A survey of 302 physicians from Colombo, Sri Lanka, reveals a strong overall acceptance of genetic counselling, prenatal diagnosis of genetic disorders and therapeutic abortion. Demographic and experiential factors, especially being older and having children, were associated with acceptance of genetic services. There was little support for prenatal diagnosis in order to satisfy curiosity about the sex of the fetus. The results of this analysis were compared to those from a study of physicians in Arizona, USA.

The laws observed among Orthodox Jews regulating coital activity according to menstrual cycle phase (the laws of Taharat HaMishpacha), in a population that generally does not use contraception, have potentially important effects on fertility. Analysis of these effects based on menstrual cycle and ovulatory phase lengths for women in the childbearing years shows that the majority of cycles are potentially exposed to coital activity during a fertile period and the increased likelihood of coitus following abstinence has potentially fertility-enhancing effects. For the individual woman with a predominance of short cycles, delays in conception are probable.

Three trends suggest that the reproductive function of the Canadian family is in transition. First, fertility has fallen and remained below the replacement level. Secondly, an increasing proportion of women are spending a larger part of their lives without having any children. Finally, an increasing proportion of women are having children without getting married.

In the Lyon region of France, 356 couples of childbearing age were interviewed regarding their fertility intentions. Couples intending to have, and not to have, further children were compared. The former are less often skilled workers or qualified office staff, the woman is less likely to work, and the couple had their first child at a relatively late age. These differences are still present after adjustment for the couple's ages and number of children.

This paper examines empirically the relationship between sexual union instability and fertility in three English-speaking Caribbean societies, Guyana, Jamaica and Trinidad/Tobago, using data collected in the World Fertility Survey Programme. An index of cumulative fertility, the duration ratio, that controls for the biological effects of age and age at first union is used as the dependent variable in a multiple regression analysis. The statistical findings are in general agreement with previous research that has found a positive association between fertility and the number of sexual unions in these societies. However, the estimated fertility effect of belonging to different union types (i.e. married, common-law and visiting) is not uniform across the three societies.

Data from birth records with information on previously born children from three maternity hospitals in Norway have been used to study the trend in breast-feeding practice from 1860 to 1984. During the whole period, the percentage of women breast-feeding for at least 1 week was remarkably high, above 90%. The results show a fairly stable duration of breast-feeding up until 1920, at least 3 months in approximately 80% of the women. After that year, the distribution of the duration of breast-feeding changed dramatically. The shortest durations were found in the late 1960s, when only about 30% lactated for 3 months or more. The duration then increased quickly, so that at the beginning of the 1980s about 80% of the women were again breast-feeding for at least 3 months.

By multiple regression methods, the relationships of several independent variables to the duration of breast-feeding were investigated. Married women lactated for 1·5–3 months longer than unmarried, the difference being largest before 1920. First-born children were breast-fed for a little shorter time than second and later-born children. Until World War II women of lowest social strata had the longest durations of breast-feeding, and then the situation was reversed, women of highest social strata continuing the longest.

Socioeconomic differences and trends in infant and child mortality in Bangladesh are examined using data from the 1975 World Fertility Survey and 1979 Contraceptive Prevalence Survey. There is evidence of some recent decline in infant and child mortality. Logit analysis of infant and child mortality indicates that sociodemographic variables such as mother's education, recent period, or higher birth orders, had significant independent effects upon the reduction of infant and child mortality. Other variables such as fetal loss, father's education, or land ownership had no consistent significant effect of upon infant and child mortality. On the other hand, the effect of urban residence on infant and child mortality was positive after the control of the sociodemographic variables. Mere concentration on the supply of modern medical services may bring limited returns unless they are reinforced by appropriate social changes, in particular those affecting the socioeconomic status of women.

Data from pregnancy histories collected by the 1976–77 Mexican Fertility Survey show wide variations in infant mortality among a sample of 125 communities. There are also large infant mortality differentials by population size, economic status, access variables, utilities, medical facilities and schools. These community-level factors, which have been little used in previous studies, are highly correlated and do not appear to affect infant survival independently of population size. As such, community size serves as a summary measure of a locality's overall level of development and comparative risk of early death for its young inhabitants.

Infant mortality in Sri Lanka between 1961 and 1980 is studied with reference to its trend and associated factors. Between the periods 1961–65 and 1976–80 deaths from exogenous and endogenous causes have declined considerably and nearly equally. The probability of survival has increased most in the first week of life.

National income or total food supply does not seem to be associated with infant mortality. Distribution of free supplementary food, increase of public health personnel, of immunization, and of institutional births appear to have initiated and sustained the transition of infant mortality during the period. Increasing levels of female education probably augmented these effects.

Multivariate analysis of the effects of maternal age at birth, birth order and the preceding birth interval on mortality risks in early childhood, using data from the Bangladesh Fertility Survey, 1975–76, confirms that the length of the preceding birth interval is the most influential single factor. But the lower mortality risks among infants and children of educated mothers are due neither to the age at which childbearing was initiated nor to the spacing between births.

The distribution of consanguineous marriages among spouses and husband's and wife's parents, was analysed using data on 9225 families in six widely different areas of Japan. With two exceptions, the consanguinity rates for husband's and wife's parents are higher in related spouses than in unrelated spouses. The familial aggregation of consanguinity was slightly decreased in more recent marriages, a change which began recently with couples who have abandoned the more traditional Japanese way of life.

In a cross-sectional study of gallstone disease, ascertained by ultrasonography, the prevalence was assessed in relation to clinically diagnosed gallstones in first degree relatives by selected socioeconomic factors. In both sexes, clinically diagnosed gallstones among first degree relatives occurred significantly more frequently among subjects with than among those without gallstone disease. None of the socioeconomic variables was significantly associated with gallstone disease in females. In males gallstone disease was positively associated with longer school education, living alone, and duration of residence in the municipality of Copenhagen.