The conception rate in Baroda and Manipal, India, is lowest during the hottest weather. The greatest extremes are found in Baroda and, following high summer temperatures, there is a prolongation of low conception rates which may indicate that part or all of the effect is mediated through an effect on scrotal temperature. However, other factors may also be involved and a reduction of coital frequency is likely at extremes of temperature. Seasonal changes in abortion, stillbirths and prematurity are also observed. Changes in spontaneous abortion could be due to heat stress in the mother or possibly to abnormal sperm production at high temperature or to less frequent coitus, leading to embryonic defects.

Current fertility rates of Asian and West Indian immigrant women in Britain are estimated by an indirect procedure. The data on which the estimates are based are the published statistics of registered births, and the 1971 Census country of birth tabulations.

It is shown that between 1969 and 1974 the total fertility rate of both groups declined at a faster rate than that of the indigenous population. The estimated total fertility of Asian women is, however, higher than that of West Indian women; the differences can be attributed at least partly to differential timing of migration.

The estimates of fertility rates for Asian and West Indian women provide a basis for a more realistic appraisal of local birth data.

The publication in 1976 of a 64-page pamphlet with the unlikely title 11 Million Teenagers: What Can Be Done About the Epidemic of Adolescent Pregnancies in the U.S. (AGI, 1976) precipitated a dialogue quite new to the American public. For the first time, attention was centred on the fact that pregnancy among teenagers was almost as prevalent as the common cold and that those who were getting pregnant increasingly were younger, and more of them were white and middle class. The figure of one million pregnancies experienced by women aged 15–19 showed that one in ten female adolescents and one out of four sexually active teenagers are conceiving each year.

Results are presented from an analysis of the intervals between births from Imesi, Western Nigeria. The mean interval following births of children who survived to 1 year was 35·03 months, but nearly half this value at 18·8 months following stillbirths or deaths under 1 year. Both these results confirm an early study done in the village (Martin, Morley & Woodland, 1964), and the role of post-partum sexual abstention as an explanation for these results is discussed. Attempts were made to look for effects of birth interval variation on the survival of the following child, but no strong trends emerged. Similarly, analyses of many growth variables by preceding and following birth intervals gave very little evidence of real effects. There were, however, hints of trends which were possibly caused by birth order biases; higher birth orders had been found to have correspondingly higher birth intervals. An intriguing result was that those children who had ever suffered from kwashiorkor showed a significantly higher preceding mean birth interval, and also a higher mean interval to the next birth.

This paper reports the diffusion of knowledge of screening for a genetic disorder (Tay–Sachs disease) in two fairly well defined, urban, Jewish populations in the Baltimore and Washington metropolitan areas, and on some of the sociological variables which influence the diffusion. Differences between the two populations are shown.

Pupils in schools in the Glasgow area show incidences of colour vision defect higher in the Roman Catholic schools than in the non-denominational. This may be due to the Celtic origins of Roman Catholics in the West of Scotland.

This article, based on retrospective survey data, examines the fertility performance of third-order parity women in Korea, following births of specified sexes of children already born. Although the study indicates that additional births and spacing of children after the third birth are strongly influenced by the sex composition of the first three children, this influence becomes apparent only after the introduction of a vigorous national family planning programme. It seems that both the number of sons and the sequence of sons and daughters play an important role in determining subsequent fertility. More than twice as great a proportion of third-parity women proceeded to the fourth parity if the women had three daughters rather than three sons.

Except for the year 1931, no information is available on age at paternity in England and Wales before 1961. But such information is needed to determine the aetiological significance of raised maternal age, for example that which has been reported for several types of psychiatric disorder. Parental age at the birth of a respondent was studied in a survey of 2000 persons forming a quota sample of the adult population of England and Wales. Checks against the available national statistics suggest the findings for age at paternity can be accepted with some confidence.

Pregnancy in adolescence is now a very great concern for doctors, teachers and social workers throughout the world and yet about 95% of the publications on this topic have come from the USA. The remainder are mainly from the UK and Scandinavia. Other countries have produced only a small number of papers, focusing mainly on clinical problems such as the pathological events and complications during pregnancy or delivery. In France, the first paper to appear in a paediatric journal was published in 1977 in the French journal of school health (Martin, 1977). On the other hand, teenage magazines often contain articles about sexual behaviour and pregnancy in adolescence. There is now a great concern in the adolescents' press about the problems of sexuality, contraception, abortion and pregnancy, including advertising for pregnancy tests.

There is little statistical information from developing countries on the prevalence of early and late teenage pregnancies and associated health and psychosocial sequelae. Developing countries cannot be studied as an entity since they differ widely in terms of cultural background, religion, traditions, etc. However, characteristics of an underprivileged situation are: an early reproductive debut, high fertility and close spacing of pregnancies, and high maternal and infant mortality. The high maternal and infant mortality rates are related to socio-economic parameters but also specifically to the age of the mother, being increased for mothers under the age of 20, particularly for the younger ones and when there are repeated teenage pregnancies. Low minimum age of marriage for girls, typical of many developing as well as developed countries, means a consent of society for early family formation.

Epidemiological studies and studies on changing reproductive behaviour in situations undergoing modernization processes are required to estimate the magnitude of the problem from health and psychosocial aspects, and in order to design appropriate services.

Routinely collected data on the 37,094 families with severely handicapped children who have applied to the Family Fund are used to examine the relationship between certain handicapping disorders and the year of birth, season of birth, birth order, region of domicile, social class, sex and presence of a disabled sibling. Differences between each handicapping disorder, and differences between the handicapping disorders and the general population are noted.

The weight charts for the six infants of a 20-year-old Aboriginal woman are examined. They all show satisfactory growth whilst being exclusively breast-fed, yet all demonstrate growth failure following the introduction of supplementary feeding. The double benefits of optimal infant growth and delay in the next conception derived from exclusive breast-feeding indicate its desirability for women in these circumstances. The problems associated with supplementary feeding and the non-utilization of family planning methods are demonstrated in the low maternal age at first pregnancy, the lack of adequate family spacing during the mother's teenage years, excessive family size and the impaired growth rate of the children.

Of 40 women who had abortions between 20 and 24 weeks gestation and had felt fetal movements, eleven had a history of significant menstrual irregularity, six had changed their minds about an initially welcome pregnancy, five had been told that they were not pregnant, and five had either been refused by the NHS or were unable to get sympathetic advice at an earlier stage. In only fourteen cases was ‘wishful thinking’ or an unrealistic attitude to the possibility of pregnancy an important cause.

Twenty-five of the women were followed-up at a minimum of 3 months after their abortion. Five reported feeling depressed because of their abortion but none of them had required specialist advice, and only one had time off work or school for this reason.

The present study was designed to assess the preference for and the continuation rates achieved with two previously available contraceptives (the pill and the IUD), and one newly introduced method (depomedroxypro-gesterone acetate, or DMPA), in a rural area of Thailand. After the presentation of balanced educational material on the three contraceptives, women were offered a free choice of method. It was found that 73·8% of all women adopted DMPA as their method of choice, and that this preference was not influenced by the educational lecture. In contrast, 16·9% of women chose the pill and 9·3% chose the IUD. The injection was perceived as a convenient method when compared to the other routes of administration, but the dominant preference for DMPA appeared to be largely due to ill-defined personal factors and the influence of friends. The 1-year life-table continuation rates with DMPA (75·5 per 100 women) were significantly higher than the continuation rate achieved with the IUD in this rural population (66·5 per 100 women). The continuation rates with the pill were 72 per 100 women, but the excessively high loss to follow-up with this method made the interpretation of the results difficult. It is suggested that if women are offered a free choice of contraceptive methods under a quasi experimental situation, useful information can be obtained on the potential value of new methods for an on-going family planning programme.

During the last 10 years an increasing number of pregnancies have been noted in adolescents. The children of these pregnancies are often at risk. The problem was discussed in a meeting on Pregnancy and Abortion in Adolescence in 1974, held at WHO headquarters, Geneva. An annotated bibliography was prepared for that meeting, from which this review originated. The literature covered a wide range of subjects, but an attempt has been made in this review to discuss the problem in six main sections: social aspects; sexual attitudes and behaviour; sex education and information; contraceptive services for adolescents; medical and clinical aspects and legislation. Quite a number of teenagers are sexually active even in their early teens but often keep to one partner. Their use of contraception is poor, partly because of a lack of education and information. Young people are demanding better information and services, which would probably best be provided through special teenage clinics. So far, there have been very few investigative studies dealing exclusively with adolescent use of different contraceptive methods. Methods of contraception available at present are often unsuitable for use by adolescents, and further research on the problem is needed.

Two independent, concurrent demographic surveys in rural India, one male, the other female, were used to examine misreporting of ever-born children among 223 couples common to both samples. Husband-wife disagreements were checked in detail and characteristics of the errors and of the misreporters themselves were analysed. ‘Forgetting’ of dead children was the main cause of mistaken reporting. Another type of error was found to be sex-related: men, but not women, confused fetal deaths with live births. Of the various correlates of male misreporting tested, only age appeared to be a determining factor. On the other hand, traditional attitudes and overall response reliability were more important than age in explaining female errors. No significant relationships between faulty reporting and socio-economic status or family size were established. Various suggestions are made for minimizing fertility misreporting in surveys of rural, illiterate populations.