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At least 163 records · Page 9Linked to original sources

A prospective multicentre trial of the ovulation method of natural family planning. I. The teaching phase.

The percentage of 869 women in five countries capable of being taught to recognize the periovulatory cervical mucus symptom of the fertile period was determined in a prospective multicentre trial of the ovulation method of natural family planning. The women were ovulating, of proven fertility, represented a spectrum of cultures and socioeconomic levels, and ranged from illiteracy to having postgraduate education. In the first of three standard teaching cycles, 93% recorded on interpretable ovulatory mucus pattern. Eighty-eight per cent of subjects successfully completed the teaching phase; 7% discontinued for reasons other than pregnancy, including 1.3% who failed to learn the method. Forty-five subjects (5%) became pregnant during the average 3.1-cycle teaching phase. The average number of days of abstinence required by the rules of the method was 17 in the third teaching cycle (58.2% of the average cycle length). To what extent the findings of this study can be extended to other couples remains to be demonstrated.

Adult↗

Cryptorchidism: a general surgical perspective.

BACKGROUND: The treatment of cryptorchidism has changed, with surgery now advocated before the age of two years. Delayed treatment affects fertility, malignant potential and psychological stress. AIMS: To assess the pattern of referral of cryptorchid patients to a surgical clinic, management and follow-up. METHODS: A four-year review of 114 cryptorchid patients examined age at presentation, waiting time, timing of surgery and length of follow-up. RESULTS: The mean age at presentation to the surgical clinic was 6.7 years (neonatal to 71). The mean age at orchidopexy was 5.6 years. Seventy per cent had a surgical procedure within eight weeks of presentation to a surgeon. Seven per cent were kept under surveillance until a maximum age of three years before orchidopexy was considered. Only 29% proceeded to surgery before the age of two. Seventeen were referred to a paediatric urology unit for further management. CONCLUSIONS: Orchidopexy seems prudent between one and two years of age. Only one-quarter of patients underwent early orchidopexy. It is vital that it is detected early, by paediatricians at birth or the general practitioners (GPs) at the six-week check up. Prompt referral to a surgeon with a paediatric interest is essential in order to permit surveillance or surgery.

Adolescent↗

The malleability of fertility-related attitudes and behavior in a Filipino migrant sample.

The malleability of fertility-related attitudes and behavior was studied by analyzing data collected from cross-sectional groups of Filipino migrants who had lived in the United States for varying lengths of time, in conjunction with data from a comparison group of Caucasians from the Filipinos' neighborhoods. With increasing number of years lived in the United States, Filipino migrants' fertility-related knowledge, attitudes, and desires became increasingly similar to those of the Caucasian group, but their contraceptive behavior did not. While approximately equal numbers of Filipinos and Caucasians were contracepting, Filipino couples regardless of duration of stay in the United States were using less effective methods with less regularity. Despite these contraceptive behavior patterns, Filipino migrants perceived that they would have 0.32 fewer children in the United States than they would have had had they remained in the Philippines. By far the most predominant reason given by Filipino respondents for changing fertility patterns in the United States was the difficulty of obtaining child care in the new environment.

Adult↗

Robustness of life table methods in large populations--a study by computer simulation.

The robustness of the product life table estimator of the survival function was studied for large populations under perturbations in the age distribution, changing levels of mortality and changing patterns of fertility. A macrosimulation system, based on a class of stochastic population models called generalised age-dependent branching processes, was used to carry out the numerical investigations. Aside from drastic perturbations in the age distribution and changes in levels of mortality, the product life table estimator of the survival function was found to be robust in large populations, under a variety of conditions.

Age Factors↗

Female sterilization by tubal ligation: a re-appraisal of factors influencing decision making in a tropical setting.

BACKGROUND: Female sterilization by tubal ligation is the most commonly used method of fertility regulation. However, in some lesser-developed countries like Nigeria, it has not been accepted as a popular method of contraception. OBJECTIVE: To assess the pattern of female sterilization and determine factors that may influence its acceptability. METHOD: A retrospective study of 102 cases of tubal ligation (TL) performed between January 1999 and December 2004. RESULT: Of the 102 patients/clients, 60 (58.8%) had TL at caesarean section, 28 (27.5%) had TL with repair of ruptured uterus and 14 (13.7%) clients had TL alone on request. In the reproductive age group, the rate of TL increased with age. In the group that had TL at caesarean section, the highest incidence of TL (65%) was recorded against parity 4. However, in the groups that had TL with repair of ruptured uterus and TL alone, the highest proportion of TL was recorded against parity 6, with rates of 46.3 and 57.1%, respectively. The rates of TL increased with the level of literacy. In the group that had TL alone, 92.9% of the clients were in a monogamous union. On the contrary, 89.3% of patients that had TL with repair of uterine rupture were in a polygamous union. There was relative distribution of patients/clients amongst the two religions and five ethnic grouping. In 55 of the 102 patients/clients, the indication for TL was completion of family size, though 41 of the 55 patients had TL at caesarean section. CONCLUSION: Demand for TL alone was low. A greater percentage of the patients had TL in conjunction with another surgical procedure.

Adult↗

Functional changes and motility characteristics of Japanese Black bull spermatozoa separated by Percoll.

Spermatozoa from two Japanese Black bulls (Bull-ATF and Bull-KTG) were separated by centrifugation at 700 x g for 15min in modified TALP with or without 45-90% Percoll. Control washed spermatozoa and those collected from the bottom of 45 and 90% Percoll fractions were examined for viability and membrane integrity (using Hoechst bis-benzimide 33258 or propidium iodide and 6-carboxyfluorescein diacetate (PI-CFDA)), acrosomal status (using fluorescence isothiocyanate (FITC) conjugated Pisum Sativum agglutinin (PSA) and Peanut agglutinin (PNA), Naphthol Yellow S and Erythrosin B (NE) or triple staining (TS)), capacitation status (using chlortetracycline (CTC)), motility characteristics (using a computer-assisted sperm motion analysis system (CASA)) and for in vitro fertility. Percoll-separated spermatozoa showed greater viability and membrane integrity than controls, as determined by supravital staining. Differences were observed in the results regarding viability and acrosomal status of spermatozoa among sperm staining methods. Bull-ATF, which showed significantly greater in vitro fertility than Bull-KTG (P<0.05), showed a significantly higher rate of CTC-B-pattern (capacitated) spermatozoa (P<0.01) than Bull-KTG. The motility characteristics of control washed spermatozoa and those separated by 45-90% Percoll were analyzed by CASA. More motile and progressively motile spermatozoa were observed in the fraction at the bottom of the 90% Percoll solution than in the 45% Percoll fraction or in controls (P<0.01). Moreover, the spermatozoa of Bull-KTG, which showed lower in vitro fertility than Bull-ATF, did not show significant differences in motility from those of Bull-ATF. These results provided basic information about Japanese Black bull spermatozoa, and suggested that spermatozoa with greater motility and viability can be obtained by Percoll separation than without separation. However, Percoll separation did not enhance their in vitro fertility.

Acrosome↗

Ineffective contraceptive use and its causes in a natural fertility population in southern Jordan.

Based on our interview survey of 574 randomly selected married women from a rural population in the South Ghor district, Jordan, where traditional Arab customs have been persistently maintained, in this paper we analyze the age-specific marital fertility rates (ASMFRs) and contraceptive practices, especially the prevalence and duration of contraceptive use. The ASMFRs fitted the natural fertility pattern proposed by Coale and Trussell's model, and the total fertility rate was estimated to be 7.2. Even though the prevalence rate of modern contraceptive methods has reached 14.3%, because of the recent increase among young women in particular, the users had larger numbers of children than the nonusers and the duration of contraceptive use was short, especially at young ages (e.g., about 90% 24-month discontinuation probabilities in 15-19- and 20-24-year-olds). These ineffective contraceptive uses were related to traditional Arab norms, represented by the pooled proportion of "as many as possible" and "up to God" answers to the ideal number of children (70% of men and 30% of women).

Adolescent↗

Clinical and laboratory findings in a trial of norgestrel, a low-dose progestogen-only contraceptive.

Norgestrel, a progestogen-only oral contraceptive, was given continually at a dose of 75 mug/day to 144 women of proved fertility. It was an efficient contraceptive with a failure rate of 2.1% (assessed by the "life-table" method) within the first 12 cycles and 3.6% within the first 30 cycles (or 2.0 conceptions per 100 woman-years when assessed by the Pearl index). The overall conception rate for the entire trial period was 2.1% and 1.3 pregnancies per 100 woman-years respectively. Norgestrel caused a high proportion of irregular and generally short bleeding intervals, about one-fifth of the cycles lasting less than 17 days. This irregularity appeared to be due to individual variance in cycle length between women rather than that between their successive cycles. No confirmed instances of thromboembolism were observed. Norgestrel apparently exerts its contraceptive action by several mechanisms: reduction in the sperm penetrability of the cervical mucus and an impairment of luteal function appear important. The serum concentrations of cholesterol and globulin were significantly reduced in women taking norgestrel. Preliminary observations suggest that on discontinuing the medication fertility is promptly restored. Of the 144 women originally enrolled 57 (40%) withdrew for reasons connected with the method before completing 30 months on trial, over half of them because of the irregular menstrual pattern. Nonetheless, in view of its main clinical and laboratory characteristics and simple mode of administration, norgestrel appears to be a useful alternative to the combined type of pill for women unsuitable for, or unable to tolerate, oestrogen-containing preparations.

Blood Chemical Analysis↗

Stress and fertility. A review.

The effect of both environmental and management related stressors on fertility is discussed. While environmental heat as a stressor is significant in disrupting normal reproductive cyclicity, management induced stress is becoming more important when related to the requirements of modern production methods. Deviations in hormonal patterns are noted, and the clinical manifestations brought about by these changes are described. Since reproduction is the ultimate measure of an animal's ability to adapt to an ever changing external milieu, as well as forming the basis of life-time productivity, research should be aimed at obtaining greater clarity of the hormonal interactions involved. The role of neurotransmitters in these physiological mechanisms should not be overlooked. Psychobiological studies must be extended so as to provide a positive input into management procedures that should be used in intensive production units for optimal fertility and productivity.

Adaptation, Physiological↗

Peptides corresponding to the epidermal growth factor-like domain of mouse fertilin: synthesis and biological activity.

A key step leading to fertilization is the binding of sperm to the egg plasma membrane. When a mammalian sperm reaches the egg plasma membrane, fertilin, an extracellular sperm membrane protein, is believed to bind to an egg plasma membrane receptor mediating fusion. Fertilin is composed of two subunits, and each subunit contains several domains, i.e., metalloprotease, disintegrin, epidermal growth factor (EGF)-like and fusion domains. This investigation examined the role of the EGF-like domains of mouse fertilin alpha and fertilin beta. Peptides corresponding to the N-terminal subdomain, containing four cysteines, and the C-terminal subdomain, containing two cysteines, were synthesized by solid-phase synthesis methods. Disulfide bonds were formed regioselectively according to the canonical EGF-like disulfide pattern. The activity of these peptides and their linear counterparts were tested for activity in a mouse in vitro fertilization assay. One peptide, 4a, corresponding to the cystine-constrained N-terminal subdomain of fertilin beta, had an activating effect on fertilization. The fertilization rate (number of eggs fertilized), fertilization index (number of sperm fused per egg), and level of polyspermy (three or more sperm fused per egg) increased in the presence of 500 microM 4a (12, 56, and 190%, respectively). Its linear counterpart, 4b, had no effect on in vitro fertilization. These data suggest that the EGF-like domain of fertilin beta has a function in sperm-egg binding and fusion. Previously, it has been shown that the fertilin beta disintegrin domain has a role in sperm-egg binding. Considered together, these studies suggest that fertilin is a modular, multidomain protein with more than one mechanism of action. This modularity may be used to design inhibitors of fertilin-receptor interactions that have high specificities for the fertilization process.

ADAM Proteins↗

Current fertility: a first glimpse from the 1983 National Demographic Survey.

This paper highlights initial findings from the 1983 National Demographic Surveys (NDS) based on a 25% sub-sample of the survey respondents. The discussion focuses on measures of current fertility as well as on selected fertility "predictors" for the 3 major island groups -- Luzon, Visay, and Mindanao. Owing to the restrictive nature of the data set, no statistical tests are performed to measure the influence on fertility of these explanatory variables. Instead, inferences are drawn from a descriptive analysis of the patterns exhibited. Findings point to a continuation of fertility decline as evidenced by the estimated crude birthrate of 33.6 births/1000.

Asia↗

[[A dynamic model for populations reproduced by first marriage]].

Using data for Japan, the author analyzes "the effect of nuptiality and of marital fertility [on population trends and constructs] a population model in which childbearing occurs only within first marriage....First, we can prove that...we can construct a stable population theory based on nuptiality and marital fertility....Next..., we investigate the effect of [the age shift in first marriage patterns on total fertility rates], since delay of marriage has been thought to be one of [the] major causes for long-term fertility decline in Japan. We conclude that although [the age shift in first marriage patterns] could decrease Japanese fertility, its effect seems to be insufficient to induce such rapid fertility decline as is observed recently in Japan." (SUMMARY IN ENG)

Age Factors↗

Differential infiltration of macrophages and prostaglandin production by different uterine leiomyomas.

BACKGROUND: The association between uterine myoma and infertility is still controversial. The anatomical defect of endometrium by uterine fibroids could be a factor for reducing pregnancy rates and increasing miscarriage rates. However, pregnancy and implantation rates were found to be significantly lower in women with intramural myomas (IMMs), when there was no deformity of uterine cavity. This could be due to other biological factors such as increased accumulation of inflammatory cells within fibroid tissue and corresponding endometrium that might impair fertility. Therefore, we tried to investigate the pattern of macrophage (Mvarphi) accumulation in different uterine fibroids and the production of chemokine and prostaglandin (PG) by these tissues. METHODS: The selection criteria of uterine fibroids were based on the classification of European Society of Hysteroscopy. Biopsy specimens were collected from respective nodules and autologous endometrium of 20 women with submucosal myoma (SMM), 29 women with IMM and 18 women with subserosal myoma (SSM). CD68 immunoreactive Mvarphis were identified in these tissues by immunohistochemistry. A fraction of corresponding tissues were homogenized, and levels of monocyte chemotactic protein-1 (MCP-1) and PGF(2alpha) were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: Mvarphi infiltration in the myoma nodule and corresponding endometrium of women with SMM and IMM was significantly higher than that of women with SSM or control women (P<0.01 and P<0.05, respectively). This tissue accumulation of inflammatory cells was independent of the sizes of the myoma nodules and phases of menstrual cycle. The tissue concentration of MCP-1 corresponded to increased Mvarphi infiltration and was significantly higher in women with SMM and IMM than that in women with SSM (P<0.05 for each). A positive correlation was observed between MCP-1 concentration and accumulated Mvarphi numbers in the endometrium of women with SMM and IMM but not in women with SSM. The tissue levels of PGF2alpha were also significantly higher in the nodule and corresponding endometrium of women with SMM and IMM than that in SSM or control women (P<0.05 for each). CONCLUSIONS: Higher production of MCP-1 could be responsible for the increased accumulation of Mvarphi in women with SMM and IMM. The augmented inflammatory reaction in endometrium and increased PGF2alpha levels might be detrimental to reproductive outcome in women with SMM or IMM.

Adolescent↗

Menstrual cycle characteristics: associations with fertility and spontaneous abortion.

BACKGROUND: Epidemiologists often use menstrual cycle patterns as indicators of endocrine function in environmental and occupational studies, yet few studies have considered whether menstrual cycle characteristics are associated with fertility or pregnancy outcome. METHODS: We prospectively studied 470 women to determine whether cycle length or bleed length were associated with fertility or spontaneous abortion. Women completed daily diaries with information on menstrual bleeding, intercourse, birth control use, and covariates. For each menstrual cycle, women collected at least 2 urine samples, which were assayed for human chorionic gonadotropin to define early pregnancies. Women were followed for 1 year or until the end of a clinical pregnancy. RESULTS: Cycles with lengths of 30 to 31 days preceded cycles with the highest fecundity. Shorter cycles were less likely to be followed by conception (fecundity ratio [FR] = 0.6; 95% confidence interval [CI] = 0.4-1.0). Compared with 30- to 31-day cycles, conceptions after shorter and longer cycles were more likely to be spontaneously aborted (for shorter cycles, odds ratio [OR] = 3.0 [95% CI = 0.9-9.6] and for longer cycles, OR = 3.0 [0.9-10.6]). Cycles with 5 days of menstrual bleeding had the highest fecundity. Cycles with up to 4 days of bleeding had lower fecundity (for bleed lengths of 4 days, FR = 0.5 [0.3-0.8] and for bleed lengths less than 4 days, FR = 0.6 [0.3-0.9]). Spontaneous abortion was less likely after bleeds greater than 5 days (OR = 0.4 [0.1-1.1]) when compared with 5-day bleeds. CONCLUSIONS: Menstrual cycle characteristics appear to be associated with fertility and spontaneous abortion.

Abortion, Spontaneous↗

Egg activation is the result of calcium signal summation in the mouse.

Egg activation in mammals is caused by cytosolic Ca(2+) oscillations that are essential for development. However, despite increasing knowledge about signal transduction mechanisms, the functional linkage between frequency number, amplitude and duration of the Ca(2+) signal and the kinetics of pronucleus formation has not yet been defined. While a wide range of Ca(2+) signal parameters are efficient in causing egg activation, the basic rules governing how the egg integrates these signalling events are not yet clear. Thus, in the perspective of better understanding how the egg processes Ca(2+) signalling events, the objective of this study was to determine experimentally whether the efficiency of egg activation and the subsequent early developmental stages rely on Ca(2+) signalling summation. Non-fertilized, but freshly ovulated mouse eggs, were subjected to a series of repetitive Ca(2+) influxes of various patterns modulated by a non-invasive membrane electropermeabilization method. Using a combination of two suboptimal treatments we have shown that mouse eggs can sum up the effects caused by various patterns of intracellular Ca(2+) concentrations transient during the period of egg activation. In addition, overloading the intracellular milieu by repetitive Ca(2+) influxes did not seem to inhibit the process of activation. The kinetics of pronuclear formation among a population of eggs treated in the same conditions became accelerated when the total dose of Ca(2+) signal 'experienced' by the eggs was increased. The results suggested that summation of the biological effects of all Ca(2+) signals constitutes an important mode of Ca(2+) signal integration.

Animals↗