Natural fertility, age patterns, levels and trends
Natural fertility includes consideration of the age pattern of natural fertility and a number of factors which could potentially influence it--breastfeeding, postnatal abstinence, terminal abstinence, declines in pathological infertility, age differences between the spouses, age at marriage, and premarital pregnancy. Historical demography and studies from contemporary developing countries are the basis for this discussion. Natural fertility is defined as the fertility of a population that makes no deliberate effort to limit births. This was later refined to refer to fertility in the absence of parity-dependent birth control. The specification that natural fertility be free of parity-dependent control suggests that the shape of the age-specific schedule of marital fertility will be determined by the decline of fecundity with age. Breastfeeding depresses fertility by delaying the return of ovulation following a birth. The practice of postnatal abstinence is often linked to lactation; however, there is no correspondence between the period of sexual abstinence following a birth and breastfeeding. Terminal abstinence poses a greater challenge to the concept of natural fertility than does postnatal abstinence. Practice of terminal abstinence is associated with age; therefore the potential for changing the shape of the age pattern of natural fertility is substantial. Declines in pathological sterility can temporarily distort the age-gradient of sterility and the age pattern of fertility. There is a significant influence of husbands' ages on their wives' natural fertility. The marital fertility of women at any given age is generally inversely related to the age of their husbands. There is a very strong inverse relationship between the number of children ever born and marriage age at the individual couple level. The extent and age pattern of premarital pregnancy can influence the age pattern of natural fertility.
Natural fertility includes consideration of the age pattern of natural fertility and a number of factors which could potentially influence it--breastfeeding, postnatal abstinence, terminal abstinence, declines in pathological infertility, age differences between the spouses, age at marriage, and premarital pregnancy. Historical demography and studies from contemporary developing countries are the basis for this discussion. Natural fertility is defined as the fertility of a population that makes no deliberate effort to limit births. This was later refined to refer to fertility in the absence of parity-dependent birth control. The specification that natural fertility be free of parity-dependent control suggests that the shape of the age-specific schedule of marital fertility will be determined by the decline of fecundity with age. Breastfeeding depresses fertility by delaying the return of ovulation following a birth. The practice of postnatal abstinence is often linked to lactation; however, there is no correspondence between the period of sexual abstinence following a birth and breastfeeding. Terminal abstinence poses a greater challenge to the concept of natural fertility than does postnatal abstinence. Practice of terminal abstinence is associated with age; therefore the potential for changing the shape of the age pattern of natural fertility is substantial. Declines in pathological sterility can temporarily distort the age-gradient of sterility and the age pattern of fertility. There is a significant influence of husbands' ages on their wives' natural fertility. The marital fertility of women at any given age is generally inversely related to the age of their husbands. There is a very strong inverse relationship between the number of children ever born and marriage age at the individual couple level. The extent and age pattern of premarital pregnancy can influence the age pattern of natural fertility.
Communication and coping as predictors of fertility problem stress
According to a research of Copenhagen University about the fertility problem stress, among both men and women, difficulties in partner communication predicted high fertility problem stress (odds ratio for women, 3.47, 95% confidence interval 2.09–5.76; odds ratio for men, 3.69, 95% confidence interval 2.09–6.43). Active-avoidance coping (e.g. avoiding being with pregnant women or children, turning to work to take their mind off things) was a significant predictor of high fertility problem stress. Among men, high use of active-confronting coping (e.g. letting feelings out, asking other people for advice, seeking social support) predicted low fertility problem stress in the marital domain (odds ratio 0.53, 95% confidence interval 0.28–1.00). Among women, medium or high use of meaning-based coping significantly predicted low fertility problem stress in the personal and marital domain. It is very important to intervene with fertility patients in order to reduce their stress after medically unsuccessful treatment.
Stress and infertility
"There is now compelling evidence that psychosocial stress is a cause of reproductive suppression in humans", says a group of researchers (Cardiff University, Copenhagen University, Western Australia University).. However, women continue to conceive in the harshest conditions of war, poverty, or famine, suggesting that suppression can be bypassed. The reproductive suppression model (RSM) proposes that natural selection should favor factors that reliably predict conditions for reproduction. In this study, we examine two such factors, age and social position, in women undergoing fertility treatment. We hypothesized that stress-related reproductive suppression would be more likely in younger compared to older women and in women in lower compared to higher social positions. The final sample consisted of 818 women undergoing fertility treatment. Psychosocial stress and sociodemographic data were collected prior to the start of treatment (Time 1), whereas fertility, as indexed by pregnancy or live birth, was assessed 12 months later (Time 2). The results showed that younger women were four times more likely to suppress than older women, and that unskilled and manual workers were more likely to suppress than those in middle social positions (e.g., white collar workers). However, significant associations between stress and fertility were also observed for women in higher social positions (e.g., professionals and executives).
"There is now compelling evidence that psychosocial stress is a cause of reproductive suppression in humans", says a group of researchers (Cardiff University, Copenhagen University, Western Australia University).. However, women continue to conceive in the harshest conditions of war, poverty, or famine, suggesting that suppression can be bypassed. The reproductive suppression model (RSM) proposes that natural selection should favor factors that reliably predict conditions for reproduction. In this study, we examine two such factors, age and social position, in women undergoing fertility treatment. We hypothesized that stress-related reproductive suppression would be more likely in younger compared to older women and in women in lower compared to higher social positions. The final sample consisted of 818 women undergoing fertility treatment. Psychosocial stress and sociodemographic data were collected prior to the start of treatment (Time 1), whereas fertility, as indexed by pregnancy or live birth, was assessed 12 months later (Time 2). The results showed that younger women were four times more likely to suppress than older women, and that unskilled and manual workers were more likely to suppress than those in middle social positions (e.g., white collar workers). However, significant associations between stress and fertility were also observed for women in higher social positions (e.g., professionals and executives).
