The characteristics of the first 200 cases of vasectomy reversal have been analysed. The mean time from vasectomy to reversal was 4.8 years. It varied according to the reason for requesting reversal, and was particularly short when the operation had been performed at the time of the partner's pregnancy. Thirty percent of the men were with the same partner and 70% a new partner. Vasectomy reversal cases tended to be younger than vasectomy patients as a whole but did not differ significantly in social class. In this series of reversals, spermatozoa were present in the ejaculate throughout the 20-week follow-up time in 80% of the men; the pregnancy rate was 44%.

This paper examines the social and demographic features of divorcing couples by the grounds on which their decrees are made absolute and by the party granted the divorce. The demographic characteristics include ages at marriage and at divorce of husbands and of wives granted decrees, duration of marriage, number of children, and the social class of both the husband and the wife. The data are also analysed for particular categories of couples: those in which the wife is a housewife, couples where the husband is unemployed, couples who have a child which was pre-maritally conceived, and couples who have dependent children. There are clear and interesting differences in the demographic characteristics of couples who successfully petition on the various grounds, suggesting that the law is used in different ways by different couples. Reasons for the observed patterns are considered. The data provide some basis for assessing the possible repercussions on divorce of socioeconomic changes, and for informed discussion on whether and how divorce law might sensibly be improved.

The study examines the effects of nursing practices on the duration of lactation in middle-class American women. Thirty-two nursing mothers were followed for 2 years post-partum, data being collected at eight home visits by interview and by nursing records kept by the mothers. Those women who nursed frequently (>8/day) during exclusive breastfeeding remained amenorrhoeic longer than infrequent nursers, introduced supplements later and did not resume menses as promptly thereafter. They continued an hour or more of night nursing during supplemented nursing. Duration of exclusive nursing and night nursing after supplementation were the major influences on duration of amenorrhoea. Mothers' age, weight-for-height, and nursing frequency before supplementation showed no significant effect but night nursing after supplementation was a major factor in post-supplementation duration of amenorrhoea. Those women who both supplemented later and maintained an hour of night nursing after supplementing remained amenorrhoeic for 6–10 months longer than those who supplemented early and/or reduced subsequent night nursing.

Depot medroxyprogesterone acetate (DMPA) was approved as an investigational new drug for contraceptive use in the United States between 1967 and 1978. Patterns of contraceptive choice and changing methods were determined among 36,298 women attending a family planning clinic between 1967 and 1976. This population was the largest concentration of US women who had DMPA available as a contraceptive option. By 1974, women in the age group 35–49 were as likely to choose DMPA as either oral contraception or an intrauterine device. Coincidentally, use of the most popular choice, oral contraception, declined in older women and IUD use dropped sharply in all age groups. On average, users of DMPA were more likely to continue their method than were users of IUDs or barrier methods. Among women in the 35–49 age group, DMPA users were the group least likely to change methods.

The attitudes of women of reproductive age to IVF therapy and human embryo research were investigated. A questionnaire was given to 1920 consecutive women attending clinics for family planning (1050), ante-natal care (705) and infertility (165). This paper reports the analysis of 1701 returned questionnaires, all from women of reproductive age. The great majority (94%) were in favour of IVF treatment. Sixty-seven percent approved of research on human embryos up to 14 days to improve IVF treatment, and a further 10% supported research on embryos designed to avoid birth defects. The majority (79%) thought women should be allowed to donate ova for research. The social characteristics of the infertility group were similar to those of the ante-natal group except for lower parity. In the family planning and ante-natal groups attitudes were not related to age, social class or parity, but were influenced by religious beliefs.

Sexual experience is increasingly common among teenagers. Evidence suggests that while many teenage pregnancies are unintended, teenagers remain less than totally effective users of contraception. Among a sample of 102 teenage mothers, only two-thirds had ever used contraception, although only a quarter of the pregnancies were planned. About half of the teenagers were upset on hearing the initial news of the pregnancy; half of these had been using the pill, which in many cases had been given up without another form of contraception substituted. These girls present a formidable challenge to providers of contraceptive services, especially in view of the restricted opportunities available to working-class girls.

The subsequent contraceptive behaviour following reported side effects in users of oral contraceptives in the southern region of Brazil is examined in relation to discontinuation of pill use, changing to other methods, termination of contraceptive use, the role of the physician in influencing a woman's decision to discontinue pill use, and discontinuation according to the type of problem experienced.

In 2904 currently married women, aged 15–44, almost 75% reported that they had used the pill at some time, and of these 45.6% were still doing so. Women who reported problems with the pill were less likely to be current users (25%) than the women who did not (65%). However, overall contraceptive prevalence was about the same in both groups. Women who stop using oral contraceptives are more likely to be using traditional methods than women in the general population, especially if they want more children. Termination of pill use varies little according to the type of problem reported. Women with problems who sought medical attention were more likely to stop using the pill and so were women advised to stop by their physician, but the major factor affecting discontinuation was the reported experience of a problem.

Data from a sample interview survey conducted in Accra in 1982 show that there is a very high level of knowledge of contraceptive methods among mothers aged 25–39 years (92%). However, only about 41% of the women had ever used any form of contraception, and only 18% were using modern methods at the time of the study. This is low for a city where an official family planning programme has been in operation for 15 years, even when the confounding effects of availability and accessibility of services have been controlled for. Suggestions are made for increasing the effectiveness of such programmes.

Examination of the effect of various socioeconomic, cultural and demographic characteristics of married women in Ilorin, Nigeria, who are in their prime childbearing ages, on their contraceptive knowledge and on their attitudes towards modern contraception shows that only the woman's education, age and area of residence within the city have significant independent effects on contraceptive knowledge. More than 90% of the women interviewed thought that women should be free to practise family planning. Also, more than 95% of all the women believed that too frequent births could endanger the health of the mother and her children. However, only the women with previous contraceptive knowledge overwhelmingly (more than 80%) thought that the best way to prevent too frequent births is by family planning. On the contrary, 66.5% of those without previous contraceptive knowledge before this study suggested that traditional abstinence should be used and only 28.9% suggested family planning. Adequate awareness of the availability and usefulness of family planning methods can influence attitudes of women towards contraception and may also enhance contraceptive use.

The 1981 Bangladesh Contraceptive Prevalence Survey found that 55% of ever-married women had some knowledge of traditional methods of contraception and the overall level of ever use was 23%. There was a positive relationship between use and socioeconomic variables. Current use of traditional methods at 7·7% was only slightly below the figure for modern methods (10·9%). It is suggested that traditional methods still have an important role in family planning and that this should not be disregarded.

The changes in the average male-female performance difference for nine running, six swimming and four skating events between the years 1936 and 1984 are examined. The data, world records and verified best performances, confirm the conclusions derived in earlier more circumscribed studies that women's performances relative to men's have improved markedly and are continuing to improve. This improvement is manifest in long and short distance events and in those in which women have been competing for a long time as much as those they have taken up recently. Regression analyses suggest that eventual equality of performance may be attained in the foreseeable future. The implications of these findings for women's sport are discussed. Women still have a more restricted programme in these three sports and many others; in particular several of the longer distance events are not open to them at Olympics, World Championships and so forth. These restrictions are obviously based on false perceptions of women's biology. With increasing participation, media exposure, training and social acceptance, women's improvements are likely to continue. The reasons for and implications of the previous incorrect scientific assessment of women's sporting potential are also discussed.

This paper discusses fertility trends in Singapore during the decade 1975–84. Fertility first dropped below the replacement level in 1975 when the gross reproduction rate reached 1·006, and fell further to the low of 0·772 in 1984. During the same period all of the three main races, Chinese, Malays and Indians, experienced fertility below replacement level. The shortfall in the number of births required to ensure replacement fertility increased during the decade until it approached one-quarter in 1984.

This study examines the factors affecting age at first marriage—place of residence, education, premarital work status, religion, husband's childhood residence, education and occupation. Women's education appears to be the strongest determinant of variation in marriage age, and all the other factors show statistically significant influences.

A study of families affected by thalassaemia major demonstrated that before antenatal diagnosis became an option, premature curtailment of reproduction was the most common parental response to their understanding of the genetic implications of the diagnosis. Subsequently parents of younger patients used antenatal diagnosis to meet or almost meet their birth expectations. There was no evidence that antenatal diagnosis contributed to any process of ‘compensating’ for existing affected offspring.

This article employs the analytical model of Bongaarts and Potter to compare the proximate determinants of fertility among three populations in Nepal's Kathmandu valley with the following characteristics: (1) high and low caste, (2) urban and urban fringe residence, and (3) users and non-users of contraception. It is shown that while Nepal, as a whole, is firmly entrenched in Phase 1 of the fertility transition, each of the populations studied has begun to experience a demographic transition to different degrees. In fact, greater progress in controlling fertility has been made than previously known.

Relationships between migration and fertility are examined, using data from the OPCS Longitudinal Study of England and Wales, including linked information from the 1971 and 1981 Censuses and birth registration data for the period 1971–80. The results showed that the proportion moving between the 1971 Census and the first subsequent birth was higher among tenants than owner occupiers, particularly for women in shared accommodation in 1971. The association between tenure and moving was more consistent than the relationship between moving and the husband's social class. Differences in the proportions moving between the censuses were positively associated with fertility in the same period particularly for women in potentially crowded accommodation in 1971. Moving in 1970–71 was not associated with differences in parity progression ratios 1971–81. There were, however, differences in the timing of births, suggesting that long distance migration was associated with a postponement of the first or second child, probably because both longer distance migration and fertility behaviour are associated with other characteristics such as education.

This paper examines the levels, trends, patterns and Kuwaiti-non-Kuwaiti differentials in fertility, by socioeconomic variables and the major factors that may account for recent changes. Kuwaiti fertility is very high: in 1980, the crude birth rate was about 47 and the total fertility was 6–8 per woman. Childbearing still extends to later ages but fertility in the early and middle reproductive years has declined recently, as a result of the rise in age at marriage and the fall in the proportion of currently married women in the younger age groups. Non-Kuwaiti fertility is consistently lower, with total fertility at about 69% of the Kuwaiti level. This differential cannot be explained by the age structure of the populations alone. Analysis of completed fertility by education and economic activity status indicates an inverse relationship.

The relation between infant mortality and fertility is studied using data from the 1975 fertility surveys in Pakistan and Sri Lanka. It is found that the unadjusted data support child replacement, but that this is much less the case once controls are introduced for demographic and socioeconomic factors. Replacement is slightly more pronounced when there are fewer surviving male children.

This paper examines the broad movements of Canadian period and cohort fertility over the last hundred years or so, and compares them with corresponding trends in the United States and other industrialized countries. The main movement in Canada was a decline in fertility extending from the nineteenth century to the present time, interrupted in the 1940s and 1950s by a ‘baby boom’. The long decline in cohort fertility is largely explained by the decrease in the proportions of families of six or more children. This decrease continued during the baby boom, but in these years was more than offset, though not for Catholics, by the effects of increases in the proportions of families with three, four, and five children.

In data from the Bangladesh Fertility Survey on 4998 live births, the mean duration of breast-feeding in Bangladesh was 27·3 months. Duration of breast-feeding was positively related with the age of women. Female children were breast-fed for periods about 5 months shorter than for male children. Children born to urban mothers of all age groups were breast-fed for shorter durations than children born to rural mothers of all age groups. The duration of breast-feeding decreased with the increase of education of mother.