Analysis was made of relations between the ABO blood group system and mother–child pairs in an ethnically homogeneous sample of Australian births. There was an increase in the proportion of B-positive (AB or B) children with increasing number of pregnancies and maternal age. A discriminant analysis indicated that pregnancy number was the basic determinant of the effect. A decreasing proportion of parturients of group O was noted as the number of previous fetal deaths, due to natural abortion or stillbirth, increased. This was independent of maternal Rh type. A dominant effect whereby the gestation period lengthened according to the proportion of O-containing genes in the phenotypes was also observed.

The term colour blindness is generally used to describe the lack of sensitivity to colours. Although there are instances of total colour blindness, in most cases the people confuse red or green, and this defect is an X-linked trait. This colour vision anomaly is widely used as a genetic marker in the study of human variation, and is frequently cited as ‘relaxed selection’ according to the Post (1962) and Pickford (1963) hypothesis.

The Western Abelam of Papua New Guinea display an annual cycle of social conflicts and births which is a function of a system of ritual beliefs involved in the growing of ceremonial yams. This sociorhythmic ritual complex involves adherence to various taboos which encourage a 6-month period in which social conflict is avoided and sexual activity is markedly curtailed. Conflict case studies and demographic data collected from one village over a 15-month period indicate significant seasonal variation in various areas of Abelam social life and suggest that sociorhythmic phenomena can affect both social behaviour and demographic patterns of human groups. Alternative environmental and nutritional hypotheses are also investigated.

Fertility variation in Japanese agricultural immigrant women in Bolivia is examined by birth cohort, educational status, religious affiliation, the agricultural system of their households, and prefectural origin in Japan. Only the place of origin in Japan makes a singnificant contribution to variations in fertiligy; higher fertility was found among the women from the Nagasaki prefecture. The results suggest that fertility differentials in this community represent the survival of different fertility norms from the area of origin, which are not due to educational and religious differences.

Urine was collected at weekly intervals at weekly intervals for three or more months from 139 menstruant women aged 40–55 years. Menstrual cycles were classed as ovulatory if the 24-hr pregnanediol output was > 5 μmol on a single occasion, or if the total excreted on 2 days 1 week apart was > 7 μmol. Of the 81 women who reported no change in menstrual frequency, 95% ovulated in every cycle. Only 34% of the 53 with a recent history of oligomenorrhoea ovulated without fail. Ovalation occurred in 93% of all 21–35-day menstrual cycles, in 55% of 36–50-day cycles, in 40% of 51–75-day cycles and in 17% of those lasting > 76 days. Pregnanediol increases suggestive of ovulation and followed by menstruation were observed on 31 occasions after amenorrhoea of from 2 to 6 months' duration.

Data from interviews with 131 women who had a live birth and 109 who had a stillbirth about their experience of childbearing have been compared with information obtained from doctors.

For the live births medical information was more often obtained for those in teaching than in non-teaching hospitals. It is estimated that 84% of miscarriages, abortions and stillbirths were reported by women whereas 62% were recorded accessibly in the notes. Nerves and depression during pregnancy were reported much more frequently by the women than by the doctors.

Correlations over gestation were around 0·8. Concordance was greater over induction than over acceleration; it was high in relation to epidural anaesthesia and less good for other types of anaesthetic. Among the live births, reports of the baby's weight fell in the same half-pound group in 82% of instances and within adjoining groups for a further 12%. There appeared to be a tendency for mothers to report a slightly higher weight. In general agreement was less good for the stillbirths than for the live births.

Probable reasons for the discrepancies are discussed. Problems of precise definition, inaccuracies and inadequacies in the medical records and limitations of women's knowledge appeared to be the main sources of disparities.

A study of 2447 patients treated for incomplete abortion in three major hospitals in Khartoum, the Sudan, was carried out from 1974 to 1976. Analysis focused particularly on socio-demographic variables, reproductive history and contraceptive behaviour before and after the abortion. This paper presents the epidemiological analysis and reproductive characteristics of these patients in an attempt to show the value of such service oriented research in evaluating clinical problems.

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.

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 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.