Length Of Birth Interval Research Articles

Birth intervals, breastfeeding and determinants of childhood mortality in Malawi

Childhood mortality in Malawi is analyzed by employing proportional hazards models. The analysis uses highly reliable data collected from the 1992 Demographic and Health Survey (DHS) of Malawi. The results show that the substantial birth interval and maternal age effects are largely limited to the infant period. The influence of social and economic variables on the mortality risk and on the relationship between biodemographic variables and mortality risk is much enhanced with increasing age of the child. It has also been found that consideration of breastfeeding status of the child does not significantly alter interpretation of effects of preceding birth interval length on mortality risk, but does partially diminish the succeeding birth interval effect. The results are discussed and then summarized in the context of policy implications for Malawi. The paper addresses a very important issue in Malawi and it adds valuable insights to the base of knowledge in childhood mortality in sub-Sahara Africa.

High Fertility in Rural Uganda: The Role of Socioeconomic and Biological Factors

Data from Demographic and Health Surveys comparative surveys conducted in Ankole and a 1984 survey of the elderly in Ankole are used in this monograph to present a comprehensive analysis of fertility in Ankole Uganda. This monograph is different from preceding monographs in this series by including several additional variables: an analysis of household property the influence of the extended family the length of birth intervals and the incidence of infertility as explanations for the high fertility in Ankole. The analysis of data on the elderly and the comparison of mens and womens fertility desires are also included. Censuses of population over four decades are used to measure population and fertility trends. Other chapters are devoted to the value placed on children sexual customs land and cattle ownership and marriage patterns. The study questionnaires are included in the appendices. It is concluded that in Ankole society childless men and women desired a large family of around 6.7 and 7.5 children respectively. Ideal family size was higher among families with children. Women had ideals of 7.8 children and men had ideals of 8.9 children. The strong extended family system reinforces the desire for a large family by providing financial support for education and weddings. Children begin to help around the house at an early age and are viewed as assets. Sexual customs are practiced that enhance a large family size: return to sexual relations soon after the birth of a child ritual sexual practices high sexual mobility between relatives and the lack of a postpartum abstinence sexual taboo. The number of children ever born was higher among cattle owners. Marriage variables had the strongest impact on fertility in the analysis of the proximate determinants of fertility. Contraception induced abortion and infertility had a limited impact. It is recommended that policy address mortality reduction as a means of reducing fertility levels in Ankole.

Modelli log-linearigraflici-catena per l'analisi della durata di intervalli tra nascite

Log-linear graphical chain models have a one-to-one correspondence to directed graphs where any missing eUge represents a conditional independence statement. Hence, they can be considered in the study of directional links among categorical variables. The meaning of these models, following an asymmetrical approach in the analysis of demographical data, is presented. Making use of WFS (Italy, 1979) data referring to the lenght of two birth intervals (first and between first and second birth), some applications of log-linear graphical chain models are performed. The structure of the relationships among background variables, intermediate variables and birth interval lengths is described.

Is the reduction of birth intervals an efficient reproductive strategy in traditional Morocco?

SummaryBirth interval lengths are analysed from reproductive life histories of 517 Berber peasant women of the region of Marrakesh (Southern Morocco), whose fertility developed in a full traditional context. The high mortality rates associated with short birth intervals indicate that a rapid succession of births is detrimental to the progeny. The reproductive efficiency of the traditional propensity to a large family size is therefore examined by means of two different evaluations of reproductive success: the ‘absolute’ reproductive success (the absolute number of offspring surviving to maturity) and the ‘relative’ reproductive success (the proportion of live born surviving to maturity). The first shows that close pregnancies increase the fertility rate to such an extent that the associate higher number of deaths is more than compensated for, so that the women practising short birth intervals produce more surviving offspring than the others by the end of their reproductive life. The second shows that the probability of survival is directly associated with birth interval length, the efficiency of the reproductive process being therefore greater as birth intervals grow. It is suggested that these two behaviours are not contradictory, and that they represent two successive steps of the same reproductive adjustment to evolving environmental conditions.

Infant and child mortality determinants in Bangladesh: are they changing?

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.

Sex preference and third birth intervals in a traditional Indian society.

The traditional preference for sons may be the main hindrance to India's current population policy of two children per family. In this study, the effects of various sociodemographic covariates, particularly sex preference, on the length of the third birth interval are examined for the scheduled caste population in Assam, India. Life table and hazards regression techniques are applied to retrospective sample data. The analysis shows that couples having two surviving sons are less likely to have a third child than those without a surviving son and those with only one surviving son. Age at first marriage, length of preceding birth intervals, age of mother, and household income have strong effects on the length of the third birth interval.

Do Fertility Intentions Predict Subsequent Behavior? Evidence from Peninsular Malaysia

Data from the 1984 Malaysian Population and Family Survey were matched with birth registration records for 1985-87 to determine the accuracy of statements regarding desired family size that were reported in a household survey in predicting subsequent reproductive behavior. The findings of this study were that stated fertility intention provides fairly accurate forecasts of fertility behavior in the subsequent period. In other words, whether a woman has another child is predicted closely by whether she wanted an additional child. Informational, educational, and motivational activities of family planning programs would, therefore, have greater success in reducing family size if fertility intentions were taken into account.

Comparison of effects of breast-feeding practices on birth-spacing in three societies: nomadic Turkana, Gainj, and Quechua

Variation in the duration and pattern of breast-feeding contributes significantly to inter-population differences in fertility. In this paper, measures of suckling frequency and intensity are used to compare the effects of breast-feeding practices on the duration of lactational amenorrhoea, and on the length of the birth interval in three prospective studies undertaken during the 1980s, among Quechua Indians of Peru, Turkana nomads of Kenya, and Gainj of Papua New Guinea. In all three societies, lactation is prolonged well into the second year postpartum, and frequent, on-demand breast-feeding is the norm. However, the duration of lactational amenorrhoea and the length of birth intervals vary considerably. Breast-feeding patterns among Gainj and Turkana are similar, but Turkana women resume menses some 3 months earlier than do the Gainj. The average birth interval among the Gainj exceeds that of nomadic Turkana by over 15 months. Suckling activity decreases significantly with increasing age of nurslings among both Gainj and Quechua, but not among Turkana. Earlier resumption of menses among Turkana women may be linked to the unpredictable demands of the pastoral system, which increase day-to-day variation in the number of periods of on-demand breast-feeding, although not in suckling patterns. This effect is independent of the age of infants. The short birth intervals of Turkana women, relative to those of the Gainj, may be related to early supplementation of Turkana nurslings with butterfat and animals' milk, which reduces energetic demands on lactating women at risk of negative energy balance.

Determinants of birth intervals in Vietnam: a hazard model analysis.

There was absence of any regional differences in parity progressions and length of birth intervals, although urban-rural differences persisted at most birth orders, suggesting that, as in other studies, the urban-rural differentials are the primary source of variations in fertility between different areas of a country. The significantly higher probability of a subsequent birth after birth order 2 in areas with high infant mortality compared to those with low infant mortality suggests that women in the high-risk provinces may be more likely to advance beyond parity 2 and continue on into the advanced parities. The provinces identified as having high infant mortality had also been identified in other studies as the provinces with the highest crude birth rates and population growth rates, the least available family planning services, and highest crude death rates. Mothers' education was consistently related to the likelihood of another birth at each birth order, with the most-educated women experiencing a significantly lower probability of having a subsequent birth at every birth order. This concurs with results in other studies, suggesting that the woman's education is a prime determinant of fertility and that increasing the educational attainment of women is one of the most beneficial measures to reduce fertility. The significant relationship between the previous birth interval of the index child and the probability that the index child would be followed by a subsequent birth conforms with other studies of birth interval dynamics that suggest that pregnancy-spacing for a given woman remains constant throughout her reproductive career.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of oxygen and neostigmine on stillbirth and pig viability

In this experiment, 98 multiparous Yorkshire sows blocked on farrowing date were randomly assigned to four treatments in a 2 x 2 factorial arrangement. Oxygen inhalation (6 L/min) by the sow was tested in an effort to reduce stillbirth rate and improve pig viability. This study also tested the effect of increasing uterine contractions using neostigmine (5 mg) to determine whether simultaneous administration of oxygen to the sow could improve the inconsistent response of stillbirth rate to neostigmine. Pig viability was assessed using viability scoring and blood gas analysis of samples obtained from the suborbital sinus immediately after birth. The farrowings averaged 12.2 pigs/litter, 7.8% stillbirths, and 3.5% low viability (viability score < or = 6) pigs. Treatment had no effect on stillbirth rate or pig viability. Oxygen treatment increased pO2 (P = .0002), increased pCO2 (P = .02), and decreased pH (P = .02) in sow venous blood sampled after the birth of the last pig, but it had no effect on pig venous blood gases. Neostigmine treatment had no effect on either sow or pig venous blood gases. Oxygen treatment doubled the length of the first birth interval after the start of treatment (P = .003) but had no effect on remaining birth intervals. Neostigmine had no effect on birth interval. It is suggested that the effect of oxygen on birth interval is the reason for the lack of improvement in stillbirth rate.

Age at return marriage and timing of first birth in India's Uttar Pradesh and Kerala states.

The study investigates the relationship between age at marriage and the length of first birth interval in two states of India: Uttar Pradesh and Kerala. Life tables of first-birth intervals and median first-birth intervals are computed for several subgroups of the study population. Multivariate hazards modelling technique is used to study the net effect of age at marriage, controlling for a multiple of socioeconomic factors. The result shows that the average first-birth interval varies by age at marriage and is much longer in Uttar Pradesh than in Kerala.

Preceding Birth Intervals and Child Survival: Searching for Pathways of Influence

The importance of the length of preceding birth intervals for the survival chances of young children has been established, but the debate concerning the causal biomedical or behavioral mechanisms continues. This article uses data from 17 Demographic and Health Surveys to investigate the effect of birth intervals on child mortality: Anthropometry of children, recent morbidity of children, and use of health services are examined in addition to child survival data for children born in the five years before the survey. Various methodological approaches are used to investigate the relative importance of the postulated mechanisms linking birth intervals and child survival. Short preceding birth intervals are associated with increased mortality risks in the neonatal period and at 1-6 months of age, and, to a much lesser extent, at 7-23 months of age. The effects of short birth intervals on nutritional status are rather moderate, and there is a weak relationship with lower attendance at prenatal care services. No consistent relationship exists between the length of birth intervals and other health status or health-service utilization variables. The results indicate that prenatal mechanisms are more important than postnatal factors, such as sibling competition, in explaining the causal nature of the birth interval effect.

Polygyny and Fertility among the Shipibo of the Peruvian Amazon

This report describes a study of the fertility experience of an Amazon Indian tribe that has shown evidence of having the highest documented fertility of any human group. The Shipibo, who live in the upper Peruvian Amazon, are experiencing rapid cultural change, including a decline in the prevalence of polygyny. This study tests the specific hypotheses that polygyny limits individual female and community fertility through the mechanism of post partum sexual abstinence and longer birth intervals. Total population counts in eight villages and reproductive histories of all females age 13+ show that mean birth interval lengths of polygynous women are four months longer than those of monogamous women. Fertility of polygynous women was lower, with 1.3 fewer term-births per reproductive span than that of monogamous women. The community general fertility rate is negatively associated with the proportion of polygynous birth intervals in the community. In this study, cultural change is strongly associated with higher fertility.

Management parameters affecting the reproductive potential of captive, female black rhinoceros, Diceros bicornis

AbstractWith deterioration of the wild population over the last two decades, captive reproduction of black rhinoceros has become a high priority for zoological gardens. Several reproductive parameters of female black rhinoceros were analyzed with data from the international studbook, and compared to data from field studies. These analyses yielded comparisons for ages of females at first calving, length of birth intervals, and span of reproductive life. The implications for rhino productivity are discussed, and some suggestions for increasing productivity are presented. © 1992 Wiley‐Liss, Inc.

Birth spacing and infant mortality: evidence for eighteenth and nineteenth century German villages

Data from an historical population in which fertility control was minimal and modern health services were mostly unavailable are used to show that there appears to have been a strong association between previous birth interval length and infant mortality, especially when the previous child survived. Although only imperfect proxies for breast-feeding practices and other potentially confounding factors are available for this population, the results suggest that the association between previous interval length and infant mortality in this population is not solely, or primarily, a function of differences in breast-feeding behaviour or socioeconomic status. Other factors, e.g. maternal depletion or sibling competition, are more likely to explain the observed association.

On some probability distributions for forward birth interval.

Statisticians from Varanasi, India have proposed 2 mathematical models for forward birth interval which are more realistic than past models. For example, past models have assumed fecundability to be constant throughout a woman's reproductive life. On the other hand, the proposed models assume fecundability changes with parity. Further the statisticians use all types of marital durations making their models usable even for short marriage durations. The 1st model uses a parity specific model to develop a model for forward birth interval regarless of parity. The statisticians also include moments of the 1st and 2nd models as expressed for the rth order raw movement of these models to estimate some of their parameters. These models can be used to conduct prospective surveys of family planning programs since birth intervals can best evaluate the effect of these programs. These models have not yet been advanced enough to follow women over a fixed period, however. They only observe women until the last woman conceives. The statisticians do not apply the models to parity specific data because they were not available. Yet they do run the models with parities 0 and 1. The models reveal that the mean length of forward birth interval is strongly influenced by the conception rate which the woman has at the time of the survey. Thus, if women with a certain parity in a community begin an effective family planning method on the survey day, which in effect would reduce the prevailing conception rate, that method would significantly postpone the next live birth.

Birth Interval Among Breast-Feeding Women Not Using Contraceptives

One hundred twelve Orthodox Jewish mothers were surveyed by means of questionnaire about birth interval in relationship to formula-feeding (n = 30) and breast-feeding (n = 236) experiences in the absence of birth control. Analyses indicate that mothers who breast-fed have longer birth intervals than those who did not. Moreover, data obtained from the same mothers show that birth intervals preceded by breast-feeding were longer than those preceded by formula-feeding of the previous infant. For those mothers who breast-fed, there was significant positive correlation between duration of breast-feeding and the length of lactational amenorrhea and total birth interval. The age at which night feeding was terminated had corresponding but less strong associations with lactational amenorrhea and total birth interval.

Birth Spacing Patterns and Correlates in Shaanxi, China

This study shows that most women in Shaanxi Province, China try to have their first birth as soon as possible after their first marriage, and that the length of the interval between marriage and first birth is strongly correlated with the woman's age at first marriage. The length of the second and third birth intervals and the likelihood of going on to have a second or third birth are strongly influenced by the sex composition of children already born, the survival time of the child initiating the interval, the duration of breastfeeding, and the woman's occupation. There is significant regional variation in the length of birth intervals and in the prevalence of second and third births in Shaanxi. The findings indicate that China's one-child policy is far from being universally accepted in Shaanxi, including its urban areas. The persistence of many social, economic, institutional, and cultural factors promoting high fertility poses many obstacles to further fertility decline.

Correlates of Short Interbirth Intervals in Peninsular Malaysia: Their Pathways of Influence Through Breastfeeding and Contraceptive Use

Recent research has shown that children born before and after short birth intervals run a considerably greater risk of dying in infancy or childhood than do others. This report investigates which women have short interbirth intervals, under what circumstances, and for what reasons. The analysis uses data from the Malaysian Family Life Survey to examine influences on the two main behaviors--breastfeeding and contraceptive use--that affect birth interval length, and assesses the the impact of these same variables on the probability of having a birth interval of less than 15 months. The analysis shows that many of the independent variables affect breastfeeding and contraceptive use in opposite directions, with no significant net effect on the likelihood of a short interval. For example, a woman's education is negatively related to the probability that she breastfeeds, positively related to the probability that she uses contraceptives, and has no significant effect on the likelihood that the interpregnancy interval is less than 15 months. Having a family planning clinic nearby is associated with less breastfeeding, offsetting whatever positive effects family planning clinics have on contraceptive use in terms of the percentage of birth intervals that are so short as to be detrimental to infant and child health. Hence, factors that increase contraceptive use do not necessarily reduce the incidence of short interbirth intervals, because they are also associated with reduced breastfeeding. We simulate the proportion of intervals that would be short for alternative combinations of breastfeeding and contraceptive use in the population and show that over the period covered by the data (1961-75), breastfeeding had a considerably greater effect on preventing short interbirth intervals than did contraceptive use.

Birth Interval Among Breast-Feeding Women Not Using Contraceptives

One hundred twelve Orthodox Jewish mothers were surveyed by means of questionnaire about birth interval in relationship to formula-feeding (n = 30) and breast-feeding (n = 236) experiences in the absence of birth control. Analyses indicate that mothers who breast-fed have longer birth intervals than those who did not. Moreover, data obtained from the same mothers show that birth intervals preceded by breast-feeding were longer than those preceded by formula-feeding of the previous infant. For those mothers who breast-fed, there was significant positive correlation between duration of breast-feeding and the length of lactational amenorrhea and total birth interval. The age at which night feeding was terminated had corresponding but less strong associations with lactational amenorrhea and total birth interval.