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PubMed1987

Correlations between the human sperm-hamster egg penetration assay and in vitro fertilization results.

The human sperm-hamster egg penetration assay (SPA) has been used to evaluate male fertility under in vivo conditions. The test is not only unstandardized, but agreement does not exist as to the lower limits of normal penetration rates. Therefore, it is not surprising that there is considerable doubt as to whether any correlation exists between SPA results and the behavior of sperm in an in vitro laboratory situation. We investigated this question by examining the SPA results and the subsequent fertilization and cleavage rates in the in vitro fertilization program at Pennsylvania Hospital. The sperm from men whose SPA results were 11% or more fertilized 86% of the morphologically normal and mature human oocytes to which they were exposed. Men whose SPA scores ranged from 1% through 10% fertilized 65% of human oocytes, and men whose sperm failed to penetrate hamster eggs still were able to fertilize 41% of the human oocytes. The differences between these groups are statistically significant. This information can be of practical prognostic value during in vitro fertilization cycles in which the number of mature oocytes seen ultrasonographically appears to be at a minimum.

Animals↗
PubMed1985

Measuring the effect of sex preference on fertility: the case of Korea.

Preferences for male or female children or a balanced number of sons and daughters are common throughout the world. The dominant preference is for male offspring, particularly in less developed countries. Strong son preference is often tempered, however, by a desire to have at least one child of each sex. In more developed countries a balance preference is more common, often together with a strong preference for the first child to be a son. Although it is usually assumed that sex preference can substantially influence fertility, some analysts argue that the effect is negligible. An intermediate position is taken by those who say that sex preference may not have much impact at high fertility levels, but that as average family sizes begin to fall, sex preference will become a more important factor in fertility decisions. Despite the keen interest that has been shown in sex preference, there is surprisingly little empirical evidence of its effects on fertility. Moreover, much of the research in this area is methodologically weak. The measures that have been used in the past have been subject to a number of criticisms that call their results into question. This paper proposes a new measure of the effect of sex preference on fertility that avoids many of the problems inherent in other methods. The measure is based on widely available survey data on the sex composition of children and can be used with any measure of fertility or family planning. It can handle any type of sex preference and does not assume a linear relationship between sex preference and fertility.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMedDate not supplied

[Is the sperm bacteriology important for the results of in vitro fertilization?].

A total of 140 ejaculates from patients taking part in the in vitro fertilization program were examined. In 60 ejaculates (42.9%) bacteria concentrations of greater than 10(5)/ml were found. 80 (57.1%) of the probes were negative or had bacteria concentrations less than 10(4)/ml. Microplasma was found in 30 of the examined ejaculates (21.4%) and the second most frequent group of microorganisms were enterococci found in 15 patients (10.7%). Anaerobic organisms in concentrations of more than 10(5)/ml were detected. After insemination of one of more pelviscopically obtained oocytes with sperm of the husband in 14 out of 22 cases (63.6%) with bacteria concentrations greater than 10(5)/ml the cleavage of at least one oocyte occurred leading to an embryo transfer rate of 63.6%. 14 of 31 ejaculates with negative bacteriological findings (45.2%) fertilized at least one of the inseminated oocytes. From the results obtained up to now any direct effect of microorganism contaminated sperm on the human in vitro fertilization system resulting in reduced fertilizations rates cannot be demonstrated. It can be said that there is no correlation between microbiological and cytological findings of ejaculates used for insemination of oocytes and the obtained fertilization, cleavage and embryo transfer rates in the human in vitro fertilization program here. But since the negative effect on implantation rates or embryonic development cannot be excluded detailed bacteriological examinations and probably antibiotic treatments may be recommended before admission of the in vitro fertilization program.

Embryo Implantation↗
PubMedDate not supplied

Significance of the ultrasonic morphology of preovulatory ovarian follicles prior to in vitro fertilization.

Forty-eight oocytes were collected from 47 follicles in 36 cycles from 24 patients with tubal infertility by ultrasonically guided percutaneous puncture under local anesthesia. The ultrasonic represented morphology of the aspirated follicles was compared to the presence of an egg-cumulus-mass in the follicular aspirate and the result of oocyte fertilization. There was a higher frequency of a cumulus-mass in the aspirate from follicles containing echoes (90 per cent) compared to ultrasonically empty follicles (37 per cent). Thirty-four oocytes were fertilized corresponding to a fertilization rate of 71 per cent. The mean diameter of follicles in the fertilized group was bigger (20.9 mm) than the mean diameter of follicles in the non-fertilized group (18.5 mm). The fertilization rate was higher in oocytes collected from follicles with internal echoes (87 per cent) compared to echo-free follicles (50 per cent). It seems that the ultrasonic demonstration of a fine cloud projecting into the follicle or a clouding of the cavity increases the possibility of collecting an oocyte suitable for in vitro fertilization.

Embryo Transfer↗
PubMed1983

Do couples make fertility plans one birth at a time?

Criteria are specified for distinguishing one-decision from sequential-decision models of fertility. Sequential decisions are not demonstrated by parity-specific differences in fertility determinants. Sequential models must demonstrate the importance of unanticipated intervening events in changing fertility plans or fertility experience. They must demonstrate that the intervening events are not caused by the fertility. Two empirical tests are designed to determine which model best fits the data. One test predicts fertility plans, the other fertility events. Both tests provide some support for sequential models.

Birth Intervals↗
PubMed1981

The effect of female education on fertility: a simple explanation.

This paper investigates the structure of the relationship between female education and fertility. It is based on data published in First Country Reports of the World Fertility Surveys for eleven countries--Costa Rica, Colombia, Dominican Republic, Panama, Fiji, Korea, Malaysia, Pakistan, Sri Lanka, Thailand, and Indonesia. The cumulative marital fertility of educated women is shown to be similar in different settings. A lack of uniformity in the education and fertility relationship including the curvilinear nature of this relationship observed across countries is shown to be attributable to marked differences between countries in the average fertility of women with no education rather than to the presumed differences in the average fertility of the educated women. The structure of the relationship is shown to be similar across several developing countries. This analysis suggests that advancement in female education can be expected to influence fertility behavior even without simultaneous changes in other factors such as increasing opportunity for participation in the paid labor force in the modern sector.

Breast Feeding↗
PubMed1994

What do we know about the timing of fertility transitions in Europe?

The Princeton project on the decline of fertility in Europe (the European Fertility Project) suggested that this historical fertility transition occurred virtually simultaneously in a wide variety of economic and social environments. This finding has been cited widely as evidence for an innovation/diffusion view of fertility transitions. We demonstrate that the demographic methods used to date the fertility transition in Europe--primarily Ig, and (to a lesser extent) the Coale-Trussell M&m indices--may fail to detect the initial stages of a fertility transition and therefore cannot be used as the basis for strong statements about the timing of transitions. We review these measurement problems and their implications for the current understanding of the European fertility transition.

Contraception↗
PubMedDate not supplied

[Epidemiological study of fertility in adolescents in the Autonomous Community of Madrid].

OBJECTIVE: The purpose of this study was to research the frequency and distribution of fertility in adolescence and, in looking at different environments within the Autonomous Community of Madrid (ACM), to evaluate the relationship of fertility rates to determined variables of a socio-economic, educational and demographic nature. DESIGN: An observational crossover study was carried out. SETTING: Autonomous Community of Madrid. PATIENTS AND OTHERS PARTICIPANTS: In this study, the specific rate of fertility in adolescents (SRFA) was calculated and the correlation between the SRFA and variables of a socioeconomic, educational and demographic nature were analysed by means of the multiple linear regression method. MEASUREMENTS AND MAIN RESULTS: We found important differences in the distribution of fertility within the ACM. There was also a positive correlation (p < 0.05) between the SRFA and those variables which expressed the percentages of illiteracy, industrial workers and with the synthetic youth index. A negative correlation (p < 0.05) was found for the percentages of graduates, professionals and technicians, managers and directors and with the synthetic ageing index. We found no correlation with the unemployment index. On applying the multivariant model, the variable that weighed most on fertility was the level of education, which was in our case measured by the percentage of illiteracy. CONCLUSIONS: We found an uneven spread of adolescents' fertility rates in the Autonomous Community of Madrid. The fertility rates were higher in those boroughs where there was more illiteracy.

Adolescent↗
PubMed1993

Effect of lysoplatelet-activating factor on human sperm fertilizing ability.

OBJECTIVE: To evaluate the penetration rates in the hamster zona-free oocyte sperm penetration assay (SPA) after exposure of spermatozoa to lysoplatelet-activating factor (LPAF) and lysophosphatidyl choline (LPC). DESIGN: Washed human spermatozoa were exposed to 100 microM of LPAF or LPC, followed by the assessment of their fertilizing ability using the SPA. The percentage of penetration, the sperm binding in the SPA, the percentage of motile spermatozoa, and the acrosome reaction rates were quantified. SETTING: Private research and university laboratories. PATIENTS, PARTICIPANTS: Fresh and frozen semen samples from fertile donors with proven fertility were used as well as fresh semen from infertile patients attending a fertility clinic. All the infertile patients had abnormal semen analysis. INTERVENTIONS: Human spermatozoa were incubated for 90 minutes in the presence or absence of LPAF or LPC at 100 microM with 0.3% albumin in Ham's F-10 (GIBCO, Dorval, Quebec, Canada), and their fertilizing ability was evaluated using the SPA. The effect of these lysophospholipids on the percentage of acrosome reaction was evaluated with a fluorescent microscopy technique. RESULTS: The penetration rates of the SPA in male factor increased significantly from 3% +/- 6% with controls to 19% +/- 9% and 34% +/- 22% after incubation with LPC and LPAF, respectively. Sperm-oocyte binding was not significantly increased in this group. Sperm penetration assay penetration rates were also increased in fertile cryopreserved spermatozoa with LPC and LPAF. In this group, the acrosome reaction was significantly increased from 2% +/- 1% in controls to 10% +/- 6% and 8% +/- 3% after incubation with LPC and LPAF, respectively. CONCLUSION: Lysoplatelet-activating factor and LPC independently increased the penetration rate of spermatozoa and the percentage of acrosome reaction. Lysophosphatidylcholine and LPAF may be beneficial in the treatment of spermatozoa with male factor infertility and may increase fertilization rates in IVF.

Acrosome↗
PubMed1995

Analysis of 76 total fertilization failure cycles out of 2732 intracytoplasmic sperm injection cycles.

From October 1992 to December 1994, 2732 cycles of treatment by intracytoplasmic sperm injection (ICSI) were carried out in couples mainly with severe male-factor infertility. The overall fertilization rate in these 2732 cycles was 71% of intact oocytes. However, in 76 (72 couples) of these cycles, none of the injected oocytes became fertilized, so the total fertilization failure rate was 3% (76/2732 cycles). Details of these 76 cycles were analysed. The results show that total fertilization failure after ICSI may be explained by different factors related to (i) semen characteristics (only immotile or round-headed spermatozoa for ICSI) or (ii) the oocytes (number, abnormal morphology, damage after ICSI). Of 26 couples, 22 achieved fertilization in their subsequent ICSI cycles. In conclusion, total fertilization failure after ICSI for the treatment of severe male-factor infertility was mainly caused by the poor viability of the spermatozoa used for injection; it was also associated with a low number and poor quality of oocytes. Repeated ICSI treatment may be useful or necessary in couples with total fertilization failure.

Adult↗
PubMed1996

Influence of sperm number per straw on the post-thaw sperm viability and fertility of Swedish red and white A.I. bulls.

Semen from 5 Swedish Red and White bulls, approved in the fertility and progeny testing programme of a bull center, was split-frozen to produce straws with 15 or 10 x 10(6) spermatozoa each (control and treatment dose, respectively). Post-thaw sperm viability was evaluated by visual assessment of sperm motility (MOT), measurement of ATP (Adeinosin Tri Phosphate) contents by luminometry, assessment of membrane integrity with combined fluorophore probes [Calcein AM (CAM)/Ethidium homodimer (EthD-1)] and by using a hyposmotic swelling test (ORT). The straws were used for a total of 16,651 artificial inseminations (A.I.). No statistically significant difference was recorded between the 2 treatments for any of the post-thaw sperm viability parameters. In addition, a significant bull effect was evident for most post-thaw sperm traits assayed. Significant variation in overall fertility (56-days NRR) was recorded among the bulls used. A.I. with a reduced number of spermatozoa (10 x 10(6)/straw) resulted in a 2%-units decrease (n.s.) compared with controls (67.8% +/- 4.8%, means +/- SD) in overall fertility. In the control split-sample (15 x 10(6) spermatozoa/straw), MOT did not show any statistically significant correlation with fertility (r = 0.41, p = 0.07). However, MOT was correlated with the percentage of spermatozoa depicting progressive motility (category A1, r = 0.45, p < 0.05) as assessed with CAM/EthD-1. The latter was correlated with ATP contents (r = 0.57, p < 0.01), expressed as the percentage of viable spermatozoa. Both CAM/EthD-1 and ATP contents showed a statistically significant correlation with ORT (r = 0.45, p < 0.05 and r = 0.61, p < 0.05, respectively). In the straws with the reduced sperm number (10 x 10(6) spermatozoa), post-thaw motility was significantly correlated with fertility (r = 0.50, p < 0.05) and ATP-total contents (r = 0.48, p < 0.05). CAM/EthD-1 and ATP contents (as million viable spermatozoa) were significantly correlated (r = 0.47, p < 0.05), CAM/EthD-1 was significantly correlated with ORT (r = 0.48, p < 0.05). In conclusion, the results indicated that the freezing-thawing of straws with a reduced sperm concentration (10 x 10(6) spermatozoa) did not alter the post-thaw viability or overall fertility of the bull semen used. However, in view of the significant bull effect found in the limited population studied, we recommend that such a reduction in sperm number/straw be based on the fertility of the bull in question.

Animals↗
PubMed1977

Target fertility, contraception, and aggregate rates: toward a formal synthesis.

This paper develops a stock adjustment model relating total expected births to conventional aggregate fertility rated for married women over 25. Each year, cohorts bear about 20 percent of their additional expected births. Aggregate U.S. rates have been consistent with expectations as expressed in surveys between 1955 and 1975; indeed, total expected births may be inferred from aggregate fertility behavior. A peculiar empirical finding is that the additional expected fertility of nonterminators has not changed since 1955, despite the dramatic decline in total expected and actual fertility. The model leads to a dynamic expression for the duration pattern of current and cumulative fertility and for the proportion of couples who have terminated childbearing. The model is also used to analyze the effects of changing contraceptive failure rates on fertility patterns. For example, a decline in "timing" failure rates increases duration-specific fertility five years later.

Adult↗
PubMedDate not supplied

Partial sympathetic denervation of the rat epididymis permits fertilization but inhibits embryo development.

The rat cauda epididymidis receives sympathetic innervation from the inferior mesenteric ganglion (IMG). We have previously demonstrated that surgical removal of the IMG and proximal hypogastric nerves (IMG denervation) results in significant and cauda-specific changes in epididymal sperm transport, sperm motility, luminal fluid protein composition, and tissue histology. In the present study we used natural mating trials and intrauterine insemination (IUI) techniques to determine whether or not IMG denervation affects male fertility and reproductive capacity. For the initial studies, adult male Sprague Dawley rats were mated with estrous females 1 and 4 weeks following IMG denervation. Nine days after mating, uterine implantation sites and corpora lutea (CL) were counted. In females mated with sham-operated control males, 85.8% of ovulated oocytes were fertilized and subsequently implanted. In contrast, females mated with IMG-denervated males 1 or 4 weeks following surgery had 0% and 3.5%, respectively, of ovulated oocytes fertilized and implanted. For rats maintained 21 days after mating, an average of 13 +/- 1 pups were delivered by each of nine females mated with sham-operated control male rats; whereas, only seven morphologically normal pups were delivered by one of 14 females mated with IMG-denervated male rats. Additional experiments demonstrated that the decrement in offspring was, in part, due to a significant decrease in the number of spermatozoa in the female uterus following mating with IMG-denervated males. To determine whether IMG denervation exerted an additional effect directly on the fertilizing ability of spermatozoa, IUI experiments were performed. Six million cauda epididymal spermatozoa from 1- or 4-week IMG-denervated males were inseminated into the uterine horns of luteinzing hormone-releasing hormone (LHRH)-synchronized females and 9 days later implantation sites and CL were counted. Implantations were observed for 78%, 28%, and 25% of ovulated oocytes following IUI with spermatozoa from sham-operated controls and from 1- and 4-week IMG-denervated rats, respectively. To determine whether the reduction in implantation sites following IUI with spermatozoa from IMG-denervated rats resulted from impaired oocyte fertilization, studies were performed in which oocytes were retrieved and stained 24 hours after IUI. Comparable fertilization rates of 76.5% and 89.0% were observed using cauda epididymal spermatozoa from IMG-denervated and sham-operated control males, respectively, indicating that oocyte fertilization was not affected by the loss of innervation. These studies establish the importance of innervation from the IMG for ejaculatory competence and sperm reproductive capacity in the male rat. These data further suggest that sympathetic innervation in the epididymis critically influences paternal factors associated with embryonic development.

Animals↗
PubMedDate not supplied

Sperm motion predicts fertility in male hamsters treated with alpha-chlorohydrin.

An understanding of the relationship between altered sperm motion and sperm function (fertility) is important when interpreting the biological significance of toxicant-induced changes in sperm velocity in rodent test species. Previous studies showed that a brief (4-day) exposure of male hamsters to the model chemical alpha-chlorohydrin (ACH) results in significant deficits in epididymal and uterine sperm velocity, which are associated with both a delay and a failure of fertilization in vivo. To characterize this effect in terms of fertility, similarly treated male hamsters were bred to untreated females and pups were counted the day before parturition. ACH treatment resulted in a dose-dependent decline in the percentage of sperm-positive females that were pregnant at the end of gestation (100, 78, 67, 22, and 0 where males were treated with 0, 33, 49, 66, and 83 mg ACH/kg/day, respectively). Cauda epididymal sperm from the same males were assayed for motion characteristics using computer-assisted sperm analysis (CASA), and for fertilizing ability in vitro. While the percentage of motile sperm was unaffected by ACH treatment, sperm velocity declined in a dose-dependent manner at all ACH treatment levels. Furthermore, the velocity of sperm from infertile males was shifted downward consistently across the entire velocity distribution. Since treated males tended to either be infertile (no pups) or have near normal litter size, the correlation between sperm velocity and litter size was nonlinear. Therefore, logistic regression models using velocity cut-off values were the most useful models for predicting fertility. These results support the contention that fertility relies on there being a sufficient number of sperm that exceed a velocity threshold. Sperm from treated males were also less likely to support in vitro fertilization (IVF), providing further evidence of impaired sperm function associated with acute exposure to ACH.

Animals↗
PubMed1997

Molecular mechanisms of gamete recognition and fusion at fertilization.

Advances in many areas of reproductive technology have been rapid and, in many respects, have outstripped our knowledge of the fundamental processes of human and animal sperm-egg interactions at fertilization. This is particularly true of human fertilization, where the availability of eggs for research purposes is severely restricted. As a consequence of this, most of the significant advances in our understanding of mammalian fertilization have resulted from studies on animals, particularly the mouse. This review summarizes our current knowledge of the molecular aspects of mammalian fertilization from the point of view of the fertilizing spermatozoon. Particular reference is made to those advances in our knowledge of human fertilization mechanisms. Further understanding of the molecular basis of human fertilization is of paramount importance for the development of new methods of contraception and also for the rational diagnosis and treatment of certain forms of infertility.

Acrosome↗
PubMedDate not supplied

Fertility and childbearing practices in rural African community.

This longitudinal, community based study was carried out to gain insight into factors which influence child bearing practices and fertility in a typical Yoruba village in S.W. Nigeria. Although fertility is shown to be on the decline in most developing countries, a relatively high fertility is still sustained in the rural areas of this country. Women start child bearing early and continue into advanced reproductive ages. Median age of the women who delivered in the 2 year study period was 24 years with peak fertility seen between ages 20-24 years. Seasonality of births was observed due to religion and the agricultural cycle. Unadjusted Total Fertility Rate (TFR) for 1993 was 8.83 and for 1994 was 8.47. This small decline in TFR was not significant (Paired t-test t = 1.3, p = 0.28). Traditional attitudes which favour high fertility are maintained because of ignorance about modern family planning methods, low child survival rates and the ingrained custom of using children as a source of help on the farms. In addition, children are still the major source of support in old age. It is recommended that in order to reduce National total fertility rate, attention be paid to the rural areas where the majority of the people reside. Potential modifiable factors include improving child survival rates, increasing contraceptive awareness and education and a general improvement in the socio-economic conditions of the rural areas of this country.

Adolescent↗
PubMed1982

The World Fertility Survey: charting global childbearing.

Interviewing some 350,000 women in 42 developing countries and 20 developed countries representing nearly 40% of the world's population, the World Fertility Survey (WFS) is in a unique position to document the historic 1970s slowdown in global population growth. This Bulletin describes efforts begun in 1972 to ensure high quality, internationally comparable, accessible data, the data's importance for policymakers, planners and researchers, and major findings available by early 1982 from directly assisted WFS surveys in 29 developing countries and contraceptive use data from WFS-type surveys in 16 developed countries. Marital fertility has declined in all developing regions except Africa but still averages from 4.6 children/woman in Latin America to 6.7 in Africa, while preferred family size ranges from 3.0 children in Turkey to 8.9 in Senegal--far above the average 2.2-2.5 children/woman needed to end developing countries' population growth in the long run. However, women ages 15-19 prefer nearly 2 children fewer than the oldest women ages 45-49; 3.8 vs. 5.7 on the average. Nearly 1/2 (48%) of married women surveyed in 27 countreis said they wanted no more children. Preventing all unwanted births would reduce birth rates up to 15 births/1000 population in these countries. Overall, 32% of married, fecund women in developing countries are using contraception compared to an average 72% in 16 developed countries. Education, literacy, and more available family planning services increase contraceptive use. Age at marriage is rising in Asia, but this factor alone has little effect on fertility. Infant mortality is higher in many developing countries than previously thought. Breastfeeding is an important restraint on fertility in most developing countries but is declining among more educated, employed, and urban women which could raise fertility if not compensated for by gains in contraceptive use.

Africa↗
PubMed1981

Fertility decline and differences in less-developed countries: an anthropological microstudy of some communities of West Bengal, India and Upper Khumbu, Nepal.

The role of socioeconomic and other cultural factors as determinants of fertility change has been widely discussed, with some scholars emphasising an inverse relation between socioeconomic development and fertility, others suggesting that no such relation necessarily exists, and yet others indicating that by using data from various sources it is possible to "prove" that a given country's crude birth rate has declined, remained unchanged or increased. Demographic data are presented on age-sex structure, completed and total fertility rates, and age specific fertility rates by age cohorts of women, from several small, anthropological population units of West Bengal, India and Upper Khumbu, Nepal, exposed to various physical and cultural environmental stresses. The data show that fertility has declined in most of the populations/subpopulations studied and that the decline may, deductively, be attributed to economic development via greater family planning practices.

Adolescent↗