Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “FERTILITY”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,171 records · Page 65Linked to original sources
PubMed1982

Reliability and accuracy of the zona-free hamster ova assay in the assessment of male fertility.

The efficacy of the zona-free hamster ova assay in assessing male fertility was studied in 22 men of proven fertility, 16 of unproven fertility, and 31 who were members of infertile couples. The mean hamster ova penetration rates were significantly higher in males of proven fertility (34%) and unproven fertility (30%) than in infertile males (11%). Sperm from 21 of 22 men of proven fertility penetrated greater than 15% of ova; one man had a zero penetration rate. Sperm from 8 of 16 men of unproven fertility and 24 of 31 men of infertile couples penetrated less than 15% of ova. There was no correlation between penetration rates and any of the traditional measures of semen analysis. Two assays were performed on every male and six assays were performed on six males. There was good interassay reliability in all 69 males (r = 0.86) and in the six males with six tests (r = 0.97). The mean interassay variation was 8.6%.

Adult↗
PubMed2004

Complete fertilization failure in ICSI.

Fertilization failure is one of the causes of infertility that becomes evident only after in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) have been attempted. Although the frequency of incidence of fertilization failure is low, if fertilization failure is encountered, medical treatment is usually stopped and serious psychological damage may occur to the patient. While fertilization failure in IVF can be dealt with using ICSI, there is no treatment for fertilization failure in ICSI. At present, clinical investigations are being conducted to evaluate oocyte activation in combination with ICSI to cope with fertilization failure of ICSI.

Animals↗
PubMed2006

Effect of seminal plasma fractions from entire and vasectomized rams on the motility characteristics, membrane status, and in vitro fertility of ram spermatozoa.

Whole seminal plasma from ram semen collected before and after vasectomy was separated into 2 fractions, supernatant and pellet of vesicles, and their protein profiles characterized by one-dimensional (1D) gel electrophoresis. The effects of autologous whole seminal plasma and these fractions on motility characteristics (assessed subjectively and by computer-assisted sperm analysis), membrane status (assessed by chlortetracycline staining patterns), and in vitro fertility (assessed by fertilization success and timing of fertilization events) of washed frozen-thawed ram spermatozoa were studied. Regardless of vasectomy, whole seminal plasma and supernatant displayed similar protein patterns. These fractions, when included in the postthaw buffer, improved the motility characteristics (59.6% +/- 6.21% and 39.6% +/- 6.21% vs 31.7% +/- 6.46% and 15.5% +/- 6.46% total motility) and membrane integrity (36.6% +/- 8.52% and 31.2% +/- 8.19% vs 30.3% +/- 11.49% and 21.6% +/- 10.28% B staining pattern [characteristic of capacitated acrosome-intact cells] for whole seminal plasma and supernatant vs control at 3 and 6 hours of postthaw incubation, respectively) of frozen-thawed spermatozoa and improved their ability to fertilize in vitro-matured oocytes compared with control buffer without seminal plasma fractions (25.3%, 47.4%, and 37.4% vs 12.3%, 20.2%, and 20.5% oocytes fertilized for spermatozoa incubated with supernatant vs control at 2, 6, and 18 hours after insemination, respectively). Vesicles were absent from semen collected after vasectomy. Pellets of vesicles collected before vasectomy had no effect on spermatozoa at their normal protein concentration but marginally improved both motility characteristics and in vitro fertility, possibly due to contamination from supernatant proteins, when their concentration in the postthaw medium was increased by threefold. It was concluded that the vesicle-free supernatant fraction of seminal plasma, but not the seminal plasma membrane vesicles, improved the function and fertility of frozen-thawed ram spermatozoa when added to the postthaw medium.

Animals↗
PubMed2004

Fertilization and blastocyst development in oocytes obtained from prepubertal and adult pigs.

Polyspermic fertilization and embryo quality are important issues for the in vitro production of pig embryos. We hypothesized that oocyte donor (prepubertal gilt vs. sow) affects polyspermy and blastocyst development in vitro and that the sexual maturity of the oocyte donor affects the response to sperm concentration in the fertilization medium. In Exp. 1, oocytes of sows and gilts were mounted and stained 12 h after insemination to provide fertilization data. In Exp. 2, putative embryos were developed in vitro to 144 h post-insemination before mounting. In both experiments, cumulus-oocyte complexes (COC) were collected from ovaries of prepubertal gilts and adult sows. Sperm were added after maturation of COC for 40 to 44 h. Sperm from two boars at 0.5 to 5.0 x 10(6) sperm/mL was used for insemination. More (P < 0.01) monospermic fertilizations were observed in oocytes derived from gilts than for oocytes from sows. There were fewer (P < 0.02) penetrated sperm per fertilized oocyte in oocytes from gilts compared with sows. There were effects of semen donor (boar) on the percentage of monospermic (P < 0.01) and polyspermic (P < 0.002) fertilizations, and on the number of penetrated sperm/fertilized oocyte (P < 0.02). In Exp. 2, cleavage and blastocyst formation was evaluated at 2 and 6 d postinsemination, respectively. More (P < 0.001) blastocysts developed from sow-derived oocytes than from gilt-derived oocytes. More (P < 0.05) total cells per blastocyst were observed in embryos from sow-derived oocytes than from gilt-derived oocytes. Semen donor affected the percentage of oocytes cleaving (P < 0.02), and a boar x sperm concentration interaction affected (P < 0.05) the incidence of blastocyt formation. Results indicate that sexual maturity of the donor is not responsible for the high incidence of polyspermy in porcine in vitro fertilization. However, blastocyst development is improved by the use of oocytes from sows rather than from prepubertal gilts.

Animals↗
PubMed2026

Parenting styles and fertility intention: Mediating effects of childbearing beliefs and psychological resilience.

China's declining fertility rate is partly due to low fertility intention among childbearing population. To understand family influence on young people's fertility intention and its underlying mechanisms, this study examines how parenting styles (authoritarian vs. permissive) affect Chinese college students' fertility intention, with traditional childbearing beliefs and resilience as mediators. Data were collected from 839 participants (Age: M = 21.1, SD = 1.7 years) using structured questionnaires. Logistic regression found that a positive correlation between permissive parenting style and fertility intention, with authoritarian parenting having no impact. Mediation analysis showed the association between permissive parenting style and fertility intention was fully mediated through resilience (&#xf062; = 0.0, 95%CI = [0.0,0.1]) and greater childbearing beliefs (&#xf062; = 0.0, 95%CI = [0.0,0.1]). The findings indicate that permissive parenting is related to higher fertility intention in youth via resilience and childbearing beliefs. Promoting positive family environments and permissive parenting may enhance childbearing intention.

Humans↗
PubMed1995

[Fertility decline in China and family planning programs].

"The article looks in detail at the population development in China since the 1950s, highlighting some dramatic changes. In the late 1950s the country was hit by widespread famine, which resulted in increased mortality and decreased fertility. Infant mortality climbed to almost 300/1,000. During the 1960s fertility began to increase again and mortality declined. From the beginning of the 1970s fertility started to decline, dropping from about six to just over two children per woman in the late 1980s. Today, fertility is thought to be below replacement level. The main reason for this fertility decline lies in the highly efficient family planning programmes implemented in China since the 1950s and particularly since the 1970s. The decline in infant mortality and the favourable socio-economic development have also been important factors in the decline in fertility. Although fertility in China is currently at a low level, the country's population is still set to grow." (SUMMARY IN ENG)

Asia↗
PubMed1991

Factors that influence fertility after vasovasostomy in rats.

OBJECTIVE: To determine if fertility after vasovasostomy of immunologically responsive Lewis rats differs from that of the less responsive Sprague-Dawley strain and to relate fertility to antisperm antibodies, fluid flow in the vas deferens, and testicular structure. DESIGN: Male rats received: (1) bilateral vasectomies; (2) vasectomies followed 3 months later by vasovasostomy; or (3) sham operations. SETTING: Research laboratory. MAIN OUTCOME MEASURES: Fertility was assessed by caging males with three females for 2 weeks and subsequently counting implantation sites. Antisperm antibodies were measured with an enzyme-linked immunosorbent assay, fluid flow through vas deferens segments was tested in vitro, and testicular structure was studied microscopically. RESULTS: Nearly all vasovasostomized Lewis rats were infertile (33 of 34), whereas 62% (18 of 29) Sprague-Dawley rats were fertile after vasovasostomy (P less than 0.001). In fertile Sprague-Dawley males, significant correlations existed between: (1) implantation sites or females impregnated; and (2) antisperm antibodies early after vasectomy, vas flow, and testicular morphology. CONCLUSIONS: Genetic differences affect fertility after vasovasostomy. Fertility after vasovasostomy is also influenced in a multifactorial manner by the immune response, mechanical elements, and structural changes in the reproductive tract.

Animals↗
PubMedDate not supplied

Chemical constituents of human seminal plasma: relationship to fertility.

Eighteen different chemical constituents of seminal plasma from 52 patients in an in vitro fertilization (IVF) program were quantitated. The ejaculates were divided into "fertile" and "infertile" groups depending on whether the spermatozoa did or did not fertilize oocytes. Glycerylphosphorylcholine showed a significant difference between the two groups and was also significantly correlated with fertility, suggesting that GPC may influence the fertilizing ability of the spermatozoa. No such differences/correlations were found for the other constituents although a number of these components were lowest in the "infertile" group. In no case was the correlations between a seminal constituents and fertilization high enough to predict whether an ejaculate is fertile or infertile.

Female↗
PubMedDate not supplied

Determinants of fertility decline in China, 1981: analysis of intermediate variables.

This study examines the proximate determinants of fertility in China by making use of the data collected by the One-per-Thousand Sample Fertility Survey of 1982. The results indicate that the most important inhibitor of potential fertility is deliberate control. Its contribution to fertility change has been far greater than all other proximate determinants. The marital structure of the population is also an important factor, while lactational infecundability and induced abortion are relatively unimportant. Comparative results by using data from the In-depth Fertility Survey conducted in Shanghai Municipality, Hebei and Shaanxi Provinces in April 1985 agree well in the ranking of the four intermediate factors. The findings point to successful family planning program and government population policies, which propelled the fertility transition to a substantial degree. Further research needs and policy implications of the results of the study are discussed.

Adolescent↗
PubMed1991

Fertility rates in 238 HIV-1-seropositive women in Zaire followed for 3 years post-partum.

Birth-control use and fertility rates were prospectively determined in 238 HIV-1-seropositive and 315 HIV-1-seronegative women in Kinshasa, Zaire, during the 36-month period following the delivery of their last live-born child. No women delivered children during the first follow-up year. Birth-control utilization rates (percentage use during total observation time) and fertility rates (annual number of live births per 1000 women of child-bearing age) in the second year of follow-up were 19% (107.4 per 1000) for HIV-1-seropositive women and 16% (144.7 per 1000) for HIV-1-seronegative women. In the third year of follow-up these rates were 26 (271.0 per 1000) and 16% (38.6 per 1000) for HIV-1-seropositive and HIV-1-seronegative women, respectively (P less than 0.05 for the difference in birth-control utilization and fertility rates between seropositive and seronegative women in the third year of follow-up). Seven (2.9%) of the 238 HIV-1-seropositive women initially included in the study brought their sex partners in for HIV-1 testing; three (43%) of these men were found to be HIV-1-seropositive. New HIV-1 infection did not have a dramatic effect on the fertility of seropositive women. The nearly uniform unwillingness of HIV-1-seropositive women to inform husbands or sexual partners of their HIV-1 serostatus accounted in large part for the disappointingly high fertility rates in seropositive women who had been provided with a comprehensive program of HIV counseling and birth control. Counseling services for seropositive women of child-bearing age which do not also include these women's sexual partners are unlikely to have an important impact on their high fertility rates.

AIDS-Related Complex↗
PubMedDate not supplied

[Proximate determinants of fertility in Cuba. The Bongaarts model].

"The results of the implementation of the Bongaarts method for quantitating the effects of [proximate] determinants on fertility are presented. The model used is of the multiplicative kind and relates the global fertility rate to the so called natural fertility rate. Thus, it is possible to quantitate and separate the effect of each determinant and thus find out what factors have been responsible for the rapid change in fertility [in Cuba] from 1972 on. The determinant of highest impact on the fertility level attained in each province was assessed. The most important results point [to] the use of contraceptives as the cause for the rapid decline in the fertility level and the married state as the variable conditioning provincial differences." (SUMMARY IN ENG AND FRE)

Americas↗
PubMed1998

Impact of rural-urban migration on fertility: a population ecology analysis in the Kombio, Papua New Guinea.

The Anjangmui dialect group of the Kombio in Papua New Guinea has experienced a rapid increase in rural-urban migration since European contact commenced in the 1930s. Population ecology analyses of birth and migration histories for 240 Anjangmui women showed a higher total marital fertility rate in the cohort born in 1940-59 than that born in 1920-39. A decline in the age at menarche for nutritional reasons, and reduction in the birth interval for behavioral reasons, may explain the fertility difference between cohorts. Comparison of age-specific marital fertility rates between migrants in urban areas and non-migrants in rural areas revealed higher rates among migrants in the 15-19 and 20-24 year age groups, but lower rates in the 25-29 year or older age groups; the total marital fertility rate for migrants was lower than that for non-migrants. The differences may be attributable to the different influences of birth control practices on fertility reduction between the migrants in urban areas and non-migrants in rural areas. It is suggested that rural-urban migration in the Anjangmui during the post-contact period has had the effect of reducing fertility in the population as a whole.

Adolescent↗
PubMedDate not supplied

Gender, education, and fertility: a cross-national analysis of Sub-Saharan African nations.

According to the demographic transition theory and the wealth flows model, it is expected that fertility will decline with socioeconomic development, manifested in part through increasingly greater proportions of the population with formal education. Since their independence in the 1960s, most sub-Saharan African nations have experienced rapid changes in educational levels. However, recent estimates indicate that high levels of fertility are being maintained as reflected in the high rates of population increase of approximately 3%/year. Controlling for socioeconomic development as measured by per capita energy consumption and percentage of labor force in agriculture, this article examines the relationship between education and fertility for men and women in 37 sub-Saharan nations. Results indicate that primary school enrollment in 1960 and 1980 for both males and females had a weak negative and nonsignificant relationship with the total fertility rate 15-30 years later. Secondary school enrollment in 1960 for both males and females had weak relationships with the total fertility rate. However, secondary school enrollment for males in 1980 had a significant negative effect on the total fertility rate 10-25 years later. Implications are discussed.

Africa↗
PubMed1982

[Socio-spatial heterogeneity and differential fertility in Bolivia. Pt. 2 (author's transl)].

In this research, based on the 1976 census, the population is simultaneously disaggregated in 3 regions, 5 urbanization levels, and 5 social sectors. This 2nd part discusses the role of intermediate variables both through the differential analysis of marital fertility and a simulation exercise with the Bongaarts model. An analysis is also made of the trends of general fertility between 1963-1972, estimated through the "own children method." The findings show that the stability of fertility in the country would be the consequence of the fertility rise in the rural areas and its decrease in the urban areas, particularly in the intermediate strata. There is indirect evidence that this decrease would mainly be the result of the growing practice of birth control. The effect of education on fertility would be strongly conditioned by the urbanization level. The higher fertility in the region of "los Llanos" would be the consequence of a higher nuptiality conditioned by the sex composition of internal migrations.

Americas↗
PubMed1985

Differentials in urban-rural fertility in the countries of the ESCAP region.

Fertility differentials between rural and urban populations are investigated using World Fertility Survey data for Bangladesh, Fiji, Indonesia, Malaysia, Nepal, Pakistan, the Philippines, the Republic of Korea, Sri Lanka, and Thailand. "The fertility measure used in this analysis is the number of children ever born to a woman. An attempt is made first to establish the differential in fertility levels between urban and rural areas after necessary control of the demographic factors..., and then the possible explanation of the differential is sought in terms of socio-economic variables such as education of the respondent, and occupation, work pattern, work status and place of work of the respondent as well as that of the husband." Data concerning the fertility differentials and the associated explanatory variables are presented in tables and charts. "The results tend to show that the countries of Asia are undergoing similar patterns of fertility transition as was experienced in the advanced countries. Perhaps one can graduate the countries in the transition scale as follows: Bangladesh, Indonesia, Nepal, Pakistan and Malaysia are in the initial stage; Fiji, the Philippines, the Republic of Korea, Sri Lanka and Thailand are in the middle stage of transition."

Age Factors↗
PubMed1991

[[The tempo and quantum components in trends in period fertility measures in present-day Japan: a Butz-Ward-type model and its application]].

"This paper examined the validity of a Butz-Ward-type model by applying it to trends in Japan's fertility rates from 1968 to 1986. Most of the existing studies on the Butz-Ward model used total fertility rates as the dependent variable. As the Butz-Ward model is concerned with couples' fertility behaviors, [the author uses]...total marital fertility rates. We first calculated total marital fertility rates (TMFR) from 1968 to 1986 by using data of Japan's National Fertility Surveys.... As a result of the auto-regression analysis of TMFR, we found a statistically significant negative effect of a rise in employed wife's wage rate as was expected. As for the timing indices, the third birth timing index was significantly positively affected by an increase in husband's income when his wife was employed, while the third birth was likely to be delayed by a rise in employed wife's wage rate." An English summary is available from the author.

Asia↗
PubMed1986

A preliminary note on fertility differentials by social class in Suriname.

This paper examines the fertility differentials by social class in Suriname in the 1960s and 1970s, and analyses the sudden stagnation in the decline in fertility that occurred between 1962 and 1974. Substantial differences in fertility by social class existed in the 1960s and 1970s in Suriname, with the number of liveborn children to mothers at each age during the childbearing period being higher for lower class than for middle class mothers. Both social classes contributed to the drop in overall fertility which occurred between 1962-74 although the middle class displayed the largest reduction in fertility. The stabilization of the fertility trend since 1974 is limited to the middle class which seems to have realized its ideal family size.

Age Factors↗
PubMed1999

Rise of intracellular Ca2+ level causes the decrease of cyclin B1 and Mos in the newt eggs at fertilization.

Unfertilized eggs of the newt, Cynops pyrrhogaster, are arrested at the second meiotic metaphase, with activity of the M-phase promoting factor (MPF) maintained at a high level. After fertilization, the eggs resume the cell cycle, and emit the second polar body. When the change in [Ca2+]i in the fertilized eggs was monitored by aequorin, an early increase in [Ca2+]i was observed 5-10 min after insemination and continued for about 30 sec. A late increase in [Ca2+]i then occurred 10-15 min after fertilization and continued for 30-40 min. The injection of 1,2-Bis (2 aminophenoxy) ethane-N,N,N',N',-tetraacetic acid (BAPTA) into unfertilized eggs inhibited reinitiation of the cell cycle after fertilization. Western blot analysis with antibodies against cyclin B1 or Mos indicated that both cyclin B1 and Mos were present in unfertilized eggs, but both disappeared within 30 min after fertilization. Treatment with Ca2+-ionophore decreased both cyclin B1 and Mos. Chymotryptic activity in Cynops egg extracts was not significantly increased after fertilization or activation by treatment with the Ca2+-ionophore. No change in [Ca2+]i was observed following treatment with cycloheximide, but the amount of both cyclin B1 and Mos rapidly decreased. These results indicate that resumption of meiosis in Cynops eggs is induced by an increase in [Ca2+]i at fertilization, which causes degradation of both cyclin B1 and Mos by inhibition of de novo synthesis of those proteins.

Animals↗