Long-term effects of childbearing on mortality: evidence from pre-industrial Sweden

This paper presents an analysis of the impact of childbearing history on later-life mortality for ever-married men and women using historical micro-level data of high quality for southern Sweden. The analysis uses a Cox proportional hazards model, estimating the effects on old-age mortality of number of births and timing of first and last births. By studying the effects of previous childbearing on mortality by sex and social status, we also gain important insights into the mechanisms relating childbearing to mortality in old age. The results show that number of children ever born had a statistically significant negative impact on longevity after age 50 for females but not for males. Analysis by social group shows that only landless women experienced higher mortality from having more children, which seems to indicate that the main explanations are to be found in social or economic conditions specific to females, rather than in the strictly biological or physiological effects of childbearing.     

Long-term effects of childbearing on mortality: Evidence from pre-industrial Sweden

This paper presents an analysis of the impact of childbearing history on later-life mortality for ever-married men and women using historical micro-level data of high quality for southern Sweden. The analysis uses a Cox proportional hazards model, estimating the effects on old-age mortality of number of births and timing of first and last births. By studying the effects of previous childbearing on mortality by sex and social status, we also gain important insights into the mechanisms relating childbearing to mortality in old age. The results show that number of children ever born had a statistically significant negative impact on longevity after age 50 for females but not for males. Analysis by social group shows that only landless women experienced higher mortality from having more children, which seems to indicate that the main explanations are to be found in social or economic conditions specific to females, rather than in the strictly biological or physiological effects of childbearing.     

An analysis of baby boom characteristics in China

This article analyzed the 3rd Chinese baby boom and its causes by focusing on the fertility intensity of women and the number of births per year. The 3rd baby boom is expected to end in 2002 and to peak in 1995. The baby boom in urban areas will last a much shorter time than in rural areas. Particular differences are manifested between provinces: 1) The baby boom will last 3-4 years in Beijing, Shanghai, and Tianjin, and will last 10 years in Liaoning, Jilin, and Jiangsu. In other provinces, the boom will last 15-23 years; 2) The peak years are different between provinces; 3) The base number of births curves are province-specific; 4) The absolute base birth numbers are different between provinces (Jiangsu, Shandong, Henan, and Sichuan 700,000; Beijing, Tianjin, Qinghai, and Ningzia 100,000); and 5) The shapes of progressive increases for base number of births are province specific. The increase in the number of childbearing-age women, the unplanned higher parity births, and early marriage and childbearing have all contributed to the current baby boom. Recommendations to control the problem include controlling higher parity births, observing birth spacing, and controlling the age of marriage and childbearing.     

Proximate determinants of Philippine fertility: 1983 levels and patterns

Data from the 1983 National Demographic Survey are used to analyze the proximate determinants of Philippine fertility in each of the 3 stages of family formation and to identify all of the direct and indirect factors affecting fertility levels and trends. 10,843 ever-married women and 12,771 children were included. The analysis pertains first to the starting patterns of family formation, the age at first birth, and the proximate determinants (age at menarche, age at first marriage/union, conception before first birth, fetal wastage first birth, interval between first marriage and first birth). Further analysis examines birth spacing patterns including the postpartum nonsusceptible period, the exposure interval and stopping patterns. Almost all births occur within marriage, and childbearing begins late at 22.5 years. However, 15.4% of first births are conceived premaritally. The mean age at first birth increases from younger to older cohorts. Urban women were slightly older (23.0 years) at the birth of their first child. Those with education below the 4th grade had first births 3.5 years earlier. Contraceptive use was low at 1.8% before first birth. Younger cohorts were more likely to use birth control and urban wives were more likely to use it than rural wives. 6.4% reported a first pregnancy ending in nonlive births, which were primarily spontaneous abortions (5.2%), stillbirths (1.0%), and induced abortions (.2%). 5.8% report never having been pregnant and 1.1% never having given birth to a live-born child. 20.4% were childless between the ages of 15-24 years, and 4.6% between 25-34 years. Childlessness was slightly higher among urban women (7.1%) than rural women (6.7%). A decreasing age at menarche has appeared; i.e., 13.6 years for the cohort 15-24 years, and 14.0 for the oldest cohort. By age 15, 82.9% had begun menstruating. The mean age at marriage is early at 20.7 years, and older cohorts tended to marry later at 21.4 years. Urban women marry a year later (21.4 years) than rural women. Lower educated women marry 4 years earlier. The mean length between first marriage and first birth was 18.4 months. In the younger cohorts, spacing patterns are shorter. Postpartum susceptibility is short. Return to sexual relations after a birth occurred at 2.8 months. The exposure time required to conceive is fairly long at 16.6 months and is attributed to contraceptive use, since coital frequency is high and temporary separation is infrequent. The average age at last birth is late at 37.6 years.     

Age at last birth and its components

This paper examines the ways in which the behavior of twentieth century cohorts of American women changed simultaneously in the three components of fertility that determine age at last birth--age at first birth, spacing between subsequent births, and parity progression ratios of subsequent births--to produce changes in the timing of the completion of childbearing. It decomposes changes in the mean age at last birth among cohorts and between whites and nonwhites to changes in these three components. To perform these analyses, we developed and applied a method to estimate the distributions and means of ages and last births, birth intervals, and parity progression ratios from age- and parity-specific fertility rates available from vital statistics data. Results show that the cohorts increased and decreased their age at first birth, birth intervals, and parity progression ratios of lower and higher birth orders in almost every possible combination so as to achieve a relatively young age at final birth.     

Sibling models of socioeconomic effects on the timing of first premarital birth

Data on 1,090 pairs ofsisters from the National Longitudinal Survey of Youth are used to estimate the effects of observed individual-level factors, common family-level variables, and shared unobserved family-level traits on the timing of premarital births. Results show a moderate correlated risk of premarital childbearing among siblings after controlling for the effects of measured covariates. The effect of older sisters’ out-of-wedlock childbearing on the timing of younger sisters’ premarital birth is overestimated when shared unmeasured family-level traits are ignored. Public policy measures designed to reduce premarital births have a smaller multiplier effect via reduced younger sisters’ premarital births because unmeasured family-level factors are less amenable to policy measures. However, because the older-sibling effect is large when other sources of variability in premarital birth timing are controlled, interventions may be effective in reducing premarital births among young women in high-risk families.     

The family formation process among U.S. marriage cohorts

The family formation process is viewed as the progression of women through first marriage, first, subsequent, and last births and is examined for differential patterns of timing in 1930–1969 marriage cohorts. Based on the childbearing histories of approximately 17,000 white women once and still married, extracted from the June 1975 Current Population Survey, the study uses a dynamic model to show the varying importance across cohorts of the first birth interval as an important indicator of the total time spent in childbearing, social background effects in differentiating the timing of the first two births, and of prior birth transitions as affecting subsequent ones.     

Childbearing Across Partnerships in Australia,the United States,Norway, and Sweden

This article compares mothers’ experience of having children with more than one partner in two liberal welfare regimes (the United States and Australia) and two social democratic regimes (Sweden and Norway). We use survey-based union and birth histories in Australia and the United States and data from national population registers in Norway and Sweden to estimate the likelihood of experiencing childbearing across partnerships at any point in the childbearing career. We find that births with new partners constitute a substantial proportion of all births in each country we study. Despite quite different arrangements for social welfare, the determinants of childbearing across partnerships are very similar. Women who had their first birth at a very young age or who are less well-educated are most likely to have children with different partners. The educational gradient in childbearing across partnerships is also consistently negative across countries, particularly in contrast to educational gradients in childbearing with the same partner. The risk of childbearing across partnerships increased dramatically in all countries from the 1980s to the 2000s, and educational differences also increased, again, in both liberal and social democratic welfare regimes.     

Intergenerational patterns of teenage fertility

One of the frequently cited consequences of teen childbearing is the repetition of early births across generations, which thereby perpetuates a cycle of poverty and disadvantage. We use data from the 1988 National Survey of Family Growth (NSFG), Cycle IV, to examine trends and determinants of the intergenerational teen fertility link for women who reached adolescence between the 1950s and the 1980s. We find that daughters of both white and black teen mothers face significantly higher risks of teen childbearing than daughters of older mothers. We also find, more generally, that patterns of teenage family formation (i.e., both marriage and childbearing behaviors) tend to be repeated intergenerationally. The results suggest that the intrafamily propensity for early childbearing is not inherited biologically, at least not through factors related to the timing of puberty. Rather, the intergenerational patterns appear to operate at least in part through the socioeconomic and family context in which children grow up.     

The Effect on Fertility of the 2003–2011 War in Iraq

This article provides the first detailed account of recent fertility trends in Iraq, with a particular focus on the changes resulting from the 2003–2011 war and the factors underlying them. The study is based on retrospective birth history data from the 2006 and 2011 Iraq Multiple Indicator Cluster Surveys (I‐MICS). Estimates from the two surveys indicate that total fertility remained stable from 1997 to 2010, at about 4.5 children per woman. However, examination of the age patterns of fertility reveals an abrupt shift in the timing of births, with adolescent fertility rising by over 30 percent soon after the onset of the war. A decomposition analysis shows that the rise in early childbearing is due to an increased prevalence of early marriage among less‐educated women. The prevalence of early marriage and childbearing among women with secondary or higher education is relatively low and has not increased after 2003.     

Age at marriage and timing of the first birth

Summary An attempt has been made to measure the effect of age at marriage of brides on the timing of the first birth. In Australian vital statistics, first nuptial confinements have been tabulated by age of mothers and by single years of marriage duration in single months for the first two years and by single years for all other durations since 1916. A simple technique has been used to link such data with marriage cohorts. The study briefly reviews the prevailing patterns of the timing of first births by mothers' age at marriage and changes in this pattern since the marriages of the 1925/9 period. The analysis shows that after a period of relative stability of family formation patterns in the 1950s and early 1960s, women married in the late 1960s started postponing the first birth beyond the first two years of marriage. It is suggested that a fraction of the decline in total births recorded in Australia since 1972 can be attributed to the postponement of first nuptial confinements by women married in the late 1960s and early 1970s.     

Interrelationships Between Childbearing and Housing Transitions in the Family Life Course

Research has examined the effect of family changes on housing transitions and childbearing patterns within various housing types. Although most research has investigated how an event in one domain of family life depends on the current state in another domain, the interplay between them has been little studied. This study examines the interrelationships between childbearing decisions and housing transitions. We use rich longitudinal register data from Finland and apply multilevel event history analysis to allow for multiple births and housing changes over the life course. We investigate the timing of fertility decisions and housing choices with respect to each other. We model childbearing and housing transitions jointly to control for time-invariant unobserved characteristics of women, which may simultaneously influence their fertility behavior and housing choices, and we show how joint modeling leads to a deeper understanding of the interplay between the two domains of family life.     

The effect of number of births on women's mortality: systematic review of the evidence for women who have completed their childbearing

Mortality in women who have completed their childbearing may increase with the number of births experienced because of maternal depletion or a trade-off between reproduction and mortality. We report a systematic review of the evidence on this association. We searched Medline, Embase, Popline, and the Science Citation Index for published and unpublished studies up to September 2003, and the book catalogues of relevant London libraries. Where necessary we also contacted authors for additional information. Mortality declined with increasing numbers of births in twelve historical cohorts, but in eight contemporary cohorts the highest mortality was seen in the nulliparous and in women with more than four births. All effects seen were small and there were few statistically significant results. Studies examining the relationship in other ways (such as by linear trends or by mean number of births by age at death) found inconsistent associations. We discuss methodological, social, and biological factors that may have affected these associations.     

What’s happening to the age at first birth in the United States? A study of recent cohorts

This paper analyzes cross-cohort trends in the age pattern of women at first birth in the United States. The analysis involves fitting the Coale-McNeil marriage model to the age distribution of first birth frequencies for a number of recent white and nonwhite cohorts. Methodologically, the results (a) provide support for the application of the Coale-McNeil marriage model to first birth data, and (b) demonstrate the ability of the model to accurately project first birth fertility for cohorts which have yet to complete their childbearing years. Substantively the results indicate (a) that the proportion of women who will never have a first birth is increasing across cohorts and can be expected to be as high as .25 and .20 for recent white and nonwhite cohorts respectively; (b) that recent nonwhite cohorts have an appreciable number of first births at earlier ages than their white counterparts, as well as a lower mean age at first birth and increasingly less dispersion (across cohorts) in their age at first birth; and (c) that the mean age at first birth and the proportion of first births occurring between ages 25 and 34 is increasing across cohorts of white women but is stable across cohorts of nonwhite women.     

Target Fertility,Contraception, And Aggregate Rates: Toward A Formal Synthesis

This paper develops a stock adjustment model relating total expected births to conventional aggregate fertility rates for married women over 25. Each year, cohorts bear about 20 percent of their additional expected births. Aggregate U.S. rates have been consistent with expectations as expressed in surveys between 1955 and 1975; indeed, total expected births may be inferred from aggregate fertility behavior. A peculiar empirical finding is that the additional expected fertility of nonterminators has not changed since 1955, despite the dramatic decline in total expected and actual fertility. The model leads to a dynamic expression for the duration pattern of current and cumulative fertility and for the proportion of couples who have terminated childbearing. The model is also used to analyze the effects of changing contraceptive failure rates on fertility patterns. For example, a decline in “timing” failure rates increases duration-specific fertility five years later.     

Individual and aggregate influences on the age at first birth

This study examines the role of both individual adolescent expectations of market and nonmarket income and aggregate influences on first birth timing for Blacks and Whites and for three birth cohorts of American women. Using two panels of the National Longitudinal surveys, results suggest that between-race differences in age at first birth result from differences in individual expectations about market and nonmarket income. Cohort differences in age at first birth result from relationship differences in both individual and aggregate influences, with aggregate influences differentially altering the role of individual expectations on first birth timing. These results suggest that employment policies that reduce poverty and increase wages would effectively delay childbearing. For Blacks, since early childbearing results from lower expectations about future economic success, similar fertility timing patterns between the races would result if Blacks had White employment and wage levels. Over time, these employment and wage policies will not only alter individual expectations about economic success but also will alter the impact of expectations on fertility timing.     

Labour-market status and first-time parenthood: the experience of immigrant women in Sweden, 1981-97

This paper investigates the impact of labour-market attachment on first births of foreign-born women in Sweden. The study uses a longitudinal, register-based dataset consisting of the entire population of immigrants from ten nations and a 5-per-cent random sample of natives. The effects of earned income are evident, with increased income levels increasing the probability of becoming a mother for all observed nationalities. The effects of various forms of participation and non-participation in the labour force do not vary greatly between immigrants and the Swedish-born. Among all subgroups, we find a higher propensity to begin childbearing among those who are established in the labour market. Contrary to popular belief, receiving welfare benefits clearly reduces first-birth intensity for immigrants but not for natives. The similarity in patterns across widely different national groups supports the notion that various institutional factors affecting all subgroups are crucial in influencing childbearing behaviour.     

Does It Matter What She Wants? The Role of Individual Preferences Against Unmarried Motherhood in Young Women’s Likelihood of a Nonmarital First Birth

Most young people in the United States express the desire to marry. Norms at all socioeconomic levels posit marriage as the optimal context for childbearing. At the same time, nonmarital fertility accounts for approximately 40 % of U.S. births, experienced disproportionately by women with educational attainment less than a bachelor’s degree. Research has shown that women’s intentions for the number and timing of children and couples’ intent to marry are strong predictors of realized fertility and marriage. The present study investigates whether U.S. young women’s preferences about nonmarital fertility, as stated before childbearing begins, predict their likelihood of having a nonmarital first birth. I track marriage and fertility histories through ages 24–30 of women asked at ages 11–16 whether they would consider unmarried childbearing. One-quarter of women who responded “no” in fact had a nonmarital birth by age 24–30. The ability of women and their partners to access material resources in adulthood were, as expected, the strongest predictors of the likelihood of nonmarital childbearing. Nonetheless, I find that women who said they would not consider nonmarital childbearing had substantially higher hazards of fertility postponement and especially of marital fertility, even after controlling for race/ethnicity, mother’s educational attainment, family of origin intactness, self-efficacy and planning ability, perceived future prospects, and markers of own educational attainment and work experience into early adulthood.     

UNIVERSAL VERSUS ECONOMICALLY POLARIZED CHANGE IN AGE AT FIRST BIRTH: A FRENCH-BRITISH COMPARISON

France and the United Kingdom represent two contrasting institutional models for the integration of employment and motherhood, respectively the 'universalistic' regime type that offers subsidized child-care and maternity-leave benefits to women at all income levels, and the 'means-testing' regime type that mainly offers income-tested benefits for single mothers. Using the two countries as comparative case studies, we develop and test the hypothesis that the socio-economic gradient of fertility timing has become increasingly mediated by family policy. We hypothesize and find increasing polarization in age at first birth by pre-childbearing occupation between the 1980s and 1990s in the U.K. but not in France. Early first childbearing persisted in the U.K. only among women in low-skill occupations, while shifts towards increasingly late first births occurred in clerical/secretarial occupations and above. Increases in age at first birth occurred across all occupations in France, but this was still much earlier on average than for all but low-skill British mothers.     

A probability model applicable to the study of inter-live birth intervals and random segments of the same

Abstract This paper deals with an analytical study of two types of birth intervals, viz. 'closed intervals' and 'open intervals' through the application of simple probability theory. The 'closed interval' stands for the time interval between two successive live births of a woman, and the 'open interval' denotes the interval between the date of last live birth and the date of survey for a married woman in the reproductive age group surveyed at a point of time. The study considers the 'closed interval' as the sum of independent random variables, each representing a particular component like post-partum amenorrhea, waiting time in the susceptible state, etc. Approximations to the patterns of distributions of these component random variables are made from the available data collected in fertility surveys at Gandhigram. The 'open interval' for any parity is studied separately for two different (mutually exclusive) categories of women, viz. those who have at least one more live birth at some time or other during their reproductive period and those who cease childbearing. In the first case the 'open interval' is considered as a random segment or partition of the corresponding 'closed interval'; in the second as a random segment of the interval between the date of birth of the last child and date at which the woman attains 45 years of age. The mean and variance of the 'open interval' is obtained separately in each case, and the moments of the 'open interval' distribution for women chosen at random from the population are obtained as an appropriate mixture of the two types.