Vol. 21, No. 2 (April 1989), pp. 169–177

AGE AT FIRST INTERCOURSE

Hanne Wielandt & Jesper Boldsen

In the first paragraph on page 174, Walløe (1978) was erroneously cited. The data analysed by Walløe were not incompletely known. Consequently, the estimated median ages at sexual debut are not spurious, as stated, since the whole sample was included in the denominator.

We sincerely regret this miscitation and offer our apologies to our distinguished Norwegian colleagues.

This paper examines the changing nuptiality pattern of rural China, particularly rural Anhui in relation to the planned social changes since 1949 and their effect on fertility. The data are from the 1/1000 Fertility Survey of China, conducted by the Family Planning Commission in 1982. Before the family planning programme was introduced to rural Anhui (1972), the changing nuptiality pattern was indirectly affected by the planned social changes; after 1972, the substantial increase in age at first marriage was mainly due to the family planning programme. More recently, the centrally controlled social structure is loosening, due to the economic reform and the nuptiality pattern seems to join the 1972 trend, suggesting that the dramatic change of nuptiality pattern during the early 1970s to early 1980s was a temporary one. But its effect on fertility is clear, and the shortening interval between marriage and first birth may bring difficulties for future population control in rural China.

Analysis of perinatal mortality attributed to congenital malformations in England and Wales, using data from birth and death registration over the years 1974–81 showed significant declines in England and Wales as a whole and in the individual Regional Health Authority (RHA) areas. A greater decrease in death rate from congenital malformations, particularly central nervous system malformations, was seen among stillbirths than among early neonatal deaths. There were marked regional differences in perinatal mortality due to central nervous system malformations over the period but not in cardiovascular system malformations or in other malformations. The highest mortality rates due to central nervous system malformations occurred in the North, North-West, West and South-West of England and in Wales, and the lowest rates in the South and South-East. The larger percentage reductions in the mortality rates were found in most of the regions which had had the highest rates. Possible explanations for the decline in regional rates are suggested.

The effects of initiation of solid and liquid supplementation on resumption of post-partum menstruation are examined, 0using data from a 2-year prospective study of birth interval dynamics from central Java, Indonesia. The sample analysed consisted of 444 women who experienced resumption of menses while breast-feeding, women who were breast-feeding and amenorrhoeic at the end of the study, or women who resumed menstruation or were censored after infant mortality and weaning which preceded the resumption of menses. Multivariate hazard model analysis was used to assess the significance of supplementation, various breast-feeding covariates, and age and parity of the dependent variable. Because the timing of supplementation varies, the supplementation variables were introduced into the analysis as time-varying covariates. For the mothers in the sample, solid and liquid supplementation was initiated at medians of 2·1 and 8·0 months respectively. The former had a significant effect on resumption of menses, while the latter was only marginally significant. Earlier supplementation meant shorter durations of amenorrhoea for the majority of women. However, the effect was not consistent across all categories of women. For the small group of mothers who were low intensity breast-feeders (≤6 minutes per nursing episode) or as low frequency day-time breast-feeders (≤6 nursing episodes per day-time), earlier supplementation had no additional effect on their rate of resumption of menses post-partum.

In a comparative study to enquire whether parents of twins, especially of dizygotic twins, have a higher frequency of sexual intercourse than parents of singleton infants, data on sociodemographic status, coital frequency and other variables were collected using a postal questionnaire. Parents of all twins born alive in Denmark in 1984 or 1985 were included as cases and a random sample of parents of singleton infants born in the same period were controls. No evidence of any difference in coital frequency was found between parents of twins (neither dizygotic twins nor monozygotic) and parents of singleton infants.

Contraceptive prevalence surveys from sub-Saharan Africa typically show low rates of method use. The current study of one zone in Kinshasa, Zaïre, provides a more detailed view of fertility control in an urban population by examining the relative duration of breast-feeding, amenor-rhoea and sexual abstinence during the post-partum period. While motivations to prevent pregnancy remain high until the youngest child is over 24 months, the average duration of abstinence is only 4 months. This paper describes the methods women use to avoid pregnancy and the changes over the post-partum period.

From 1 January 1981 to 31 December 1982 information on all births to Bedouin Arab women residing in the Negev Desert of Israel showed a previously unreported seasonal pattern. The peak season, November-February, coincided with the period of cool temperatures and the Bedouin Arab cultural seasons of winter and spring. This pattern is different from those of Jewish and Christian groups in the same region, a difference not attributable to religion alone.

Sociodemographic factors associated with the peak season of birth include traditional occupations of fathers, multiparae 2+, and traditional place of residence. This pattern has persisted over the past 15 years although it is less apparent among the more recently sedentarized Bedouin Arabs.

Recent data from Bangladesh reveal evidence of some fertility decline. Although fertility increased among younger age groups between 1975 and 1983, it was offset by a decrease in fertility in the older age groups, resulting in a slight overall decrease in total fertility in 1983. Fertility was lower among urban residents, educated mothers and contraceptive users than among rural residents, uneducated mothers and contraceptive non-users, respectively, particularly in 1983.

The effects of frequency of intercourse on perceptions of two of the most widely used contraceptive methods, the pill and condom, were assessed in 128 female college students currently involved in a sexual relationship. Intercourse frequency was found to be strongly associated with knowledge of both methods. People experiencing more frequent sexual intercourse were more favourably disposed towards the pill and less towards the condom than people experiencing intercourse less frequently. Implications of these results are discussed.

This paper analyses the socioeconomic and health care determinants responsible for the decline over the last two decades in infant mortality in Kuwait. Published data and the results of a national health survey conducted in 1984–85 show the following. With the overall affluence of the society, health care in terms of immunization has improved dramatically and more than 90% of all children are covered. Of all births, 99% now occur in a hospital or clinic. About half of the mothers continue to breast-feed their babies for about 16 months. Despite these favourable conditions, differences still exist between social classes. The risk of stillbirth remains much higher among the poorer women, those without any education and those who gave birth at home. These findings are consistent with developed countries like the USA and Japan, where the social class differences in mortality still persist.

Biological fertility is poorly measured by the number of children born in industrially advanced societies. The time elapsing from when a couple decides to have a child to clinically recognizable pregnancy is a useful alternative. Time to pregnancy can be collected in broad categories in large samples. A model for condensing important information from such data is presented, which fits several large samples of reported waiting times. It is shown that multiparous women conceive more quickly than primiparous women.