improved fertilization and pregnancy rates.

Embryo Transfer↗
PubMed1998

Fertilization failures and abnormal fertilization after intracytoplasmic sperm injection.

This study addresses the incidence of failed (0%) and suboptimal (<50%) fertilization after intracytoplasmic sperm injection (ICSI), variation in the ICSI fertilization rate for specific couples, and the causes of fertilization failure and abnormal fertilization after ICSI. Failed fertilization occurred in only 37 of 1343 cycles (3%). The risk of failure was highest (37%) when only one oocyte was injected, and was lowest (0.8%) when five or more oocytes were collected. The incidence of suboptimal fertilization and the variation in the fertilization rate were studied in 87 couples who each had three cycles of ICSI in which four oocytes were injected with ejaculated spermatozoa. Approximately 74% of these couples achieved >50% fertilization in every cycle. Only 26% of the couples had <50% fertilization in one or more cycles, and most of these (17%) had only a single cycle with suboptimal fertilization. Only four of the 87 couples (5%) had suboptimal fertilization in all three cycles. The difference between the maximum and minimum fertilization rate for a couple was used as an index of variation of the fertilization rate. It was found that 47 couples (54%) had 0-25% variation, 33 couples (38%) had 26-50% fertilization and only seven couples (8%) had >50% variation. The causes of failed and abnormal fertilization were studied in unfertilized and abnormally fertilized oocytes after staining with Hoechst 33342. In total, 1005 unfertilized oocytes were studied, of which 828 (82%) were still at metaphase II and 177 (18%) were activated. Most of the oocytes (83%) contained a spermatozoon and, in the majority of these oocytes, the sperm head was partially or completely decondensed. Hence, failure of oocyte activation was the principal cause of fertilization failure. A similar pattern was observed in activated, unfertilized oocytes, although there was a higher incidence of intact spermatozoa in these oocytes compared with metaphase II, unfertilized oocytes. Interestingly, 56% of the activated oocytes contained a decondensed sperm head which was not processed into a male pronucleus. A total of 169 abnormally fertilized oocytes was also studied. Two anomalies were found: digyny due to retention of the second polar body and its subsequent transformation into a third pronucleus, and abnormal pronuclear size and number.

Adult↗
PubMed1998

Low pregnancy rate is achieved in patients treated with intracytoplasmic sperm injection due to previous low or failed fertilization in in-vitro fertilization.

The main indications for intracytoplasmic sperm injection (ICSI) are severe male factor and fertilization failure or a low fertilization rate in previous in-vitro fertilization (IVF) treatments. The fertilization and pregnancy rates after ICSI, however, are seldom reported separately for these two different indications. The aim of this study was to compare the treatment outcome and pregnancy rate after ICSI between 65 patients with previous failed fertilization or a low fertilization rate without male factor, and 219 patients with a primary male factor. From the 2726 oocytes collected, 2087 (77%) were micro-injected and 1355 (65%) achieved normal fertilization. The oocyte fertilization rate was similar in the group with previous failed fertilization or a low fertilization rate and the group with a male factor (65 and 65% respectively), as was the cleavage rate of normally fertilized oocytes (92 and 94% respectively). Despite the similar fertilization and cleavage rates and the similar number and morphological quality of embryos transferred in both groups, the pregnancy rate was significantly lower (P < 0.05) in the group with previous failed fertilization or a low fertilization rate than in the group with a male factor (19.6 versus 33.5% respectively; 95% confidence intervals for the difference, 2-26%). The implantation rate was also lower (P = 0.01) in patients with previous failed fertilization or a low fertilization rate (9.6%) than in the group with a male factor (19.5%). We conclude that patients with previous failed fertilization or a low fertilization rate in standard IVF without male factor have a significantly smaller chance of becoming pregnant after subsequent ICSI than patients with a primary male factor. This poor outcome probably reflects intrinsic oocyte defects not bypassed by ICSI.

Adult↗
PubMed1992

Sperm creatine phosphokinase M-isoform ratios and fertilizing potential of men: a blinded study of 84 couples treated with in vitro fertilization.

OBJECTIVE: To examine the value of sperm creatine phosphokinase M-isoform (CK-MM) measurements toward predicting fertilizing potential of men. DESIGN: In 84 in vitro fertilization (IVF) couples without knowing the semen parameters, reproductive history or the outcome of the IVF cycles, we determined the sperm CK-MM ratios (the proportion of sperm CK-MM versus CK-MM+CK-BB). Husbands with less than 10% or greater than or equal to 10% CK-MM ratios were classified as "low likelihood for fertilization" (CKMM-Infertile, n = 22) or "high likelihood for fertilization" (CKMM-Fertile, n = 62), respectively. RESULTS: Both the CKMM-Infertile and CKMM-Fertile groups (CK-MM ratios: 4.9% +/- 0.6% versus 31.1% +/- 1.8%) were in the normospermic range (31.5 +/- 6.9 versus 78.4 +/- 5.9 x 10(6) sperm/mL and 45.6% +/- 5.0% versus 54.0% +/- 2.0% motility). The fertilization rates (6.2 versus 4.9 oocytes inseminated) were 14.2% versus 53.4%, and 72.7% versus 25.8% of the couples failed to achieve any oocyte fertilization. All 14 pregnancies (16.7% rate) occurred in the CKMM-Fertile group. The pregnancy rate in the 62 CKMM-Fertile couples was 22.6%, and considering only the 46 CKMM-Fertile women in whom oocyte fertilization occurred, it was 30.4%. Among the 22 CKMM-Infertile men, 9 were normospermic and 9 of the 62 CKMM-Fertile men were oligospermic. Within the CKMM-Fertile group, 12 and 2 of the 14 pregnancies occurred by the 53 normospermic and 9 oligospermic men (22.6% versus 22.2% rate). CONCLUSIONS: Sperm CK-MM ratios, a measure of normal sperm development, predict fertilizing potential independently from sperm concentrations. Sperm CK-MM ratios also detect unexplained male infertility (infertile men with normospermic semen), a diagnosis that until now could not be substantiated.

Biomarkers↗
PubMed1999

Fertilization after standard in vitro fertilization versus intracytoplasmic sperm injection in subfertile males using sibling oocytes.

OBJECTIVE: To compare conventional IVF with ICSI in the subfertile male population using sibling oocytes. Results from males with isolated severe teratozoospermia also are analyzed. DESIGN: Prospective experimental study. SETTING: University based IVF clinic. PATIENT(S): Group A: 18 patients with one or more abnormalities in count, motility, or morphology. Group B: 20 patients with isolated severe teratozoospermia (< or = 4% Kruger Strict Criteria). INTERVENTION(S): Ovulation induction, random allocation of sibling oocytes, and IVF or ICSI. MAIN OUTCOME MEASURE(S): Fertilization rates (fertilization per cycle, fertilization per oocytes, and fertilization per couple) and embryo quality. RESULT(S): In group A, fertilization occurred in 13 of 18 (72%) of IVF cycles and 17 of 18 (94%) of ICSI cycles. Overall, 69 of 120 (58%) oocytes fertilized after IVF, whereas 80 of 131 (61%) fertilized after ICSI. The mean (+/-SEM) percent of oocytes fertilized per couple was 44.6%+/-9.0% with IVF and 62.7%+/-5.6% with ICSI (not statistically significant). In group B, fertilization occurred in 18 of 20 (90%) cycles after IVF and 20 of 20 (100%) cycles with ICSI. Overall, 54 of 113 (48%) of the oocytes fertilized after IVF, whereas 82 of 124 (66%) fertilized with ICSI. The mean (+/-SEM) percent of oocytes fertilized per couple was 50.9%+/-7.1 % with IVF and 66.6%+/-4.7% with ICSI. No statistically significant difference in embryo quality after IVF versus ICSI was demonstrated. CONCLUSION(S): With severe teratozoospermia, ICSI results in higher fertilization rates than conventional IVF, without altering embryo quality. In our subfertile male population, there is a trend toward improved fertilization with ICSI, with less failed fertilization.

Embryo Transfer↗
PubMed2000

D-penicillamine and granulosa cells can effectively extend the fertile life span of bovine frozen-thawed spermatozoa in vitro: effect on fertilization and polyspermy.

The effect of D-penicillamine on the fertile life span of frozen-thawed bull spermatozoa was studied in Experiment 1. After thawing, the washed spermatozoa were incubated for 8 h in fertilization medium with 1 mg/mL polyvinyl alcohol (PVA) and 0.5 mg/mL D-penicillamine. The addition of cumulus-free oocytes together with 10% of bovine serum (BOS) + 4 IU/mL heparin to the 8-h incubated spermatozoa resulted in high fertilization and polyspermy rates (97/103, 94.2% and 49/97, 50.5%, respectively). When BOS was substituted with 3 mg/mL of BSA, the fertilization and polyspermy rates decreased to 33/91 (36.3%) and 3/33 (9.1%), respectively. The total absence of fertilization was observed after substitution of proteins with PVA. The 8-h sperm incubation in fertilization medium without D-penicillamine and following fertilization in medium + different capacitation supplements resulted in the total absence of or a very low fertilization rate. In Experiment 2, the first set of cumulus-oocyte complexes (COC) and cumulus-free oocytes were fertilized for 8 h with nonincubated spermatozoa. The second set of COC and cumulus-free oocytes were fertilized in the same wells with spermatozoa after removal of the first set. The fertilization rate for the first set of COC and cumulus-free oocytes was 65/67 (97%) and 73/73 (100%), respectively, with 21/65 (32.3%) and 32/73 (43.8%) polyspermy, respectively. In the second set, the high penetration rate (67/73, 91.8%) was observed only for COC, while that for cumulus-free oocytes (19/76, 25%) was significantly lower (P < 0.01). In Experiment 3, the fertilization rate of COC in medium + PVA + 10 or 100 IU/mL heparin was 69/92 (75%) and 52/74 (70.2%), respectively, with no polyspermy. In medium + BSA + 10 or 100 IU/mL heparin, the fertilization rate of COC was 64/72 (88.9%) and 70/79 (88.6%), respectively, with polyspermy at 2/64 (3.1%) and 7/70 (10%), respectively. In medium + BOS + 10 or 100 IU/mL heparin, the fertilization rate was 79/82 (96.3%) and 79/80 (98.7%), respectively, with a significantly (P < 0.05) higher polyspermy rate (34/79, 43% and 30/79, 38%, respectively). The vitality and capacitation changes of frozen-thawed and 8-h incubated spermatozoa were assessed by Hoechst and chlortetracycline (CTC) staining.

Animals↗
PubMed2001

Biogeochemical cycling bacteria as indices of pond fertilization: importance of CNP ratios of input fertilizers.

AIMS: The influence of carbon-nitrogen and nitrogen-phosphorus ratios of input fertilizers, and that of pond water, on the growth of heterotrophic and phosphate-solubilizing bacteria of water and sediment, was examined in relation to fertilizer mineralization indices using different modes of fertilization through inorganic and organic sources. METHODS AND RESULTS: The first experiment used carbon-nitrogen-phosphorus ratios varying from 12 : 2 : 1 to 151 : 6 : 1, applied at the rate of 0.043 g l(-1) week(-1), whereas in the second ratios varied from 25.6 : 6.2 : 1 to 150 : 12 : 1 applied once at the rate of 3.33 g l(-1). Different fertilizers (cattle dung, poultry droppings, urea, single superphosphate and starch) were mixed in different proportions to achieve the desired carbon-nitrogen-phosphorus ratio. The heterotrophic and phosphate-solubilizing populations were more responsive to an early manuring phase than later, implying that pond fertilization was microbiologically more dynamic in the earlier phase. The carbon-nitrogen and nitrogen-phosphorus ratios of 11.8 (88.6 : 7.5) and 7.5 (7.5 : 1), respectively, of input fertilizers favoured growth of both heterotrophic and phosphate-solubilizing bacterial populations much better than the other ratios tested. Likewise, water carbon-nitrogen and nitrogen-phosphorus ratios of 11.9 and 3.34 induced bacterial growth. The carbon-nitrogen ratios of 12.63 (101 : 8) (input fertilizer)-4.54 (water), and nitrogen-phosphorus ratios of 8 (8 : 1) (input fertilizer)-2.93 (water), gave gross primary productivity values higher than the remaining ratios, exhibiting overall curvilinear relationships. The values of gross primary productivity were the direct function of values of fertilizer mineralization indices for carbon, nitrogen and phosphorus. CONCLUSION: It is concluded that the mixed fertilizer (carbon-nitrogen-phosphorus-88.6 : 7.5 : 1) comprising cattle dung (95%), poultry droppings (2.5%), urea (2%) and single superphosphate (0.5%), applied at the rate of 23,000 kg ha(-1) year(-1), was a suitable cost-effective fertilization option for aquaculture practices. SIGNIFICANCE AND IMPACT OF THE STUDY: As chemical fertilizers are expensive and cause some adverse effects on the soil structure, composition, microflora and other characteristics of the pond, mixed combinations of inorganic and organics with narrow range of carbon-nitrogen-phosphorus ratio can be suitable and cost-effective fertilization tools in aquaculture practices, which is to be linked with the microbial activities of the pond.

Animals↗
PubMed1984

Effect of selection for fertility of frozen-thawed semen in chickens on the fertility of fresh and stored semen.

Studies were conducted using 68 males from the seventh generation of a line of meat-type breeder chickens selected for increased duration of fertility of frozen-thawed semen and 69 males of the randomly selected control line. These chickens were used to determine the presence or absence of differences between the selected and control lines with respect to fertility and spermatozoal motility when the semen was subjected to the following preinsemination treatments: 1) frozen in a diluent containing 13.6% glycerol; 2) frozen in a diluent containing 1.7% glycerol; 3) fresh undiluted; 4) fresh diluted; 5) diluted and stored for 24 hr; and 6) diluted and stored for 48 hr. Semen from each male was inseminated into 4 to 6 White Leghorn tester hens per experiment. The effects of genotype (line) by preinsemination semen treatment interaction on fertility and spermatozoal motility were also examined. When semen was frozen (Treatments 1 and 2), the selected line had significantly (P less than .01) higher duration of fertility, percent fertility for 7 days postinsemination, and percent fertility for the duration of fertility and spermatozoal motility than the control line. For fresh semen (Treatments 3 and 4), the selected line had significantly (P less than .01) higher fertility estimates and spermatozoal motility than the control line except for percent fertility for the duration of fertility (P greater than .05) of undiluted semen. For stored semen (Treatments 5 and 6), the selected line only had significantly (P less than .05) higher duration of fertility after 24 hr storage and percent fertility for the duration of fertility after 48 hr storage than the control line.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Total acrosin activity correlates with fertility potential after fertilization in vitro.

OBJECTIVE: To evaluate the possible relationship between total acrosin activity in spermatozoa and fertility potential after fertilization in vitro. DESIGN: Total acrosin activity of spermatozoa was measured in 101 in vitro fertilization (IVF) cases by an observer unaware of fertilization and cleavage results. SETTING: University Hospital is a tertiary referral center offering a government supported In Vitro Fertilization Programme. PARTICIPANTS: Participants were couples undergoing IVF. INTERVENTIONS: A miniature assay measured total acrosin activity in the semen sample used for IVF. OUTCOME MEASURES: The proportion of mature oocytes fertilized, the proportion of mature oocytes transferred, and fertilization of at least one mature oocyte were considered outcomes with fertility potential. RESULTS: Total acrosin activity correlated with both the proportion of mature oocytes fertilized and the proportion of mature oocytes that were transferred as cleaving embryos. Total acrosin activity was higher in cycles when one or more mature oocyte fertilized compared with cycles with failed fertilization of all mature oocytes. CONCLUSIONS: The likelihood ratio for subnormal results indicates that measurement of total acrosin activity is a fair test of the fertilizing capacity of sperm.

Acrosin↗
PubMed1998

Implications of complete fertilization failure after intracytoplasmic sperm injection for subsequent fertilization and reproductive outcome.

With the introduction of intracytoplasmic sperm injection (ICSI), couples with severe male factor infertility have achieved fertilization and clinical pregnancy rates comparable to other in-vitro fertilization (IVF) patients. However, failure of fertilization still occurs in some patients despite the utilization of microsurgical sperm injection techniques. How such fertilization failure after ICSI might impact later ICSI treatment(s) is unknown. In this investigation, couples with complete fertilization failure after ICSI treated from August 1993 to August 1996 were identified (index cycle, n = 21). Additionally, fertilization data from any previous or subsequent infertility treatments were evaluated. Seven patients (33%) had at least one IVF treatment before the index cycle, although no deliveries occurred. Of patients with complete fertilization failure in the index cycle, 48% (n = 10) underwent at least one subsequent ICSI cycle which proceeded to oocyte retrieval. The remainder (n = 11) elected to discontinue treatment. Although six subsequent cycles were cancelled due to poor follicular response (< or = 2 mature oocytes), all patients electing to continue treatment eventually achieved a subsequent embryo transfer. The clinical pregnancy rate per transfer was 45.4% for this group; the delivery and ongoing pregnancy rate per transfer was 36.3%. Review of semen parameters, superovulation characteristics or other clinical parameters during the three study cycles (pre-index, index, and post-index) was not prognostic of fertilization success or reproductive outcomes in later treatments. Fertilization failure with ICSI therefore could not be predicted by prior cycle performance, although total immotility of spermatozoa at time of oocyte retrieval, total teratozoospermia, and low oocyte yield were common characteristics of couples experiencing complete fertilization failure with ICSI. These findings suggest that fertilization failure in one ICSI cycle does not preclude successful fertilization and delivery in a later ICSI treatment.

Counseling↗
PubMed1992

Migration sedimentation technique as a predictive test for the fertilizing capacity of spermatozoa in an in-vitro fertilization programme.

The migration-sedimentation technique (MST) has been proposed as a means of separating high quality motile spermatozoa. The present study was conducted in order to evaluate whether sperm performance following separation by MST predicts their fertilizing capacity in an in-vitro fertilization (IVF) programme. Ninety semen specimens were analysed for use in an IVF-embryo transfer (ET) programme. Each specimens was divided into two parts: one was processed in the IVF programme and was used after sperm swim-up separation for insemination of human ova. The other aliquot (0.2 ml) was separated by MST, and the sperm then characterized by their concentration, motility, degree of motility and morphology. Sperm characteristics after separation by MST were then correlated with the results of the IVF-fertilization rates. In 79 of 90 IVF-ET cycles, at least one oocyte was fertilized. All post-MST sperm characteristics were significantly higher in cycles with fertilizations compared to IVF cycles without fertilization. A larger percentage of the total motile spermatozoa were recovered after MST in semen specimens with fertilization, compared to semen specimens without fertilization (39.9 +/- 3.6 and 20.6 +/- 6.6%, respectively; P < 0.05). This value was correlated with the percentage of fertilized oocytes (r = 0.24; P < 0.02). More IVF cycles with fertilizations were recorded in cases in which the recovery of motile sperm was > 25% (P < 0.005), or when more than 1.5 x 10(6) motile spermatozoa were recovered after MST (P < 0.0001). As sperm characteristics after MST correlated significantly with their fertilizing capacity, the MST test could be used in evaluation of the fertilizing capacity of spermatozoa.

Cell Separation↗