SEARCH · PubMed Health

Results for “Reproduction”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 937 records · Page 52Linked to original sources

PubMed1999

Postmenopausal hormone replacement in the woman with a reproductive risk factor for breast cancer.

OBJECTIVE: to assess the interaction between postmenopausal hormone replacement therapy (HRT) and various reproductive risk factors for breast cancer such as early menarche, late menopause, late first delivery and nulliparity. DESIGN: three cohort studies and fourteen case control studies, published between 1975 and 1997, provided relative risks (RRs) of HRT use in women with, as well as in those without, a reproductive risk factor for breast cancer. METHODS: using an additive RR model reported before, we investigated whether the RR for breast cancer in women with a combination of HRT and a given reproductive risk factor result from a simple addition of RRs of HRT on the one hand, and of the pre-existing reproductive risk factor on the other hand, or that synergism between both risk factors occurs. RESULTS: simple addition of RRs was shown in the case of early menarche and late menopause. Less increase of risk, suggesting antagonism, was found for both late first delivery and nulliparity in combination with HRT use. CONCLUSION: we could not observe any synergistic effect of the combined risks of any of the following reproductive risk factors for breast cancer: early menarche, late menopause, late first delivery or nulliparity on the one hand, with the risk resulting from HRT use on the other hand. Therefore, as far as the risk of breast cancer is concerned, the use of HRT appears not to be highly detrimental in women with a reproductive breast cancer risk factor, as it results in not more than a simple addition of risks at the most.

Breast Neoplasms↗

PubMedDate not supplied

Effect of butyl benzyl phthalate in Sprague-Dawley rats after gavage administration: a two-generation reproductive study.

Butyl benzyl phthalate (BBP), a plasticizer, has been shown in in vitro studies to be weakly estrogenic, and in in vivo studies to possess testicular toxicity and teratogenicity, but few experimental data on BBP multigeneration effects on reproduction in mammals are available. The present two-generation reproductive study was conducted in male and female Sprague-Dawley rats using oral doses of 0, 20, 100, and 500 mg/kg/day BBP. Endpoints were chosen in order to evaluate both subchronic and reproductive toxicity. In the parent animals (F(0)), a decrease in body weight gain was observed in males in the 500 mg/kg/day group, although no significant decrease in food consumption was found. No dose-related changes were observed in estrous cyclicity, fertility, or lactation. A dose-dependent increase in kidney weight in rats of both sexes, an increase in liver weight in males, and a decrease in the weight of the ovaries in females were observed. No macroscopic or microscopic changes were found in the reproductive system of males or females. Oral administration of BBP caused a decrease in the serum concentration of testosterone, and an increase in FSH. In the next generation (F(1)), the body weight of male and female offspring at birth in the 100 and 500 mg/kg groups was significantly decreased, and the body weight in the 500 mg/kg group was lower throughout the study, while viability was not affected. Anogenital distance (AGD) at birth was decreased in male pups and was increased in female pups of the 500 mg/kg/day group. Preputial separation for male offspring in the 500 mg/kg/day group was delayed, while vaginal opening for female offspring in this group was not affected. BBP did not affect reproductive ability, including delivery and lactation, at any dose whereas macroscopic and microscopic changes of the testis, and decreased serum concentrations of testosterone were observed in male offspring of the 500 mg/kg/day group after puberty. From these data, it would appear that 20 mg/kg BBP is a no observed adverse effect level (NOAEL) for reproductive effects on parent animals and the next generation.

Administration, Oral↗

PubMedDate not supplied

Reproductive effects of nonylphenol in rats after gavage administration: a two-generation study.

The potential reproductive toxicity of nonylphenol (NP) was assessed in a two-generation reproductive toxicity study. Groups of 25 male and female Crj:CD (SD) IGS rats were given NP by gavage at levels of 2, 10, or 50 mg/kg, and 25 males and females were given corn oil as controls. No adverse changes in clinical signs were observed in any rats throughout the study. Significant increases in the liver, kidney and pituitary gland weights in males, and decreases in thymus weight in males and in ovary weight in females were observed in the 50 mg/kg group. NP did not affect sperm characteristics or the estrous cycle at any dose administered. A significant increase in the TSH level was observed in males in the 50 mg/kg group. No adverse effects of NP on reproduction were found. At necropsy, no treatment-related alterations were observed in any organs including the reproductive tissues in any group. Histopathologic changes were found in the liver of male and female rats and kidneys of males in the 50 mg/kg group. The viability of offspring from postnatal day 0 to 4 in the 50 mg/kg group was reduced as compared with that in the controls, although growth was not affected by NP administration. On postnatal day 22, an increase in the serum FSH level and decrease in T(3) level for males, and decreases in LH and TSH levels and an increase in T(3) levels for females were observed in the 50 mg/kg group. NP did not affect the timing of preputial separation, while vaginal opening was accelerated in the 50 mg/kg group. No adverse changes were found in behavior or learning in the offspring of NP-treated groups. There were no treatment-related changes in any reproductive parameter, including estrous cycle, mating, fertility, delivery, and lactation, except for significant decreases in the numbers of implantation sites and live pups, and a significant decrease in ovary weight in the 50 mg/kg group. Kidney and liver weight were increased in males in the 50 mg/kg group. Histopathologic examination revealed changes in the liver of males and females of the 50 mg/kg group. No treatment-related changes were observed in the sperm characteristics. Hormone data should be interpreted cautiously until the findings are repeated and confirmed by further studies. These results of NP suggested that the no observed adverse effect level (NOAEL) on reproductive capacity is 50 mg/kg/day or greater in parent animals, and 10 mg/kg/day in the next generation under the present experimental condition.

Administration, Oral↗

PubMedDate not supplied

Aging and responses to toxins in female reproductive functions.

Reproductive senescence in laboratory rodents has been well characterized using vaginal smear analysis, a relatively simple and inexpensive technique to monitor changes in estrous cyclicity. Although some differences exist, laboratory animal models are available to study most aspects of age-related changes in human reproductive physiology (4,13). Thus presumptive reproductive toxins can be tested on laboratory rodents using the qualitative and quantitative parameters for estrous cyclicity described here to assess damage. Before implementing such tests, however, certain limitations must be considered. Quantitative changes in estrous cycles, for example, cycle length distribution, which indicate more subtle impairments in reproductive function, require more refined data analysis. In particular, baseline data for at least one month is required before exposure to the presumptive toxin. In addition, the period of maximum cycling regularity is fairly short (three to four months duration) so long-term exposures to presumptive toxins would not be applicable. Longer term exposure (greater than or equal to six months) would be permissible if qualitative changes in cyclicity (i.e., acyclic vs. cyclic) were the dependent variable used to assess toxicity. Finally, if other parameters of reproductive function (e.g., fertility, litter size) are used to assess reproductive toxicity, we urge that cycling characteristics of the offspring be carefully monitored to assess possible cryptic damage to later neuroendocrine functions that occurred to the fetuses in utero.

Aging↗

PubMedDate not supplied

Juvenile hormone is a marker of the onset of reproductive canalization in lubber grasshoppers.

To meet the challenge of unpredictable environments, many animals are initially developmentally flexible (plastic) but then may become inflexible (canalized) at major developmental events. The control of reproductive output can undergo a switch from flexible to inflexible (Moehrlin, G.S., Juliano, S.A., 1998. Plasticity of insect reproduction: testing models of flexible and fixed development in response to different growth rates. Oecologia 115, 492-500), and juvenile hormone (JH) may control this switch. By manipulating food availability, we tested the hypothesis that JH is involved in the reproductive canalization that appears during oogenesis in lubber grasshoppers. We used four food treatments: (1) high (H); (2) high switched to low (HL); (3) low switched to high (LH); and (4) low (L). We collected hemolymph samples approximately every 4 days and measured the ages at which maximum JH level (JH(max)) and oviposition occurred. Diet significantly affected both age at JH(max) and age at oviposition. In contrast, diet had no significant effect on the time from JH(max) to oviposition nor on the maximum JH level observed. Our data demonstrate that, after JH(max) is reached, the time to oviposition in our grasshoppers was unresponsive to food availability. Hence, reproductive timing appears to be canalized after the JH(max). This is the first demonstration in a phytophagous insect that a particular factor (in this case, JH) can be used to mark the switch from reproductive plasticity to reproductive canalization.

Animals↗

PubMed2003

The impact of decentralisation on sexual and reproductive health services in Ghana.

This paper analyses the impact of decentralisation on the political organisation, management and provision of sexual and reproductive health services in Ghana. It draws on qualitative research and interviews with key informants from the Ministry of Health, donors, NGOs, regional and district health management teams, local government and community leaders. Within a national reproductive health policy framework, previously disparate family planning, maternal and child health, STI and HIV/AIDS programmes have become more integrated, and donors have pooled or co-ordinated their funding. Some decision-making about resource allocation is meant to happen at district and regional level but in practice, this remains centrally controlled, which may be a necessary safeguard for sexual and reproductive health services. Earmarked donor funds still ensure a regular supply of contraceptives and STI drugs. However, paying for these is problematic at local level. Sexual and reproductive health staff make up a large proportion of primary health care staff, but especially in rural areas they experience poor working conditions, and there is high turnover and vacancies. District and sub-district level links are working well in this new system, but clarity is still needed on how different national sexual and reproductive health bodies relate to each other and to regional and district health authorities. The development of formal mechanisms for priority setting and advocacy at local levels could help to secure benefits for sexual and reproductive health care.

Attitude of Health Personnel↗

PubMed2003

Incorporating sexual and reproductive health care in the medical curriculum in developing countries.

Medical educators have a responsibility to train physicians and other health professionals in the core competencies needed to improve the sexual and reproductive health of their communities. Yet sexual and reproductive health care is significantly under-represented in the basic educational curriculum for medical and other health professionals, as well as in continuing medical education and professional development programmes for practising physicians and other health professionals. The Commonwealth Medical Association Trust is developing a model curriculum on sexual and reproductive health that can be integrated into undergraduate medical education and used with appropriate amendments for continuing medical education. This paper outlines topics for inclusion in the curriculum and three strategies for incorporating core components of sexual and reproductive health in the curriculum--by developing themes that can be integrated into the general curriculum in a multi-disciplinary fashion, adding free-standing modules as electives, and delegating cross-cutting issues such as gender issues and adolescent reproductive health to courses run by other departments. It argues for the use of problem-solving and case-based learning methodologies, as well as lectures, as the best way to teach health professionals how to provide information, counselling and support for sexual and reproductive health, as well as to cover the range of prevention and treatment needs of women and men seeking these services.

Curriculum↗

PubMed2003

The contribution of sexual and reproductive health services to the fight against HIV/AIDS: a review.

Approximately 80% of HIV cases are transmitted sexually and a further 10% perinatally or during breastfeeding. Hence, the health sector has looked to sexual and reproductive health programmes for leadership and guidance in providing information and counselling to prevent these forms of transmission, and more recently to undertake some aspects of treatment. This paper reviews and assesses the contributions made to date by sexual and reproductive health services to HIV/AIDS prevention and treatment, mainly by services for family planning, sexually transmitted infections and antenatal and delivery care. It also describes other sexual and reproductive health problems experienced by HIV-positive women, such as the need for abortion services, infertility services and cervical cancer screening and treatment. This paper shows that sexual and reproductive health programmes can make an important contribution to HIV prevention and treatment, and that STI control is important both for sexual and reproductive health and HIV/AIDS control. It concludes that more integrated programmes of sexual and reproductive health care and STI/HIV/AIDS control should be developed which jointly offer certain services, expand outreach to new population groups, and create well-functioning referral links to optimize the outreach and impact of what are to date essentially vertical programmes.

Breast Feeding↗

PubMed2005

Strategy to accelerate progress towards the attainment of international development goals and targets related to reproductive health.

Reproductive and sexual ill-health account for 20% of the global burden of ill-health for women, and 14% for men. The strategy presented in this document is the World Health Organization's first global strategy on reproductive health. It was adopted by the 57th World Health Assembly (WHA) in May 2004. Five priority aspects of reproductive and sexual health are targeted: improving antenatal, delivery, postpartum and newborn care; providing high-quality services for family planning, including infertility services; eliminating unsafe abortion; combatting sexually transmitted infections, including HIV, reproductive tract infections, cervical cancer and other gynaecological morbidities; and promoting sexual health. The strategy was developed as a result of extensive consultations in all regions with representatives from ministries of health, professional associations, non-governmental organizations, United Nations partners and other key stakeholders. It lays out actions needed for accelerating progress towards the attainment of the Millennium Development Goals (MDGs) and other international goals and targets relating to reproductive health, especially those from the International Conference on Population and Development in 1994 and its five-year follow-up. "The strong endorsement of this strategy by the WHA represents an unequivocal message that countries are committed to do all they can to achieve the goals and targets of the ICPD Programme of Action adopted in 1994." (Dr Paul Van Look, Director, WHO Department of Reproductive Health and Research).

Female↗

PubMed2005

Norway at ICPD+10: international assistance for reproductive health does not reflect domestic policies.

Norway has a long history of good reproductive health care, with some of the world's best reproductive health indicators. Early reduction of maternal mortality, good services for abortion, contraception and sexually transmitted diseases, a low rate of adolescent pregnancies and a low number people with HIV are examples, achieved through an integrated, publicly provided and funded health care package. Official Norwegian development assistance started in 1952. Emphasis on family planning assistance dates back to 1966, making Norway one of the most consistent donors to family planning and reproductive health programmes. Norway also had a high profile at the International Conference on Population and Development and strongly supported the Programme of Action. Since then, while multilateral support in these areas has stayed high, bilateral support has been downscaled. Overall, international assistance does not reflect the domestic approach to reproductive health services. Norway has given little development support to improvement of maternity services, avoided the issues of abortion and post-coital contraception, and passed up opportunities to support adolescent services. Prevention and treatment of infertility has hardly been an issue. Revitalisation of the reproductive rights discourse in Norway could provide a basis for the protection of reproductive health care domestically, and for policy discussions and decisions in relation to Norway's development assistance.

Congresses as Topic↗

PubMed2006

Obesity and assisted reproductive technology outcomes.

Obesity is a rising health problem in Western societies. It has been related to increased morbidity and mortality rates due to several pathologies. In the field of gynaecology and reproduction, obesity is associated with menstrual disorders, hirsutism, infertility, miscarriage and obstetric complications. It is known to impair human reproduction through different mechanisms such as insulin resistance, hyperandrogenism and elevated leptin levels. Weight management and dietary intervention can reverse this situation and improve reproductive function. Obesity can also impair the outcome of assisted reproductive technologies. The lower probability of a healthy live birth described in obese women seems to be the result of a combination of lower implantation and pregnancy rates, higher preclinical and clinical miscarriage rates and increased complications during pregnancy for both mother and fetus. Studies performed in infertile women undergoing assisted reproduction technologies indicate that the ovary plays a leading, but not exclusive, role in the fertility prognosis of these patients. The endocrine and metabolic environment may affect oocyte quality and, therefore, embryo development, implantation and pregnancy outcome. The endometrium seems to play a subtle role in the more negative reproductive outcome of obese women, according to recent studies based on the ovum donation model.

Endometrium↗

PubMed2006

Physical activity and its effects on reproduction.

The reproductive system is tightly coupled with energy balance, and thereby changes in the status of energy balance through changes in physical activity can impact on the reproductive system. In light of the new physical activity for health recommendations, it is therefore important to understand the inherent effects, both positive and negative, of physical activity on the reproductive system. At both extremes of the energy spectrum, disorders of chronic energy excess and energy deficiency are characterized by a wide range of reproductive disorders, including menstrual irregularity, anovulation, polycystic ovarian syndrome, and infertility in women, and erectile dysfunction and altered spermatogenesis in men. Although laboratory research indicates that individuals may be able to prevent or reverse reproductive disruptions, either by increasing energy expenditure in cases of energy excess or by dietary reform in cases of energy deficits, there is an acute need for applied research to confirm this idea and to identify mechanisms by which the availability of energy per se regulates reproductive function in humans.

Energy Metabolism↗

PubMed2003

Do environmental contaminants adversely affect human reproductive physiology?

There is increasing concern among Canadian women that unwitting and unwanted exposures to environmental contaminants are adversely affecting their health, particularly their ability to become pregnant and have a healthy baby. Evidence of adverse reproductive outcomes among populations exposed to environmental contaminants in the workplace via accidental poisoning, together with detection of environmental contaminant residues in serum and ovarian follicular fluid, has led to the hypothesis that chemical contaminants may be contributing to adverse reproductive outcomes such as infertility, endometriosis, polycystic ovary syndrome, spontaneous abortion, preterm labour, intrauterine growth restriction, and pregnancy-induced hypertension in the general population. The lack of clear evidence concerning the association between exposure to environmental contaminants and adverse reproductive outcomes hampers the clinician's ability to counsel women who are trying to conceive or who have concerns about their pregnancy. This review summarizes the evidence linking environmental contaminant exposure to selected adverse health outcomes by examining the changes in health-outcome trends, the consistency of the epidemiological evidence of an association between the health outcome of concern and exposure to environmental contaminants, and the biological plausibility for environmental contaminant mediated effects on human reproductive health. At best, only a moderate association can be found linking exposure to environmental contaminants with evidence of deleterious reproductive effects in women. Lack of disease trend data, weak exposure assessments, and limited mechanistic data supporting the biological plausibility of potential effects are the primary limitations to the hypothesis that exposure to environmental contaminants adversely affects human reproductive physiology.

Animals↗

PubMed2002

Reproduction in high altitude Aymara: physiological stress and fertility planning?

Reproductive characteristics at high altitude are described based on the reproductive histories of 720 Aymara women, collected in 1998 and 1999 in a group of twelve peasant communities at a mean altitude of 4000 m in the Bolivian Altiplano. The reproductive pattern is shaped by a late onset of childbearing, associated with a rather short reproductive span and large birth intervals. Environmental conditions could explain the particularly late age at menarche of rural girls compared with their urban counterparts, whereas the age at first birth is likely to be under cultural control. The short reproductive span appears to result from a large mean interval between last birth and menopause, which is essentially determined by cultural decisions. The birth intervals, which are longer than in many traditional societies, could be the result of a slower restoration of postpartum fecundability induced by the hard way of life inherent in the Altiplano (including poor sanitary and nutritional conditions and high workload), perhaps aggravated by hypoxia. However, a secular trend in fertility is perceptible, towards earlier menarche, earlier age at first birth, increasing reproductive span and a slight increase in live births and surviving offspring, which is probably the result of a slow improvement in living conditions. The existence of birth control on the one hand, and a total fertility rate averaging six live births among the couples who do not practise contraception on the other, are other arguments against the hypothesis of a low natural fecundity in these Aymara groups.

Adolescent↗

PubMed2005

Perceptions of men on role of religious leaders in reproductive health issues in rural Pakistan.

Religion holds unique importance in people's lives, and has been cited as an important factor in reproductive health. Pakistan has a Muslim majority and the character of the country is strongly marked by Islam. In rural areas, where the majority of the population reside, religious leaders are considered as opinion makers. The perception of adult males regarding the influence of the 'religious factor' in their use of modern contraceptive methods, and their views on the role of religious leaders in community education, were explored through a cross-sectional survey conducted in twelve rural districts of Pakistan in 2000. A sample of 180 married adult males participated in the study through consecutive sampling. The study was qualitative, utilizing tools such as in-depth and key-informant interviews. The majority of men interviewed considered that religious leaders were against fertility control, and 29% cited religion as a reason for their non-use of modern contraceptives. Respondents also suggested that the involvement of religious leaders in reproductive health programmes is essential for the programmes' effectiveness in rural areas. They thought that religious leaders could contribute positively to community education, and suggested ways in which they could educate the community in reproductive health issues. They also suggested various channels through which religious leaders could be approached to convince them to cooperate in reproductive health programmes. The study concludes that involving religious leaders in rural settings could enable reproductive health programmes and services to reach more conservative groups in society, and thus contribute effectively to bringing about positive change in the attitudes of Pakistani society towards reproductive health.

Adult↗

PubMed2005

Reproductive health status, knowledge, and access to health care among female migrants in Shanghai, China.

As the largest labour flow in human history, the recent rise in migration in China has opened up unprecedented opportunities for millions of Chinese to rearrange their lives. At the same time, this process has also posed great challenges to Chinese migrants, especially female migrants, who not only face a bias against 'outsiders' but also have a greater need for reproductive health-related services in their migratory destinations. Based on data collected via multiple sources in Shanghai, China's largest metropolis, this study profiles the changing characteristics of female migrants, presents data on self-reported symptoms of reproductive health-related problems and knowledge on reproductive health issues, compares maternal and child health measures between migrants and local residents, and examines factors related to reproductive health knowledge and migrants' access to health care in urban China. Results of this study show a relatively low level of self-reported reproductive health problems among female migrants, coupled with a relatively high level of ignorance in knowledge related to STD. Both self-reported health status and knowledge of reproductive health are related to migrants' educational attainment and length of stay in the urban destination. This study also finds ample evidence that female migrants' access to urban health care is limited by a number of institutional barriers.

Adolescent↗

PubMed1998

The consistency and validity of reproductive attitudes: evidence from Morocco.

Information on reproductive attitudes is now routinely collected in fertility surveys in developing countries, and has become very important for understanding fertility behaviour. The quality of this information, however, is rarely assessed, partly due to lack of necessary data. In this paper, the recently completed panel survey in Morocco by the Demographic and Health Surveys (DHS) was used to investigate the consistency of reporting of ideal number of children, reproductive intentions and the planning status of the last birth. The validity of reproductive intentions for subsequent fertility behaviour was also examined. The findings indicate that the three measures of reproductive attitudes are subject to different degrees of measurement error. The measure of reproductive intentions is the most consistent of the three, followed by ideal number of children. The latter is much more consistent at the aggregate level than at the individual level. The reliability of the planning status of the last birth is marred, mainly by an unwanted child being reclassified as 'wanted' with time since the birth of the child. The reproductive intentions of women were also found to be positively related to their subsequent fertility.

Adolescent↗

PubMed2001

Human reproductive cloning and related techniques: an overview of the legal environment and practitioner attitudes.

PURPOSE: This study provides an overview of the legal environment and assisted reproductive technology (ART) practitioner attitudes toward human reproductive cloning. METHODS: A review of the law and a survey of ART practitioners and a comparison group of attorneys were undertaken. RESULTS: Human reproductive cloning has been prohibited in many countries, and may soon be prohibited in others. However, many ART practitioners support its use for limited indications. CONCLUSIONS: ART practitioners were surveyed concerning their views on human reproductive cloning and related techniques. A few had considered using or had used embryo splitting or germ cell nuclear transfer. Although they expressed some concerns about the present risk of reproductive cloning, most indicated that it did not violate their religious beliefs. More than three-quarters of ART practitioners responding indicated that they would be willing to provide human reproductive cloning in indicated cases if it were legally permissible to do so. A significant percentage of the group also indicated that they currently have the ability to provide this service.

Attitude of Health Personnel↗