Anencephaly and spina bifida cystica, malformations of the central nervous system, are due to failure of closure of the neural tube. These malformations are a major cause of stillbirth, infant death and (in the case of spina bifida) of childhood morbidity in Britain today.

Their aetiology is not known in detail. There are, however, indications from family studies and from the striking racial variation in their incidence (which is in part at least maintained after migration) that genetic factors are important in their causation. There is also evidence from maternal age and birth order effects, secular and seasonal variation, and social class effects that environmental factors also are important in their aetiology.

Chinese-American and Anglo-American school children were compared on a nonverbal test of intelligence (Raven's Progressive Matrices) and on twelve chronometric variables which measure the speed with which basic information processes (e.g. stimulus apprehension, decision, and discrimination) can be carried out. All of these tasks are correlated with psychometric intelligence. The two groups differed significantly on most of the variables, but the differences appear to be multidimensional and are not simply due to a group difference in psychometric intelligence, equivalent to about 5 IQ points in favour of the Chinese-Americans. The results are compared with those of Lynn and his colleagues on British, Japanese, and Hong Kong children, and both consistencies and inconsistencies are found.

Consanguineous marriages in two population samples, one rural and one urban, from Swat (Pakistan) were studied. The frequency of consanguineous marriages was found to be 37·13% and 31·11%, and mean inbreeding coefficients were calculated as 0·0168 and 0·0162, for the rural and urban populations respectively. The most frequent type of marriage was between first cousins, in both samples. Among first cousin marriages, those with father's brother's daughter were predominant. Mean inbreeding coefficient was higher for higher socioeconomic groups in both samples. Differences by ethnic and educational groups were also found. Contrary to previous studies, a significant increase in the incidence of consanguineous marriages over the years has been observed. The incidence of premature mortality was significantly higher only in the offspring of first cousin marriages. Significantly higher incidence of morbidity in the offspring of consanguineous marriages was also observed.

Studies addressing factors associated with adverse birth outcomes have almost exclusively been based on hospital statistics. This is a serious limitation in developing countries where the majority of births do not occur within health facilities. This paper examines factors associated with premature deliveries, small baby’s size at birth and Caesarean section deliveries in Kenya based on the 1993 Kenya Demographic and Health Survey data. Due to the hierarchical nature of the data, the analysis uses multilevel logistic regression models to take into account the family and community effects. The results show that the odds of unfavourable birth outcomes are significantly higher for first births than for higher order births. Furthermore, antenatal care (measured by frequency of antenatal care visits and tetanus toxoid injection) is observed to have a negative association with the incidence of premature births. For the baby’s size at birth, maternal nutritional status is observed to be a predominant factor. Short maternal stature is confirmed as a significant risk factor for Caesarean section deliveries. The observed higher odds of Caesarean section deliveries among women from households of high socioeconomic status are attributed to the expected association between socioeconomic status and the use of appropriate maternal health care services. The odds of unfavourable birth outcomes vary significantly between women. In addition, the odds of Caesarean section deliveries vary between districts, after taking into account the individual-level characteristics of the woman.

The Journal of Biosocial Science regularly publishes papers addressing the social and cultural aspects of disease, sickness and well-being. Most of these papers attempt to understand the prevalence and distribution of disease and sickness within and between populations as well as local responses to biomedical interventions and public health policy more generally. They fall broadly within the remit of human ecology; and they embrace a ‘factorial’ model of disease in which social and cultural factors are deemed to be just one of a number of factors to be considered alongside a range of other factors. These include biological features of the infecting organism; nutritional factors; environmental factors; psychological factors; and genetic factors influencing susceptibility to disease at an individual and population level.

Maternal mortality is a serious public health concern in Bangladesh. However, most deaths could be prevented through proper and timely care seeking and adequate management. Unfortunately, fewer than half of pregnant women in Bangladesh seek antenatal care, and only one in eight receive delivery care from medically trained providers. The specific objectives of this research are to examine the socioeconomic differentials of maternity care seeking, and to determine whether accessibility of health services reduces the socioeconomic differentials in maternity care seeking. A multi-level logistic regression method is employed to analyse longitudinal data collected from a sample of 1019 women from all over Bangladesh. The study finds significant socioeconomic disparities in both antenatal and delivery care seeking. Service accessibility, however, significantly reduces the socioeconomic differentials in delivery care seeking. Services need to be made accessible to reduce the inequality in maternity care seeking between rich and poor, empowered and non-empowered.

The children in the cohort followed by the National Child Development Study were tested for cognitive ability at the age of eleven, and the influence of a number of biological and social variables was sought on the results of tests of reading, mathematics, verbal and non-verbal abilities. Reading relates strongly to social class, birth order and parental age, suggesting strong social influences upon it, but it is also related to height and acquired myopia, suggesting biological influences. Mathematics ability relates to social class and parental age, but not to birth order, but its relationship with height, birthweight and maternal smoking suggests biological effects. Verbal ability and non-verbal ability have relatively few correlates apart from sex and region. It appears that different cognitive abilities show different relationships to social, biological and personal variables.

From the data of the 1989 Bangladesh Fertility Survey, aggregate deaths reported at ages 0-12 and 13-60 months are used to estimate infant and child mortality. Multivariate analysis shows that preceding birth interval length, followed by survival status of the immediately preceding child, are the most important factors associated with differential infant and child mortality risks; sex of the index child and mother's and father's education are also significant. Demographic factors are influential during infancy as well as childhood, but social factors, particularly mother's and father's education, now emerge as significant predictors of infant mortality risks. This indicates a change in the role of socioeconomic factors, since the earlier Bangladesh Fertility Survey in 1975.

A study on perceptions, attitudes and treatment-seeking practices related to schistosomiasis was conducted among the Wasukuma in the rural Magu district of Tanzania at the shore of Lake Victoria where Schistosoma haematobium and mansoni infections are endemic. The study applied in-depth interviews, focus group discussions and a questionnaire survey among adults and primary school children. The perceived symptoms and causes were incongruous with the biomedical perspective and a number of respondents found schistosomiasis to be a shameful disease. Lack of diagnostic and curative services at the government health care facilities was common, but there was a willingness from the biomedical health care services to collaborate with the traditional healers. Recommendations to the District Health Management Team were: that collaboration between biomedical and traditional health care providers should be strengthened and that the government facilities’ diagnostic and curative capacity with regard to schistosomiasis should be upgraded. Culturally compatible health education programmes should be developed in collaboration with the local community.

The timing of transitions to sexual activity, marriage and childbearing in sub-Saharan Africa is undergoing profound changes. This study investigates the determinants of adolescent transitions in South Nyanza, a socioeconomically deprived setting in Kenya where adolescent reproductive health is a particular concern. The analysis is based on Cox regression of timing of first sexual intercourse, first marriage and first pregnancy, using data from a survey of 1247 females aged 12–19 years. The results show that higher household socioeconomic status and educational attainment are associated with delayed onset of all three transition events. Furthermore, mother’s higher educational attainment is protective for initiation of sexual intercourse while rural residence is protective for pregnancy experience. Other protective factors include communication with parents or with fellow girlfriends. However, discussing sexual matters with boyfriends, high internal locus of control, and gender bias are associated with early onset of the three transition events.

This study considers the relationship between a cumulative index of biological dysregulation (allostatic load) and several dimensions of socioeconomic status (SES) and lifestyle in adult Polish males. The extent to which lifestyle variables can explain SES variation in allostatic load was also evaluated. Participants were 3887 occupationally active men aged 25–60 years living in cities and villages in the Silesia region of Poland. The allostatic load indicator included eleven markers: % fat (adverse nutritional intake), systolic and diastolic blood pressures (cardiovascular activity), FEV1 (lung function), erythrocyte sedimentation rate (inflammatory processes), glucose and total cholesterol (cardiovascular disease risk), total plasma protein (stress-haemoconcentration), bilirubin, creatinine clearance and alkaline phosphatase activity (hepatic and renal functions). A higher level of completed education, being married and residing in an urban area were associated with lower physiological dysregulation. The association between indicators of SES and allostatic load was not eliminated or attenuated when unhealthy lifestyle variables were included in the model. Smoking status and alcohol consumption played minimal roles in explaining the association between SES and allostatic load; physical activity, however, had a generally protective effect on allostatic load.

Maternal morbidity and mortality are high in the Indian context, but the majority of maternal deaths could be avoided by prompt and effective access to intrapartum care (WHO, 1999). Understanding the care seeking responses to intrapartum morbidities is crucial if maternal health is to be effectively improved, and maternal mortality reduced. This paper presents the results of a prospective study of 388 women followed through delivery and traditional postpartum in rural Karnataka in southern India. In this setting, few women use the existing health facilities and most deliveries occur at home. The analysis uses quantitative data, collected via questionnaires administered to women both during pregnancy and immediately after delivery. By virtue of its prospective design, the study gives a unique insight into intentions for intrapartum care during pregnancy as well as events following morbidities during labour. Routine care in the intrapartum period, both within institutions and at home, and impediments to appropriate care are also examined. The study was designed to collect information about health seeking decisions made by women and their families as pregnancies unfolded, rather than trying to capture women’s experience from a retrospective instrument. The data set is therefore a rich source of quantitative information, which incorporates details of event sequences and health service utilization not previously collected in a Safe Motherhood study. Additional qualitative information was also available from concurrent in-depth interviews with pregnant women, their families, health care providers and other key informants in the area. The level of unplanned institutional care seeking during the intrapartum period within the study area was very high, increasing from 11% planning deliveries at a facility to an eventual 35% actually delivering in hospitals. In addition there was a significant move away from planned deliveries with the auxiliary nurse midwive (ANM), to births with a lay attendant or dai. The proportion of women who planned for an ANM to assist was 49%, as compared with the actual occurrence, which was less than half of this proportion. Perceived quality of care was found to be an important factor in health seeking behaviour, as was wealth, caste, education and experience of previous problems in pregnancy. Actual care given by a range of practitioners was found to contain both beneficial and undesirable elements. As a response to serious morbidities experienced within the study period, many women were able to seek care although sometimes after a long delay. Those women who experienced inadequate progression of labour pains were most likely to proceed unexpectedly to a hospital delivery.

Daily records are the only acceptable basis for determining human coital rates. A re-analysis of such data presented by earlier writers and a study of new data suggest that within the intermenstruum (viz. the days on which there is no bleeding) the rate of coitus is highest immediately after menstruation ceases, declines thereafter and is lowest (within the intermenstruum) just before menstruation recurs.

It is not clear whether there is a minor peak around ovulation time, but such a correlation, if it exists, is certainly not very powerful.

The major cause of the higher coital rate after menstruation could be abstinence during menstruation and a post-menstrual feeling of release on the part of the woman.

The fact that coital rates are largely independent of the time of ovulation might be due to their being largely determined by the male. In any case, it provides evidence for Morris's view that human sexuality has important evolutionary functions other than reproduction.

A study was made of twinning rates in mothers of different ethnic origin delivered in two hospitals in Ibadan, Nigeria; the great majority were of Western Nigerian origin. The twinning rates in mothers of Western, Eastern, Mid-Western and Northern Nigerian origin were 45, 45, 31 and 21/1000 maternities, respectively. The monozygotic twinning rates determined by sex, placentation, blood groups and other genetically determined markers in the different ethnic groups varied very little, the differences in the overall twinning rates being mainly due to variation in the dizygotic rates. The effect of factors such as hospital selection and maternal age and parity on the observed incidence of twinning is discussed.

Multifactorial analyses of data from representative British and German national contraception surveys were used to examine the principal demographic determinants of contraceptive use by women. Contraceptive use appeared to be determined mainly by reference to ‘reproductive status’ (the combined impact of age, marital status, parity and future child wish). Women who were postponing pregnancies were using oral contraceptives, whereas those who wanted no more children relied more on intrauterine devices or sterilisation. Differences between the countries suggested that the choice of contraceptive method was influenced by health care policy, the organisation of the relevant services and differential provider preferences. The contraceptive method used was also related to having occasional rather than steady sexual partners (more condom use), lower educational level (less oral contraceptive use) and frequent church attendance (greater use of condoms and periodic abstinence). Contraception decisions appeared to follow a fixed pattern, based more on a couple's demographic situation (reproductive status, country, educational level and religious beliefs) than on the characteristics of the contraceptive methods. This resulted in an unnecessarily restricted choice of methods.

The aim of this paper is to investigate the differentials and determinants of female age at first marriage in rural Nepal. The life table technique was employed to calculate median age at marriage. The proportional hazard model was used to study the effect of various socioeconomic variables, and to identify the magnitude and significance of their effects on the timing of first marriage. The data were taken from a sample survey of Palpa and Rupandehi districts in rural Nepal. Both married and unmarried females of marriageable age were included in the survey. Median age at marriage was about 17 years for data from only married females, whereas it was about 18 years for data from married as well as unmarried females of marriageable age. Median age at marriage was about 16 years for uneducated females and 19 years for females educated up to intermediate or higher level. The analysis underestimates the median age at marriage for married females, probably due to right censoring. The risk of getting married early decreased gradually with increasing year-of-birth cohort. The risk of early marriage was higher among females of high socioeconomic status compared with those of low socioeconomic status. Females engaged in service married earlier than those engaged in household work. High socioeconomic status families are motivated, for religious and prestige reasons, to get their daughters married at an early age, preferably before menarche. Thus, education, occupation and age at menarche are the most powerful factors in deciding the timing of first marriage in Nepal.

The traditional proscription against sex for women during pregnancy, and particularly in the postpartum period, in south-west Nigeria leaves many men without sexual access to their wives for extended periods of time. This practice raises the question whether men abstain or seek other sexual partners. A community-based study was conducted using 3204 married men from randomly selected local government areas of the state. These men had wives who had delivered a baby in the 36 months prior to the study. Information was obtained on their sexual practices before and during pregnancy and the postpartum period. Male sexual networking was not absent outside the pregnancy and the postpartum periods. However, during pregnancy, a higher percentage of men (43·7%) had other partners compared with the period outside pregnancy and postpartum (42·1%). The difference was not significant (p>0·05). Similarly, in the postpartum abstinence period, more men (48%) had other sexual partners when compared with the period outside pregnancy and postpartum (42·1%; p<0·001). Sexual networking with non-regular and multiple partners was also more commonly observed in the postpartum period than in pregnancy (11·9% vs 10·4%; p<0·05). Significantly more rural than urban men had multiple sexual partners when their wife was pregnant (p=0·01) or in postpartum abstinence (p<0·05). Condom use with regular partners was largely absent, and consistent condom use with extramarital partners was very low among urban and rural men (6·3% vs 1·7%). The vast majority of men were having unprotected vaginal sex. Logistic regression analysis showed that polygamous men, those under 30 years in the urban area, and men with low or no education were more likely to have sex with other women when their wife was pregnant. During a wife’s postpartum abstinence period, men in higher status occupations, younger urban men (<49 years), those with more children, the polygamous, and men with a first wife under 40 years in urban area were more likely to have other partners. In light of the heterosexual mode of HIV transmission in Nigeria, there is a dire need to design and implement an intervention programme targeted at married men, which takes into consideration cultural practices. This will hopefully help check the course of the disease in a country thought to be on the verge of an HIV epidemic.

In adult life the human breast, unlike that of other species, is sufficiently developed to allow milk secretion to occur after only a brief period of hormonal stimulation. During pregnancy the ducts and secretory alveoli develop under the influence of both oestrogen and progesterone. Growth hormone and placental lactogen are not required; the role of prolactin in mammogenesis remains questionable. Lactogenesis, the onset of milk secretion, is inhibited during pregnancy despite high levels of prolactin, by a direct inhibitory action of steroids on the breast. The clearance of placental steroids after delivery removes this inhibition and milk secretion is initiated.

Inhibition of prolactin secretion prevents milk secretion, suggesting that prolactin is the essential hormone for lactation in man. Prolactin release occurs in response to suckling and the amount released depends on the strength and duration of the suckling process. No release of prolactin occurs in response to stimuli other than stimulation of the nipple.

Removal of milk from the mammary gland is effected by the milk-ejection reflex (MER) involving the release of oxytocin in response to suckling. Unlike prolactin, oxytocin may be released in response to stimuli associated with breast-feeding, e.g. the cry of the infant. The MER may be inhibited by psychological and physical stress, either by inhibiting oxytocin release or by preventing its action upon the breast contractile elements. The susceptibility of the MER to disturbance requires consideration when encouraging the establishment of breast-feeding.

Breast-feeding is geared directly to the needs of the infant, since not only does the suckling infant obtain its present meal by inducing oxytocin release, but also by stimulating prolactin release it orders the next (Tindal, 1972).

This article documents understandings and responses to mass drug administration (MDA) for the treatment and prevention of lymphatic filariasis among adults and children in northern coastal Tanzania from 2004 to 2011. Assessment of village-level distribution registers, combined with self-reported drug uptake surveys of adults, participant observation and interviews, revealed that at study sites in Pangani and Muheza districts the uptake of drugs was persistently low. The majority of people living at these highly endemic locations either did not receive or actively rejected free treatment. A combination of social, economic and political reasons explain the low uptake of drugs. These include a fear of treatment (attributable, in part, to a lack of trust in international aid and a questioning of the motives behind the distribution); divergence between biomedical and local understandings of lymphatic filariasis; and limited and ineffective communication about the rationale for mass treatment. Other contributory factors are the reliance upon volunteers for distribution within villages and, in some locations, strained relationships between different groups of people within villages as well as between local leaders and government officials. The article also highlights a disjuncture between self-reported uptake of drugs by adults at a village level and the higher uptake of drugs recorded in official reports. The latter informs claims that elimination will be a possibility by 2020. This gives voice to a broader problem: there is considerable pressure for those implementing MDA to report positive results. The very real challenges of making MDA work are pushed to one side – adding to a rhetoric of success at the expense of engaging with local realities. It is vital to address the kind of issues raised in this article if current attempts to eliminate lymphatic filariasis in mainland coastal Tanzania are to achieve their goal.

In South Asia women are often the primary decision-makers regarding child health care, family health and nutrition. This paper examines the proposition that constraints on women’s status adversely affect the survival of their children. Survey data are used to construct indices of women’s household autonomy and authority, which are then linked to longitudinal data on survival of their children. Proportional hazard models indicate that enhanced autonomy significantly decreases post-neonatal mortality. Enhanced household authority significantly decreases child mortality. A simulation based on estimated effects of eliminating gender inequality suggests that achieving complete gender equality could reduce child mortality by nearly fifty per cent and post-neonatal mortality by one-third.