Fertility history and cause-specific mortality: A register-based analysis of complete cohorts of Norwegian women and men

Fatherhood and Cardiovascular Health, Disease, and Mortality: Associations From the Multi-Ethnic Study of Atherosclerosis

Introduction

Emerging literature links fatherhood to men's health but lacks comprehensive assessment of health outcomes, especially among multiethnic populations. This study's objective was to evaluate the associations of fatherhood (age at onset and status) with cardiovascular health scores, incident cardiovascular disease, cardiovascular disease death, and all-cause mortality, examining differences by race/ethnicity.

Methods

The study sample included men from Multi-Ethnic Study of Atherosclerosis, prospective cohort study that enrolled adults aged 45-84 years without known cardiovascular disease at baseline. Cardiovascular health was defined using the American Heart Association's Life's Essential 8 scores (0-100), excluding sleep (cardiovascular health score).

Results

In this sample of 2,814 men, mean age at cardiovascular health assessment was 62.2 years, 82% were fathers, 24% self-identified as Black, 13% self-identified Chinese, 22% self-identified Hispanic, and 41% self-identified White. Fathers who were aged <20 years and 20-24 years at their oldest child's birth had worse overall cardiovascular health than fathers who were aged >35 years (adjusted mean score of 61.1 vs 64.7 [p=0.01] and 61.0 vs 64.7 [p<0.001], respectively). Fathers had worse overall cardiovascular health (adjusted mean score of 63.2 vs 64.7, p=0.03) and more nicotine exposure (63.1 vs 66.6, p=0.04) than nonfathers. In age-adjusted models, fathers overall (hazard ratio=0.82; 95% CI=0.69, 0.98) and Black fathers (hazard ratio=0.73; 95% CI=0.53, 0.999) had a lower rate of all-cause mortality rate than nonfathers, but these associations were no longer significant in fully adjusted models.

Conclusions

Fatherhood is a social determinant of health, and understanding its influence may provide opportunities to improve men's health, particularly among men of color.

Associations of parity and cognitive decline, depression, and chronic comorbidity in West China: Results from WCHAT study

OBJECTIVE

To investigate the associations between parity (the number of offspring a female has borne) and cognitive function, depression, and chronic comorbidity in Western China.

METHODS

A total of 846 women aged 50-55 years were included in the current analysis. Cognitive status was measured using a 10-item short portable mental status questionnaire (SPMSQ). Depressive symptoms were assessed using the 15-item geriatric depression scale (GDS-15). Other characteristics were self-reported. The associations between parity and cognitive decline, depression, and chronic comorbidity were analyzed using univariable and multivariable models. Multivariable models were adjusted for age, ethnic group, occupation, marital status, educational level, lifestyle factors, and sleeping time.

RESULTS

Among the enrolled women, 26.71% were either childless or had one child, 47.40% had two children, 18.32% had three children, and 7.57% had ≥4 children. Compared to women with low parity, women with two or more children exhibited a higher risk of cognitive decline. Moreover, having four or more children was significantly associated with depression and chronic comorbidity. After adjusting covariates, women with three or more children exhibited a higher risk of cognitive decline than those with low parity. However, high parity was not significantly associated with depression or chronic comorbidity after adjustment for covariates.

CONCLUSION

Our study showed that ≥3 children was associated with cognitive decline in women. Longitudinal studies are needed to evaluate this conclusion and to investigate the mechanisms involved. More importantly, families and societies should pay more attention to women's long-term health outcomes related to fertility.

Survival costs and benefits of reproduction: A register-based study in 20th century Estonia

Patterns of individual variation in lifespan and senescence depend on the associations between parental survival and reproductive rates. We studied the associations between parity and survival among 579,271 Estonians born between 1905 and 1945 and in a cohort with a completed lifespan born in 1905-1927. For this cohort, selection for increased lifespan operated on both sexes, but it was stronger in men than in women. However, the median lifespan increased between the subsequent cohorts in women but stagnated in men. Selection for longer lifespan was caused by the below-average lifespan of individuals with no or single offspring. Despite a general positive selection for lifespan, survival costs of reproduction were also detected among a relatively small proportion of individuals with high parities, as mothers of two and fathers of two and three children had the highest median lifespans. Fathers of more than six children had better survival than fathers of few children in their reproductive age, but this association reversed after age 70. The reversal of this association between survival and parity at old age indicates that relative mortality risks between those with lower versus higher parities change across ages, as predicted by the antagonistic pleiotropy theory of aging.

Child rearing or childbearing? Risk of cardiovascular diseases associated to parity and number of children

BACKGROUND

An increased risk of cardiovascular diseases (CVD) has been associated with women's parity, but whether or not this association reflects a direct pregnancy effect, or exposure to factors related to childrearing, still appears unclear. We assessed the CVD risk associated with number of children separately by gender and tested effect modification by socioeconomic position (SEP) and employment status, in order to elucidate the possible mechanisms underlying this association.

METHODS

The study population was composed of 20,904 men and 25,246 women who were interviewed in one of two National Health Surveys conducted in 2000 and 2005 in Italy. These subjects were followed for CVD incidence up to 2014 through record-linkage with national archives of mortality and hospitalisations. CVD risk was estimated by Cox regression models that were adjusted for socio-demographics, perceived health, lifestyles, biological CVD risk factors and for other potential confounders.

RESULTS

CVD incidence was significantly increased among men with 3 or more children (HR = 1.26, 95% CI: 1.02-1.56) and among women with 2 and with 3 or more children (HR = 1.42, 95% CI: 1.10-1.83; and HR = 1.39, 95% CI: 1.03-1.87, respectively) compared to subjects without children and no significant gender differences were observed. Subjects with lower SEP displayed stronger associations with parity and a higher number of children for both genders; by contrast, no modifying effect of employment status was observed.

CONCLUSIONS

Taken together, the significant association between higher parity and CVD risk in both genders, and the higher risk of CVD associated with higher parity among lower SEP parents, suggests that childrearing has a potential effect on the development of CVD that is more pronounced among disadvantaged families, although a concurrent effect of childbearing cannot be completely excluded.

Number of children and disability pension due to mental and musculoskeletal disorders: A longitudinal register-based study in Norway

Earlier research has documented a relationship between parity and all-cause mortality, as well as parity and cause-specific mortality (e.g. cancer and cardiovascular disease mortality). Less is known about the relationship between parity and two very common (but less deadly) types of disorder: mental and musculoskeletal. We examine the association between parity and risk of disability pensioning from all causes and due to mental or musculoskeletal disorders, using Norwegian register data. In addition to controlling for adult socio-demographic characteristics, we control for unobserved confounding from family background by estimating sibling fixed-effects models. We find a higher risk of disability pensioning among the childless and those with one child than for parents with two children, both for all causes combined and for mental disorders. Childless men and fathers with one child also experience excess risk of being pensioned due to musculoskeletal disorders. For mental disorders, we find a positive association with high parity, particularly for men.

Parity and hypertension risk in couples: does number of parity matter: findings from Tehran Lipid and Glucose Study

BACKGROUND AND AIMS

As reported, hypertension (HTN) plays a leading role in explaining mortality worldwide, but it still has many confounding factors. This study explored whether the number of parity and age matters for HTN among couples from the Tehran Lipid and Glucose Study (TLGS).

METHODS

This study was conducted on 2851 couples from TLGS. All the variables were collected based on the standard protocol. The participants were categorized into four and five categories according to the number of parity (childless, one, two, three, or more parities) and age (18-30y, 30-40y, 40-50y, 50-60y, and 60-70y), respectively. Spline regression models via log link function for the binary outcome and linear link function for continuous outcomes were applied to evaluate the effect of interaction term age and parity categories on the desired outcome.

RESULTS

Among the total of 2851 pairs, 2.3% had no child, 9.5% had 1 child, 38.4% had 2 children, and 49.8% had ≥ 3 children. The adjusted risk (95% CI) of HTN in females aged 40-50y with 1 child, 2 and ≥ 3 children compared to no child were 1.14(1.04, 1.26), 1.05(1.01, 1.10), 1.12(1.07, 1.17), respectively (p < 0.05). Moreover, in those aged 50-60y with 2 and ≥ 3 children, the risk of HTN significantly increased by 4%. In females aged 60-70y with ≥ 3 children compared to those without children, the risk of HTN increased by 2%. For males aged 30-40y with 2 children compared to the no child group, the adjusted risk of HTN increased by 17%, while for those with ≥ 3 children in the same age group, this risk significantly decreased by 13%. Moreover, in males aged 30-40y with 2 children, risk ratio of HTN increased by 17%, but in males with ≥ 3 children, it decreased by 13% and in those in the same groups but aged 40-50y the risk increased by 6% and 11%, respectively.

CONCLUSION

Our findings suggest that gender, childlessness, having one child, and multi-parity had different impacts on HTN. Further research is needed to confirm our findings.

Sex-Specific Reproductive Factors Augment Cardiovascular Disease Risk in Women: A Mendelian Randomization Study

Background Observational studies suggest that reproductive factors are associated with cardiovascular disease, but these are liable to influence by residual confounding. This study explores the causal relevance of reproductive factors on cardiovascular disease in women using Mendelian randomization. Methods and Results Uncorrelated (r2<0.001), genome-wide significant (P<5×10-8) single-nucleotide polymorphisms were extracted from sex-specific genome-wide association studies of age at first birth, number of live births, age at menarche, and age at menopause. Inverse-variance weighted Mendelian randomization was used for primary analyses on outcomes of atrial fibrillation, coronary artery disease, heart failure, ischemic stroke, and stroke. Earlier genetically predicted age at first birth increased risk of coronary artery disease (odds ratio [OR] per year, 1.49 [95% CI, 1.28-1.74], P=3.72×10-7) heart failure (OR, 1.27 [95% CI, 1.06-1.53], P=0.009), and stroke (OR, 1.25 [95% CI, 1.00-1.56], P=0.048), with partial mediation through body mass index, type 2 diabetes, blood pressure, and cholesterol traits. Higher genetically predicted number of live births increased risk of atrial fibrillation (OR for <2, versus 2, versus >2 live births, 2.91 [95% CI, 1.16-7.29], P=0.023), heart failure (OR, 1.90 [95% CI, 1.28-2.82], P=0.001), ischemic stroke (OR, 1.86 [95% CI, 1.03-3.37], P=0.039), and stroke (OR, 2.07 [95% CI, 1.22-3.52], P=0.007). Earlier genetically predicted age at menarche increased risk of coronary artery disease (OR per year, 1.10 [95% CI, 1.06-1.14], P=1.68×10-6) and heart failure (OR, 1.12 [95% CI, 1.07-1.17], P=5.06×10-7); both associations were at least partly mediated by body mass index. Conclusions These results support a causal role of a number of reproductive factors on cardiovascular disease in women and identify multiple modifiable mediators amenable to clinical intervention.

Life-course fertility and multimorbidity among middle-aged and elderly women in China: Evidence from China health and retirement longitudinal study

Background

Multimorbidity has become an important public health problem in China, especially among middle-aged and elderly women. Few studies have been reported on the association between multimorbidity and female fertility, which is an important stage in the life course. This study aimed to explore the association between multimorbidity and fertility history among middle-aged and elderly women in China.

Methods

Data from 10,182 middle-aged and elderly female participants in the China Health and Retirement Longitudinal Study (CHARLS) in 2018 were used in this study. Multimorbidity was defined as the presence of at least two or more chronic conditions. Logistic regression analysis, negative binomial regression analysis, and restrictive cubic splines (RCSs) were used to analyze the relationship between female fertility history and multimorbidity or the number of chronic conditions. Multivariable linear regression was used to analyze the relationship between female fertility history and multimorbidity pattern factor scores.

Results

The results of this study showed that high parity and early childbearing were significantly associated with an increased risk of multimorbidity and an increased number of chronic conditions among middle-aged and elderly women in China. Late childbearing was significantly associated with reduced risk of multimorbidity and lessened diseases. Parity and age of first childbirth were significantly correlated with the odds of multimorbidity. The association between fertility history and multimorbidity was found to be influenced by age and urban-rural dual structure. Women with high parity tend to have higher factor scores of cardiac-metabolic, visceral-arthritic, and respiratory-psychiatric patterns. Women with early childbearing tended to have higher factor scores of the visceral-arthritic pattern and those with late childbearing tended to have lower factor scores of the cardiac-metabolic pattern.

Conclusion

Fertility history has a significant effect on multimorbidity in the middle and later lives of Chinese women. This study is of great importance for reducing the prevalence of multimorbidity among Chinese women through their life course and promoting health during their middle and later lives.

Intersections between adolescent fertility and obesity-pathways and research gaps focusing on Latin American populations

Latin America has notably elevated rates of adolescent fertility and obesity in women. Although numerous studies document associations between adolescent fertility and obesity across the life course, the pathways explaining their association are insufficiently theorized, especially regarding the factors in Latin America that may underpin both. Additionally, much of the existing research is from high-income countries, where fertility and obesity are trending down. In this paper, we review the various complex pathways linking adolescent fertility and obesity, highlighting research gaps and priorities, with a particular focus on Latin American populations. We carefully consider pregnancy's distinct impact on growth trajectories during the critical period of adolescence, as well as the cumulative effect that adolescent fertility may have over the life course. We also articulate a pathway through obesity as it may contribute to early puberty and thus, to adolescent fertility. If obesity is a cause of adolescent fertility, not a result of it, or if it is a mediator of early-life exposures to adulthood obesity, these are critical distinctions for policy aiming to prevent both obesity and early fertility. Research to better understand these pathways is essential for prevention efforts against obesity and undesired adolescent fertility in Latin America.

Number of Births and Later-Life Depression in Older Adults: Evidence from China

Previous studies on the number of births and the health of the elderly have been highly focused on physical health and used samples from developed countries. Therefore, this study aimed to explore the effect of the lifetime number of births on depression in Chinese older adults. We used panel data for men and women aged 50 and over from the 2013-2018 China Health and Retirement Longitudinal Study. Depressive symptoms were assessed through a short form of the Center for Epidemiologic Studies Depression Scale. We found that depression levels in women were significantly higher than in men, with a mean difference of 2.44 (p < 0.001). The model estimation results indicated that the number of births affected depression in older adults, and its increase could exacerbate depression in older adults. The number of births significantly impacted depression among the elderly aged 50-69. Furthermore, there was a negative relationship between the proportion of sons and older adults' depression, which was significant in older males; the number of abortions may exacerbate depression in older adults, especially in females.

The association between reproductive history and the multidimensional health of older adults in rural China and its gender differences: Evidence from the Chinese longitudinal healthy longevity survey

Background

Few studies have examined the association between reproductive history and the multidimensional health of older adults with more diverse reproductive histories and poorer health status in rural China. The purpose of this study is to explore the effect of parity, sex ratio of children and late childbearing on multidimensional health and its gender differences.

Methods

The analytical sample consisted of 3,377 older adults in rural China who participated in the Chinese Longitudinal Healthy Longevity Survey (CLHLS) in 2018. Linear regression models were applied to estimate the relationship between reproductive history and multidimensional health, with separate models for each indicator of health outcomes.

Results

Older adults in rural areas with greater parity were more likely to have better cognitive function (β = 0.409, 95% CI: 0.255–0.563), fewer Activities of Daily Living (ADL) limitations (β = −0.085, 95% CI: −0.137 to −0.034) and symptoms of depression (β = −0.396, 95% CI: −0.577 to −0.216). The social mechanism of intergenerational support from children later in life partly explained the positive effect of parity. Late childbearing had negative effects on cognitive function (β = −1.220, 95% CI: −1.895 to −0.545), ADL (β = 0.253, 95% CI: 0.028–0.478) and symptoms of depression (β = 1.025, 95% CI: 0.237–1.812). Women were more likely to be influenced by the positive effect of parity; the association between late childbearing and health was only significant in the male group.

Conclusions

Parity and late childbearing are associated with cognitive function, activities of daily living, and symptoms of depression in the older adults in rural China. Older adults with more children might be in better health, and this finding is especially significant in women. However, late childbearing had a negative effect on multidimensional health, especially for men. The social mechanism and gender differences between reproductive history and health need to be further explored.

The Role of Fertility and Partnership History in Later-life Cognition

Cognitive ageing continues to be a significant burden for society and a primary contributor to individuals’ diminishing independence and quality of life. Therefore, improving our understanding of life-course influences on cognitive function is a necessity for public health. Parenthood and marriage are two such influences that may affect cognition in old age. Using the Health and Retirement Study, the relationship between family histories and cognitive functioning in adults in the ‘older’ age group in the United States is investigated through a sequence-analysis approach. The results show that most of the relationship between fertility and partnership history and cognition later in life is explained by childhood health and socioeconomic conditions, and current sociodemographic characteristics. However, those individuals who have never been married, and in particular those who have never been married and have had no children, report a significantly lower level of cognitive functioning in older age, especially women.

Associations between epigenetic age acceleration and infertility

STUDY QUESTION

Is the use of ART, a proxy for infertility, associated with epigenetic age acceleration?

SUMMARY ANSWER

The epigenetic age acceleration measured by Dunedin Pace of Aging methylation (DunedinPoAm) differed significantly between non-ART and ART mothers.

WHAT IS KNOWN ALREADY

Among mothers who used ART, epigenetic age acceleration may be associated with low oocyte yield and poor ovarian response. However, the difference in epigenetic age acceleration between non-ART and ART mothers (or even fathers) has not been examined.

STUDY DESIGN, SIZE, DURATION

The Norwegian Mother, Father and Child Cohort Study (MoBa) recruited pregnant women and their partners across Norway at around 18 gestational weeks between 1999 and 2008. Approximately 95 000 mothers, 75 000 fathers and 114 000 children were included. Peripheral blood samples were taken from mothers and fathers at ultrasound appointments or from mothers at childbirth, and umbilical cord blood samples were collected from the newborns at birth.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Among the MoBa participants, we selected 1000 couples who conceived by coitus and 894 couples who conceived by IVF (n = 525) or ICSI (n = 369). We measured their DNA methylation (DNAm) levels using the Illumina MethylationEPIC array and calculated epigenetic age acceleration. A linear mixed model was used to examine the differences in five different epigenetic age accelerations between non-ART and ART parents.

MAIN RESULTS AND THE ROLE OF CHANCE

We found a significant difference in the epigenetic age acceleration calculated by DunedinPoAm between IVF and non-ART mothers (0.021 years, P-value = 2.89E−06) after adjustment for potential confounders. Further, we detected elevated DunedinPoAm in mothers with tubal factor infertility (0.030 years, P-value = 1.34E−05), ovulation factor (0.023 years, P-value = 0.0018) and unexplained infertility (0.023 years, P-value = 1.39E−04) compared with non-ART mothers. No differences in epigenetic age accelerations between non-ART and ICSI fathers were found. DunedinPoAm also showed stronger associations with smoking, education and parity than the other four epigenetic age accelerations.

LIMITATIONS, REASONS FOR CAUTION

We were not able to determine the directionality of the causal pathway between the epigenetic age accelerations and infertility. Since parents’ peripheral blood samples were collected after conception, we cannot rule out the possibility that the epigenetic profile of ART mothers was influenced by the ART treatment. Hence, the results should be interpreted with caution, and our results might not be generalizable to non-pregnant women.

WIDER IMPLICATIONS OF THE FINDINGS

A plausible biological mechanism behind the reported association is that IVF mothers could be closer to menopause than non-ART mothers. The pace of decline of the ovarian reserve that eventually leads to menopause varies between females yet, in general, accelerates after the age of 30, and some studies show an increased risk of infertility in females with low ovarian reserve.

STUDY FUNDING/COMPETING INTEREST(S)

This study was partly funded by the Research Council of Norway (Women’s fertility, project no. 320656) and through its Centres of Excellence Funding Scheme (project no. 262700). M.C.M. has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement number 947684). The authors declare no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Fertility decline and the emergence of excess female survival in post-reproductive ages in Italy

In Italy, at least in the cohorts born up to the beginning of the twentieth century, women’s mortality in post-reproductive ages was influenced by fertility, with large progenies (and, to a lesser extent, childlessness) leading to markedly lower survival chances. This relationship proved strong enough to affect the female-to-male ratio in old age as fertility declined. In this paper, we show that various measures of extra female survival at high ages are closely connected to the fertility transition in Italy, and to its peculiar historical and geographical evolution.

Association between Parenthood and Health Behaviour in Later Life-Results from the Population-Based CARLA Study

Previous research has focused on comparing health behaviour between parents and non-parents at younger ages, while little is known about the impact of being a parent on health behaviours in later life. We studied whether parenthood is associated with later physical activity (PA), dietary pattern, smoking status and alcohol consumption in German adults of middle and old age. We used data from the baseline examination of the population-based CARLA-study in Halle (Saale), comprising 1779 adults aged 45-83. Linear and logistic regression analyses assessed the relationship between parenthood and health behaviours while controlling for age, partner status, education, income, occupational position, socioeconomic status in childhood, and number of chronic diseases. Of the participants, 89.1% had biological children. Being a father was associated with higher PA in sports (sport index ß = 0.29, 95% confidence interval [0.14; 0.44]), but not with PA in leisure time (excluding sports), dietary pattern, consumption of alcohol and smoking status. No associations were found between being a mother with all outcome variables. Provided that PA of fathers is typically reduced when the children are young, the development towards higher PA at later age needs to be studied in more detail.

Higher Parity Is Associated With Lower Mortality in a European Population of Women With High Fertility: Results From Ireland

Research has often found a U- or J-shaped association between parity and mortality. Many researchers have suggested repeated pregnancy, childbirth, and lactation taxes the body beyond a certain parity level. Available research has concentrated on populations with controlled fertility or historic populations. Ireland presents an opportunity to explore these associations in a modern sample with high fertility. We use data from the Irish Longitudinal Study on Ageing (TILDA) to test whether parity is associated with mortality in women aged 50 years or over (n = 4177). We use Cox proportional hazards models to model survival and adjust for demographics and early life circumstances. We test whether a number of health characteristics mediate these effects. Models were also stratified by birth cohort to test possible cohort effects. Higher parity was associated with lower risk of mortality, even after adjustment for early life and socioeconomic circumstances. This effect was not mediated by current health characteristics. The effects were largely driven by those born between 1931 and 1950. Increasing parity is associated with decreasing mortality risk in this sample. The effects of parity could not be explained through any of the observed health characteristics. These findings are in contrast to much of the literature on this question in similar populations. Lack of fertility control in Ireland may have "selected" healthier women into high parity. Social explanations for these associations should be further explored.

The association between parity, CVD mortality and CVD risk factors among Norwegian women and men

BACKGROUND

Several studies have shown that women and men with two children have lower mortality than the childless, but there is less certainty about mortality, including CVD mortality, at higher parities and meagre knowledge about factors underlying the parity-mortality relationship.

METHODS

The association between parity and CVD mortality was analyzed by estimating discrete-time hazard models for women and men aged 40-80 in 1975-2015. Register data covering the entire Norwegian population were used, and the models included a larger number of relevant sociodemographic control variables than in many previous studies. To analyze the relationship between parity and seven CVD risk factors, logistic models including the same variables as the mortality models were estimated from the CONOR collection of health surveys, linked to the register data.

RESULTS

Men (but not women) who had four or more children had higher mortality from CVD than those with two, although this excess mortality was not observed for the heart disease sub-group. Overweight, possibly in part a result of less physical activity, seems to play a role in this. All CVD risk factors except smoking and alcohol may contribute to the relatively high CVD mortality among childless.

CONCLUSIONS

Childbearing is related to a number of well-known CVD risk factors, and becoming a parent or having an additional child is, on the whole, associated with lower-or at least not higher-CVD mortality in Norway. However, for men family sizes beyond three children are associated with increased CVD mortality, with risks of overweight one possible pathway.

The risk of developing a meningioma during and after pregnancy

Pregnancy has been associated with diagnosis or growth of meningiomas in several case reports, which has led to the hypothesis that pregnancy may be a risk factor for meningiomas. The aim of this study was to test this hypothesis in a large population-based cohort study. Women born in Sweden 1958–2000 (N = 2,204,126) were identified and matched with the Medical Birth Register and the Cancer Register. The expected number of meningioma cases and risk ratios were calculated for parous and nulliparous women and compared to the observed number of cases. Compared to parous women, meningiomas were more common among nulliparous (SIR = 1.73; 95% CI 1.52–1.95). The number of meningioma cases detected during pregnancy was lower than the expected (SIR = 0.40; 95% CI 0.20–0.72). Moreover, no increased risk was found in the first-year post-partum (SIR = 1.04; 95% CI 0.74–1.41). Contrary to our hypothesis, there was no increased risk for diagnosing a meningioma during pregnancy or 1-year post-partum. A lower detection rate during pregnancy, may reflect under-utilization of diagnostic procedures, but the actual number of meningiomas was homogenously lower among parous than nulliparous women throughout the study period, indicating that pregnancy is not a risk factor for meningioma.

Severe Maternal Morbidity and Risk of Mortality Beyond the Postpartum Period

OBJECTIVE

To examine long-term risks of mortality after a pregnancy complicated by severe maternal morbidity.

METHODS

We analyzed a longitudinal cohort of 1,229,306 women who delivered in the province of Quebec, Canada from 1989 through 2016. Severe maternal morbidity included conditions such as cerebrovascular accidents, acute renal failure, severe preeclampsia, and other life-threatening complications. The outcome was in-hospital mortality after the last pregnancy, categorized as postpartum (42 days or fewer after delivery) and long-term (43 days to 29 years after delivery). We estimated hazard ratios (HRs) ofr mortality with 95% CI for severe maternal morbidity compared with no severe morbidity, using Cox regression models adjusted for maternal characteristics.

RESULTS

Severe maternal morbidity occurred in 2.9% of women. The mortality rate associated with severe maternal morbidity was 0.86 per 1,000 person-years compared with 0.41 per 1,000 person-years for no morbidity. Compared with no morbidity, severe maternal morbidity was associated with two times the rate of death any time after delivery (95% CI 1.81-2.20). Severe cardiac complications (HR 7.00, 85% CI 4.94-9.91), acute renal failure (HR 4.35, 95% CI 2.66-7.10), and cerebrovascular accidents (HR 4.03, 95% CI 2.17-7.48) were the leading morbidities associated with mortality after 42 days.

CONCLUSION

Women who experience severe maternal morbidity have an accelerated risk of mortality beyond the postpartum period compared with women who do not experience severe morbidity. More intensive clinical follow-up may be merited for women with serious pregnancy complications.

Adequacy of Prenatal Care in Northeast Brazil: Pilot Data Comparing Attainment of Standard Care Criteria for First-Time Adolescent and Adult Pregnant Women

Background

Adolescent pregnancy is a public health concern worldwide, particularly in low-income settings. Adolescent mothers face higher risks during pregnancy and delivery compared to adult mothers and yet, may also experience worse quality of obstetrical care. This study evaluates adherence to meeting Brazilian recommendations for prenatal care by comparing first-time adolescent versus adult mothers in a rural, low-income setting.

Methods

Using data from the Adolescence and Motherhood Research (AMOR) project, we evaluated adherence to national recommendations as documented in the prenatal cards of 39 adolescents (13-18 years) and 37 adults (23-28 years) from a low-income area in northeast Brazil. Recommendations included ≥6 prenatal consultations, gestational age ≤12 weeks at the first visit, participation in 3 educational activities, 2 serology for syphilis (VDRL) and HIV, 1 Toxoplasmosis serology, 2 urine tests, 2 blood glucose and 2 hemoglobin/hematocrit (Hb/Ht) exams. Chi-square tests were used to compare the proportions of adolescents and adults with a record of these procedures in the prenatal cards.

Results

Compared to adult women, the adolescent group had lower attainment of almost all recommended components of prenatal care compared to the adult group, with statistically significant differences for 2 blood glucose tests (46.2% vs 78.4%; p=0.004), 2 VDRL tests (30.8% vs 54.1%; p=0.040), 2 Hb/Ht exams (35.9% vs 83.8%; p<0.001), and at least 6 consultations (84.6% vs 100%; p=0.013).

Conclusion

Despite greater health risks of adolescent fertility, the prenatal cards of adolescent mothers presented a poorer record of adherence to recommendations for adequate prenatal care compared to adult mothers from a low-income setting of Brazil. Health policies for both health professionals and the target population are needed to ensure adequacy of prenatal care and appropriate risk reduction for this vulnerable population.

Fertility Behavior and Depression Among Women: Evidence From China

Using data from the China Labor-Force Dynamic Survey, this study employed logistic regressions to investigate the association between fertility behavior and depression among Chinese women. The empirical results show that in China, women having children were significantly less likely to have depressive symptoms (OR = 0.651) compared to childless women. We also found a U-shaped relationship between fertility levels and depression in women. The results were robust to using the propensity score matching approach to address the sample selection problem. Further, our heterogeneity analysis demonstrated that the negative relationship between fertility level and depression was more significant among women who were in their 30s, lived in urban areas, and lived in high-income households. Compared to having male children (boys) (OR = 0.874), having female children (girls) (OR = 0.795) was more significantly associated with fewer depressive symptoms among women. In the meantime, we did not find a significant relationship between the childbearing period and depression. The paper discussed possible reasons for our findings and policy implications from the perspectives of the government, society, and family.

Family embeddedness and older adult mortality in the United States

Do different operationalizations of family structure offer different understandings of the links between family structure and older adult mortality? Using the American Health and Retirement Study (N = 29,665), we examine mortality risks by three measures of family structure: whether respondents have different family statuses (e.g. married vs. unmarried), volume of family members available (e.g. having one vs. two living immediate family members), and family embeddedness (e.g. having neither spouse nor child vs. having spouse but no child). We focus on three kin types: partner/spouse, children, and siblings. We find that differences in empirical estimates across measures of family structure are not dramatic, but that family embeddedness can show some additional heterogeneity in mortality patterns over family status variables or the volume of ties. This paper tests different ways of operationalizing family structure to study mortality outcomes and advances our understanding of how family functions as a key social determinant of health.

Male childlessness as independent predictor of risk of cardiovascular and all-cause mortality: A population-based cohort study with more than 30 years follow-up

In a recent population-based study, an elevated risk of the Metabolic syndrome (MetS) and type 2 diabetes was found in childless men compared to those who have fathered one or more children. Therefore, by using a larger cohort of more than 22 000 men from the Malmo Preventive Project (MPP) we aimed to expand our observations in order to evaluate the metabolic profile of childless men and to evaluate if childlessness is an additional and independent predictor of major adverse cardiovascular events (MACE), mortality and incident diabetes when accounting for well-known biochemical, anthropometric, socio-economic and lifestyle related known risk factors. Logistic regression was used to assess risk of MACE, diabetes and MetS at baseline. Multivariate Cox regression was used to evaluate the risks of MACE and mortality following the men from baseline screening until first episode of MACE, death from other causes, emigration, or end of follow-up (31^st December 2016) adjusting for age, family history, marital status, smoking, alcohol consumption, educational status, body mass index, prevalent diabetes, high blood lipids, increased fasting glucose and hypertension. Childless men presented with a worse metabolic profile than fathers at the baseline examination, with elevated risk of high triglycerides, odds ratio (OR) 1.24 (95%CI: 1.10–1.42), high fasting glucose OR 1.23 (95%CI: 1.05–1.43) and high blood pressure, OR 1.28 (95%CI: 1.14–1.45), respectively. In the fully adjusted prospective analysis, childless men presented with elevated risk of cardiovascular mortality, HR: 1.33 (95% CI: 1.18–1.49) and all-cause mortality, HR 1.23 (95%CI: 1.14–1.33), respectively. In conclusion, these results add to previous studies showing associations between male reproductive health, morbidity and mortality. Male childlessness, independently of well-known socio-economic, behavioral and metabolic risk factors, predicts risk of cardiovascular disease and mortality. Consequently, this group of men should be considered as target population for preventive measures.

Testing Comparability Between Retrospective Life History Data and Prospective Birth Cohort Study Data

OBJECTIVES

To determine whether comparable prospective and retrospective data present the same association between childhood and life course exposures and mid-life wellbeing.

METHOD

Prospective data is taken from the 1958 UK National Child Development Study at age 50 in 2008 and earlier sweeps (n = 8,033). Retrospective data is taken from the English Longitudinal Study of Ageing at ages 50-55 from a life history interview in 2007 (n = 921).

RESULTS

There is a high degree of similarity in the direction of association between childhood exposures that have been prospectively collected in National Child Development Study and retrospectively collected in English Longitudinal Study of Ageing and wellbeing outcomes in mid-life. However, the magnitude of these associations is attenuated substantially by the inclusion of measurements, which are difficult or impossible to capture retrospectively, and are only available in prospective data, such as childhood poverty, cognitive ability, and indices of social and emotional adjustment.

DISCUSSION

The findings on the one hand provide some reassurance to the growing literature using life history data to determine life course associations with later life wellbeing. On the other hand, the findings show an overestimation in the retrospective data, in part, arising from the absence in life history data of childhood measures that are not well suited to retrospective collection.

Frailty: A cost incurred by reproduction?

Evolutionary theories of senescence, such as the ‘disposable soma’ theory, propose that natural selection trades late survival for early fecundity. ‘Frailty’, a multidimensional measure of health status, may help to better define the long-term consequences of reproduction. We examined the relationship between parity and later life frailty (as measured by the Frailty Index) in a sample of 3,534 adults aged 65 years and older who participated in the English Longitudinal Study of Ageing. We found that the most parous adults were the most frail and that the parity-frailty relationship was similar for both sexes. Whilst this study provided some evidence for a ‘parity-frailty trade-off’, there was little support for our hypothesis that the physiological costs of childbearing influence later life frailty. Rather, behavioural and social factors associated with rearing many children may have contributed to the development of frailty in both sexes.

Association of Childbearing With a Short-Term Reduced Risk of Crohn Disease in Mothers

Our aim in this study was to analyze the importance of childbearing for risk of inflammatory bowel disease. Using data from the Norwegian Population Register and the Norwegian Patient Register, we fitted discrete-time hazard models for diagnosis of Crohn disease (CD) or ulcerative colitis (UC) among men and women aged 18-81 years in 2011-2016. Year and various sociodemographic factors were controlled for. The data included 4,304 CD cases and 8,866 UC cases. Women whose youngest child was ≤4 years of age had lower CD risk the following year than childless women (odds ratio (OR) = 0.73, 95% confidence interval (CI): 0.62, 0.86). There was no such reduction in CD risk among fathers. Men whose youngest child was aged ≥20 years had higher risks of CD (OR = 1.22, 95% CI: 1.01, 1.49) and UC (OR = 1.15, 95% CI: 1.02, 1.30) than childless men. UC risk was also increased among men whose youngest child was aged ≤4 years (OR = 1.14, 95% CI: 1.02, 1.27). The short-term reduction in women's CD risk after a birth may reflect biological effects of pregnancy. Alternatively, it may reflect residual confounding or lifestyle effects of parenthood that are of special relevance for CD in women. In particular, differences in use of oral contraceptives (which it was not possible to control for) may have contributed to the observed pattern.

Men's age at first birth and alcohol-related morbidity and mortality among siblings

BACKGROUND

Men's age at first birth may negatively or positively affect alcohol-related morbidity and mortality, although little evidence is available.

METHODS

We used register data of over 22,000 brothers to analyze the associations between age at first birth and alcohol-related morbidity and mortality from the age of 35 until the age of 60 or 72. We employed conventional Cox models and inter-sibling models, which allowed adjustment for unobserved social and genetic characteristics shared by brothers.

RESULTS

The findings show that men's age at first birth was inversely associated with alcohol-related morbidity and mortality, independent of unobserved characteristics shared by brothers and of observed demographic confounders. Men who had their first child late at 35-45 years experienced lower alcohol-related morbidity and mortality (hazard ratio (HR) = 0.57, 95 % confidence interval (CI) = 0.43, 0.75) than men who had their first child at 25-29. Men who had their first child before age 20 had the highest morbidity and mortality among all fathers (HR = 1.36, 95 % CI = 1.09, 1.69), followed by men who had their child at 20-24 (HR = 1.12, 95 % CI = 1.00, 1.25).

CONCLUSIONS

The results imply that the inverse association between men's age at first birth and alcohol-related morbidity and mortality is not driven by familial characteristics.

Fertility History and Biomarkers Using Prospective Data: Evidence From the 1958 National Child Development Study

Research on the later-life health implications of fertility history has predominantly considered associations with mortality or self-reported indicators of health. Most of this previous research has either not been able to account for selection factors related to both early-life and later-life health or has had to rely on retrospectively reported accounts of childhood circumstances. Using the 1958 National Child Development Study, and in particular the biomedical survey conducted in 2002-2003, we investigate associations between fertility histories (number of children and age at first and at last birth) and biomarkers for cardiometabolic risk and respiratory function in midlife among both men and women. Results from models that adjusted for a very wide range of childhood factors, including early-life socioeconomic position, cognitive ability, and mental health, showed weak associations between parity and biomarkers. However, we found an inverse association between age at first birth and biomarkers indicative of worse cardiometabolic health, with poorer outcomes for those with very young ages at entry to parenthood and increasingly better outcomes for those becoming parents at older ages. A very young age at last birth was also associated with less favorable biomarker levels, especially among women. Results highlight the value of prospectively collected data and the availability of biomarkers in studies of life course determinants of health in midlife and later.

Mental health problems in adolescence, first births, and union formation: Evidence from the Young HUNT Study

While a large literature documents how mental health problems in adolescence have long-term consequences for adult socioeconomic outcomes, less is known about the relation with family-formation behavior. In this paper, we use data from a population based Norwegian health survey (the Young-HUNT study) linked to administrative registry data (N = 8,113) to examine the long-term consequences of symptoms of internalizing and externalizing problems, the two most common forms of mental health problems, on family-formation outcomes: the likelihood of a first birth, the union status of a first birth, and entering first marriage. For men, externalizing problems are associated with earlier parenthood, especially becoming a father without having a coresidential relationship with the child's mother. Internalizing problems, on the other hand, are associated with lower first-birth rates and the association grows progressively stronger with age. We also find that the associations are more pronounced among men with low childhood socioeconomic status. In contrast, women's family-formation appears for the most part unrelated to their mental health.

Parents survive longer after stroke than childless individuals: a prospective cohort study of Swedes over the age of 65

BACKGROUND

Parents have lower mortality than childless individuals, and one possible explanation is support provided by adult children. Since stroke often results in functional limitations, support from children may be of particular importance. Here, we examine whether the presence of children matters for survival after stroke among older Swedish men and women.

METHODS

This prospective cohort study linked data from several Swedish population registers. Individuals aged 65 years and older hospitalized for their first ischemic stroke between 1998 and 2002 (33 960 men and 36 189 women) were followed 12 years for survival. Hazard ratios for all-cause mortality were calculated by number of children using Cox proportional hazard regression stratified by sex and marital status and adjusted for education, income and comorbidities.

RESULTS

Childlessness and having only one child was associated with higher mortality after stroke compared with having two children among men and women. The relative survival disadvantage of childless individuals was largest among married women [HR 1.28 (1.18-1.39)] and smallest among married men [1.09 (1.03-1.15)]. The differences in predicted median survival between childless individuals and those with two children were 4 and 7 months among married and unmarried men, and 15 and 9 months among married and unmarried women, respectively.

CONCLUSIONS

Having children is associated with a longer survival after stroke among men and women regardless of marital status. Our findings further suggest that the presence of children is especially connected to married women's survival. These results may have implications for the improvement of informal care for childless older individuals.

Relationships Between Reproductive History and Mortality From Cardiovascular Diseases Among Japanese Women: The Japan Collaborative Cohort Study for Evaluation of Cancer Risk (JACC) Study

Background

Reproductive history has been addressed as a risk factor for cardiovascular disease (CVD). We examined the relationship between reproductive history and CVD mortality in Japanese women.

Methods

We followed 53,836 women without previous CVD or cancer history from 1988–1990 to 2009 in a prospective cohort study. Hazard ratios (HRs) and 95% confidence intervals (CIs) of CVD mortality were estimated according to the number of deliveries and maternal age at first delivery.

Results

During the follow-up, 2,982 CVD-related deaths were identified. There was U-shaped association between the number of deliveries and risk of CVD mortality with reference to three deliveries, although the excess risk of CVD mortality associated with ≥5 deliveries was of borderline statistical significance. The corresponding multivariable HRs were 1.33 (95% CI, 1.12–1.58) and 1.11 (95% CI, 0.99–1.24). In addition, higher CVD mortality was associated with maternal age ≥28 years at first delivery than maternal age of 24–27 years at first delivery. The multivariable HRs were 1.22 (95% CI, 1.10–1.36) for 28–31 years at first delivery and 1.26 (95% CI, 1.04–1.52) for ≥32 years at first delivery. Moreover, among women with ≥3 deliveries, maternal age ≥28 years at first delivery was associated with 1.2- to 1.5-fold increased CVD mortality.

Conclusion

The number of deliveries showed a U-shaped association with risk of CVD mortality. Higher maternal age at first delivery was associated with an increased risk of CVD mortality, and excessive risk in women aged ≥28 years at first delivery was noted in those with ≥3 deliveries.

Female reproductive factors and risk of external causes of death among women: The Japan Public Health Center-based Prospective Study (JPHC Study)

Although empirical data suggest a possible link between female reproductive events and risk of nonfatal accidents and suicidal behaviors, evidence to determine these effects on mortality is scarce. This study investigated the association between female reproductive factors and the risk of external causes of death among middle-aged Japanese women. We used a population-based cohort study consisting of 71 698 women residing in 11 public health center areas across Japan between 1990 and 1994. Multivariable-adjusted Cox proportional hazard regression models were used to estimate hazard ratios (HRs) of the risk of all external causes, suicide, and accidents according to female reproductive factors at the baseline survey. During 1 028 583 person-years of follow-up for 49 279 eligible subjects (average 20.9 years), we identified 328 deaths by all injuries. Among parous women, ever versus never breastfeeding [0.67 (95% CI: 0.49–0.92)] was associated with a decreased risk of all injuries. Risk of suicide was inversely associated with ever versus never parity [0.53 (95% CI: 0.32–0.88)]. A lower risk of death by accidents was seen in ever breastfeeding [0.63 (95% CI: 0.40–0.97)] compared to never breastfeeding. This study suggests that parity and breastfeeding are associated with reduced risk of death by all external causes, suicide and/or accidents among Japanese women.

Fertility histories and chronic conditions later in life in Europe

Understanding the association between fertility histories and health later in life is necessary in the context of ageing societies. Past literature has generally found a U-shaped relationship between parity, age at first birth, and several health-related outcomes. However, these findings differed to some extent depending on the country under analysis and on the measures of health considered. As such, using wave 3 (2008-2009) and 5 (2013) of the Survey of Health, Ageing and Retirement in Europe (SHARE), this work aimed to answer the question: "Are fertility histories associated with the presence of chronic conditions later in life in Europe?" The analysis included 11 European countries and compared results using two different measures of chronic conditions: self-reported chronic or long-term illness and chronic diseases diagnosed by a doctor. Results showed that age at first birth is more relevant than parity for health outcomes at older ages. Moreover, in socio-democratic and continental countries, the association between fertility and chronic conditions-in particular between age at first birth and long-term illnesses-is statistically significant among women, but not among men. Finally, the association between fertility history and health was similar when using self-reported measures and chronic diseases diagnosed by a doctor.

Is the relationship between men's age at first birth and midlife health changing? Evidence from two British cohorts

Becoming a father, particularly for the first time, is a central transition in men's lives, and whether this transition takes place early or later in life may have important ramifications on the whole later life course. Previous research has shown that men who father their first child early in life have poorer later-life health than men who postpone having children. However, it is not known how selection by cognitive ability and other childhood characteristics confound the association between the timing of fatherhood and later-life health, or how the association is changing over time as parenthood is postponed to an older age. We investigate the association between men's age at the birth of their first child and midlife self-rated health in two British cohorts born in 1958 and 1970. The study employs logit models. Relative to men who had their first child when they were between 25 and 29 years old, men who had their first child before the age of 20 have the poorest health, followed by men who had a child when they were 20–24 years old. This result was observed in both cohorts. Childhood cognitive ability, which previous research has not analyzed, strongly contributed to this association, and to a greater extent than other childhood characteristics. For the 1970 cohort, those who became fathers at age 35 or older had the best health. This advantage was not found for the 1958 cohort. These findings suggest that the relationship between young age at fatherhood and midlife health is strongly confounded by cognitive ability, and that in recent cohorts a new pattern of advantage among older fathers has emerged.

•

Early fatherhood shows associations with poorer self-rated health in midlife.

•

Childhood cognitive ability strongly confounds this association.

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First-time fathers aged 35 years or older have the best health in the 1970 cohort.

•

A similar health advantage in older fathers is not found in the 1958 cohort.

The role of children and their socioeconomic resources for the risk of hospitalisation and mortality - a nationwide register-based study of the total Swedish population over the age 70

Background

Previous studies have shown that mortality in old age is associated with both number of children and their socioeconomic resources. The underlying mechanisms are unclear, as well as when during the process of health deterioration the advantage of parents over non-parents arises. This study aims to examine how the number of children and their socioeconomic resources are associated with different health outcomes among their parents, namely the hazard for i) first hospitalisation, ii) re-admission, iii) mortality after first hospitalisation, and iv) overall mortality.

Method

This longitudinal cohort study includes all individuals born 1920–1940 who were living in Sweden at age 70 years (890,544 individuals). Individuals were linked to their offspring and spouse using administrative registers and followed for up to 25 years. Associations were estimated using multivariable Cox models adjusted for index persons’ education and income, marital status, their partners’ education, and age at first birth.

Results

In this study, having children was associated with reduced mortality risk of their parents, but not with the risk of being hospitalised, which increased as number of children increased. A higher education of children was protective for all parental outcomes independent of number of children and their financial resources. In fact, income of the children was only weakly associated with the health of their parents.

Conclusions

The benefit of having children compared to childlessness for health in old age seems to arise once individuals have become ill rather than before. Children’s education is important for parental health and mortality, in fact more important than the number of children itself in this Swedish cohort.

Electronic supplementary material

The online version of this article (10.1186/s12877-019-1134-y) contains supplementary material, which is available to authorized users.

Parity and Mortality: An Examination of Different Explanatory Mechanisms Using Data on Biological and Adoptive Parents

A growing literature has demonstrated a relationship between parity and mortality, but the explanation for that relationship remains unclear. This study aims to pick apart physiological and social explanations for the parity-mortality relationship by examining the mortality of parents who adopt children, but who have no biological children, in comparison with the mortality of parents with biological children. Using Swedish register data, we study post-reproductive mortality amongst women and men from cohorts born between 1915 and 1960, over ages 45-97. Our results show the relative risks of mortality for adoptive parents are always lower than those of parents with biological children. Mortality amongst adoptive parents is lower for those who adopt more than one child, while for parents with biological children we observe a U-shaped relationship, where parity-two parents have the lowest mortality. Our discussion considers the relative importance of physiological and social depletion effects, and selection processes.

Hearing loss, family status and mortality - Findings from the HUNT study, Norway

Hearing loss as well as being single has been associated with an increased risk of all-cause mortality. The purpose of the study is to assess whether being single or childless moderates the elevated risk of mortality in hearing impaired. The Nord-Trøndelag hearing Loss Study examined 50,462 persons above 20 years of age during 1996-1998. The Norwegian Cause of Death Registry was used to identify deaths until 2016. Data on marital status was obtained from the Norwegian Population Registry. Hearing loss was defined as the pure-tone average (0.5-4 kHz) of hearing thresholds greater than 25 dB hearing level (dB HL) in the better ear. Associations between hearing loss and mortality risk were estimated using Cox regression after an average follow-up of 17.6 years. Hearing loss was associated with increased risk of all-cause mortality before 75 years of age (hazard ratio [HR] 1.3, 95% confidence interval [CI] 1.2-1.4) and cardiovascular mortality (HR 1.8, 95% CI 1.5-2.1) but not with cancer mortality (HR 1.1, 95% CI 0.9-1.3) or mortality due to injuries (HR 1.4, 95% CI 0.9-2.3). Adjusting for socio-economic characteristics, cardiovascular risk-factors, diseases, and family status, reduced the associations for all-cause mortality (HR 1.1, 95% CI 1.0-1.2) and cardiovascular mortality (HR 1.4, 95% CI 1.2-1.6). The adjusted mortality risk was found to be significantly related to family status. Being divorced raised the mortality risk associated with hearing loss among those below 75 years of age. There was a similar tendency also for being childless, although this was only significant for females. There was also a trend for a lower mortality related to hearing loss in subjects with a well-hearing partner. More focus should be given to those who lack a family when having functional limitations such as hearing impairment.

SELF-RATED HEALTH AND TEENAGE PREGNANCIES IN ROMA WOMEN: INCREASING HEIGHT IS ASSOCIATED WITH BETTER HEALTH OUTCOMES

This paper reports on the association between early marriage, age at first reproduction and height, as an indicator of childhood environment, and maternal health outcomes among traditional Roma women in Serbia. Demographic data, marital and reproductive histories, height, weight and self-rated health were collected from 414 Roma women living in rural settlements in Serbia in 2015-2017. Data analysis showed that higher age and weight were associated with a greater risk of poor health, greater height contributed to reduced risk of poor health while reproductive variables were insignificant. The study provides evidence that the long-term effects of early childbearing may not always be associated with poorer health status. As indicated by the differences in height, it is likely that women who were capable of reproducing very early on and staying healthy in later life were probably very healthy to begin with. The results probably reflect both the biological and social differences of early childhood. Aside from height, the traditional Roma marriage pattern and social benefits may have an additional protective effect on the health of women.

Effects of Age at First Childbirth and Other Factors on Central Obesity in Postmenopausal Women: The 2013-2015 Korean National Health and Nutrition Examination Survey

Background

Waist circumference is one of the key components of metabolic syndrome. Recent studies demonstrated that the reproductive profile was associated with metabolic syndrome in postmenopausal women. This study focused on the association between central obesity and age at first childbirth. It also considered other factors associated with central obesity in postmenopausal women.

Methods

This study was based on the 2013–2015 Korean National Health and Nutrition Examination Survey and involved 3,143 naturally postmenopausal women. These women were divided into three groups according to their age at first childbirth: 19 years or younger (n=252), 20–29 years (n=2,695), and 30 years or older (n=196). Multivariate analysis using logistic regression was performed to evaluate the effects of various reproductive factors, including other confounding factors.

Results

During adjustment for confounding factors, in the early age at first childbirth group, odds ratios (95% confidence intervals) for central obesity decreased. In the final model, younger age at first childbirth was not significantly related to central obesity (waist circumference more than 85 cm) in naturally postmenopausal women after adjusting for other confounding factors.

Conclusion

Younger age at first childbirth was not significantly associated with central obesity after adjustment for confounding factors.

Fertility History and Physical and Mental Health Changes in European Older Adults

Previous studies have shown that aspects of reproductive history, such as earlier parenthood and high parity, are associated with poorer health in mid and later life. However, it is unclear which dimensions of health are most affected by reproductive history, and whether the pattern of associations varies for measures of physical, psychological and cognitive health. Such variation might provide more insight into possible underlying mechanisms. We use longitudinal data for men and women aged 50–79 years in ten European countries from the Survey of Health, Ageing and Retirement in Europe to analyse associations between completed fertility history and self-reported and observed health indicators measured 2–3 years apart (functional limitations, chronic diseases, grip strength, depression and cognition), adjusting for socio-demographic, and health factors at baseline. Using multiple imputation and pattern mixture modelling, we tested the robustness of estimates to missing data mechanisms. The results are partly consistent with previous studies and show that women who became mothers before age 20 had worse functional health at baseline and were more likely to suffer functional health declines. Parents of 4 or more children had worse physical, psychological and cognitive health at baseline and were more likely to develop circulatory disease over the follow-up period. Men who delayed fatherhood until age 35 or later had better health at baseline but did not experience significantly different health declines. This study improves our understanding of linkages between fertility histories and later life health and possible implications of changes in fertility patterns for population health. However, research ideally using prospective life course data is needed to further elucidate possible mechanisms, considering interactions with partnership histories, health behaviour patterns and socio-economic trajectories.

"Big data" in economic history

Big data is an exciting prospect for the field of economic history, which has long depended on the acquisition, keying, and cleaning of scarce numerical information about the past. This article examines two areas in which economic historians are already using big data - population and environment - discussing ways in which increased frequency of observation, denser samples, and smaller geographic units allow us to analyze the past with greater precision and often to track individuals, places, and phenomena across time. We also explore promising new sources of big data: organically created economic data, high resolution images, and textual corpora.

U-shaped association between fertility and mortality in a community-based sample of Japanese women

BACKGROUND

Prospective cohort studies of contemporary populations in both Western and Asian settings have reported a U-shaped association between fertility and mortality. We examined whether an association exists between fertility and all-cause and cause-specific mortality in a sample of Japanese women.

METHODS

A prospective cohort study was conducted in one rural and one urban community in Gunma Prefecture, Japan, in 1993. A follow-up survey was conducted in the year 2000 in 4858 women aged 47-77 years, and information on demographic and lifestyle characteristics was collected. Mortality and migration data through December 2008 were obtained. A Cox proportional hazard model was used to examine the relationship between parity and mortality.

RESULTS

Compared with women with 2-4 children (reference group), higher total mortality was observed among women with 0-1 or 5+ children. Low (HR 1.7, 95% CI 1.2 to 2.3) and high (HR 2.1, 95% CI 1.0 to 4.7) parities were both associated with higher all-cause mortality even after adjusting for potential confounders. Mortality due to ischaemic heart disease exhibited a significant association with parity; the HRs were 3.2 (95% CI 1.1 to 9.2) for women with 0-1 child and 8.7 (95% CI 1.7 to 45.5) for women with 5 or more children. No significant association was observed for mortality from malignancies, cancer of the digestive system, cardiovascular disease or cerebrovascular disease.

CONCLUSIONS

There exists a U-shaped association between parity and all-cause mortality and cause-specific mortality due to ischaemic heart disease among Japanese women.

Age Trajectories of Physical Health Among Older Adults of Mexican Descent: Implications of Immigrant Status, Age at Immigration, and Gender

OBJECTIVE

This study examines consequences of immigrant status, age at immigration, and gender on age trajectories of activities of daily living (ADL) limitations and chronic conditions among older adults of Mexican descent.

METHOD

This research draws on 7 waves of the Hispanic Established Populations for the Epidemiologic Study of the Elderly and employs growth curve models.

RESULTS

All men had similar age trajectories of ADL limitations, regardless of immigrant status and age at immigration. All women experienced steeper increases in ADL limitations, although U.S.-born women and those who immigrated by age 19 had lower initial levels. Men who immigrated between ages 20 and 49 had steeper increases in chronic conditions, despite lower initial levels. U.S.-born women and those women who immigrated by age 50 had more chronic conditions at age 65.

DISCUSSION

This study highlights the multidimensional nature of physical health by demonstrating that immigrant status-gender disparities can vary by the health outcome examined.

Offspring sex and parental health and mortality

Increased mortality has been observed in mothers and fathers with male offspring but little is known regarding specific diseases. In a register linkage we linked women born 1925–1954 having survived to age 50 (n = 661,031) to offspring and fathers (n = 691,124). Three approaches were used: 1) number of total boy and girl offspring, 2) sex of the first and second offspring and 3) proportion of boys to total number of offspring. A sub-cohort (n = 50,736 mothers, n = 44,794 fathers) from survey data was analysed for risk factors. Mothers had increased risk of total and cardiovascular mortality that was consistent across approaches: cardiovascular mortality of 1.07 (95% CI: 1.03–1.11) per boy (approach 2), 1.04 (1.01–1.07) if the first offspring was a boy, and 1.06 (1.01–1.10) if the first two offspring were boys (approach 3). We found that sex of offspring was not associated with total or cardiovascular mortality in fathers. For other diseases or risk factors no robust associations were seen in mothers or fathers. Increased cardiovascular risk in mothers having male offspring suggests a maternal disease specific mechanism. The lack of consistent associations on measured risk factors could suggest other biological pathways than those studied play a role in generating this additional cardiovascular risk.