Socioeconomic status and fertility in rural Bangladesh

Using a unique set of birth registration data from the Demographic Surveillance System of the International Center for Diarrheal Disease Research, Bangladesh, for the period 1974-77, and socioeconomic information collected in the 1974 census, fertility was studied in relation to occupation, size of dwelling, number of cows and number of boats owned. The total fertility rate was found to vary between 6 and 6.5 except in the famine year of 1975. There was no consistent relationship between fertility and education of women. The age-specific fertility rates by religion show that Muslims had higher fertility at all ages in 1974 and 1977 and at older ages in 1975 and 1976. Overall, however, fertility of Hindus is consistently lower than that of Muslims, but the relative differences are under 10%. Fertility differentials by occupation showed that the household heads who were farm laborers had relatively lower fertility compared to other occupational groups, except for the year 1977 where the families of service holders were found to have relatively lower fertility. Women in households whose heads were businessmen or farmers (owning their land) had above average fertility. In 1974, households in the business occupational groups had, on average, 1 birth more than other households. Women in households with fishermen as heads had below average fertility in 1974 and 1975, but very high fertility in 1976 and 1977. Fertility levels differed according to the type of household in which the family resided. Nuclear families had below average fertility up to the age of 35 and above average fertility at the end of the reproductive age. In the 15-19 age group, augmented families had higher fertility each year examined. The association between dwelling place and fertility is positive each year, the relative differences in fertility between the groups being largest in 1974. Positive relations were found between economic status and fertility.     

Reproduction and survival of polygynous and monogamous Blue Tit Parus caeruleus

In a seven-year study of Blue Tits in optimal habitat near Antwerp, Belgium, 45 polygynous broods involving 22 males out of 667 successful first broods were found. In another 43 nests no male was found, although a major effort was made to trap all adults. The estimated proportion of polygynous males is 3.4%, if only confirmed cases are considered, but 10.8% if all possible cases are included. One male was paired simultaneously to three females.
Primary females (laying earliest in a triangle) were as successful as monogamous ones. Secondary (laying later in a triangle) and deserted females (nests in which no male was trapped), although still quite successful, raised fewer young and in one plot had a lower probability of recruiting offspring.
Both in males and females, the frequency of polygyny was independent of age. Adult survival did not differ between monogamous and polygynous males. Among females no effect of pairing status on survival was found in one plot, but in a second plot monogamous females survived better than others. It is concluded that in any study of Blue Tits in optimal habitat one could expect to find polygyny.     

Extra-pair paternity in monogamous and polygynous Savannah sparrows,Passerculus sandwichensis

Extra-pair paternity can influence mating systems by affecting the fitness costs associated with polygyny. Polygyny is disadvantageous to males when the time and energetic demands of multiple pairings decrease either a male's success at gaining extra-pair fertilizations or his ability to ensure paternity among harem members. In Savannah sparrows,Passerculus sandwichensison Kent Island, New Brunswick, Canada, multilocus DNA fingerprinting of 136 adults and young revealed substantial female infidelity: overall, 31 of 92 young (33.7%) in 15 of 24 nests (62.5%) were the product of extra-pair fertilizations. Male mating status was a strong predictor of paternity. Each of seven monogamous females produced at least one extra-pair offspring, but only six of 11 primary females (54.5%) and two of six secondary females (33.3%) were unfaithful. As a result, nearly 80% of the young in nests of polygynous males resulted from within-pair fertilizations, compared with only 40% of the young in nests of monogamous males. Kent Island Savannah sparrows are simultaneously polygynous, and the absence of paternity costs associated with polygyny is surprising. The observed pattern of paternity suggests the operation of female choice, although male control of parentage cannot be excluded.     

Effect of famine on fertility in a rural area of Bangladesh

Data on household socioeconomic status collected in the 1974 census and registration data on births, deaths, and migrations for the 1974-77 period from the Demographic Surveillance System of the International Centre for Diarrheal Disease Research, Bangladesh, were used to investigate the effects of the 1974-75 famine on differential fertility in a rural population of Bangladesh. Occupation of household head was used as a measure of socioeconomic status. Overall, fertility declined by 34% over the 1975-76 period and increased by 17% in 1976-77 from the 1974-75 figure. Significantly lower fertility was observed in 1975-76, irrespective of socioeconomic status, but the lower socioeconomic groups were affected more than the higher groups. Post-famine fertility was significantly higher only in the 2 middle occupation categories. The age-specific fertility rates suggest that the famine affected all age groups. The post-famine fertility was higher than that of 1974-75 in all but those aged below 20. At age 40 and over the recovery was slight. Husband-wife separation showed an increase during the famine and particularly among the lower socioeconomic groups. The males of the lower socioeconomic households migrated to other regions to obtain food for the family, thus affecting frequency of coitus. The decline in fertility may be due to several factors: deferred marriage; increase in divorces and husband-wife separations; high fetal wastage; voluntary fertility control through contraception, abstention, or induced abortion; and infecundability. An indirect measure of marriage rate indicated that fewer couples entered into marriage in 1974-75, particularly in the lower socioeconomic groups. Both the higher and lower socioeconomic groups were affected by the famine but the precise mechanisms were not the same. At this stage, it is not feasible to estimate the contribution of each factor to the fertility decline. The lower socioeconomic groups were more affected by husband-wife separations and deferred marriages; the higher socioeconomic groups were affected by mental stress and anxiety.     

Marital fertility in polygynous unions in Nigeria

The effect of polygyny on fertility, by age cohort, was examined in 4 regions of Nigeria through use of data from the 1981-82 Nigerian Fertility Survey. Simple tabulation of numbers of live births by maternal age and type of marriage union indicated that, with the exception of the 30-39-year age group, fertility in polygynous unions tends to be higher than that in monogamous marriages. Overall, such tabulations reveal an average of 3.90 births among polygynous women and 3.47 births among monogamous women. However, when age-specific fertility rates were compared, except for women under 20 and over 40 years of age, rates were higher in monogamous unions (7.286 overall) than for women in polygynous households (7.200 overall). Mean completed fertility, taking into account marriage duration as well, shows a tendency for women in polygynous unions to be more fertile (with the exception of women aged 25-44 years who had been married 10-19 years). The absolute difference in fertility between the 2 types of marital unions ranged from 0.32 children in the northwest to 0.64 in the southeast. With adjustment for independent variables such as education, the absolute mean differences were reduced, from between 0.28 children in the southeast to 0.42 in the northeast, but the direction of high fertility was still in favor of women in polygynous unions. But when the covariates (e.g., age at marriage) were taken into account as well as the independent variables, there was a dramatic reduction in the mean difference between the fertility of these 2 groups of women. These findings suggest that some changes in reproductive behavior are taking place in Nigeria that are restricting the fertility of women in polygynous unions. These changes are hypothesized to reflect the spread of formal education in Nigeria, with the expectation that women will contribute to the costs involved in educating their children.     

Differentials in fertility among black doctorates

Abstract

The 1978 Contraceptive Prevalence Survey for Guatemala provides an opportunity to examine fertility levels and a number of determinants of fertility for three broad segments of the country: the Department of Guatemala and, in the remainder of the country, the Ladino and Indian populations. While Ladinos had a much higher rate of contraceptive use than did Indians, the two groups had similar birth rates. The lack of difference in fertility appears to be due to the pattern of prolonged breastfeeding among Indians and perhaps to differences in the rate of conception due to nutrition, coital frequency, or other factors.     

The effect of husbands' fertility preferences on couples' reproductive behaviour in rural Bangladesh

Bangladesh society is profoundly gender stratified, and yet male roles in reproductive health processes have not been rigorously investigated. This study examines the association between men's reproductive health knowledge, attitude and behaviour and their wives' subsequent reproductive behaviour using longitudinal data from the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B). A total of 4969 matched husband-and-wife data from a 1998 survey and women's contraceptive use history data following this survey are used. Results show a significant association between husbands' fertility preferences and current use of any family planning method. When wives' background characteristics, and husbands' background and socioeconomic characteristics are controlled for, the predicted probability of using a method of contraception among non-educated wives whose husbands want more children is 0.49 compared with 0.64 for those whose husbands do not want more children. However, the net effect of husbands' preference for additional children diminishes as wives' level of education increases. Among wives who had completed high school, the predicted probability of using a method of contraception is 0.70 for those whose husbands want more children compared with 0.69 for those whose husbands do not want more children.     

Estrous phase alters social behavior in a polygynous but not a monogamous Peromyscus species

The social organization of rodent species determines behavioral patterns for both affiliative and agonistic encounters. The neuropeptide oxytocin has been implicated in the mediation of social behavior; however, variability in both neuropeptide expression and social behavior within a single species indicates an additional mediating factor. The purpose of the present comparative study was to investigate social behaviors in naïve mixed-sex pairs of monogamous Peromyscus californicus and polygynous Peromyscus leucopus. We identified substantial inter- and intra-specific variability in the expression of affiliative and agonistic behaviors. Although all P. californicus tested engaged in frequent and prolonged intervals of social contact and rarely engaged in aggressive behaviors, P. leucopus exhibited significant variability in both measures of social behaviors. The naturally occurring differences in social behavior displayed by P. leucopus vary across the estrous cycle, and correspond to hypothalamic oxytocin, as well as circulating oxytocin and glucocorticoid concentrations. These results provide evidence for a rhythm in social behavior across the estrous cycle in polygynous, but not monogamous, Peromyscus species.     

Association between age at menarche and early-life nutritional status in rural Bangladesh

Age at menarche is associated with anthropometry in adolescence. Recently, there has been growing support for the hypothesis that timing of menarche may be set early in life but modified by changes in body size and composition in childhood. To evaluate this, a cohort of 255 girls aged <5 years recruited in 1988 were followed up in 2001 in Matlab, Bangladesh. The analysis was based on nutritional status as assessed by anthropometry and recalled age at menarche. Data were examined using lifetable techniques and the Cox regression model. The association between nutritional status indicators and age at menarche was examined in a multivariate model adjusting for potential confounding variables. Censored cases were accounted for. The median age at menarche was 15.1 years. After controlling for early-life predictors (birth size, childhood underweight, childhood stunting) it appeared that adolescent stunting stood out as the most important determinant of age at menarche. Adolescent stunting still resonates from the effect of stunting in early childhood (OR respectively 2.63 (p<0.01 CI: 1.32-5.24) and 8.47 (p<0.001 CI: 3.79-18.93) for moderately and severely stunted under-fives as compared with the reference category). Birth size was not a significant predictor of age at menarche. It is concluded that age at menarche is strongly influenced by nutritional status in adolescence, notably the level of stunting, which is in turn highly dependent on the level of stunting in early childhood. A 'late' menarche due to stunting may be detrimental for reproductive health in case of early childbearing because of the association between height and pelvic size.     

Recent evidence on trends and differentials in Bangladesh fertility

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 relationship between sociodemographic variables and pregnancy loss in a rural area of Bangladesh

This study examines the relationship between eight sociodemographic variables and the risk of pregnancy loss in a rural area of Bangladesh. The risks of spontaneous miscarriage and stillbirth were significantly associated with maternal age, pregnancy order and previous pregnancy wastage.     

Oral contraceptive non-compliance in rural Bangladesh

This paper examines incorrect use of oral contraceptives (OCs) in rural Bangladesh by using data from an OC compliance survey. Of the 1031 current users of OCs interviewed, about 13% took their pills out of sequence, while 17% left incorrect intervals between pill packs. Forty per cent of the women reported missing one active pill during the 6 months prior to the survey, and 74% of them took correct action with the missed pill. Of the women who missed two active pills (16%), only 9% took correct action. Multivariate analyses revealed that women's education and their husbands' support helped protect against taking incorrect action with a missed pill. The fieldworker's contact was found to protect against leaving an incorrect interval between pill packs. Women who had membership of non-government organizations were less likely to interrupt their pill use, and more likely to take their pill out of sequence. The present study underscores the need for providing women with more support in their pill use, and advocates that service providers should be the focal point of efforts. Husbands' support is essential to improve the pill-taking behaviour of Bangladeshi women.     

Differential fertility in Bangladesh: A path analysis

Abstract

This study attempts to show both theoretically and empirically the causal links between selected background, socioeconomic, and demographic variables, on the one hand, and between these variables and cumulative fertility, on the other. Two distinct models, urban and rural, emerge as a result of a statistical test. In both models, neither wife's nor husband's childhood background is found to have any significant direct effects on fertility. Wife's age, religion, and age at marriage are the common variables which directly affect the number of children ever born. While age and religion bear positive direct effects, age at marriage exerts a negative direct effect. The indirect effect of religion is positive both in the rural and urban area. Both the direct and indirect effects of wife's education on fertility in urban Bangladesh are negative. Husband's education, in contrast, has a positive direct effect in the urban area and no effect at all in the rural area.     

The association between HIV and fertility in a cohort study in rural Tanzania

Recent studies in sub-Saharan Africa have shown that fertility is reduced among HIV-infected women compared with uninfected women. The size and pattern of this fertility reduction has important implications for antenatal clinic-based surveillance of the epidemic and also for estimates and projections of the demographic impact of the epidemic. This paper examines the association between HIV and fertility in Kisesa, a rural area in Tanzania, where HIV prevalence among adults is about 6% and gradually increasing. The analysis is based on data obtained through a demographic surveillance system in Kisesa during 1994-98 and two large sero-surveys of all residents in 1994-95 and 1996-97. The HIV-associated fertility reduction among women was investigated by estimating fertility rates by HIV status and prevalence rates by fertility status. A substantial reduction (29%) was observed in fertility among HIV-infected women compared with HIV-uninfected women. The fertility reduction was most pronounced during the terminal stages of infection, but no clear association with duration of infection was observed. Use of modern contraception was higher among HIV-infected women. However, both among contracepting and non-contracepting women, a substantial reduction in fertility was seen among HIV-infected women.     

Determinants of pill failure in rural Bangladesh

The pill is the most popular family planning method in Bangladesh. However, the failure rate of this method in Matlab, a typical rural area, has been found to be very high. It is estimated that with the current level of failure of the pill and other temporary contraceptives in Matlab, it is unlikely that fertility in Bangladesh will come down to replacement level without a change in contraceptive method mix. It is, therefore, important to know the reasons for the high failure in pill use. Data for this study came from a case-control study in Matlab. A pill failure was considered a case, and no-failure was considered a control. The study included 167 cases and 167 controls. In addition, five focus group discussions were conducted to supplement the data collected from the cases and controls to gain a deeper understanding of pill failure. Results of the analysis of both quantitative and qualitative data suggested that the following were the risk factors for pill failure: no mobility of women, poor knowledge of women about the effectiveness and consequences of drop-out from pill use, weak confidence in the pill, a gap between the use of subsequence pill cycles, delay in starting the pill after menstruation for the first use, not taking any measures consistently for missing the pill, and not following the arrow sign given on the pill cycle. Extensive training of field workers and pill users, covering the reasons for pill failure identified in this study and strong supervision of the work of field workers, is likely to reduce the rate of pill failure in Bangladesh. Also, information, education and communication services for users, and management of side-effects, may be helpful in reducing pill failure.     

Age differences between spouses in first marriages

Absract

Vital statistics data indicate that the age difference between spouses in first marriages has narrowed for those born between 1931 and 1951 and married by age 25. It appears that the largest declines have occurred at the older ages of marriage, although there have been reductions at all ages. The possibility that the narrowing of the age gap can be attributed to the recent “marriage squeeze” is examined using data from the 1976 National Survey of Family Growth. Insofar as it is adequately measured, the squeeze is found to be insignificant. It seems that age at marriage of the wife is inversely related to a couple's age difference. That this might simply be due to the age distribution of available men is considered and rejected. It is speculated that the relation between age difference and age at marriage is a consequence of changing preferences, not of the supposed shortage of suitable single men.