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PubMed1991

Late expectations: childbearing patterns of American women for the 1990's.

"This paper will examine the changes in the timing of entry into motherhood among post World War II birth cohorts of women and the childbearing patterns of women after age 30 [in the United States]. The principal data source used in this paper will be the Census Bureau's fertility and birth expectations survey from the Current Population Survey (CPS)....A brief summary of the origins and evolving problems associated with using birth expectations data as a method to predict future fertility swings will first be examined. Next, the usefulness of expectations data as a predictor of the future will be discussed in the context of historical patterns of childbearing....Finally, this paper will examine which socioeconomic groups of women are most likely to be characterized by delays in childbearing and their current prospects for having their first birth at later ages."

Age Factors↗
PubMed2002

Contraceptive failure in China.

This study examines patterns and differentials of contraceptive failure rates by method and characteristics of users, using the Chinese Two-per-Thousand Fertility Survey data. The results show that contraceptive failure rates for modern methods including sterilization are some of the highest in the world. The first year failure rates are 4.2% for male sterilization, 0.7% for female sterilization, 10.3% for IUD, 14.5% for pill, and 19.0% for condom. There are also some differentials in contraceptive failure rates by users' sociodemographic and fertility characteristics. Contraceptive failure rate declines with women's age for all reversible methods. Rural women have higher sterilization, IUD, and condom contraceptive failure rates than urban women. Women with two or more children have a higher failure rate for sterilization methods but have lower failure rates for other methods.

Adolescent↗
PubMed2002

Anxiety, depression and anger suppression in infertile couples: a controlled study.

BACKGROUND: Although several authors have suggested an important pathogenic role for psychosocial factors in 'functional' infertility, the extent to which depression, anxiety and expressed emotional patterns correlate to infertility is not yet clear. METHODS: This study included 156 infertile couples (recruited at intake) and 80 fertile couples, whose personal characteristics were recorded. They were examined using scales for the evaluation of the degree of psychopathology [Hamilton Anxiety Rating Scale (HAM-A), Hamilton Depression Rating Scale (HAM-D)], and anger expression [State-Trait Anger Expression Inventory (STAXI)]. The 156 infertile couples were then subdivided into groups based on the cause of infertility ('organic', 'functional' or 'undetermined'). The psychometric evaluation was double-blind with respect to the causes of infertility. RESULTS: Differences emerged in the degree of psychopathology between 'organic' and 'functional' infertile subjects and fertile controls. In women, logistic regression identified three variables able to predict the diagnosis subtype; these variables are HAM-A, HAM-D, and tendency toward anger suppression. In men, anger did not emerge as a predictor for diagnosis, whereas HAM-A and HAM-D did. CONCLUSIONS: The 'functional' infertile subjects of this sample showed particular psychopathological and psychological features, independent from the stress reaction following the identification of the cause of infertility.

Adult↗
PubMed2000

Using complete breastfeeding and lactational amenorrhoea as birth spacing methods.

The aim of this study was to evaluate the effectiveness of lactational amenorrhoea and to determine the relationship between extended breastfeeding and the return of fertility. Breastfeeding pattern, basal body temperature, cervical mucus, salivary ferning, vaginal blood discharge, frequency of sexual intercourse, and the presence of ovulation in the first cycle after the resumption of menses with ultrasonography were evaluated in 40 women. All subjects completed the study with only one case of incomplete breastfeeding. No pregnancies were observed. The mean number of feeding sessions and mean interval between sessions decreased significantly (p <0.01) during the first six months postpartum (7.5 +/- 1.3 after 60 days postpartum vs. 5.7 +/- 2.1 after 180 days, and 3.6 +/- 0.8 vs. 5.1 +/- 0.9, respectively). Eight women (20%) menstruated before weaning, but none had an adequate thermal shift, while 32 (80%) had their first vaginal bleeding after weaning with 12 (37.5%) registering an adequate thermal shift. Both basal body temperature and salivary ferning proved to be suggestive of ovarian activity, while mucus characteristics were not reliable in identifying fertile periods. Our study showed that breastfeeding associated with lactational amenorrhoea proved to be a good method of postpartum fertility control. Since the importance of supplementation is still debated, it is recommended that a "complete" breastfeeding program be used.

Adult↗
PubMed1982

A reassessment of world population trends.

This reassessment is limited to observations concerning trends in mortality and fertility and concerning longrun prospects for population growth. Recorded changes in mortality are compared with 3 projections made many years ago. Projections of European mortality made in 1941-42 understated by a wide margin the actual increase in expectation of life because of unforeseen technological changes in the prevention and cure of fatal disease. On the other hand, a projection made in 1955 for India, foreseeing a rapid rise in the 1950s and slower progress later on because of the exhaustion of the easier gains, appears to have been accurate and also to depict the prospects in other populations of relatively high mortality and low income. A different projection of life expectancy in Mexico was also quite close to actual changes in Mexican mortality; it was based on a universal curve constructed to represent how life expectancy rises, increasing ever more slowly as it approaches an upper limit. This curve (1 for each sex), constructed for projection of Mexican mortality, is employed as a standard of comparison for mortality changes in many countries. A number have followed the standard for females very closely for more than 3 decades; in developed countries, male life expectancy has generally fallen short of the standard. The almost universal low fertility in developed countries contrasts with the great diversity of levels and trends of fertility in developing countries, some of which retain undiminished high fertility and others of which have recently attained rates of childbearing as low as in the developed areas. Instances of surprisingly little change and surprisingly rapid change in fertility are described. In the future, growth of populations of developed countries will probably be slight; the future rate of increase in the developing areas depends on the unpredictable timing and pace of childbearing reduction in populations where fertility remains high. In the long run, world population growth may resume its typical pattern of moderate growth interrupted by catastrophic setbacks.

Australia↗
PubMed2001

[Fertility and its intra-urban differentials of human development, São Paulo, Brazil, 1997].

OBJECTIVE: To assess potential discrepancies in reproductive patterns of women living in areas at different levels of human development by analyzing their total fertility rates and age-specific rates. METHODS: Ninety-six districts of the city of São Paulo (Brazil) were grouped in 5 areas according to their human development index (HDI). Women aged 15 to 49 years were included in the study and data was obtained from live birth certificates during the year of 1997. Data was collected from live birth certificates and population census for the year 1996. The following variables were analyzed: HDI; district of mother's residence and mother's age. RESULTS: The total fertility rate (TFR) for women living in the lowest HDI area was 2.62, and the highest specific fertility rate (SFR of 151/1,000) was found for the age group 20-24 years. For the area of highest HDI, the TFR was 1.67, and the age group of 25-29 showed the highest SFR (93/1,000). CONCLUSIONS: Women living in higher HDI areas showed a lower TFR and they tended to begin their reproductive life later in life, which suggests the coexistence of different reproductive patterns in the city of São Paulo.

Adolescent↗
PubMed2005

Did fertility go up after the Oklahoma City bombing? An analysis of births in metropolitan counties in Oklahoma, 1990-1999.

Political and sociocultural events (e.g., Brown v. Board of Education in 1954 and the German reunification in 1989) and natural disasters (e.g., Hurricane Hugo in 1989) can affect fertility. In our research, we addressed the question of whether the Oklahoma City bombing in April 1995, a man-made disaster, influenced fertility patterns in Oklahoma. We defined three theoretical orientations--replacement theory, community influence theory, and terror management theory--that motivate a general expectation of birth increases, with different predictions emerging from time and geographic considerations. We used two different empirical methodologies. First, we fitted dummy-variable regression models to monthly birth data from 1990 to 1999 in metropolitan counties. We used birth counts to frame the problem and general fertility rates to address the problem formally. These analyses were organized within two design structures: a control-group interrupted time-series design and a difference-in-differences design. In these analyses, Oklahoma County showed an interpretable, consistent, and significant increase in births. Second, we used graphical smoothing models to display these effects visually. In combination, these methods provide compelling support for a fertility response to the Oklahoma City bombing. Certain parts of each theory helped us organize and understand the pattern of results.

Adolescent↗
PubMed1995

Effects of hydrogen peroxide on human spermatozoa.

PURPOSE: Reactive oxygen species (ROS) have been reported widely to cause deleterious effects on sperm viability and function due to peroxidation of membrane lipids. However, their action appears more selective at low concentrations; recent evidence indicates that the superoxide anion can promote capacitation and induce hyperactivated motility (HA) in human spermatozoa and that hydrogen peroxide (H2O2) may participate in capacitation of hamster spermatozoa. The objective of these studies was to investigate the direct effects of H2O2 on functions crucial to fertilization in human spermatozoa. METHODS: In these prospective studies, we examined the dose- and time-dependent effects of H2O2 on sperm membrane-mediated events (binding to the zona pellucida and changes in intracellular calcium concentration [Ca2+]i, motility patterns, and acrosome reaction). Sperm from fertile donors were used in the experiments under capacitating conditions after separation of the motile fraction by wash/swim-up. [Ca2+]i was measured by the fluorescent fura-2 indicator, and sperm-zona pellucida binding was assessed with the hemizona assay (HZA). Hyperactivated motility was evaluated by computerized analysis, and the percentage of acrosome reacted sperm was detected by FITC-Pisum sativum lectin and indirect immunofluorescence. RESULTS: In the HZA, H2O2 did not influence sperm-zona pellucida binding at low concentrations (0.05 mM and 0.1 mM), but significantly reduced binding at 0.2 mM (P < 0.004 vs controls). H2O2 significantly decreased HA in a dose-dependent manner (P < 0.0001) and had a significant effect (P < 0.01) on acrosome reaction (stimulatory effect at 0.01 mM). H2O2 did not affect basal [Ca2+]i; however, H2O2 (0.1 mM through 10 mM) decreased the initial phase of progesterone-induced (P4: 1 microM) enhancement of [Ca2+]i in a dose- and time-dependent fashion. Preincubation of sperm with catalase (20 micrograms/ml) potentiated the P4-induced increase of [Ca2+]i. H2O2 did not significantly modify [Ca2+]i increase in response to inomycin (10 microM). CONCLUSIONS: These experiments show that H2O2 directly affects sperm functions crucial to fertilization in a dose- and time-dependent fashion. Low concentrations maintain capacitation, whereas higher concentrations have deleterious effects, as determined by the end points of the capacitation process. The latter effects are probably dependent on modifications of plasma membrane and intracellular homeostasis by the oxidative process.

Acrosome↗
PubMed1995

Rates of testosterone-induced suppression to severe oligozoospermia or azoospermia in two multinational clinical studies. World Health Organization Task force on Methods for The Regulations of Male Fertility.

Two multicentre studies of the contraceptive efficacy of azoospermia and severe oligozoospermia were conducted in 16 centres in 10 countries. They used a common protocol of weekly testosterone injections for sperm suppression, the patterns and degrees of which were compared among men from different population groups. Six hundred and seventy normal, health volunteers, of whom 205 were Asian (mostly Chinese) and 465 of non-Asian origin, were given weekly injections of testosterone enanthate, 200 mg IM, during the suppression (6-month) and efficacy (12-month) phases. Patterns of sperm suppression were assessed by semen analysis at monthly or 2-weekly intervals. Sperm counts suppressed more slowly in the Asian than in the non-Asian men in the first 2 months of injections but subsequently suppressed to lower sperm concentrations below 5 million/ml, 3 million/ml or azoospermia at 6 months were 97.1% 95.6%, and 66.7%, respectively for non-Asian men, compared to 99.4%, 98.4% and 89.2%, respectively for Asian men. In conclusion, a hormonal contraceptive method based on regular testosterone injections can suppress spermatogenesis to azoospermia or severe oligozoospermia in 97% of men, regardless of their ethnic origin.

Adult↗
PubMed1995

Belowground carbon allocation in unfertilized and fertilized red pine plantations in northern Wisconsin.

We estimated carbon allocation to belowground processes in unfertilized and fertilized red pine (Pinus resinosa Ait.) plantations in northern Wisconsin to determine how soil fertility affects belowground allocation patterns. We used soil CO(2) efflux and litterfall measurements to estimate total belowground carbon allocation (root production and root respiration) by the carbon balance method, established root-free trenched plots to examine treatment effects on microbial respiration, estimated fine root production by sequential coring, and developed allometric equations to estimate coarse root production. Fine root production ranged from 150 to 284 g m(-2) year(-1) and was significantly lower for fertilized plots than for unfertilized plots. Coarse root production ranged from 60 to 90 g m(-2) year(-1) and was significantly lower for fertilized plots than for unfertilized plots. Annual soil CO(2) fluxes ranged from 331 to 541 g C m(-2) year(-1) and were significantly lower for fertilized plots than for unfertilized plots. Annual foliage litterfall ranged from 110 to 187 g C m(-2) year(-1) and was significantly greater for fertilized plots than for unfertilized plots. Total belowground carbon allocation ranged from 188 to 395 g C m(-2) year(-1) and was significantly lower for fertilized than for unfertilized plots. Annual soil CO(2) flux was lower for trenched plots than for untrenched plots but did not differ between fertilized and unfertilized trenched plots. Collectively, these independent estimates suggest that fertilization decreased the relative allocation of carbon belowground.

Journal Article↗
PubMed1982

Reproductive performance of totally confined sheep bred with semen extended in a lactose-egg yolk-glycerol buffer and stored at 5 degrees C.

Two experiments were carried out in January and May 1975 to study reproductive performance (fertility, prolificacy and fecundity) of totally confined sheep synchronized for estrus. The main objective of the first experiment was to compare reproductive performance of ewes bred naturally to those bred by artificial insemination. Semen for artificial insemination was collected by either artificial vagina or electroejaculation and stored for up to 36 hours at 5 degrees C. A second objective was to evaluate the effect of pregnant mares' serum gonadotrophin on the reproductive performance of ewes synchronized for estrus. Fertility was 53% for ewes bred by natural mating, 34% for ewes receiving pregnant mares' serum gonadotrophin and bred by artificial insemination, and 9% for those not receiving pregnant mares' serum gonadotrophin and bred by artificial insemination. There was no difference in fertility between ewes bred with semen collected by artificial vagina or by electroejaculation. A similar pattern was observed for fecundity. Average prolificacy was 2.0 with no significant differences among mating methods or pregnant mares' serum gonadotrophin application being observed. In the second experiment, the reproductive performance of ewes inseminated with semen stores at 5 degrees C for 48 to 60 hours was compared to that of ewes inseminated with semen stores for 24 to 36 hours. No significant differences in the reproductive performance were detected. Although average fertility (9%) and fecundity (19%) were low, prolificacy averaged 2.0 lambs per ewe lambing.

Animals↗
PubMed2004

Localization of aquaporin-7 in human testis and ejaculated sperm: possible involvement in maintenance of sperm quality.

PURPOSE: We have previously reported the expression of aquaporin-7 (AQP7) in the rat testis and cloned human AQP7 from the testicular cDNA library. However, to our knowledge the spatial expression pattern and biological roles of AQP7 remain to be elucidated in humans. MATERIALS AND METHODS: We investigated AQP7 expression in the human testis and ejaculated sperm from fertile men and from infertile patients. RESULTS: AQP7 was expressed at the tail of spermatids and spermatozoa in the human testis. AQP7 protein was also detected at the middle piece and the anterior tale portion of ejaculated sperm. However, some infertile patients lacked AQP7 expression in ejaculated sperm, although all fertile men expressed AQP7 protein. The motility rate of AQP7 negative sperm was significantly lower than that of AQP7 positive sperm, while the sperm concentration was not different between AQP7 positive and negative subjects. CONCLUSIONS: AQP7 shows a spatial expression pattern in the human testis. AQP7 may be involved in the maintenance of sperm motility. Furthermore, a lack of AQP7 expression in sperm may be an underlying mechanism of male infertility.

Aquaporins↗
PubMed2006

Identification of AFLP markers linked to the male fertility restorer gene of CMS (Moricandia arvensis) Brassica juncea and conversion to SCAR marker.

We have developed a cytoplasmic male sterile (CMS) line of Brassica juncea through somatic hybridization with Moricandia arvensis and introgressed the fertility restorer gene into B. juncea. This fertility restorer locus is unique in that it is capable of restoring male fertility to two other alloplasmic CMS systems of B. juncea. As a first step toward cloning of this restorer gene we attempted molecular tagging of the Rf locus using the amplified fragment length polymorphism (AFLP) technique. A BC(1)F(1) population segregating for male sterility/fertility was used for tagging using the bulk segregant analysis method. Out of 64 primer combinations tested in the bulks, 5 combinations gave polymorphic amplification patterns. Further testing of these primers in individual plants showed four amplicons associated with the male fertility trait. Polymorphic amplicons were cloned and used for designing SCAR primers. One of the SCAR primers generated amplicons mostly in the fertile plants. Linkage analysis using MAPMAKER showed two AFLP and one SCAR markers linked to the male fertility gene with a map distance ranging from 0.6 to 2.9 cM. All the markers are located on one side of the Rf locus.

Fertility↗
PubMed2000

Recent trends in Tanzanian fertility.

This paper provides an assessment of the nature and magnitude of Tanzania's recent fertility decline, using robust methods for the identification of fertility trends. A decline in Tanzanian fertility began some time in the late 1970s or early 1980s. The pattern of decline exhibits similarities to patterns identified some years ago in Zimbabwe and Kenya. The decline has been especially marked in urban areas. It has been accompanied by a rapid rise in contraceptive prevalence from the very low levels before 1990 to just under 20 per cent of currently married women of reproductive age. Although falling marital fertility associated with a rise in contraceptive use is the main contributor to the decline in fertility, a rise in the average age at marriage has also made a (smaller) contribution, as has the AIDS epidemic. The fact that fertility is declining in Tanzania raises questions about the social and economic requirements for fertility transitions to begin in sub-Saharan Africa.

Fertility↗
PubMed1994

Anti-ZP3 antibodies binding to the human zona pellucida: effect of oocyte-storage conditions.

PROBLEM: The zona pellucida protein 3 (ZP3) is a zona pellucida (ZP) glycoprotein crucially involved in fertilization. ZP3 plays a major role in sperm binding and induction of the acrosome reaction. In different species, ZP3 proteins differ in their primary structure as derived from cDNA clones. The hemizona assay (HZA) is a bioassay that evaluates binding of human sperm to human ZP and is highly predictive of fertilization outcome under in vitro conditions. METHOD: In these studies, we used antisera generated against synthetic ZP3 peptides to compare antibody binding patterns to ZP with sperm-ZP binding capacity under different HZA conditions. RESULTS: Analysis of antibody binding to hemizonae derived from metaphase II human oocytes that were used either after refrigeration at 4 degrees C or stored in a hyperosmotic salt solution revealed a strong reaction with human ZP3. However, treatment of human oocytes using a protocol to freeze embryos with the addition of 1,2 propanediol drastically reduced binding of ZP3 antibodies to the hemizonae. Nevertheless, no significant difference of sperm binding occurred under HZA conditions when oocytes were refrigerated, salt-stored, or frozen with 1,2 propanediol. CONCLUSIONS: Our results indicate that the ZP3 protein backbone might be altered by 1,2 propanediol-treatment while the glycoprotein-receptor remains intact. We conclude that antisera against ZP3 peptides can be used as markers for the ZP3 protein backbone in human oocytes and might be useful tools for the evaluation of ZP3 protein integrity.

Cells, Cultured↗