In a WHO-co-ordinated prospective multi-centre study in Agra and Chandigarh (India), Cali (Colombia), Ibadan (Nigeria), Manila (Philippines) and Nottingham (UK), 926 women undergoing elective sterilization for fertility control and 924 controls using other methods of contraception, were examined before the operation and at entry into the study, respectively. Of the initial sample, 81·6% were re-examined at a 6-month follow-up and 77·4% at a 12-month follow-up. At initial examination, the prevalence of clinically significant emotional disorder ranged from 1·6% to 14·6% in four of the six centres; it was higher in Cali (25·5%) and nil in Ibadan. In all centres except Agra, women applying for sterilization had a somewhat higher rate of mental health problems than control subjects at initial examination. At the 6-month follow-up, the prevalence was within the range 1·6–15·4% for the sterilization group and 0–14·5% for the control group in all centres except Cali which continued to have a higher rate. At the 12-month follow-up the prevalence of mental ill-health ranged from 0% in Manila to 29·2% in Chandigarh; if the latter centre were removed, the range would be 0–13·6%. There were no significant differences in the frequency of mental ill-health between sterilization cases and control subjects in any of the centres. Further, there were no significant differences in the prevalence of mental ill-health in relation to the timing of sterilization, i.e. interval, post-partum or post-abortion. Chandigarh was the only centre which showed a consistent increase of the rates of psychological disorder over time; in all other centres the rates showed some fluctuations but no clear tendency either to increase or decrease. The data do not support a notion of a significant impact of sterilization on mental health of women.

As part of a prospective controlled study of the psychosomatic effects of elective tubal sterilization, 138 women were questioned about their menstrual functioning before sterilization, and again 6 months and 12 months post-operatively, using standardized interviewing procedures. Adverse changes, including (subjectively assessed) increased menstrual loss, shorter menstrual cycles and greater use of pads or tampons were reported by sterilized subjects at both of the post-operative interviews. Control subjects reported several comparable effects, although adverse changes overall were reported more commonly by sterilized women than by control subjects. However, many of the reported changes appeared to be related to pre-operative contraceptive methods, although consistent increases in use of pads or tampons were found in women who had pre-operatively used neither the pill nor the IUD.

Some hypotheses regarding birth spacing and women's work are outlined. Using British census and survey data it is shown that average second and third birth intervals were shorter in marriages taking place in the 10 years following the Second World War as compared with marriages in the period 1900–29; the intervals increased again, measured on a period basis, in the 1970s. Birth intervals for women married during the 10 years after the war were shorter among those economically active at the 1971 census than among the inactive. Some problems of method are discussed.

Variations in sex ratio with maternal age, paternal age, parity and time have been examined in data on all legitimate births (live and stillbirths) in England and Wales, 1968–77. There were significant linear declines in sex ratio with both increasing parity and increasing paternal age, and a curvilinear relationship with maternal age. These effects were largely independent. Before 1955 it seems likely that sex ratio declined with increase in maternal age. But it seems that between 1955 and 1968 there was an unexplained decline in the sex ratio of births to women aged 20–24 and an increase in that of births to women aged 30–34. There was no significant secular trend in sex ratio during the period 1968–77.

The Gainj of highland Papua New Guinea do not use contraception but have a total fertility rate of only 4·3 live births per woman, one of the lowest ever recorded in a natural fertility setting. From an analysis of cross-sectional demographic and endocrinological data, the causes of low reproductive output have been identified in women of this population as: late menarche and marriage, a long interval between marriage and first birth, a high probability of widowhood at later reproductive ages, low effective fecundability and prolonged lactational amenorrhoea. These are combined with near-universal marriage, a low prevalence of primary sterility and a pattern of onset of secondary sterility similar to that found in other populations. Of all the factors limiting fertility, by far the most important are those involved in birth spacing, especially lactational amenorrhoea.

Using a unique set of birth registration data from the Demographic Surveillance System of the International Centre for Diarrhoeal Disease Research, Bangladesh, for the period 1974–77, and socioeconomic information collected in the 1974 census, fertility was studied in relation to occupation, size of dwelling, number of cows and number of boats owned. The total fertility rate was found to vary between 6 and 6·5 except in the famine year of 1975. There was no consistent relationship between fertility and education of women. Fertility differentials by occupation showed that the household heads who were farm labourers had relatively lower fertility compared to other occupational groups, except for the year 1977 where the families of service holders were found to have relatively lower fertility. There was a consistent direct relationship between the dwelling size and fertility for each of the years.

A new set of abridged life tables for Pakistan is presented. Data from the 1971 Population Growth Survey were first analysed to estimate the degree of completeness of the reporting of male and female deaths; female deaths were substantially more under-reported than male deaths. Age–sex specific mortality schedules were adjusted accordingly.

Life expectancy was around 50 years at birth, but increased by 8–9 years for those surviving the substantial risks of dying in the first year of life. No significant sex differential in mortality could be discerned from the life tables.

A method is presented for examining the relationship between effective population size and accumulated random inbreeding in human populations. For a set of populations, the inverse of inbreeding is regressed on effective population size using a linear regression model. This procedure allows testing of several hypotheses regarding the common and unique influences on population structure. Deviations from the expected curve suggest demographic or historical change. This method is applied to surname data from nine Irish isolates. The results show that the method is very useful in assessing differential influences on population structure.

This study presents parent–offspring and sibling resemblances for verbal and visuospatial IQ components and total IQ scores in both non-manual and manual social groups. Offspring on mid parent regression coefficients provided upper limits to phenotypic IQ similarity. There were no significant differences in regressions between social groups.

The sex linked hypothesis for spatial ability was examined but neither parent–offspring nor sibling correlations were in the order predicted by the hypothesis.

In a case-control study of low birthweight deliveries, comparison of hospital records with interviews conducted soon after delivery fails to confirm the widely-held view that concurrently recorded medical notes are superior to retrospective interviewing. The overall agreement was very good, with slight under-reporting of past abortions by mothers, and marked relative under-recording in the hospital records of vaginal bleeding and especially vaginal discharge. Generally, the rates of disagreement between interviews and hospital notes were similar for those women who had low birthweight babies and those who had normal birthweight babies, except for one single item. Uncertainty or lack of information occurred in the hospital notes as often as in the interviews.

When different accounts of labour were present within a single set of medical records, the level of internal consistency was examined. There were more definite contradictions within the hospital notes than had been observed between the notes and the interviews. Moreover, a very marked association of within-hospital contradiction with birthweight was found, suggesting a possibility of bias when hospital records are used for the investigation of conditions associated with low birthweight. One should not, however, conclude that hospital notes are necessarily more error-prone than interviews, as many of the within-hospital contradictions reflected diagnostic uncertainty in complicated cases.