In order to evaluate the mental health aspects of voluntary sterilization for family planning purposes, WHO initiated in 1978 a multi-centre prospective controlled study. A total of 926 healthy women with at least two living children, who requested sterilization (interval, post-partum or post-abortion), and 924 controls using other methods of contraception, were selected for a prospective investigation which included pre-operative and post-operative (6 weeks, 6 months, and 1 year) standardized assessment of mental state and a range of variables related to physical health and psychosexual functioning. Although pre-operatively a high proportion of subjects in both index and control groups reported minor non-specific psychiatric symptoms the percentage of women meeting defined criteria of psychiatric disorder was low to moderate (less than 15%) in all centres except Cali (26%). In all centres the pre-operative rates of psychiatric disorder were somewhat higher in the sterilization groups than in the control groups, and in two centres (Cali and Chandigarh) this difference was statistically significant. Thus, the data indicate that women choosing sterilization for birth control tend to show pre-operatively more psychiatric disturbance than their control counterparts who opt for other methods of contraception.

In 375 women who accepted contraception at a clinic in northern Nigeria there were significant differences between IUD and pill acceptors. The pill acceptors were younger women of lower parity who tended to be less educated and mostly not engaged in any profession. The IUD clients were older women of high parity with better education and many had occupations outside the home. The most striking difference was in the religious affiliations of the two groups. The majority of Muslim women (72·9%) opted for the pill whereas the majority of Christian women (55·9%) chose the IUD.

In the course of this century man's control over his natural environment and its effects has vastly increased. As a result, death rates from many illnesses caused by environmental factors have fallen markedly. This is very evident in the field of infant mortality. In 1906–10, of every 1000 babies born alive in this country, 117 died before their first birthday. By 1971–75 this figure had dropped to less than 17.

The geographic distribution of the Smiths and Joneses among all persons married in England and Wales in 3 months of 1975 showed well defined frequency clines comparable to those of blood group distributions. Polynomial regressions of relative frequencies of these surnames on latitude and longitude account for 12% and 36% of the variation among registration districts in frequency of Smiths and Joneses, respectively.

In a 1982 survey of 250 men living in Khartoum, knowledge of, attitudes towards and use of contraception among Sudanese men were explored. Particular attention was given to attitudes towards male and female sterilization. Although most of the men expressed a desire to have large families, several findings suggest that they felt that they may have to be satisfied with a lower number for economic reasons. Three-fifths of the men with wives of reproductive age wished to use family planning services now but only about one-fifth were currently using an effective method. Almost 60% of the men were interested in learning more about female sterilization and about 50%, more about male sterilization. In general, attitudes towards family planning were more favourable than previously believed by providers of these services. Only 2·8% of these men had obtained services from a family planning clinic, suggesting that the demand currently exceeds the supply.

Detailed pedigrees of the small Samaritan isolate covering the last thirteen generations and consisting of 82 founders and 670 descendants allowed calculations of (a) the probability of origin of genes from particular founder members, and (b) the total number of descendants from each founder. Analysis of the matrix of distances between the thirteen generations identified the kind and the direction of the evolution of this community: rapid evolution from the first to the eighth generation due to the small population size, slowly progressing towards a stable state in the last three generations.

Seven hundred and ninety six Thai women who stopped using the long-acting injectable contraceptive depot medroxyprogesterone acetate (DMPA, Depo Provera), 437 women who stopped using oral contraceptives and 125 women who had an IUD removed to have a planned pregnancy, were followed up to ascertain the delay to conception after the end of contraception and to determine the proportion of women who did not conceive in the 4 years after discontinuation. The median delay to conception was 5·5 months plus the estimated duration of the effect of the last injection of DMPA, 3 months for oral contraceptives and 4·5 months after discontinuing the IUD. The proportion of women who did not conceive within 9 months after discontinuation of DMPA is similar to that of ex-IUD users, and by 3 years to that of the ex-pill sample. There is no evidence to suggest that prolonged use of DMPA increases the delay to conception, and the return of fertility among never pregnant ex-users resembled that of ever pregnant ex-users.

There were comparable proportions of live births among ex-DMPA users and ex-pill users and both of these showed higher proportions of live-births than ex-IUD users. There was no evidence to suggest that previous use of DMPA had any significant adverse effect on the outcome of pregnancy of the subsequent births. This study did not show any association between infertility and the previous use of DMPA or other contraceptives.

This paper considers two main issues: the definition of Henry's concept of natural fertility, and the use of standard age-specific marital fertility schedules to measure the extent of fertility control. It suggests that regional as well as temporal variations are to be expected in the pattern of marital fertility and in consequence argues the need for a variety of standard marital fertility schedules specific to the underlying fertility conditions of the particular population under investigation. A detailed example drawn from the fertility patterns of Britain, Denmark and Sweden is presented.

Data collected in Papua New Guinea between November 1979 and March 1980 show that the main reason for prolonged breast-feeding and sexual abstinence is to ensure the welfare of the mother and child (which is indirectly a means of child spacing). The mean period of breast-feeding for the rural mothers is 21·8 months and for the urban mothers is 20·7 months. The mean duration of sexual abstinence for the rural male respondents is 21·4 months and for the female is 20·2 months. The figures for their urban counterparts are 19·5 months and 16·6 months respectively.

This paper examines data on fertility levels in 33 Moslem countries between 1960 and 1980. Fertility measures include crude birth rate, total fertility rate and age-specific birth rate, and the percentage change in them between 1960 and 1980.

The analysis focuses on: (1) the current status of Moslem fertility in comparison to non-Moslem countries in the same region; (2) the emerging fertility differentials among Moslem countries; (3) how much of the recent fertility declines in some Moslem countries is associated with modernization variables and with family planning efforts.

The results indicate that: (1) Moslem fertility remains universally high and is generally higher than in non-Moslem countries in the same region; (2) very few Moslem countries have succeeded in bringing down their level of fertility to justify a search for the predictors of Moslem fertility levels; (3) in spite of a sufficient range of variations in the economic and social correlates of fertility, the corresponding fertility variables in these countries do not suggest that the reproductive behaviour of Moslem women has reacted to such variations; (4) efforts directed towards stronger family planning programmes are clearly related to fertility decline.

Data collected on fertility and family planning between November 1979 and March 1980 in eight provinces of Papua New Guinea (PNG) are presented in this report. Interviews with 2923 rural and 3360 urban male and female respondents found attitudes favouring large families. There was a relatively high level of contraceptive awareness, but the overall practice of modern contraception in both rural and urban areas is low. Despite the rural–urban differences in socioeconomic levels, awareness of family planning is only slightly higher among the urban respondents. The level of usage for the urban respondents is slightly higher than for the rural respondents.

The present study of 329 Australian and 281 Papua New Guinean (PNG) high school youth compared students' perceptions of the economic role of children, the importance of personal aspirations, evidence of support for the conjugal family and for cultural props. As predicted, the economic role of children was more important to PNG students, and considerably less so to young Australians. Predicted differences in personal aspirations were less clear cut, but young Australians cited more frequently the restrictions and economic costs in having children. In addition, Australians emphasized more than PNG students the pleasure, pride, fulfilment and achievement in having children. As expected in a low fertility country, Australian students mentioned more often the love and companionship of children, although students in both countries had similar views about the impact of children upon the marital relationship. Lineage and religious benefits from children were more salient to PNG youth.

The effect of the intermediate fertility variables on marital fertility in Kenya is examined using Bongaarts' model on group data from the Kenya Fertility Survey 1977/78. The findings suggest that variations in the proportion married among the population, level of contraceptive use and post-partum lactational infecundability can account for much but not all of the observed marital fertility differentials. Modernization through education and urbanization has had offsetting effects on fertility, by reducing lactation and increasing contraception. However, the proportion using contraception, limited mainly to those with secondary and higher education or metropolitan residence, is too small to have an appreciable impact on the overall level of fertility. The low level of marital fertility observed particularly among the metropolitan, coast and Muslim categories of population may be attributed to the prevalence of venereal diseases and unreported contraception and induced abortion.

In the area studied in the Machakos Project the total fertility estimate amounts to 7·46, which is somewhat lower than reported in the preceding article (van Ginneken et al., 1984). Evidence is provided that the low observed infant mortality rate of 49 per 1000 live births is plausible; this rate is in accordance with the relatively low and rapidly declining infant mortality rates found in Kenya. No accurate estimate on adult mortality could be obtained, probably due to serious overstatement of ages in the older age groups.

The changing pattern of fertility differences among ethnic groups in Canada during the period 1926–71 is studied. Two specific questions are addressed. (1) Do ethnic groups assimilate the fertility patterns of the general Canadian population over time, i.e. are the fertility differences disappearing? (2) Is the extent of assimilation in fertility greater in urban than in rural areas? The indirectly standardized general fertility rates, calculated by using the ethnic age distribution data from the censuses of 1931 to 1971, indicate a tendency for the population to become more homogeneous during times of increasing fertility, thus supporting the assimilative possibilities, whereas in times of declining fertility there is a tendency for the population to become more heterogeneous. The data also seem to support weaker assimilatory tendencies in rural areas than in urban areas during only the most recent period, 1966–71, and not in earlier periods.

In contrast to the USA and the UK, vasectomy is less popular than tubal ligation in Australia, and this may reflect differences in husband-wife communication. Using data from the 1979 Canberra Population Survey, it seemed that although a majority of respondents would use sterilization, female sterilization would be preferred, largely because males were more resistant to the idea than females. Respondents born outside Australia, the UK, and Eire were more resistant to the idea of sterilization, but reported higher use of tubal ligation.

The proportional hazards models of birth intervals based on the data from the 1976 Jordan Fertility Survey indicate that in Jordan the influence of infant death on subsequent fertility is not uniform among all population subgroups. Child survival seems to have only minimal influence on fertility among less educated women and women at low birth orders. In contrast, the probability of a subsequent birth increases significantly following an infant death among women in the high education class and among women in the high birth order group. The impact of infant death is similar among rural and urban women. Further analysis shows that the observed differences in the birth intervals of women with and without infant death experience cannot be attributed to the fecundity differentials of these two groups of women.

This paper analyses the impact of the length of birth intervals on mortality and growth of young children. An attempt has been made to improve the methodology of birth interval studies and the results of an analysis of longitudinal data from a rural area in Kenya with a relatively favourable level of health are presented. It is shown that children with short retrospective or short prospective birth intervals do not run a higher risk of mortality or growth retardation than children with longer intervals, neither during the perinatal period nor during the first 2 years of life. This suggests that the socioeconomic setting, in which a birth interval study is carried out, is of ultimate importance.

Using a two-stage stratified sampling procedure, a representative random sample of 1021 rural families in North Arcot District of Tamil Nadu State in South India was studied to determine the inter-relationships of utilization of medical care and health behaviour with social, demographic and economic factors. The research was directed towards a better understanding of how medical and social deprivations are connected in a rural setting of India. Distance from a town, education, and accessibility of medical facilities seem to play a prominent role in the various decision-making processes of the family in utilization of the best available health care and in improving their health status. The policy implications arising from this study are outlined.

Data on fertility in a white Australian population based upon the vital records of the nineteenth century for two districts in Tasmania are presented. Mean family size was apparently low (3·2) and reproductive period short. However, when allowance was made for the truncation of birth records of migrant families, family size increased (4·9) markedly. Social class is shown to have a consistent effect on fertility levels in the larger community with low fertility associated with inferior economic status. Owing to the paucity of information contained within the vital records, it was impossible to investigate either age structure or migration effects on fertility. There is also evidence to suggest inbreeding is associated with higher, not lower, fertility.