Parallel analyses of recent data from the United States, Thailand, Belgium, and Japan all confirm the finding that female age and not male age is the more important contributor to the decline in frequency of marital intercourse during the childbearing ages. The most probable explanation is the decline in female (but not male) androgen levels during the age span examined.

In a survey of 1475 urban Moslem wives in the age group 15–49 living in the capital city of the Sudan, knowledge of birth control was reported by almost all respondents while a significant proportion had used contraception at least once. The mean age of the users was 32·8 years, their duration of marriage was 15·1 years and their mean number of surviving children was 4·6. Those who had never used contraception had a higher mean age, a longer duration of marriage and more surviving children. Most of the users had an urban residential background and belonged to the high socioeconomic class. They held favourable attitudes to family planning. Although they thought that having a large family (more than five children) was not desirable, their mean preferred family size was no different from that of the never users.

The results indicate that contraception is used for the purpose of spacing births rather than limiting their ultimate number. At this early stage of contraceptive adoption in Sudan, the characteristics of the pioneer acceptors are similar to those observed in other African countries.

The attitudes of 38 voluntarily childless husbands and wives towards contraception were studied. The couples used a range of birth control methods, the most popular being the pill. Although sterilization appears to be the optimal method of contraception for couples who do not want children, several disincentives to it were mentioned. Broadly these are the finality of surgical sterilization, the dislike some individuals have for undergoing surgery and the opposition individuals anticipate meeting to a request for surgery from their GP or a consultant. Overall, contraception presents at least as many problems to childless couples as it does to parents. Some problems are unique to the childless, resulting from the continuity and length of time of birth control.

An analysis of the use-effectiveness of fertility awareness methods of family planning among clients in a San Diego, California, clinic reveals a 12-month failure rate (life-table method) of 13·2 failures per 100 women. This is comparable to results from previous studies of the use of fertility awareness methods (as defined by the sympto-thermal method) in developed nations. Also consistent with previous studies is the finding that fertility awareness method users tend to be young and well-educated. Motivational factors are identified as being most closely associated with successful use of this method of family planning.

Cytogenetic investigations were undertaken on 120 couples in Newcastle with repeated pregnancy loss for which no anatomical or other obvious reason could be established. The level of major chromosome anomalies was high, with 6·7% of couples showing one member with an abnormal karyotype. One major anomaly occurred in a control series of 240 random newborns. The couples also showed an elevated incidence of chromosomal heteromorphisms. Similar studies in the literature are reviewed. It seems that major chromosome anomalies make an appreciable contribution to repeated reproductive loss, but proof of the involvement of minor chromosome variants though suspected is less clear.

Seventy women with rhesus isoimmunization, referred to hospital in Newcastle upon Tyne, when compared with the overall hospital population, showed an excess of pregnancies by more than one partner. By comparing them with a control group it was demonstrated that the differences in marital pattern were explained in terms of age, parity and social class. One or other parent of babies affected by haemolytic disease of the newborn was more likely than controls to undergo subsequent sterilization.

The paper explores the social and demographic factors that influence fertility in Sri Lanka since the second world war employing multiple regression analysis, and how these factors change with time. The dominating contribution made by female proportions currently married in the age group 20–24 in explaining fertility variation is emphasized.

Births to women aged 35 years and older are compared with births to women aged 20–34 in three hospitals, one each in Mexico, Egypt and Hungary. In the two developing countries, babies born to the older women had lower rates of survival until hospital discharge, and were more likely to have depressed 5-minute Apgar scores. They were not, however, more likely to be of low birth weight. The differences were statistically significant, and remained when several other variables were controlled. The variables controlled were known to be age-related and to influence pregnancy outcome.

Hungary, the only developed country in the analysis, was quite different. Age had a significant influence on the weight of the infant, but not on survival or Apgar score. It seems therefore that when older women are in general good health and there are no concurrent social risk factors, advanced maternal age does not necessarily increase the risk of an adverse pregnancy outcome.

With the increase in labour force participation by wives and mothers in the United States, family roles of modern women are becoming increasingly complex. As mother/provider, women are faced with problems in planning their lives to accommodate their modern roles. Three variant lifetime patterns of fertility and employment are identified in a study of second-generation Japanese American women, a group which has experienced high rates of labour force participation. Analysis of socio-economic background factors suggests that these patterns are alternative modes of integrating the complex lifetime demands on women in the modern world.

Regression surface analysis was used to examine relationships between sibling variables and measures of cognitive performance at different levels of family environment measures, for children from different Australian ethnic groups. Included in the sample were 460 Anglo-Australian, 170 Greek, and 120 Southern Italian families. Each family had an 11-year-old child and interviews with parents related to those children. There were no associations between the sibling variables and intellectual ability scores. For word-test scores the findings provided some tentative support for an admixture explanation of sibling correlates of children's cognitive performance. Generally, the study revealed that at different levels of family environment dimensions, sibling variables had few associations with various cognitive measures for children from different ethnic groups.

A sample of 838 children aged 5–15 in Australia, England, North America and Sweden were interviewed about how they perceived biological and sexual development. One of the six sections covered gestation and the birth process. Responses were scored on a biological realism scale. The English-speaking children's estimates of the gestation period achieved realistic levels by 11 years, with Swedish children generally at 9 years. In perceiving where the baby emerged at birth, several orifices were named with strong support for cloacal theory at 5 and 7 years. English-speaking children tended to nominate the realistic birth exit by 11 years, Swedish children earlier at 9 years. The necessity of birth at about 9 months was explained realistically between 11 and 13 years although the explanations were couched in crude and simplistic terms. Certain sex and cultural differences are discussed.