The desire for multiple pregnancy in male and female infertility patients

BACKGROUND: It is apparent that many fertility patients consider multiple birth an ideal treatment outcome. We wished to evaluate the desire for multiple birth among patients, and the effect of patient demographics and recognition of the increased fetal risks of multiple pregnancy on this desire. METHODS: This was a prospective questionnaire study completed by 801 male and female infertility patients attending a tertiary level Canadian university fertility clinic. Two logistic regression analyses were performed with desire for multiple birth with next fertility treatment and recognition of the increased fetal risks of multiple pregnancy as the dependent variables. RESULTS: 41% of patients desired a multiple birth. Increasing duration of infertility or previous assisted reproductive treatment increased, and having previous children or recognition of the increased fetal risks decreased, this desire. Patient age or sex did not affect desire for multiple birth. Previous assisted reproductive treatment was associated with increased recognition of the fetal risks of multiple pregnancy. CONCLUSIONS: A significant proportion of fertility patients considers multiple birth an ideal treatment outcome. Recognition of the increased fetal risks of multiple pregnancy significantly reduced this desire. Patient education may play an important role in assisting physicians in the quest to reduce the contribution of assisted reproductive treatment to multiple births and their attending complications.     

Early life environment, life history and risk of endometrial cancer

Endometrial cancer risk is influenced by reproductive behaviours, including parity and breastfeeding, and timing of life history events such as age at menarche and menopause. One potential mechanism by which altered reproductive strategies may influence endometrial cancer risk is through exposure to reproductive hormones. Current theory suggests that high lifetime exposure to oestrogen, unopposed by progesterone, increases endometrial cancer risk; here we suggest that progesterone deficiency itself may also play a significant role. Additionally, given that reproductive profile variables are themselves influenced by early childhood conditions, we hypothesise that endometrial cancer risk may be influenced by the childhood psychosocial environment as mediated through changes to adolescent and adult reproductive behaviours and hormone exposures. Investigating reproductive cancers, including endometrial cancer, using a life history approach may help to increase understanding of why these cancers occur and potentially help implementation of early detection and screening processes in the future.     

They also serve: Chamorro male fertility in the pre-world war ii period

Male fertility, a generally overlooked aspect in studies of human reproductive patterns, is examined from the reproductive life histories of Chamorro males with essential completed fertility by 1941. Males in this “natural fertility” indigenous population of the Pacific island of Guam exhibit low levels of couple infertility which are counteracted by high levels of adult male mortality, while new unions formed after the death of female partners tend to reduce completed fertility by only about one child. Delayed age at the time of union formation is largely compensated by reduction in birthspacing intervals among offspring of older fathers. Early terminators, formerly fertile couples of reproductive age who fail for unspecified biological or behavioral reasons to continue reproducing, affect an equal or even larger impact than adult male mortality on failure to attain theoretical male fertility maxima in this population. Am. J. Hum. Biol. 10:23–35, 1998. © 1998 Wiley-Liss, Inc.     

Epigenetic risks related to assisted reproductive technologies: risk analysis and epigenetic inheritance

A broad spectrum of assisted reproductive technologies has become available for couples with fertility problems. Follow-up studies of children born as a result of assisted reproduction have shown that neonatal outcome and malformation rates are not different from those of the general population, except for a low birthweight and a slight increase in chromosomal abnormalities. The safety aspect of assisted reproduction at the epigenetic level has not been well studied. Epigenetics refers to phenomena where modifications of DNA methylation and/or chromatin structure underlie changes in gene expression and phenotype characteristics. This article intends to analyse epigenetic risks related to assisted reproduction on the basis of an overview of epigenetic reprogramming events in the gamete and early embryo. Two epigenetic modifications, methylation and imprinting, are considered in more detail. The interference of in-vitro embryo culture, immature sperm cells and nuclear transfer with epigenetic reprogramming is discussed, as well as the possibility of epigenetic inheritance.     

Ectopic pregnancies after infertility treatment: modern diagnosis and therapeutic strategy

Ectopic pregnancy (EP) is a major event in a woman's reproductive life. It complicates infertility treatment and must be recognized early to simplify the treatment strategy, which must always be directed towards optimizing subsequent fertility. Epidemiological findings indicate that tubal history and smoking are the principal risk factors of those EP that are considered reproductive (rather than contraceptive) failures. Adding together the attributable risks for EP allows the construction of a risk scale to determine its probability for any given patient. This risk calculation makes it easier to establish a diagnostic strategy that uses abdominal and transvaginal ultrasound and hCG assays. Progesterone assays are useful only for determining the activity of the pregnancy but do not help to identify its site. Conservative treatment is to be preferred unless the EP occurs on a known hydrosalpinx. All the treatment trials and the Cochrane database meta-analysis show that medical treatment with methotrexate, preferably multidose, is equivalent in efficacy to conservative treatment with laparoscopy in the populations studied. Heterotopic pregnancies, which occur most often after assisted reproduction technology (1-3%), should preferably be treated by salpingectomy except in interstitial sites. There is no consensus that IVF is indicated after EP. The patient's age is probably the determining factor: fertility treatment should not be delayed to an age where the results would be altered, especially with the risk of a recurrent EP.     

Inbreeding and fertility in a South Indian population

Among 1913 women in Karnataka State, South India, 37.74% had married a relative (a consanguineous union), 60.79% were non-consanguineously married, and 1.46% did not know whether they had married a relative. Mean number of living offspring for consanguineously married women who had completed their reproduction was 3.89, and for the non-consanguineous 4.07. There is no significant difference in the mean level of fertility for the two groups measured in this way. Pre-natal mortality is lower (but not significantly) among consanguineously married women who have completed their reproduction than among the non-consanguineous group, but post-natal mortality is significantly higher among the conceptuses of the consanguineously married women. Although consanguineously married women conceive more frequently, that is, are more fecund than the non-consanguineous women (mean number of conceptions being 6.61 and 6.28, respectively), the difference is not significant. The differential survival of the offspring results in the consanguineous group having slightly lower net fertility, although the difference is not statistically significant. The lower sterility rates of the consanguineously married women (3.21% of all consanguineously married women show primary sterility compared to 3.47% of the non-consanguineous) may be due to greater compatibility of uniting gametes in the consanguineous marriages. The data reveal that women married to a relative and having completed their reproduction show higher fecundity, lower pre-natal mortality, higher post-natal mortality, lower sterility rates, and thus no significant difference in net fertility to those who had not married a relative.     

Fortpflanzung zwischen Natürlichkeit und Künstlichkeit

There are now many ways in which reproduction can be influenced. When natural boundaries are exceeded this means taking responsibility. The author reflects on what sort of action reproduction is meant to be and what kind of risks are associated with seeing reproduction as a manufacturing process. The nature of reproduction as a ‘good’ is then analysed. Against this backdrop the impact of individual starting points on the way persons see themselves and on the relationship between parents and their children is then considered, and some thought is devoted to the extent of reproductive freedom that might be seen as a right. Being natural has no inherent moral weight; it just has a normative function insofar as it can protect such ethically important ‘goods’ as freedom and equality.     

Menarche, pregnancy, birth spacing and menopause among the Agta women foragers of Cagayan province, Luzon, the Philippines

The reproductive histories of 74 post-menarcheal Agta Negrito women, tropical foragers of Cagayan province, north-eastern Luzon, the Philippines are described and analysed in comparison with data collected by Howell on Dobe !Kung hunter-gatherers. Among the Agta, mean age at menarche is 17, mean age at first live birth is 20.14 years, mean completed parity is 6.53 and mean age at menopause is 44. Average height is 141.24 cm and average weight 36.72 kg. No time trends were detected in age at menarche and age at first live birth among the Agta. Average spacing between live births where an infant survives until the birth of the next sibling was 2.85 years. Compared to the Dobe !Kung, Agta women have later menarche, but shorter birth spacing and a longer active childbearing span.     

Demographic consequences of unpredictability in fertility outcomes

Child survival is probabilistic, but the unpredictability in family formation and completed family size has been neglected in the fertility literature. In many societies, ending the family cycle with too few or too many surviving offspring entails serious social, economic, or fitness consequences. A model of risk‐ (or variance‐) sensitive adaptive behavior that addresses long‐term fertility outcomes is presented. The model shows that under conditions likely to be common, optimal, risk‐sensitive reproductive strategies deviate systematically from the completed family size that would be expected if reproductive outcome is were predictable. This is termed the “variance compensation hypothesis.” Variance compensation may be either positive or negative, resulting in augmented or diminished fertility. Which outcome obtained is a function of identifiable social, economic, and environmental factors. Through its effect on fertility behavior, variance compensation has a direct bearing on birth spacing and completed fertility, and thereby on problems in demography and human population biology ranging from demographic transitions to maternal depletion and child health. Risk‐sensitive models will be a necessary component of a general theory of fertility. Am. J. Hum. Biol. 14:168–183, 2002. © 2002 Wiley‐Liss, Inc.     

Reproductive life of Bhoksa women

The paper discusses the reproductive life of 111 ever-married Bhoksa women. The mean age at marriage for women of all ages among Bhoksas, like other tribal populations, is high, unlike the caste populations. The mean ages at first birth of the pooled sample and of the completed fertility cases suggest late and early marriages of the older and younger generations. The maximum number of marriages occur between 15 and 19 years and of first births between 16 and 20 years.

Percentage of reproductive wastage is high in both the lower and higher age groups. Young mothers with low birth orders and older mothers with high birth orders display a high frequency of reproductive wastage. Evidently, both birth order and the age of the mother have effects on reproductive wastage.

Average number of children ever born (including stillbirth but not abortion or miscarriage) per mother of all ages is the highest among Bhoksas of all the studied ethnic groups of India. The Bhoksa, like caste populations, show a high number of children ever born per mother of completed fertility. Quite a high masculinity in the secondary sex ratio, like other mongoloid population is noticed.

The contribution of mortality component to the Total Index of Opportunity for Selection is more than that of the fertility component. Bhoksas conform to the general low range of net reproductive index, which is however greater than unity, suggesting that they are in a growth stage.     

Menarche,pregnancy, birth spacing and menopause among the Agta women foragers of Cagayan Province,Luzon, the Philippines

The reproductive histories of 74 post-menarcheal Agta Negrito women, tropical foragers of Cagayan province, north-eastern Luzon, the Philippines are described and analysed in comparison with data collected by Howell on Dobe! Kung hunter-gatherers. Among the Agta, mean age at menarche is 17, mean age at first live birth is 20·14 years, mean completed parity is 6·53 and mean age at menopause is 44. Average height is 141·24cm and average weight 36·72 kg. No time trends were detected in age at menarche and age at first live birth among the Agta. Average spacing between live births where an infant survives until the birth of the next sibling was 2·85 years. Compared to the Dobe !Kung, Agta women have later menarche, but shorter birth spacing and a longer active childbearing span.     

Reproductive ageing in women

The traditional view in respect to female reproduction is that the number of oocytes at birth is fixed and continuously declines towards the point when no more oocytes are available after menopause. In this review we briefly discuss the embryonic development of female germ cells and ovarian follicles. The ontogeny of the hypothalamic-pituitary-gonadal axis is then discussed, with a focus on pubertal transition and normal ovulatory menstrual cycles during female adult life. Biochemical markers of menopausal transition are briefly examined. We also examine the effects of age on female fertility, the contribution of chromosomal abnormalities of the oocyte to the observed decline in female fertility with age and the possible biological basis for the occurrence of such abnormalities. Finally, we consider the effects of maternal age on obstetric complications and perinatal outcome. New data that have the potential to revolutionize our understanding of mammalian oogenesis and follicular formation, and of the female reproductive ageing process, are also briefly considered.     

Social stress and reproductive success in the female Syrian hamster: endocrine and behavioral correlates

In many mammal species, reproduction is not shared equally among the members of a social unit. Even though reproductive skew seems unlikely in females of solitary species, this phenomenon could result from environmental factors. Although solitary in the wild, captive Syrian hamsters (Mesocricetus auratus) are generally housed in groups. We investigated whether social stress produces some degree of reproductive skew in this solitary species and whether female reproductive success varies as a function of social rank. To assess the physiological relationship between social stress and fertility, we monitored reproductive hormones and glucocorticoids of solitary and pair-housed females during pregnancy by means of recently established non-invasive methods for measuring hormone metabolites in the feces. The patterns of fecal progesterone, estrogen and glucocorticoid metabolites were similar to those found in blood and reported in the literature for pregnant hamsters. As expected, dominant females had higher breeding success than subordinate females. However the rate of reproductive failure was also very high among the singly housed females of our control group. The number of pups per litter, the average sex-ratio in each group, and the mean weight of pups did not differ significantly among groups. Glucocorticoid concentrations were unaffected by housing and social rank and the few differences between the endocrine profiles of singly- and pair-housed females are not sufficient to explain the observed difference in breeding success. It is likely that social isolation impairs reproduction in the same manner as subordination. Our findings suggest that social isolation of animals accustomed to group living was equally as disturbing as cohabitation with an unknown conspecific.     

Somatic versus reproductive energy allocation in Papua New Guinea: Life history theory and public health policy

A fundamental evolutionary problem faced by organisms is how to allocate energy to somatic and reproductive functions in ways that optimize fitness. Given that energy is limited in all environments, energy allocation necessarily involves physiological tradeoffs between such factors as growth and reproduction, reproduction and condition, and current reproduction and future survival. Ultimately, the “decisions” that are made about energy allocation among growth, survival, and reproduction determine life history patterns and trajectories of organisms. For humans, knowing how energy allocation to reproduction will likely impact other aspects of the somatic well‐being of individuals may also have practical implications for public health policy. This article reviews the evidence for energy tradeoffs between somatic and reproductive functioning in a range of human societies. It also seeks to corroborate the results of earlier work in Papua New Guinea on lactation‐related maternal energy depletion using an independent measure of maternal energy reserves, tetrapolar bioelectrical impedance analysis. The current analysis shows that maternal energy reserves decline over the course of lactation and that a cumulative parity‐specific decline in maternal energy reserves also exists. A longitudinal follow‐up of five women over 11 years shows the decline to amount to about 3 mm of subcutaneous fat per round of pregnancy and lactation. The results corroborate predictions from life history theory and have applied public health implications. In particular, It is suggested that policies such as lactation advocacy that encourage enhanced energy allocation to reproduction in order to promote child health may have the unintended result of compromising maternal well‐being, particularly in nations of the developing world. Consequently, it is recommended that nutritional support of mothers be implemented in concert with lactation promotion. Am. J. Hum. Biol. 14:621–626, 2002. © 2002 Wiley‐Liss, Inc.     

Does human ejaculate quality relate to phenotypic traits?

A given man's phenotype embodies cues of his ancestral ability to effectively defend himself and his kin from harm, to survive adverse conditions, and to acquire status and mating opportunities. In this review, we explore the hypothesis that a man's phenotype also embodies cues to fertility or the probability that an ejaculate will fertilize ova. Female mate choice depends on the ability to discern the quality of a male reproductive partner through his phenotype, and male fertility may be among the traits that females have evolved to detect. A female who selects as mates males that deliver higher quality ejaculates will, on average, be more fecund than her competitors. Data on several non‐human species demonstrate correlations between ejaculate quality and secondary sexual characteristics that inform female mate choice, suggesting that females may select mates in part on the basis of fertility. While the non‐human literature on this topic has advanced, the human literature remains limited in scope and there is no clear consensus on appropriate methodologies or theoretical positions. We provide a comprehensive review and meta‐analysis of this literature, and conclude by proposing solutions to the many issues that impede progress in the field. In the process, we hope to encourage interest and insight from investigators in other areas of human mating and reproductive biology. Am. J. Hum. Biol. 28:318–329, 2016. © 2015 Wiley Periodicals, Inc.     

Leptin and reproduction: is it a critical link between adipose tissue, nutrition, and reproduction?

Exercise-associated reproductive disorders are frequently reported among recreationally active and elite female athletes. Although an association between exercise and menstrual disorders has been established, the mechanism by which exercise disrupts reproductive function remains unknown. Recent findings suggest that low energy availability rather than inadequate body fatness or exercise stress is likely the mechanism by which exercise impinges negatively on the hypothalamic-pituitary-ovarian axis in female athletes. The peripheral signal that informs the neural network of energy availability remains unknown. The identification of the adipocyte-derived ob gene product, leptin, and subsequent findings of its association with reproduction in both rodents and humans, led to speculations that it may be involved in the interactions between nutrition and reproduction. This review article focuses on leptin's role in modulating reproduction, and in particular, as a peripheral signal of nutritional status that integrates adipose tissue, nutrition, and reproduction in female athletes.     

Understanding the link between the IL-6 cytokine family and pregnancy: implications for future therapeutics

Cytokines are involved in almost all processes during the menstrual cycle, the fertilization period and pregnancy. They are expressed in numerous reproduction-related body fluids and tissues. Disorders of cytokine expression patterns may cause pregnancy pathologies. Therefore, cytokines have the potential as new biomarkers in different body compartments for a variety of such pathologies. Furthermore, cytokines may also serve to treat fertility and pregnancy disorders. The IL-6-like family of cytokines is an intensively investigated group of cytokines with well-accepted functions in fertility and pregnancy. This article summarizes current knowledge on IL-6-like cytokines in regard of their role in reproduction and their potential for new strategies in the treatment of reproductive pathologies.     

Understanding the link between the IL-6 cytokine family and pregnancy: implications for future therapeutics

Cytokines are involved in almost all processes during the menstrual cycle, the fertilization period and pregnancy. They are expressed in numerous reproduction-related body fluids and tissues. Disorders of cytokine expression patterns may cause pregnancy pathologies. Therefore, cytokines have the potential as new biomarkers in different body compartments for a variety of such pathologies. Furthermore, cytokines may also serve to treat fertility and pregnancy disorders. The IL-6-like family of cytokines is an intensively investigated group of cytokines with well-accepted functions in fertility and pregnancy. This article summarizes current knowledge on IL-6-like cytokines in regard of their role in reproduction and their potential for new strategies in the treatment of reproductive pathologies.     

The role of circadian rhythmicity in reproduction

Circadian rhythmicity is evident in a wide range of physiological systems including the reproductive axis. The recent discoveries of rhythmic clock gene expression in peripheral tissues, including reproductive tissue, suggests that they may play an important role in optimizing fertility. The evidence for rhythmic control of reproduction from studies in laboratory animals is reviewed and where possible this includes evidence from human studies. Clock genes are highly conserved across species including humans and there is no reason to suggest that they are functionless in humans. The challenge issued here is for researchers to probe their function and the consequences of their disruption in both animal and human reproduction.