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Fertilization of human oocytes following cryopreservation; normal karyotypes and absence of stray chromosomes.

Survival following cryopreservation of fresh and aged human oocytes by the propanediol (PROH) procedure was observed in 51 and 73% of oocytes respectively, immediately after thawing. This survival was reduced in both types of oocytes at the time of insemination (3-4 h) to 41% in fresh and 61% in aged oocytes. Insemination of the cryopreserved and control oocytes with spermatozoa from one donor resulted in total fertilization rates similar to our in-vitro fertilization (IVF) rate for non-male factor patients. The normal fertilization rate for fresh cryopreserved oocytes was slightly lower (46%) than the rate for IVF oocytes (59%) (P < 0.05), while the abnormal fertilization rates were not significantly different (16 and 15% respectively). In contrast, a reduction in the normal fertilization rate was observed for the aged cryopreserved oocytes (13%) compared to the IVF rate (P < 0.001). Associated with this was an increase in the abnormal fertilization rate for the aged cryopreserved oocytes, which was significantly higher (47%) than the IVF rate (15%) (P < 0.001). Significant differences in the total and normal fertilization rates were observed between cryopreserved oocytes obtained from cohorts with < or = 27 (total: 84%, normal: 68%) and > 27 oocytes (total: 55%, normal: 33%) (P < 0.05). Fertilized oocytes and oocytes with abnormal or absent spindles were examined for chromosomal loss and no stray chromosomes were observed in any of these cryopreserved oocytes (n = 137). In the cryopreserved oocytes which had undergone normal fertilization, four scorable karyotypes were achieved and in all of these two sets of 23 chromosomes were observed.

Cell Survival↗

Human fertilization with round and elongated spermatids.

Human spermatids from ejaculate and testicular tissue have been utilized for evaluating human fertilization by intracytoplasmic sperm injection (ICSI) and, where possible, compared with spermatozoa utilizing sibling oocytes. Round and elongated spermatids obtained from ejaculates were either prepared through Percoll gradients or isolated and washed individually using subzonal insemination needles (SUZI; 10-14 microm internal diameter). Seminiferous tubules obtained after biopsy were placed into HEPES-buffered Earle's medium and dissected using 21-gauge needles. Spermatogenic cells and spermatozoa were isolated and washed individually using SUZI needles. Spermatozoa were subsequently injected into the ooplasm using 5 microm (internal diameter) ICSI needles, whereas 8-9 microm (internal diameter) needles were used for spermatid injection. Only metaphase II oocytes (n = 207) were injected: 64 with round spermatids, 92 with elongated spermatids and 51 with spermatozoa; the fertilization rate was 30, 24 and 67% respectively. There was a significant (P < 0.001) increase in the fertilization rate using spermatozoa compared with spermatids. The fertilization rate was not different between round and elongated spermatids, although the fertilization rates for round and elongated spermatids in the ejaculate were 33 and 18% respectively, compared with 22 and 38% respectively when testicular spermatids were utilized. In three patients sibling oocytes were used to compare round and elongated spermatids found in the ejaculate with spermatozoa extracted from seminiferous tubules. The fertilization rate was 24% for spermatids and 79% for testicular spermatozoa. This result suggests that, should only spermatids be available in the ejaculate, a testicular biopsy in the hope of obtaining testicular spermatozoa would be worth while.

Cell Size↗

Hyaluronidase removal of the cumulus oophorus increases in vitro fertilization.

The effect of hyaluronidase removal of the cumulus oophorus on the in vitro fertilization rate of oocytes obtained from patients with poor oocyte fertilizability has been evaluated. Eighty-eight oocytes were obtained from 13 patients undergoing in vitro fertilization and embryo transfer (IVF-ET) for indications of male-factor, immunological, and idiopathic infertility. In addition, patients in whom fertilization did not occur on previous IVF cycles were evaluated in the study. The oocytes of each individual patient were randomly assigned into a treatment (removal of the cumulus; N = 40 oocytes) or nontreatment group (control; N = 48 oocytes). Hyaluronidase was used to remove the cumulus immediately following oocyte retrieval, and insemination was performed 6-8 hr later. The overall oocyte fertilization rate (both treated and untreated) was 42%. The treatment group demonstrated a higher rate of fertilization compared to the nontreatment group (55% vs 31%; P less than 0.05). Examination of various patient groups revealed a statistically significant difference in fertilization rates between the treated and the untreated oocytes only in the "no previous fertilization" group (60% vs 28%; P less than 0.05). A higher rate of fertilization of the treated oocytes was also seen in the immunologic infertility group, however, statistical significance was not achieved (50% vs 25%; P = 0.07). Only one clinical pregnancy was achieved in this group of 13 patients. We conclude that in this group of patients, removal of the cumulus prior to insemination may, in some cases, increase the fertilization potential of the oocyte.

Female↗

An indiscriminate use of pentoxifylline does not improve in-vitro fertilization in poor fertilizers.

In order to enhance fertilization in vitro, pentoxifylline (PTX) was used in couples showing low fertilization rates in previous in-vitro fertilization (IVF) attempts for the treatment of male-factor infertility. Sibling oocytes were inseminated at random with spermatozoa prepared with or without PTX. After selection by Percoll gradient, sperm samples were divided into two equal aliquots. One aliquot was incubated in Earle's medium containing approximately 3.6 mM PTX (treatment group), the other aliquot was incubated with PTX-free Earle's medium (control group). After 30 min, both suspensions were washed twice. Sperm parameters after preparation did not differ between treatment and control samples, and nor did the mean fertilization rates, which were 49.3 and 42.6% respectively. Cleavage characteristics and morphological quality of the embryos were not significantly different between the treatment and control groups. The results of this study demonstrate that indiscriminate use of PTX in an IVF programme increases neither fertilization rate nor embryo transfer rate in poor fertilizers. More prospective research is needed to evaluate the role of PTX in IVF in couples selected according to the effect of the compound on sperm function, e.g. hyperactivation and acrosome reaction.

Adult↗

FSH injections and intrauterine insemination in protocols for superovulation of ewes.

In Exp. 1, five injections of crude FSH (20 mg total), starting 36 h before removal of progestin pessaries or injection of prostaglandin F2 alpha (PGF2 alpha), were found to be as effective for superovulation of ewes as seven injections starting 72 h before removal of pessaries. Seven injections caused superovulation (more than three ovulations) in 13 of 15 ewes with an average (all ewes) of 12 +/- 2.3 ovulations. Five injections caused superovulation in 17 of 19 ewes with an average of 11.5 +/- 1.6 ovulations after pessary-regulated estrus in 12 of 16 ewes with an average of 12.4 +/- 2.2 ovulations after PGF2 alpha injection. In Exp. 2, intrauterine artificial insemination (IUAI) of naturally mated ewes provided ovum fertilization rates of 75.3% with an embryo recovery rate of 39.4%, whereas mating alone (MATED) provided fertilization rates of 64.2% with an embryo recovery rate of 72.1%. However, subsequent replications of the MATED protocol (MATED2) resulted in a low fertilization rate (34.2%). In Exp. 3, surgical IUAI at 22 h after removal of pessaries resulted in a low rate of superovulation (5 of 12 ewes), presumably as the result of pentobarbital anesthesia. Conducting IUAI at 46 h after removal of pessaries resulted in a high rate of superovulation (14 of 16 ewes) but a low embryo recovery rate (30.7%). In two subsequent trials, IUAI at 40 h after removal of pessaries resulted in most ewes superovulating (33 of 35 in April/May and 16 of 17 in September) with acceptable embryo recovery (65.2% and 71.3%) and high fertilization rates (82.8% and 96.4%).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Effect of freezing-thawing protocols on the performance of semen from three rabbit lines after artificial insemination.

The effect of different freezing and thawing protocols on the results observed after artificial insemination with semen from three different rabbit lines (two maternal lines selected for litter size at weaning, lines A and V, and one line selected for growth rate from weaning to slaughter, line R) was studied. The sperm were frozen with a Tris-citric acid-glucose extender which included 1.75 M DMSO and 0.05 M sucrose as cryoprotectants. The straws were cooled to 5 degrees C for 45 min and then some of them were frozen in a freezer at -30 degrees C for 30 min, whereas the other group of straws were frozen in liquid nitrogen vapor (LNV, 5 cm above the liquid nitrogen level) for 10 min. Straws were thawed at two different temperatures: 50 or 70 degrees C for 10-12s. Significant differences were observed between freezing-thawing protocols, obtaining better results in fertility rate (percentage of pregnant females) when sperm had been frozen in LNV (fertility rate increased between 30 and 50 points in all the lines); the best prolificacy was observed when sperm had been frozen in LNV and thawed at 50 degrees C (70% versus 32% fertility rate, P<0.01 and 7.4 versus 5.9 total number of young born, P<0.01 when sperm had been frozen in LNV or at -30 degrees C and thawed at 50 degrees C, respectively). As for the rabbit line, significant differences were observed between lines in fertility rate (62 and 68% versus 45% fertility rate for lines A, V and R, P<0.01), and total number of young born (5.8 versus 6.9 versus 4.6 total number of young born for lines A, V and R, P=0.02). The best results for all lines in both fertility and total number of young born were observed when sperm had been frozen in LNV and thawed at 50 degrees C (85% versus 84% versus 50% fertility rate and 6.7 versus 8.3 versus 7.3 total number of young born for lines A, V and R, respectively), when compared to the results of the control group, frozen at -30 degrees C and thawed at 50 degrees C (30% versus 52% versus 19% fertility rate and 6.7 versus 6.4 versus 4.5 total number of young born for lines A, V and R, respectively). In conclusion, the best results (fertility rate and prolificacy) for all the rabbit lines were obtained after freezing in liquid nitrogen vapor and thawing at 50 degrees C, being more pronounced in the line selected for high growth rate (line R).

Animals↗

Human sperm movement assessed with the Hamilton-Thorn motility analyzer and in vitro fertilization.

UNLABELLED: The relationship between sperm movement characteristics obtained by computerized analysis and the in vitro fertilization rates of human oocytes was studied. In 144 consecutive in vitro fertilization treatments a sample of prepared semen was analysed by a Hamilton-Thorn Motility Analyzer. In addition a visual estimation of sperm count and motility was made. Significant correlations with the fertilization rate were found for all visual parameters. Of the computerized measurements, the mean velocities of motile spermatozoa and the concentration of motile cells were significantly correlated. The average path velocity correlated best (r = 0.42, P < 0.001). There was no relationship between the percentage of motile sperm showing hyperactivated movement and the fertilization rate. A forward stepwise logistic regression analysis selected the following variables of predictive value for fertilization: average path velocity, male factor infertility as indication for in vitro fertilization, motility and concentration, as measured by the Hamilton-Thorn analyzer. A logistic regression model to predict the cases with low (< 0.2) or high fertilization rates, included the average path velocity as a significant variable and classified the samples with 90% overall accuracy. IN CONCLUSION: movement characteristics of spermatozoa in culture medium, especially the average path velocity are of prognostic value in prediction of human oocyte fertilization rates.

Computers↗

Induction of estrus and superovulation in seasonally anestrous ewes.

The induction of estrus in 17 previously cycling nulliparous ewes, 9 to 10 months of age, was attempted with Medroxyprogesterone acetate (MAP) pessaries during the early anestrous period (March-April). Ewes were verified to be anestrous by the lack of estrous behavior in the presence of a vasectomized ram and by a radioimmunoassay for serum progesterone in two samples taken 7 days apart showing less than 1 ng/ml serum progesterone. Superovulation was attempted with injections of either FSH or FSH + LH. MAP vaginal pessaries remained in place for a period of 12 days and FSH was administered to all ewes (IM) at 12 hr intervals over a 3 day period; 5 mg was injected twice on day 11 after pessary insertion, followed by 4 and 3 mg injections twice daily on each succeeding day, for a total of 24 mg per ewe. Nine ewes were given 25 mg LH (IV) within 8 hrs after the onset of behavioral estrus in addition to FSH. Ewes were hand-mated to several rams at 12 hr intervals throughout the estrus period. Ovulation and fertilization rates were recorded for each ewe following midline laparotomy and embryo collection. All ewes were in estrus between 36 and 48 hrs after removal of the MAP pessaries. In ewes injected with FSH only, 8 of 8 ovulated with a mean ovulation rate of 6.0 +/- 4.4 and a fertilization rate of 70%. Nine of 9 ewes receiving both FSH + LH ovulated with a mean ovulation rate of 13.9 +/- 13.1 and a fertilization rate of 72%. Statistical analysis by Students t-test resulted in differences in number of ova recovered (P<.05) between FSH only and FSH + LH treated ewes and a trend towards increased ovulation rate in FSH + LH treated ewes. These results show that early seasonally anestrous ewes can be successfully induced and synchronized for estrus with MAP pessaries and the number of ova recovered is increased with the inclusion of LH in the superovulation regime.

Journal Article↗

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↗

Discrepancy between sperm acrosin activity and sperm morphology: significance for fertilization in vitro.

BACKGROUND: In routine semen analysis, discrepancies may occur between sperm acrosin activity test results and sperm acrosomal morphology. METHODS: Discrepant test results of sperm acrosin activity (spectrophotometric assay) vs. sperm morphology (strict criteria) in the initial diagnostic investigation of 107 infertile couples were evaluated with respect to fertilization rate (% oocytes with 2 pronuclei) further obtained in IVF treatment. RESULTS: Acrosin activity positively correlated with sperm morphology (% normal forms) (r=0.537) and fertilization rate (r=0.526). ROC curves for the prediction of > or =50% fertilization rate were comparable for acrosin activity and sperm morphology, with optimal cutoff values at 25 microIU/10(6) sperm and 10%, respectively. In multiple regression analysis, sperm acrosin activity (P=0.002) predicted fertilization rate independently of sperm morphology (P<0.001) and sperm vitality (eosin-nigrosin stain) (P=0.03). Acrosin activities > or =25 microIU/10(6) sperm were observed in 36% of severe teratozoospermic samples (< or =4% normal spermatozoa) associated with low fertilization rate. Twenty percent of the morphologically normal ejaculates showed a low acrosin activity (<25 microIU/10(6) sperm) and low hypoosmotic swelling test (HOST) scores (31.4+/-7.6%) and were associated with low fertilization rate. CONCLUSION: The sperm acrosin assay can help to predict sperm fertilizing capacity in IVF independently of sperm morphology.

Acrosin↗

Immature oocyte retrieval: lessons from unstimulated IVF cycles.

OBJECTIVE: To describe retrieval of immature oocytes during unstimulated IVF and assess the in vitro maturation and fertilization rates. DESIGN: Retrospective analysis. SETTING: The USC program for assisted reproduction. PATIENT(S): Spontaneously ovulatory women with predominantly pelvic factor as their principal cause of infertility, under the age of 40, and no male factor. INTERVENTION(S): HCG administration in mid-cycle, aspiration of all visible follicles, in vitro maturation of immature oocytes in culture media versus 50% follicular fluid in media, IVF, and embryo transfer. MAIN OUTCOME MEASURE(S): Rates of in vitro maturation, fertilization, and implantation after embryo transfer. RESULT(S): A total of 101 immature oocytes were obtained during 59 follicle aspirations. Thirty percent of prophase I oocytes matured to metaphase II in vitro compared with 44% of metaphase I oocytes. Fertilization rates for matured prophase I oocytes were 62% for those cultured in standard culture media (controls) and 87% for follicular fluid culture media. Two pregnancies resulted from the transfer of embryos derived from immature oocytes when no other embryos were transferred. CONCLUSION(S): Immature oocytes may be retrieved successfully during the mid-cycle aspiration of the dominant follicle in unstimulated IVF cycles. Maturation of immature oocytes in vitro with follicular fluid results in similar maturation and fertilization rates as for control incubation. Immature oocytes thus retrieved contribute to the overall pregnancy success of unstimulated IVF cycles. It may be better to retrieve immature oocytes during unstimulated cycles than during the follicular phase of natural cycles.

Cellular Senescence↗

Caesarean section and subsequent fertility in sub-Saharan Africa.

OBJECTIVE: To determine the impact of caesarean section on fertility among women in sub-Saharan Africa. DESIGN: Analysis of standardised cross-sectional surveys (Demographic and Health Surveys). SETTING: Twenty-two countries in sub-Saharan Africa, 1993-2003. SAMPLE: A total of 35 398 women of childbearing age (15-49 years). METHODS: Time to subsequent pregnancy was compared by mode of delivery using Cox proportional hazards regression models. MAIN OUTCOME MEASURES: Natural fertility rates subsequent to delivery by caesarean section compared with natural fertility rates subsequent to vaginal delivery. RESULTS: The natural fertility rate subsequent to delivery by caesarean section was 17% lower than the natural fertility rate subsequent to vaginal delivery (hazard ratio = 0.83, 95% CI 0.73-0.96, P < 0.01; controlling for age, parity, level of education, urban/rural residence and young age at first intercourse). Caesarean section was also associated with prior fertility and desire for further children: among multiparous women, an interval > or =3 versus <3 years between the index birth and the previous birth was associated with higher odds of caesarean section at the index birth (OR = 1.4, 95% CI 1.1-1.7, P= 0.005); among all women, the odds of desiring further children were lower among women who had previously delivered by caesarean section (OR = 0.67, 95% CI 0.54-0.84, P < 0.001). Caesarean section did not appear to increase the risk of a subsequent pregnancy ending in miscarriage, abortion or stillbirth. CONCLUSIONS: Among women in sub-Saharan Africa, caesarean section is associated with lower subsequent natural fertility. Although this reflects findings from developed countries, the roles of pathological and psychological factors may be quite different because a much higher proportion of caesarean sections in sub-Saharan Africa are emergency procedures for maternal indication.

Adolescent↗

Impact of immunoglobulin isotype and sperm surface location of antisperm antibodies on fertilization in vitro in the human.

OBJECTIVE: To investigate the impact of immunoglobulin (Ig) isotypes and their location on the human sperm surface on fertilization in vitro. DESIGN: Restrospective review and analysis. SETTING: Reproductive endocrine division of a level 3 academic center. PATIENTS: Forty-eight couples (80 IVF cycles) with males showing positive antisperm antibodies on the sperm surface by immunobead test, treated by IVF at the Norfolk Program. MAIN OUTCOME MEASURE: Evaluation of total fertilization rate of preovulatory oocytes (metaphase II-metaphase I). RESULTS: Immunoglobulin G and IgA antibody levels have no significant correlation with total fertilization rate of preovulatory oocytes by logistic regression. Immunoglobulin M, present in 44% of the couples, had a strong correlation with fertilization. When IgA showed very high levels of binding (> 68%) and IgM binding was > 40%, the fertilization rate dropped significantly. A strong correlation between presence of antibodies and fertilization rate was seen when IgM was directed to the head or tail tip of the sperm. Immunoglobulin A induced a statistically significant reduction of fertilization only when it was present on the head. CONCLUSION: Two male antisperm Ig isotypes significantly impaired fertilization rates. Immunoglobulin A exerted its impact only when high level of binding was detected on the head. Immunoglobulin M, present in 44% of the males, was the Ig isotype that most significantly affected fertilization rates when localized both at the head and at the tail tip level.

Autoantibodies↗

The use of pure FSH alone or in combination for ovulation stimulation in in vitro fertilization.

The experience of the Norfolk Program, from the beginning of 1981 until mid 1984, is reviewed. Two groups of patients are compared. The initial experience goes from the very beginning until early 1984 in which knowledge has accumulated; the patients treated afterwards up to mid 1984 where the previous experience was used to monitor them in a more accurate way is reviewed as a separate category. Different protocols, in each group, are compared: concomitant combination of hFSH/hMG (protocol # 1), sequential combination of the two gonadotropins (protocol # 2), and pure FSH administration (protocol # 3). Several parameters were used in the evaluation of the results: 1) day of laparoscopy, 2) volume of the follicles obtained, 3) number of preovulatory oocytes obtained, 4) number of immature oocytes obtained, 5) number of atretic oocytes induced, 6) number of oocytes with abnormal zona pellucida, 7) fertilization rate of preovulatory and immature oocytes, 8) abnormal fertilization rate of preovulatory and immature oocytes, 9) cleavage rate of the normally fertilized preovulatory immature oocytes, 10) transfer rate, single and multiple, 11) follicular and luteal phases as evaluated by estradiol levels in the preovulatory phase and by E2 and progesterone in the post ovulatory phase, 12) pregnancy rate. Pure FSH seems to prolong somewhat the follicular phase. Preovulatory oocytes derived from small follicles may originate pregnancies that may end in abortion. The concomitant combination rendered a larger number of preovulatory oocytes. The number of immature oocytes tend to be higher in the pure FSH stimulated group, but this seems to depend on the way FSH is used. The normal fertilization rate for preovulatory oocytes tends to be similar as the criteria used in the stimulation protocol improved. The abnormal fertilization rate for both types of oocytes decreased in the latest series. The number of embryos transferred was higher in the concomitant combination stimulation. Shortening the hMG/hCG interval in the pure FSH category seems to induce a deficient follicular phase except in cases with rapid high response. When using the hFSH/hMG combination the values of estradiol in the follicular phase tend to be much higher than when the original pure hMG protocol is used. This does not seem to be true when pure FSH stimulation is used. The number of multiple transfers increased substantially in both types of stimulation as experience increased.(ABSTRACT TRUNCATED AT 400 WORDS)

Chorionic Gonadotropin↗

Enhancement of bovine oocyte fertilization in vitro with a bovine oviductal specific glycoprotein.

The purpose of this study was to determine the effect of a partially purified bovine oviductal glycoprotein (bOGP) on fertilization rates of bovine oocytes. The effect of albumin (control protein) or bOGP at 100 micrograms ml-1 during the 16-18 h fertilization period was evaluated in a standard IVF system using a sperm concentration between 0.5 and 0.125 x 10(6) spermatozoa ml-1. bOGP maintained a higher (P < 0.05) fertilization rate (62.0% versus 31.2%) at 0.125 x 10(6) spermatozoa ml-1 compared with the albumin control. The enhancement of fertilization by bOGP was blocked by the inclusion of a specific antibody to bOGP, whereas the antibody with albumin had no effect. A 2 h gamete preincubation step was subsequently included in the IVF procedure (0.125 x 10(6) spermatozoa ml-1) to determine whether the effect of bOGP was mediated through an interaction with the oocyte, the spermatozoon or both. When oocytes were preincubated with bOGP the fertilization rates were higher (P < 0.05) than with the albumin control (oocytes and spermatozoa exposed to albumin), whereas preincubation of spermatozoa with bOGP did not affect fertilization rates. There was no synergistic effect of preincubating oocytes and spermatozoa with bOGP. The increase in fertilization rate achieved by preincubating oocytes with bOGP was blocked with a specific antibody to bOGP. These results suggest that the increase in fertilization rates observed when bOGP is included during the 16-18 h fertilization period are primarily mediated through the interaction of bOGP with the oocyte since the same facilitatory effect was observed with a 2 h preincubation of oocytes before IVF. The ability to block these effects with a polyclonal antibody specifically generated against bOGP shows that this biological activity is due to bOGP. In summary, bOGP enhances fertilization in bovine oocytes whether it is included during preincubation or insemination and this appears to be due to a direct effect on the oocyte.

Animals↗

Evaluation of a cut-off value for sperm motility after different hours of incubation to select the suitable reproductive technology (IVF or ICSI).

BACKGROUND: The aim of this study was to enhance the predictability of conventional semen parameters for in-vitro fertilization outcome. The utility of late sperm motility in presence of a cumulus-oocyte complex after different hours of incubation was investigated to predict the outcome of IVF in borderline and normal ejaculates (at least 5 x 10(6) motile sperm). METHODS: The study was done on 52 infertile couples undergoing conventional in-vitro fertilization and embryo transfer. Sperm were prepared by the Percoll cushion centrifugation with swim-down. Cocultures were established by inseminating the cumulus-oocyte complexes with 100000 motile spermatozoa and incubating them for 48 hours. Another 100000 spermatozoa were incubated in culture medium for 48 hours. Sperm motility (WHO a+b) was determined at 0, 4, 24 and 48 hours of incubation. RESULTS: The fertilization rate was 65.5% (42.9-88.1). The conventional semen parameters did not correlate with the fertilization rate. Sperm motility measured after different hours of incubation was found to be significantly positively correlated with the fertilizing ability of sperm in vitro in Spearman's rank correlation test: motility after 0 h (p<0.02), after 4 h (p=0.0025). after 24 h (n.s.) and after 48 h (p=0.0071). Cut-off values for late sperm motility were determined and differences in fertilization rates were calculated for these cut-off values after different hours of incubation. A cut-off value of 20% progressive motile spermatozoa after 48 hours gave the best statistical power (fertilization rate 71.7 vs. 50.2%, p<0.001). Significant differences in the fertilization rates were also observed for a cut-off value of 35% after 24 hours of incubation (70.1 vs. 46.2%, p=0.001) and for a cut-off point of 60% after 4 hours (72.4 vs. 51.5%, p=0.001). CONCLUSIONS: The predictive power of sperm motility after 48 h for fertilization outcome provides support in the decision-making process within the assisted reproduction setting. If less than 20% of sperm are motile after 48 h micromanipulatory techniques should be considered.

Adult↗

Annual summary of vital statistics--1995.

Recent trends in the vital statistics of the United States continued in 1995, including decreases in the number of births, the birth rate, the age-adjusted death rate, and the infant mortality rate; life expectancy at birth increased to a level equal to the record high of 75.8 years in 1992. Marriages and divorces both decreased. An estimated 3,900,089 infants were born during 1995, a decline of 1% from 1994. The preliminary birth rate for 1995 was 14.8 live births per 1000 total population, a 3% decline, and the lowest recorded in nearly two decades. The fertility rate, which relates births to women in the childbearing ages, declined to 65.6 live births per 1000 women 15 to 44 years old, the lowest rate since 1986. According to preliminary data for 1995, fertility rates declined for all racial groups with the gap narrowing between black and white rates. The fertility rate for black women declined 7% to a historic low level (71.7); the preliminary rate for white women (64.5) dropped just 1%. Fertility rates continue to be highest for Hispanic, especially Mexican-American, women. Preliminary data for 1995 suggest a 2% decline in the rate for Hispanic women to 103.7. The birth rate for teenagers has now decreased for four consecutive years, from a high of 62.1 per 1000 women 15 to 19 years old in 1991 to 56.9 in 1995, an overall decline of 8%. The rate of childbearing by unmarried mothers dropped 4% from 1994 to 1995, from 46.9 births per 1000 unmarried women 15 to 44 years old to 44.9, the first decline in the rate in nearly two decades. The proportion of all births occurring to unmarried women dropped as well in 1995, to 32.0% from 32.6% in 1994. Smoking during pregnancy dropped steadily from 1989 (19.5%) to 1994 (14.6%), a decline of about 25%. Prenatal care utilization continued to improve in 1995 with 81.2% of all mothers receiving care in the first trimester compared with 78.9% in 1993. Preliminary data for 1995 suggests continued improvement to 81.2%. The percent of infants delivered by cesarean delivery declined slightly to 20.8% in 1995. The percent of low birth weight (LBW) infants continued to climb in 1994 rising to 7.3%, from 7.2% in 1993. The proportion of LBW improved slightly among black infants, declining from 13.3% to 13.2% between 1993 and 1994. Preliminary figures for 1995 suggest continued decline in LBW for black infants (13.0%). The multiple birth ratio rose to 25.7 per 1000 births for 1994, an increase of 2% over 1993 and 33% since 1980. Age-adjusted death rates in 1995 were lower for heart disease, malignant neoplasms, accidents, and homicide. Although the total number of human immunodeficiency virus (HIV) infection deaths increased slightly from 42,114 in 1994 to an estimated 42,506 in 1995, the age-adjusted death rate for HIV infection did not increase, which may indicate a leveling off of the steep upward trend in mortality from HIV infection since 1987. Nearly 15,000 children between the ages of 1-14 years died in the United States (US) in 1995. The death rate for children 1 to 4 years old in 1995 was 40.4 per 100,000 population aged 1 to 4 years, 6% lower than the rate of 42.9 in 1994. The 1995 death rate for 5- to 14-year-olds was 22.1, 2% lower than the rate of 22.5 in 1994. Since 1979, death rates have declined by 37% for children 1 to 4 years old, and by 30% for children 5 to 14 years old. For children 1 to 4 years old, the leading cause of death was injuries, which accounted for for an estimated 2277 deaths in 1995, 36% of all deaths in this age group. Injuries were the leading cause of death for 5- to 14-year-olds as well, accounting for an ever higher percentage (41%) of all deaths. In 1995, the preliminary infant mortality rate was 7.5 per 1000live births, 6% lower than 1994, and the lowest ever recorded in the US. The decline occurred for neonatal as well as postneonatal mortality rates, and among white and black infants alike.

Global Health↗

Zona pellucida autoantibodies in women undergoing ART.

The presence of ZP autoantibodies in serum and Ffl samples of 109 women attending the ART Center in Kiev was investigated using IIF and ELISA. Positive serum and Ffl samples examined by both methods were found in 20 (18.34%) and in 19 (17.43%) patients respectively; 31 (28.44%) serum samples and 33 (30.27 %) Ffl samples analyzed by IIF were positive; of the samples analyzed by ELISA 21 (19.26%) and 20 (18.34%), respectively, were positive. No relationship was found between ZP autoantibody incidence and the type and cause of infertility. A significant prevalence of ZP autoantibodies detected by ELISA in Ffl was found in patients with fertilization failure (39.13%) and with low fertilization rate (42.85%) when compared to patients with middle fertilization rate (5.71%) and high fertilization rate (8.1%). The clinical significance of ZP autoantibodies in Ffls for in vitro fertilization outcome was suggested.

Adult↗