BACKGROUND & AIMS: OBJECTIVES:The first and second demographic transitions have led to profound changes in family networks. However, the timing and extent of these transitions vary widely across contexts. We examine how common it is for contemporary older adults to lack living kin and whether such individuals are uniformly disadvantaged around the world. METHODS:Using surveys from 34 countries that together contain 69.6% of the world's population over age 50 and come from all regions of the world, we describe the prevalence and correlates of lacking immediate kin. We examine macro-level demographic indicators associated with the prevalence of kinlessness as well as micro-level associations between kinlessness and sociodemographic and health indicators. RESULTS:There is great variation in levels of kinlessness, from over 10% with neither a spouse nor a biological child in Canada, Ireland, the Netherlands, and Switzerland to levels below 2% in China and the Republic of Korea. There are strong macro-level relationships between kinlessness and lagged or contemporaneous fertility, mortality, and nuptiality measures and more marginal relationships with other demographic forces. Micro-level associations between kinlessness and respondent attributes are varied. The kinless are more likely to live alone than those with kin in all countries. In most countries, they have equivalent or worse self-rated health and lower education, although there are notable exceptions. There is substantial variation in the gender composition of the kinless population. DISCUSSION:As demographic changes affecting kinlessness continue, we expect the scale of the kinless population to grow around the world.

背景与目标： 目标：第一次和第二次人口转变导致家庭网络发生了深刻的变化。但是，这些过渡的时间和范围在不同情况下差异很大。我们研究了当代老年人缺乏亲属的情况是多么普遍，以及这些人在世界范围内是否普遍处于弱势地位。
方法：我们使用来自34个国家/地区的调查资料，这些国家/地区占世界50岁以上人口的69.6％，他们来自世界所有地区，它们描述了缺乏直系亲属的普遍程度及其相关性。我们研究了与虚假患病率相关的宏观人口统计学指标，以及虚假程度与社会人口统计学和健康指标之间的微观关联。
结果：无亲属的水平差异很大，从加拿大，爱尔兰，荷兰和瑞士的既没有配偶也没有亲生子女的比例超过10％，到中国和大韩民国的比例都低于2％。赤裸裸与生育力，死亡率和婚后状况的落后或同时代之间存在密切的宏观关系，与其他人口因素之间的边际关系更为密切。无情和被访者属性之间的微观关联是多种多样的。在所有国家中，无亲人比有亲人的人更有可能独自生活。在大多数国家中，他们的自我评估健康水平和教育水平较低甚至与之相当，但也有例外。无亲人口的性别组成存在很大差异。
讨论：随着影响无家可归的人口变化继续，我们预计无家可归人口的规模将在世界范围内增长。

BACKGROUND & AIMS: :Since the early 1980s, the number of births to women over age 35 has been increasing in most European countries. Consequently, the period of highest fertility shifted from the 20-25 to the 25-30 age range. During the baby boom after World War II in France, the annual number of births rose from 610,000 in 1938 to 870,000 by the end of the 1940s. In 1964 when the baby boom children reached reproductive age, annual births were close to 850,000. The number of births in mothers over 35 increased from 47,000 in 1980 to 70,000 in 1985. The total fertility ratio was 3 children/woman by the end of the 1940s, then it declined to 1.8 between 1964 and 1976, below the replacement level up to the present time. The proportion of the ratio attributable to women over 35 age declined during the 20th century from 25% to the current 9%. Between 1964 and 1976, all the age-specific birth rates fell. In France in 1978, unwanted births dropped from 21% to 13.5% between the periods 1963 and 1967, and 1973 and 1977, respectively. In 1976, fertility in the 25-39 and the 30-34 age ranges started to increase. The main reason for the increase in fertility beyond age 35 was the decrease in nuptiality at younger ages due to more efficient birth control. Illegitimate fertility rates also rapidly increased along with single women at all ages. In Sweden, the illegitimacy ratio is currently close to 1 out-of wedlock birth in every 2 births. The illegitimacy ratio nearly doubled between 1976 and 1985 to reach 17% in the UK and 20% in France. It is not close to 6% in Switzerland, 8.5% in the Netherlands, and 9% in West Germany. On the one hand, the increase in the number of births at maternal ages over 35 occurred because the baby boom cohorts are not 25-40 year old. New cohorts will marry later and often get divorced, while out-of-wedlock fertility continues to increase. These changes will bring about the decline in fertility before age 25 and an increase between ages 25 and 35. Late fertility after age 35 will probably increase to a much smaller extent than mid-period fertility.

背景与目标： ：自1980年代初以来，大多数欧洲国家/地区中35岁以上女性的分娩数量一直在增加。因此，最高生育率的时期从20-25岁转变为25-30岁。在法国第二次世界大战后的婴儿潮时期，每年的出生人数从1938年的61万增加到1940年代末的870,000。 1964年，婴儿潮时期的孩子达到了生殖年龄，每年的出生人数接近850,000。 35岁以上母亲的出生人数从1980年的47,000人增加到1985年的70,000人。到1940年代末，总生育率是3个孩子/妇女，然后在1964年至1976年间下降到1.8个，低于替代水平直到现在的时间。在20世纪，归属于35岁以上女性的比例从25％下降到目前的9％。在1964年至1976年之间，所有特定年龄的出生率均下降。 1978年的法国，在1963年和1967年以及1973年和1977年之间，意外生育率分别从21％下降到13.5％。 1976年，年龄在25-39岁和30-34岁之间的生育率开始增加。 35岁以后生育能力增加的主要原因是由于更有效的节育措施，年轻时的婚育性下降。与所有年龄段的单身女性一起，非法生育率也迅速增加。在瑞典，非婚生比率目前接近每2胎非婚生胎1胎。在1976年至1985年之间，非婚生率几乎翻了一番，在英国达到了17％，在法国达到了20％。瑞士的这一比例接近6％，荷兰为8.5％，西德为9％。一方面，由于婴儿潮一代的年龄不在25至40岁之间，因此孕产妇在35岁以上出生的人数有所增加。新婚夫妇将在以后结婚，并且通常会离婚，而婚外生育能力则继续增加。这些变化将导致25岁之前的生育力下降，以及25岁至35岁之间的生育率增加。35岁之后的后期生育率可能会比中期生育率的增长幅度小得多。

BACKGROUND & AIMS: :The constancy of fertility levels in Ghana, Senegal and southwest Nigeria since 1970 is separated into its nuptiality and marital fertility elements. The age-specific changes in the two components are examined and these show that the apparent stability in observed total fertility rates is essentially the outcome of the offsetting impact of increased marital fertility below age 25 and above age 40, over the effect of the increasing proportion of women remaining single up to 25 yr of age. Continuity in traditional fertility behaviour and stable nuptiality has remained operative over the broad middle segment of the reproductive lifespan of women in the three areas. The paper thus concludes that West Africa is likely to continue to display stably high fertility for many years into the next century. The social and cultural conditions behind this trend are discussed with special reference to the continued high demand for children and the low and only slowly rising contraceptive prevalence level.

背景与目标： ：自1970年以来，加纳，塞内加尔和尼日利亚西南部的生育率处于恒定状态，分为其婚育性和婚姻生育率要素。研究了这两个组成部分的特定年龄变化，这些结果表明，观察到的总生育率的明显稳定性基本上是25岁以下和40岁以上婚姻生育率增加抵消的影响的结果，到25岁的单身女性。在这三个地区，妇女生育寿命的广泛中段一直保持着传统的生育行为和稳定的婚姻状态。因此，本文得出的结论是，到下个世纪，西非很可能会继续稳定地显示出高生育率。讨论了这种趋势背后的社会和文化条件，并特别提到了对儿童的持续高需求以及避孕普及率较低且仅在缓慢上升的情况。

BACKGROUND & AIMS: BACKGROUND:Complex seasonal variations in abortions and seasonal trends have been reported worldwide, but there are no data from Australia. MATERIAL/METHODS:Hospital morbidity and birth data were modelled using time series and regression techniques to describe seasonal changes in births and abortions (1989-99) in NSW, Australia. Data were also analysed to determine demographic predictors of abortions. RESULTS:A higher proportion of births in NSW were recorded in March and September-October. Irrespective of the nuptiality the lowest seasonal indices were recorded in February and November. For married women aged 20-49 years, voluntary abortions were significantly higher in February (t=0.04) and significantly lower in April (t<0.001) and June (t=0.03) and non-voluntary abortions were significantly higher in February (t=0.002) and March (t=0.006). There was seasonality in voluntary abortions (F=4.3, p<0.001) and no seasonality in non-voluntary abortions (F=2.4, p=0.01) for never married women aged 20-49 years. As similar to married women, voluntary abortions among never married women were significantly higher in February (t<0.001) and significantly low in April (t=0.009). The lowest number of abortions were in April. Non-voluntary abortions occurred mostly in March for married women. The average number of voluntary abortions were significantly higher for never married women than for married women. CONCLUSIONS:There was a significant seasonality of births and abortions in NSW, Australia, with a peak of conceptions in December/January. Abortions were lowest in April and non-voluntary abortions were peaked in March. These data suggest that the human reproductive behaviour has a close relationship with environmental factors.

背景与目标： 背景：全球已有流产和季节趋势的复杂季节性变化报告，但澳大利亚没有相关数据。
材料/方法：使用时间序列和回归技术对医院发病率和出生数据进行建模，以描述澳大利亚新南威尔士州出生和流产的季节性变化（1989-99年）。还对数据进行分析以确定堕胎的人口统计学预测因素。
结果：3月和9月至10月在新南威尔士州出生的比例更高。不论婚宴如何，最低的季节性指数都记录在二月和十一月。对于年龄在20-49岁之间的已婚妇女，自愿流产在2月显着升高（t = 0.04），在4月显着降低（t <0.001）和6月（t = 0.03），非自愿流产在2月显着升高（t = 0.002）和三月（t = 0.006）。对于年龄在20-49岁之间的未婚女性，自愿流产有季节性（F = 4.3，p <0.001），非自愿流产没有季节性（F = 2.4，p = 0.01）。与已婚妇女类似，从未婚妇女中的自愿堕胎在2月显着增加（t <0.001），在4月显着降低（t = 0.009）。堕胎次数最少的是四月。非自愿堕胎主要发生在三月份的已婚妇女身上。未婚妇女的平均自愿堕胎次数明显多于已婚妇女。
结论：澳大利亚新南威尔士州有明显的出生和堕胎季节性，在12月/ 1月受孕高峰。流产在四月最低，非自愿流产在三月达到高峰。这些数据表明，人类的生殖行为与环境因素有着密切的关系。

BACKGROUND & AIMS: :The relationship between female age and infertility is examined using a single-island Micronesian population case. Demographic data, derived primarily from reproductive history interviews, show that a significant age-associated decline in marital reproductive performance is absent before women reach their late thirties in this population but a substantial decline is present once women reach their forties. Ethnographic data support the demographic inference that couples are maintaining relatively high levels of conjugal coital activity with both advancing female age and increasing marital duration. Thus coital activity levels appear to be an important factor in the maintenance of fertility in this group before the mid-thirties but decreases in fecundability after this age are due primarily to reductions in fecundity, not to declines in coital activity. The description of the Butaritari case lends support to Underwood's (1990) suggestion that a "Micronesian pattern" of reproductive performance may exist for the region's atoll-based populations and underscores the promise of further investigations of these special cases in the fields of demography and reproductive ecology. :The aim of this study of infertility was to describe demographic patterns of infertility by age and their link with age-associated behavior changes, such as coital activity, on the Butaritari Atoll north of Tungaru in the Republic of Kiribati. The population is relatively circumscribed on this high-population-density island; there were high rates of nuptiality, minimal premarital exposure to pregnancy risk, low contraceptive usage, and an absence of sexually transmitted diseases that cause infertility. The population in 1990 was 3800, of which almost 50% were aged 15 years. Fertility was high, at a mean of 4.5 births for ever married women (N=791) and a completed fertility of 7.14 for ever married postmenopausal women. Almost all men and women marry. Primary infertility levels were only 1.29% of ever married postmenopausal women (N=231). Data on reproductive histories were collected from 87.1% (N=203) of all women aged 15 years in the village in 1990/91 and supplemented with other archival records. A subsample of 34 women were interviewed for a detailed analysis of life course changes in reproductive and sexual behavior. Census data from 1990 were also collected and checked against vital registration records. The following measures were examined: infertility in relation to marriage duration, current reproductive status of women in relation to age, infertility in relation to parity, infertility in relation to age, pregnancy failure in relation to age, and ethnographic factors. The findings indicated that infertility rarely occurred before the late 30s because of the low levels of subfecundity, no age variation in breast feeding patterns, no significant increase in reported fetal death rates before the 40s, and sustained coital frequency with increasing marriage duration. Coital frequency declined after the age of 40 years, as did fecundity. The coital patterns were found to be similar to the Micronesian region; women produce as many children at later ages as they do at earlier ages.

背景与目标： ：使用单岛密克​​罗尼西亚人口案例研究了女性年龄与不孕之间的关系。主要从生殖史访谈中获得的人口统计数据表明，在该年龄段的女性中，在三十岁以下之前，与婚姻相关的生殖性能没有明显的年龄相关性下降，但是，一旦女性达到40岁，则存在显着下降。人种学数据支持人口统计学推断，即随着女性年龄的增长和婚姻持续时间的延长，夫妻保持着较高的夫妻性交活动。因此，在三十多岁之前，性交活动水平似乎是维持该组生育能力的重要因素，但在这个年龄之后，生育能力下降主要是由于生育力下降，而不是交往活动下降。对Butaritari案的描述为Underwood（1990）的建议提供了支持，该建议认为该地区环礁地区的人口可能存在生殖活动的“密克罗尼西亚模式”，并强调了在人口统计学和生殖领域进一步研究这些特殊情况的希望。生态。
：这项不育研究的目的是描述基里巴斯共和国北部通加鲁北部的Butaritari环礁按年龄划分的人口统计学特征及其与与年龄相关的行为变化（如性活动）的联系。在这个人口稠密的岛屿上，人口相对有限。婚内率高，婚前极少有怀孕风险，避孕药具使用率低以及没有引起不育的性传播疾病。 1990年的人口为3800，其中将近50％的年龄为15岁。生育能力高，已婚妇女平均生育4.5胎（N = 791），已婚绝经妇女平均生育力7.14。几乎所有男人和女人都结婚。原发性不育水平仅是已婚绝经后妇女的1.29％（N = 231）。 1990/91年该村所有15岁妇女的87.1％（N = 203）收集了生殖史数据，并附加了其他档案记录。采访了34位女性的子样本，以详细分析生殖和性行为中生命过程的变化。还收集了1990年的人口普查数据，并对照人口动态登记记录进行了核对。检查了以下措施：与婚姻持续时间有关的不育，与年龄有关的妇女目前的生殖状况，与性别有关的不育，与年龄有关的不育，与年龄有关的妊娠失败和人种学因素。研究结果表明，不孕症在30年代末之前很少发生，这是因为生育力低下，母乳喂养的年龄没有年龄变化，40年代之前报告的胎儿死亡率没有显着增加以及随着婚姻持续时间的增加而持续的性交频率。 40岁以后，性行为频率和生殖力都下降了。发现其性交方式与密克罗尼西亚地区相似。妇女在较晚年龄生育的子女与在较早年龄的子女一样多。

BACKGROUND & AIMS: :The Guatemala National Survey of Maternal and Child Health was national in scope, but lacked data from 1 region (2% of the population). 5459 households took part; complete interviews with 5160 women aged 15-44 took place. The survey was done between September 25-December 16, 1987. Summary statistics are presented in tables. They give general population characteristics (both demographic and economic); distribution of survey sample population by socioeconomic characteristics (percent women); fertility statistics--trends, differentials, and age-specific fertility; fertility preferences (ideal number of children, desire to stop childbearing; planning status of births by birth order); current contraceptive use--contraceptive prevalence differentials; contraceptive prevalence by age and parity; source of contraceptive supply for current users of supply or clinic methods; contraception facts--"knowledge and use of contraceptive methods among women married or in union;" reaction to getting pregnant among women who do not use contraceptives, and women who gave up a method in the last 5 years. Nuptiality and contraceptive status are given in charts headed by "current marital status." Postpartum variables given include: "duration of postpartum interval by current status;" "differentials in breast feeding and amenorrhea;" and "postpartum status by duration since birth." Infant mortality trends, differentials, 1977-87; and children ever-born and surviving are also given. "Health: disease, treatment, and prevention, as given by "percent of children 12-23 months of age with health and, of those, percent immunized;" "percent of children under 5 years" with diarrhea 2 weeks before the survey, and of those, percent receiving different treatments;" and "type of assistance during delivery for births" in the 5 years before the survey. Nutritional status: anthropometric measures lists the percent of undernourished among children who are aged 3-36 months according to child's weight-for-height; and percent of undernourished children aged 3 to 36 months according to children's height-for-age.

背景与目标： 危地马拉全国孕产妇和儿童健康调查的范围是全国性的，但缺乏来自1个地区（人口的2％）的数据。有5459户家庭参加；对5160名15-44岁的女性进行了完整访谈。这项调查是在1987年9月25日至12月16日之间进行的。汇总统计信息显示在表格中。它们具有一般的人口特征（人口和经济特征）；按社会经济特征分列的调查样本人口分布（妇女百分比）；生育率统计-趋势，差异和特定年龄的生育率;生育偏好（孩子的理想数量，停止生育的愿望；按出生顺序计划生育状况）；当前的避孕药具使用情况-避孕药具的流行率差异;按年龄和性别划分的避孕普及率；当前使用避孕药具或临床方法的避孕药具的供应来源；避孕事实-“已婚或同居妇女对避孕方法的了解和使用；”在过去5年中，不使用避孕药的女性以及放弃使用避孕方法的女性对怀孕的反应。婚姻状况和避孕状况在以“当前婚姻状况”为标题的图表中给出。给出的产后变量包括：“根据当前状态的产后间隔时间”； “母乳喂养和闭经的差异；”和“从出生起的持续时间划分的产后状态”。婴儿死亡率趋势，差异，1977-87；还提供了长生不老的孩子。 “健康：疾病，治疗和预防，例如在调查前两周出现腹泻的12％至23个月大的儿童百分比，其中免疫接种的百分比； 5岁以下儿童的腹泻百分比，当中有百分之百接受不同待遇；”以及调查前5年内的“分娩时的帮助类型”。营养状况：人体测量法根据身高体重列出了3-36个月大儿童中营养不良的百分比；以及3至36个月大的营养不良儿童的百分比，具体取决于儿童的年龄高度。