This study analysed factors associated with unintended pregnancy among adolescent and young adult women in Santiago, Chile. Three variations of a behavioural model were developed. Logistic regression showed that the effect of sex education on unintended pregnancy works through the use of contraception. Other significant effects were found for variables reflecting socioeconomic status and a woman's acceptance of her sexuality. The results also suggested that labelling affects measurement of ‘unintended’ pregnancy.

Assortative mating for 22 anthropometric and body composition characteristics and social indicators was studied in a Spanish sample of 114 married couples. Significant spousal similarity was found for occupation, educational level and number of siblings. Sex–age adjusted spouse correlations were significant for stature, ileospinal height, total arm length, and biacromial breadth. Spouse correlations were not altered after allowance for socioeconomic effects. When couples were grouped according to marriage duration, differences in mate correlations for fatness were detected, suggesting a cohabitational effect on spouse resemblance.

Data from the 1988 Tanzania census were used to examine child mortality in three regions populated with Burundi refugees. Logistic and least squares analyses show that for both Tanzanian nationals and refugees low levels of maternal education are associated with high child mortality levels. Children born to mothers who are housewives are associated with low levels of mortality compared to those born to employed mothers, though the results were not statistically significant for the refugees. Maternal demographic status, computed from age and parity, has a strong effect on child survival. Unexpectedly, child mortality was lower where the water source was a well outside the village. Tanzanian mothers who are at highest risk of childbearing are roughly 6·4 times more likely to have a child death than those at lowest risk; the corresponding figure for the refugees is 36·8. This emphasises the need to intensify family planning programmes in these regions.

This paper examines the effects of a child's place of birth, mother's education, region of residence and rural and urban residence on infant mortality in Nigeria between 1965 and 1979, using data from the 1981/82 Nigeria Fertility Survey. Infant mortality rates declined in all regions between 1965 and 1979. Children born in modern health facilities, irrespective of their mothers' place of residence, experienced significantly lower rates of infant mortality than those born elsewhere. Logistic regression analysis showed that all other variables tested were also significant, although some to a lesser degree. Efforts to reduce infant mortality in Nigeria should include policies that rectify rural and urban differentials in the distribution of health facilities and encourage their use.

The daily activities observed in a Colombian village community of contemporary hunting and gathering people were analysed with respect to their time structure. Short term cycles of about 2 hours could be detected in both individual and common behavioural patterns. These behaviour cycles of individual group members appear to have been synchronised by social interaction. From temporal variations of individual activities a common ultradian time frame emerged.

This study examines fertility differentials by religious affiliation in Liberia, within the context of two competing hypotheses: the characteristic and particularised theology. Using a subsample of currently married women from the 1986 Liberian Demographic and Health Survey, the study examines the fertility of five religious groups: Catholic, Protestant, Moslem, traditional, and other women. Overall, the findings are more consistent with the characteristic hypothesis, because the small fertility differentials by religious affiliation are largely accounted for by differences in the socioeconomic and demographic characteristics of these women.

This study uses sets of historical family reconstitutions from all of Quebec and from four villages of the Haut-Jura, France—first marriages of 2226 and 994 women, respectively—to investigate the physiological and social factors affecting age of mother at last birth before and during fertility transition. Age remained high throughout the period covered in Quebec, under ‘natural’ conditions, but showed a steady decline in the French material which extends to late 19th century generations practising family limitation.

Age at marriage had no influence in Quebec; in France, however, women with the most surviving children at age 35 continued childbearing the latest. There was no link between biological ability to achieve a live birth, or in health status or aging rhythm, and age at last birth. Behaviour of mothers and daughters showed no relation. The variability in age at last birth thus appears to be random under natural conditions; with the onset of controls, social differences seem to influence not only the end of childbearing, but all aspects of behaviour governing final family size and child survival.

Duration of postpartum amenorrhoea (PPA) was compared among women who breast-fed For ≥ 6 months (breast-feeding group) Or ≤ 3 Months (formula-feeding group) and was found to be significantly shorter among the latter. associations between maternal factors and duration of PPA were examined. within the formula-feeding group, the only variable associated with duration of PPA was duration of breast-feeding. among breast-feeding mothers who resumed menstruation after 3 months postpartum, duration of PPA was positively associated with parity and negatively associated with maternal body mass index (bmi) at 3 months postpartum. Among breastfeeding mothers who resumed menstruation after 6 months, duration of PPA was positively associated with parity, pregnancy weight gain, number of night feeds and milk volume at 6 months, and negatively associated with maternal age and bmi at 6 months postpartum. These results indicate that maternal anthropometric status is related to duration of PPA, even in a relatively well-nourished population of lactating women.

According to the 1991/92 Tanzania Demographic and Health Survey, a Tanzanian woman has, on average, 6·1 births before she reaches age 50, a decline of about one birth per woman since the early 1980s. The major proximate determinant of fertility is universal and prolonged breastfeeding. An analysis of the social and demographic correlates of fertility shows that infant and child mortality, level of education and age at first marriage are among the factors which significantly influence fertility in Tanzania.

The variability of three behavioural risk factors for heart disease—heavy alcohol and tobacco consumption and physical inactivity—was assessed in an Australian Aboriginal community, where heart disease death rates were high. Prevalence levels were assessed by comparison with those experienced by all adult Australians and by evaluating whether Aboriginal rates were influenced by underlying sociodemographic conditions. Relative risk ratios, odds ratios and logistic regression analysis were used.

A total of 159 males and 114 females participated. Compared to all Australians, Aborigines are significantly more likely to drink five or more drinks on a drinking day, to be current smokers, and not to participate in vigorous exercise. In the Aboriginal community, univariate analysis indicates that: the odds of being a heavy drinker are significantly higher for those in unsatisfactory health; odds of being a current smoker are significantly higher for those in unsatisfactory health or unemployed; odds of not participating in vigorous exercise are significantly higher for those in unsatisfactory health, unemployed or without secondary education. Multivariate analysis shows that risk of being a heavy drinker is independently associated with sex, age, and health status; risk of being a current smoker is associated with health and employment status. The risk of not participating in vigorous exercise is significantly related to all sociodemographic variables examined. Reasons for these associations are discussed.

This paper assesses the impact of husband's and wife's education and occupation on family size in Zimbabwe. Results from the 1988 Male Fertility Survey indicate that husband's education had a strong negative effect, and wife's education had a moderate negative effect on the number of children ever born. Contrary to the literature, wives who were not employed had significantly fewer children than those who work in agriculture, and fewer, but not significantly, than those in non-agricultural occupations. Findings show the importance of husband's education and the changing dynamics of wife's occupation in fertility decline.