The biological and social factors which may interact to determine the level and pattern of fertility during the last decades of the reproductive life are complex, and because of the paucity of data, the mechanisms regulating fertility at late ages must in part remain speculative. This review focuses on two major questions. First, why is there a decline of fertility prior to the menopause? Second, why does reproduction cease at the menopause and what factors influence the age at which this occurs?

This paper examines the effect of age at first marriage, number of wives and type of marital union on fertility among Yoruba females in Western Nigeria. The evidence indicates that age at first marriage and hunband's number of wives do not have a significant effect on completed fertility. Type of marital union, on the other hand, seems to have an effect on fertility. Women in de facto unions experience lower fertility than women in formal marriages.

A survey of 15,324 abortion patients of the Population Services International clinics in Sydney revealed that 16·7% reported prior induced abrotion experience. Comparisons with other Australia clinics produced similar findings. World figures indicate that Australian patients have had fewer prior abortions than those in most other countries, with the exception of England, and Wales. Significant factors were age, material status, religious affiliation, reproductive history, employment status and education. Use of contraception increased after the abortion experience.

In rural Bangladesh, early fetal wastage and stillbirth are higher among pregnancy orders one and six or higher than among orders two and three. The increased risk is particularly apparent among those pregnancies following two or more previous fetal deaths. Woman in the higher pregnancy orders who have not experienced previous fetal deaths or only one fetal death have only a slight increase in the risk of fetal death compared to women in pregnancy orders two and three. The virtual absence of obstetric care and the high maternal mortality in this Bengali population may allow only woman without reproductive impairmetns to reach the higher pregnancy orders.

Cases of βthalassaemia and haemophilia (factor 8 and 9 deficiency) in pre-war Lebanon were examined for social and genetic information, using medical records. All diagnosed cases admitted to the American University Hospital in Beirut between 1960 and 1970 were examined. Muslims and families of lower socioeconomic status predominated in the data, and many cases were located in the semi-rural poverty belt of Beirut, where many rural migrants and Palestinian refugees congregate. Parental consanguinity rates among male haemophiliacs were used as estimates for the general population. Consanguinity is higher in the thalassaemic population. In the Christian population the incidence of this autosomal recessive disorder appears to have been inflated by consanguinity more than in the Muslims

The monthly distribution of births in the south-eastern states of Nigeria shows a seasonal pattern with a peak during the months of April-June, and a trough during November-January. This suggests that a disproportionate number of conceptions or matings occurs during the relatively cool months of July-September. In south-eastern Nigeria, these are months of relative idleness characterized by reduced work on the farms, abundance of fruits, vegetables and palm wine, and an increased tendency to stay indoors due to heavy and frequent rains. These conditions are considered conducive to increased intercourse

A programme of artificial insemination, using donor semen, within the NHS began in Nottingham in 1975. Since the inception of the programme all couples have been interviewed by a senior medical social worker, either at home or, later in the programme, within the clinics. This paper reports on features including education, employment, relationship to fertility status, relationship to parents and childhood, religion and reaction to adoption or fostering from the first 147 couples interviewed. All couples have stated a willingness for follow-up assessments and further studies are planned to review their marriages and psychological make-up in later years.

The United States Food and Drug Administration and the International Planned Parenthood Federation recommend that women over the age of 40 should utilize forms of contraception other than the pill. This decision was reached as a result of the 1975 clinical papers by Mann and his associates (Mann et al., 1975; Mann & Inman, 1975) and the epidemiological reports of the Royal College of General Practitioners (1977), Mann, Inman & Thorogood (1976) and Vessey, McPherson & Johnson (1977). Several authoritative bodies believed it prudent to suggest that the age limit for oral contraceptive use be lowered to 35, and even to 30 years (Anon, 1977; Planned Parenthood memorandum, 1977). The investigations of Inman & Vessey (1968) point to a precarious rise in mortality figures for women over age 35 on oral contraceptives.

The sexual behaviour of 71 teenage girls who attended an information and discussion session at a family planning clinic was examined. Sixty-one of these girls later received contraceptive services at the clinic (clinic group) and their behaviour was compared at follow-up with that of the ten girls who did not attend the clinic again (non-clinic group). The mean frequency of sexual intercourse of the clinic group increased after receiving contraceptive services but did not differ significantly from the figure for the non-clinic group. The majority of the girls restricted their sexual activity to one partner.

This paper tests the hypothesis that the inverse relationship between population density and migration distances in pre-industrial Europe results from variation in the social class composition of communities. Data from two pyrenean valleys in Navarre, spain, provide support for the hypothsis. Further effect on mugration distances may result from vatiation in the settlement pattern of communities. Seasonal movement associated with certain occupations seems to be unimportant.

This paper presents results of a cross-sectional analysis of family planning programme costs per unit for a group of 28 countries. The costs per unit are analysed using regression techniques with variables of programme (age, scale and type of programme) and setting (demographic structure, socio-economic level of development, health, accessibility and other). The Couple-Years of Protection Index is used for standardization and the variation in personnel costs among the countries is allowed for. There is considerable variation among programmes in cost per unit. Some of this variation is explained by differences in socio-economic structure. The cost per unit, measured in US $, is considerably higher than is generally thought.

This paper examines the effects of income and consumption of modern goods on fertility level and contraceptive practice among working class families in three Iranian cities. A j-shaped relationship is found between fertility and income after controlling for other variables. Expectation about future changes in income does not have any significant effect on the number of children ever born, but those who expect an increase in their income in the near future are more likely to be currently using contraception. Consumption of modern goods is positively related to fertility level and does not have any significant effect on contraceptive practice.

There are many factors which affect the choice of contraceptive practice in middle age. Co-existing disease is only one and in some ways is the least important. Childbirth itself poses a considerable risk to the health of the mother in as much as maternal mortality rises steeply with age especially after 45 years (Fig. 1); similarly perinatal mortality increases with age (Fig. 2). Together these two factors make the need for careful contraception all the more important. Fertility is reduced with age and this unfortunately lulls some couples into a false sense of security and they may take unnecessary risks.

Potts: There are differences in the risks associated with hormonal contraception in relation to smoking, obesity and previous patterns of thromboembolic disease. In a study carried out in Bangkok and Oxford (Chumnijarakij & Poshyachinda, 1975) comparing the incidence of thrombosis, as measured by 125I-labelled fibrinogen, after hysterectomy or cancer surgery, there was a higher incidence of postoperative thrombosis, measured by objective criteria, in Oxford (12–35%) than in Bangkok (1·7–3·8%). The argument could be made by inference that Asian women have less risks with the pill, although there are no data to prove it either way.