Age at first birth and cardiovascular risk factors in the 1958 British birth cohort

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.

Socioeconomic disparities in the association of age at first live birth with incident stroke among Chinese parous women: A prospective cohort study

Background

Stroke has become a significant public health issue in China. Although studies have shown that women's age at first live birth (AFLB) might be associated with incident stroke, there is limited evidence on this relationship among Chinese parous women. Likewise, the nature of this association across urban-rural socioeconomic status (SES) has yet to be explored. In this prospective study, we sought to investigate the associations of women's AFLB with the risk of incident stroke and its subtypes (ischaemic stroke, intracerebral haemorrhage, and subarachnoid haemorrhage) and to explore the differences of these associations as well as the population-level impacts across SES classes.

Methods

We used data on 290 932 Chinese parous women from the China Kadoorie Biobank who were recruited in the baseline survey between 2004 and 2008 and followed up until 2015. We used latent class analysis to identify urban-rural SES classes and Cox proportional hazard regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for AFLB's association with incident stroke. We then calculated population attributable fraction (PAF) to demonstrate the population-level impact of later AFLB on stroke.

Results

Around 8.9% of parous women developed stroke after AFLB. Compared with women with AFLB <22 years, those with older AFLB had a higher risk of total stroke, with fully adjusted HRs (95% CI) of 1.71 (95% CI = 1.65-1.77) for 22-24 years and 3.37 (95% CI = 3.24-3.51) for ≥25 years. The associations of AFLB with ischaemic stroke were stronger among rural-low-SES participants. We found the highest PAFs of ischaemic stroke (60.1%; 95% CI = 46.2-70.3) associated with later AFLB for urban-high-SES individuals.

Conclusions

Older AFLB was associated with higher risks of incident stroke and its subtypes among Chinese parous women, with stronger associations between AFLB and ischaemic stroke among rural-low-SES participants. Targeted medical advice for pregnant women of different ages could have long-term benefits for stroke prevention.

Reproductive factors and risk of cardiovascular diseases and all-cause and cardiovascular mortality in American women: NHANES 2003-2018

BACKGROUND

The evidence regarding the association of reproductive factors with cardiovascular diseases (CVDs) is limited.

AIMS

To investigate the relationship of reproductive factors with the risk of CVDs, as well as all-cause and cardiovascular mortality.

METHODS

This study included 16,404 adults with reproductive factors from the National Health and Nutrition Examination Survey (NHANES) and followed up until 31 December 2019. Logistic models and restricted cubic spline models were used to assess the association of reproductive factors with CVDs. COX proportional hazards models and restricted cubic spline models, with adjustment for potential confounding, were employed to analyze the relation between reproductive factors and cardiovascular and all-cause death.

RESULTS

There is a nonlinear relationship between age at menarche and CVDs. Age at menopause ≤ 11(OR 1.36, 95% CI 1.10-1.69) was associated with an increased risk of CVDs compared to ages 12-13 years. Age at Menopause ≤ 44 (OR 1.69, 95% CI 1.40-2.03) was associated with increased CVDs compared to age 35-49 years. Number of pregnancies ≥ 5(OR 1.26, 95% CI 1.02-1.55) was associated with an increased risk of CVDs compared to one pregnancy. In continuous variable COX regression models, a later age at menopause (HR 0.98, 95% CI 0.97-0.99) and a longer reproductive lifespan (HR 0.98, 95% CI 0.97-0.99) were associated with a decreased risk of all-cause death. A later age at menopause (HR 0.98, 95% CI 0.97-0.99) and a longer reproductive lifespan (HR 0.98, 95% CI 0.97-0.99) were associated with a decreased risk of cardiac death.

CONCLUSIONS

Female reproductive factors are significant risk factors for CVDs American women.

The contributions of fertility during adolescence to disability across the life-course: hypothesized causal pathways, research gaps, and future directions

CONTEXT

Robust associations have been identified between fertility during adolescence and the disablement process, including pathologies, impairments, functional limitations and disability. Limited theoretical or empirical research considers how and why such relationships exist generally or with the individual associated components of disablement.

OBJECTIVE

To consolidate and critically evaluate literature to describe testable, theory-based hypotheses to guide future research on the mechanisms by which fertility during adolescence contributes to disablement.

METHODS

Targeted literature review of research from diverse global settings contextualised in two well-accepted theoretical frameworks in life-course epidemiology: the cumulative risk model and the critical period approach.

RESULTS

Five hypothesised causal pathways linking adolescent fertility to disablement in later life are described: 1) Causal relationship initiated by fertility during adolescence; 2) Common cause(s) for both, such as adverse childhood experiences; 3) Contributing cause(s) to adolescent fertility; 4) Interaction between adolescent fertility and other risk factors; and 5) Critical period effects unique to adolescence. Most research on the topic is on pathologies versus functional limitations and disability.

CONCLUSION

We highlight promising research avenues to inform future research and interventions on adolescent fertility and the disablement process. This work provides theoretical clarity, identifies research gaps, and offers hypotheses-testing opportunities for future research.

Establishing the relationships between adiposity and reproductive factors: a multivariable Mendelian randomization analysis

BACKGROUND

Few studies have investigated associations between adiposity and reproductive factors using causal methods, both of which have a number of consequences on women's health. Here we assess whether adiposity at different points in the lifecourse affects reproductive factors differently and independently, and the plausibility of the impact of reproductive factors on adiposity.

METHODS

We used genetic data from UK Biobank (273,238 women) and other consortia (EGG, GIANT, ReproGen and SSGAC) for eight reproductive factors: age at menarche, age at menopause, age at first birth, age at last birth, number of births, being parous, age first had sexual intercourse and lifetime number of sexual partners, and two adiposity traits: childhood and adulthood body size. We applied multivariable Mendelian randomization to account for genetic correlation and to estimate the causal effects of childhood and adulthood adiposity, independently of each other, on reproductive factors. Additionally, we estimated the effects of reproductive factors, independently of other relevant reproductive factors, on adulthood adiposity.

RESULTS

We found a higher childhood body size leads to an earlier age at menarche, and an earlier age at menarche leads to a higher adulthood body size. Furthermore, we find contrasting and independent effects of childhood and adulthood body size on age at first birth (beta 0.22 SD (95% confidence interval: 0.14, 0.31) vs - 2.49 (- 2.93, - 2.06) per 1 SD increase), age at last birth (0.13 (0.06,0.21) vs - 1.86 (- 2.23, - 1.48) per 1 SD increase), age at menopause (0.17 (0.09, 0.25) vs - 0.99 (- 1.39, - 0.59) per 1 SD increase), and likelihood of having children (Odds ratio 0.97 (0.95, 1.00) vs 1.20 (1.06, 1.37) per 1 SD increase).

CONCLUSIONS

Our findings demonstrate the importance of considering a lifecourse approach when investigating the inter-relationships between adiposity measures and reproductive events, as well as the use of 'age specific' genetic instruments when evaluating lifecourse hypotheses in a Mendelian randomization framework.

Female Reproductive Factors and Risk of New-Onset Heart Failure: Findings From UK Biobank

BACKGROUND

A comprehensive evaluation of woman-specific risk factors in relation to incident heart failure (HF) is limited.

OBJECTIVES

This study sought to investigate the association of multiple female reproductive factors with the risk of HF.

METHODS

Between 2007 and 2010, 229,026 women (mean age: 56.5 years) without prevalent HF from the UK Biobank cohort were included and followed until December 2020. The relation between (self-reported) reproductive factors and HF was analyzed using Cox proportional hazards models with adjustment for potential confounding.

RESULTS

Menarche at age <12 years, compared to age 12-13 years, carried a 9% larger risk of HF (HR: 1.09 [95% CI: 1.01-1.18]). Younger age at menopause was associated with a higher risk of HF (HRage <45 y vs 50-51 y: 1.15 [95% CI: 1.03-1.28]; HRage 45-49 y vs 50-51 y: 1.11 [95% CI: 1.01-1.23]). Younger maternal age at first live birth (HRage <21 y vs 24-26 y: 1.42 [95% CI: 1.28-1.59]; HRage 21-23 y vs 24-26 y: 1.14 [95% CI: 1.03-1.26]) and at last live birth (HRage <26 y vs 29-31 y: 1.19 [95% CI: 1.07-1.33]) were associated with higher risk of HF. Compared to women with 1 or 2 children, having 3 or 4 children (HR: 1.09 [95% CI: 1.02-1.17]) or >4 children (HR: 1.24 [95% CI: 1.05-1.47]) was associated with higher HF risk. Experiencing miscarriages or abortions was not significantly associated with incident HF, whereas experiencing 1 stillbirth and recurrent stillbirths conferred a 20% and 43% larger risk of HF, respectively, compared to no stillbirth.

CONCLUSIONS

The findings emphasize the importance of female reproductive history in the assessment of HF risk.

Genetic liability to age at first sex and birth in relation to cardiovascular diseases: a Mendelian randomization study

BACKGROUND

Growing evidence suggests that various reproductive factors, including early menarche, early menopause, and age at first birth, may increase the risk of developing cardiovascular disease (CVD) later in life. However, the associations between reproductive factors and CVDs are inconsistent and controversial. Therefore, we conducted a two-sample Mendelian randomization (MR) analysis to explore the potential links between age at first sex (AFS) and age at first birth (AFB) and several CVDs.

METHODS

We obtained summary statistics for exposure from the largest genome-wide association studies of AFS and AFB. To serve as instrumental variables, we selected 259 SNPs associated with AFS and 81 SNPs associated with AFB at the genome-wide significance level. We employed a random-effects inverse-variance weighted method to pool estimates, and conducted multivariable MR analysis to determine the direct association between AFS and AFB with CVDs, while accounting for the effects of confounders.

RESULTS

The genetic liability to later AFS was associated with decreased risks of heart failure (odd ratio [OR] 0.700; 95% confidence interval [CI] 0.639-0.767; p = 2.23 × 10^-14), coronary artery disease (OR 0.728; 95% CI 0.657-0.808; p = 1.82 × 10^-9), myocardial infarction (OR 0.731; 95% CI 0.657-0.813; p = 8.33 × 10^-9), stroke (OR 0.747; 95% CI 0.684-0.816; p = 6.89 × 10^-11), and atrial fibrillation (OR 0.871; 95% CI 0.806-0.941; p = 4.48 × 10^-4). The genetic liability to later AFB was also associated with decreased risks of CVDs, including myocardial infarction (OR 0.895; 95% CI 0.852-0.940; p = 8.66 × 10^-6), coronary heart disease (OR 0.901; 95% CI 0.860-0.943; p = 9.02 × 10^-6), heart failure (OR 0.925; 95% CI 0.891-0.961; p = 5.32 × 10^-5), and atrial fibrillation (OR 0.944; 95% CI 0.911-0.978; p = 0.001). However, no association was found between AFB and stroke. The associations remained independent from the effects of AFS and AFB on potential confounders, including smoking, alcohol intake, body mass index, and depression. Mediation analysis suggested that education attainment partly mediates the link from AFS and AFB to CVD outcomes.

CONCLUSION

Our results observed a causal relationship between later AFS, AFB and lower CVDs risk; it emphasizes the importance of providing sex education since early sex and birth may have undesirable effects. Cardiovascular risk stratification that considers reproductive factors may help address CVD risk.

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.

Exploring the associations between number of children, multi-partner fertility and risk of obesity at midlife: Findings from the 1970 British Cohort Study (BCS70)

BACKGROUND

Early parenthood, high parity, and partnership separation are associated with obesity. However, the emergence of non-marital partnerships, serial partnering and childbearing across unions, means that it is important to consider their association to obesity. This paper examined the associations between number of biological children and multi-partner fertility (MPF)-defined as having biological children with more than one partner, with obesity at midlife.

METHOD

The sample consisted of 2940 fathers and 3369 mothers in the 1970 British Cohort Study. The outcome was obesity (BMI 30 or over) at age 46. Fertility and partnership histories ascertained the number of live biological children and MPF status by age 42. The associations were tested using logistic regression adjusting for confounders at birth, age 10 and age 16. Adult factors recorded at age 42 including age at first birth, smoking status, alcohol dependency, educational attainment and housing tenure were considered as mediators.

RESULTS

For fathers, obesity odds did not differ according to number of children or MPF. In unadjusted models, mothers with one child (OR 1.24 95%CI 1.01-1.51), mothers who had two children with two partners (OR 1.45 95%CI 1.05-1.99), and mothers who had three or more children with two or more partners (OR 1.51 95%CI 1.18-1.93) had higher odds of obesity. In adjusted models, there remained an association between mothers with one child and odds of obesity (OR 1.30 95%CI 1.05-1.60). All other associations were attenuated when confounders were included.

CONCLUSIONS

Mothers who had children with multiple partners had higher odds of obesity. However this association was completely attenuated when parental and child confounders were accounted for; suggesting that this association may be explained by confounding. Mothers who had one child only may be at increased odds of obesity, however this could be due to multiple factors including age at first birth.

Childhood Socioeconomic Position and Cardiovascular Disease Among Older Women and Men: The Moderating Role of Parenthood Onset

Objectives: Based on a life-course approach, the purpose of this study is to analyze how the age at the birth of a first child moderates the relationship between childhood socioeconomic position (SEP) and cardiovascular diseases (CVD) incidence in old age, separately for women and men.

Methods: We used a rich and representative life history survey of people aged from 65 to 75 living in Santiago, Chile (n = 802), and weighted multivariate statistical models. Data collection process involved the use of face-to-face life history calendars, administered by well-trained interviewers.

Results: Early motherhood increases the risk of suffering CVD among older women with a disadvantaged childhood SEP, while late motherhood decreases it. By contrast, early fatherhood decreases CVD risk among older men with an adverse childhood SEP, while late fatherhood increases it.

Conclusion: Our findings about the moderating role of parenthood onset on CVD risk among older women and men with a disadvantaged childhood SEP contributes to public health reflections on unexplored cardiovascular risk factors, which lead to substantial changes in women’s and men’s life courses, and might optimize cardiovascular prevention strategies.

Age at first birth and risk of urinary incontinence after delivery: a dose-response meta-analysis

Studies investigating the impact of age at first birth on urinary incontinence after delivery have reached inconsistent conclusions. We performed this systematic review and meta-analysis of studies assessing the risk of urinary incontinence after delivery, regardless of the type, with age at first birth. MEDLINE via PubMed and Web of science databases were searched up to March 13, 2021. Restricted cubic splines were used to model the dose–response association. Twelve publications were included in this meta-analysis. The summary odds ratio (OR) and 95% confidence interval (CI) per 1-year increase in age at first birth were 1.01 (95% CI (0.99, 1.02)) for urinary incontinence (America: 1.00 (0.99, 1.00); Europe: 1.03 (1.00, 1.06); Asian: 0.99 (0.89, 1.10)). A non-linear dose–response (P_nonlinearity < 0.01) indicated that age at first birth older than 32 (P < 0.05) increases the risk of urinary incontinence. First birth before age 32 make decrease the risk of urinary incontinence after delivery.

Childhood adversity and cardiometabolic biomarkers in mid-adulthood in the 1958 British birth cohort

Studies that have examined associations between adverse childhood experiences (ACEs) and cardiometabolic biomarkers in adulthood are limited as they mainly focus on childhood maltreatment. This study aimed to examine the association between a range of prospectively and retrospectively reported ACEs and cardiometabolic biomarkers in mid-adulthood. Multiply-imputed data on 8511 participants from the National Child Development Study (1958 British birth cohort) were used. ACEs were prospectively reported at ages 7, 11 and 16, and retrospectively reported at age 33/44/45. Cardiometabolic outcomes assessed at age 44/45 included glycated haemoglobin (HbA1c), cholesterol (total, low-density lipoprotein (LDL) and high-density lipoprotein (HDL)), triglycerides, blood pressure (systolic and diastolic), body mass index, waist circumference and metabolic syndrome. Parental separation/divorce, physical neglect, emotional neglect and psychological abuse were associated with lower HDL cholesterol. Parental offending and physical neglect were associated with higher triglyceride concentrations. Parental offending was also associated with increased HbA1c. Exposure to 2+ (vs. 0) prospective ACEs was associated with lower HDL cholesterol. All these associations were after adjustment for sex and multiple early life factors. To conclude, several individual ACEs are associated with poorer cardiometabolic risk factor profiles in mid-adulthood. Furthermore, exposure to two or more prospective ACEs is associated with lower HDL cholesterol concentrations in mid-adulthood.

•

Parental separation/divorce in childhood is associated with lower high-density lipoprotein cholesterol in mid-adulthood.

•

Physical neglect in childhood is associated with poorer lipid profiles in mid-adulthood.

•

Psychological abuse in childhood is associated with lower high-density lipoprotein cholesterol in mid-adulthood.

•

Parental offending in childhood is associated with higher triglycerides and glycated haemoglobin in mid-adulthood.

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.

Fertility History and Risk of Cognitive Impairment Among Older Parents in the United States

OBJECTIVES

I work from a gendered life-course perspective to examine the association between older parents' fertility history (i.e., timing and parity) and their risk of cognitive impairment in the United States.

METHODS

I analyze nationally representative data from 9 waves over 16 years of the Health and Retirement Study (2000-2016). The sample includes 14,543 respondents (6,108 men and 8,435 women) aged 50 and older at the baseline survey. I examine the relationship between parity, age at first birth, and age at last birth with risk of cognitive impairment using nonlinear discrete-time hazard models.

RESULTS

Adjusting for the effects of full covariates, there are U-shaped relationships between women's age at last birth and risk of cognitive impairment and between women's parity and risk of cognitive impairment. In the sensitivity tests, the relationships remain robust when sampling weights are applied, or mortality selection is corrected.

DISCUSSION

Fertility timing and parity are likely factors associated with the risk of cognitive impairment for older women. Understanding fertility history and its impact on cognition can help identify the most vulnerable subpopulations, so that more effective interventions can be made to improve cognitive functioning among older adults.

Fertility Histories and Heart Disease in Later Life in China

Purpose

Based on life course theories, health among older people is driven by a continuous and cumulative process that develops over the life course. To better understand the aging process, it is important to assess associations between parity and heart disease in older people of China.

Method

The associations between heart disease prevalence and number of births, number of boys or girls ever born were evaluated among 5,990 samples (mean age 64.1 years) using the Probit regression model based on the data from China Health and Retirement Longitudinal Study (CHARLS) conducted in 2013 and 2018. The model was adjusted only for rural or urban residents, and multivariate regression models were run separately by gender.

Results

Our results showed that more than three children or more than two boys ever born were associated with a higher risk of heart disease. However, the number of girls ever born had no significant effect on heart disease in the elderly. We further analyzed the group difference between urban and rural residents using the regression model. More than three children or more than two boys ever born were associated with a high risk of heart disease in rural areas. Compared to urban residents, rural residents were more likely to be suffering from heart disease due to high parity. When considering the digender difference the paper found that more than three children ever born were associated with a high risk of heart disease in the female group. Late age at the time of giving birth for the first time was associated with a poorer risk level of heart disease in the rural residents, because the phenomenon of early childbearing was serious in the rural residents. But after considering the impact on the physical health of using chronic diseases, the first birth and the last birth both increased the risk of heart disease.

Conclusions

Some policy implications were being put forward. Firstly, parents who were ready to give birth should be aware of the possible health loss of high parity. Postpartum nutrition supplements and chronic disease prevention were suggested to prevent heart disease in later life. Secondly, the elderly in rural areas should pay more attention to heart diseases. Participating in more daily exercise and physical examinations was a good choice to reduce the risk of heart disease. Thirdly, women who give birth prematurely have a higher risk of CVD. Based on our results, age at entry to parenthood was closely related to the risk of heart disease in later life.

Advanced Maternal Age and Its Association With Cardiovascular Disease in Later Life

INTRODUCTION

Fertility among women at advanced maternal age (AMA) is increasing at a rapid rate in the United States. Although much is known about the impact of older maternal age on the risk for proximate adverse pregnancy outcomes, it is unclear whether older maternal age affects subsequent health. The objective of this study was to evaluate whether AMA is associated with cardiovascular disease (CVD) later in life, adjusting for important social and health factors related to maternal age.

METHODS

Data were obtained from the Nurses' Health Study II, a longitudinal prospective cohort study. We investigated whether women with an AMA first or subsequent birth were at higher risk for developing CVD (myocardial infarction or stroke) after age 42 than women without births at AMA. Cox proportional hazard models were estimated to evaluate this association, adjusting for demographic, fertility, and health characteristics.

RESULTS

A total of 5,471 women (7.7%) in the sample had a first birth at an AMA and 1,282 (1.8%) developed CVD at age 42 or older. Women with first births at AMA had a 26% lower unadjusted hazard of CVD than women not at an AMA during their first birth (hazard ratio, 0.74; 95% confidence interval, 0.57-0.95). This association was attenuated (hazard ratio, 0.80; 95% confidence interval, 0.62-1.05) and no longer significant after adjustment for covariates; the modest association remained significant for women with any AMA birth.

CONCLUSIONS

We found no evidence that AMA births were associated with increased risk for developing CVD later in life in this sample.

Pregnancy, preeclampsia and maternal aging: From epidemiology to functional genomics

Women live longer than men but experience greater disability and a longer period of illness as they age. Despite clear sex differences in aging, the impact of pregnancy and its complications, such as preeclampsia, on aging is an underexplored area of geroscience. This review summarizes our current knowledge about the complex links between pregnancy and age-related diseases, including evidence from epidemiology, clinical research, and genetics. We discuss the relationship between normal and pathological pregnancy and maternal aging, using preeclampsia as a primary example. We review the results of human genetics studies of preeclampsia, including genome wide association studies (GWAS), and attempted to catalog genes involved in preeclampsia as a gateway to mechanisms underlying an increased risk of later life cardio- and neuro- vascular events. Lastly, we discuss challenges in interpreting the GWAS of preeclampsia and provide a functional genomics framework for future research needed to fully realize the promise of GWAS in identifying targets for geroprotective prevention and therapeutics against preeclampsia.

Work-family life courses and psychological distress: Evidence from three British birth cohort studies

This study uses multi-channel sequence analysis to characterize work-family life course types between the ages of 16 and 42, and multivariable logistic regression to examine their association with psychological distress at age 42/43 for men and women in three nationally-representative British birth cohorts born in 1946 (N = 2,858), 1958 (N = 9,140), and 1970 (N = 7,095). We hypothesised that work-family life courses characterized by weaker links to employment and earlier transitions to partnerships and parenthood would be associated with a greater probability of psychological distress at age 42, and that this association would be become more pronounced across cohorts. Levels of psychological distress were higher amongst men and women with weaker long-term ties to employment, although these were largely explained by early life factors. Teen mothers had higher levels of psychological distress in the two later-born cohorts, and this remained unexplained in adjusted models for the 1970 cohort.

The role of multiparity and maternal age at first pregnancy in the association between early menarche and metabolic syndrome among middle-aged and older women

OBJECTIVE

To analyze whether maternal age at first pregnancy and parity are mediators of the association between early menarche and metabolic syndrome in a sample of middle-aged and older women.

METHODS

Cross-sectional study of 428 women (40 to 80 y), who had experienced a pregnancy in their lifetime, was performed between 2014 and 2016. Age at first pregnancy, parity, and early menarche were self-reported. Metabolic syndrome was assessed using the criteria described by the National Cholesterol Education Program's Adult Treatment Panel III. The association between metabolic syndrome and early menarche was assessed by logistic regression analysis. The mediating role of age at first pregnancy and multiparity in the relationship between early menarche and metabolic syndrome was assessed through mediation analysis, adjusted for covariates.

RESULTS

According to adjusted logistic regression models, early menarche was associated with higher odds of prevalent metabolic syndrome (OR: 2.26; 95% CI: 1.15-4.46). Mediation analysis showed a significant direct effect of early menarche on metabolic syndrome (β: 0.808; 95% CI: 0.107-1.508). Of the two mediators tested, age at first pregnancy was significant (β: 0.065; 95% CI: 0.004-0.221), ie, participants with and without early menarche differ, on average, by 0.879 SDs in the log odds of MetS (total effect), of which 0.065 SDs (8%), on average, would be attributable to the effect of early menarche on age at first pregnancy (indirect effect), which, in turn, affects MetS.

CONCLUSIONS

Age at first pregnancy may partially contribute to the association between early menarche and metabolic syndrome among middle-aged and older women who had experienced a pregnancy over their lifetime.

Age at first birth and lung cancer: a two-sample Mendelian randomization study

Background

Growing evidence suggests that female reproductive factors, like age at first birth (AFB), may play a potential role in the progression of lung cancer (LC). However, previous studies are susceptible to confounding factors, inadequate attention to variation by histology or reverse causality. Few studies have comprehensively evaluated their association and the causal effect remains unclear.

Methods

We aimed to determine whether AFB is causally correlated with the risk of LC, by means of utilizing aggregated data from the large genome-wide association studies conducted on AFB (251,151 individuals) and data of LC from International Lung and Cancer Consortium (ILCCO, 11,348 cases and 15,861 controls). We used 10 AFB-related single nucleotide polymorphisms as instrument variables and applied several two-sample Mendelian randomization (MR) methods. Secondary results according to different histological subtypes of lung cancer were also implemented.

Results

Conventional inverse-variance weighted method indicated that genetic predisposition towards number unit (1 year) increase of AFB was associated with a 18% lower risk of LC [odds ratio (OR) =0.82, 95% confidence interval (CI): 0.69–0.97; P=0.029]. When results were examined by histotypes, an inverse association was observed between genetically predisposed number unit (1 year) increase of AFB and lung adenocarcinoma (OR =0.75, 95% CI: 0.59–0.97, P=0.017) but not with squamous cell lung cancer (OR =0.77, 95% CI: 0.57–1.05, P=0.103). The results demonstrated no association between number unit decrease of AFB and LC. Pleiotropy was not presented through sensitivity analyses including MR pleiotropy residual sum and outlier test (P=0.412). Genetic predisposition towards older AFB was additionally associated with longer years of schooling (OR =1.12, 95% CI: 1.08–1.16, P<0.001), lower body mass index (OR =0.93, 95% CI: 0.88–0.98, P=0.004) and less alcohol consumption (OR =0.99, 95% CI: 0.99–1.00, P=0.004).

Conclusions

Our study suggested that older AFB was a causal protective factor in the progression of LC. Further studies elucidating the potential mechanisms are needed.

Longitudinal changes in HDL-cholesterol concentration are associated with different risk factors in primiparous and nulliparous young women: The NHLBI Growth and Health Study (NGHS)

BACKGROUND

Previous studies report that first pregnancy is associated with persistent decreases in HDL-cholesterol (HDL-C) concentrations.

OBJECTIVE

This study evaluated factors associated with declines in HDL-C concentration in parous and nulliparous young women.

METHODS

This study leverages data from African-American and white women from the NHLBI Growth and Health Study. Parity-related changes in lipids, BMI and percent body fat were assessed longitudinally. A subset of primiparous and nulliparous women with paired lipid measurements were analyzed regarding changes in HDL-C concentrations.

RESULTS

Among 870 women in longitudinal analyses, African-American women had higher parity (p<0.0001), with baseline measurements of each parity group being similar. HDL-C concentration decreased significantly and remained lower after the first pregnancy, while BMI and percent body fat increased with increasing parity. In the subset of 401 women, HDL-C concentration decreased among primiparous women (-4.81 ± 0.93 mg/dl), with no overall change in nulliparous (p = 0.003). In both groups, greater HDL-C concentration declines were independently associated with higher initial HDL-C concentration and greater increases in BMI (both p<0.0001). Among primiparous women, younger delivery age (p = 0.0001) and birth control use (p = 0.004) were associated with greater HDL-C concentration decline. Nulliparous white women's HDL-C concentration increased over time, with no change in African-American women (p = 0.008); no racial difference was seen in primiparous women.

CONCLUSION

Persistent decreases in HDL-C concentration were associated with the first pregnancy, and were greater with higher initial HDL-C concentration. Racial differences in HDL-C concentration emerged over time in nulliparous women, but not primiparous women. Potential impacts of these findings on women's long-term cardiometabolic health should be evaluated.

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.

Pregnancy-related events associated with subclinical cardiovascular disease burden in late midlife: SWAN

BACKGROUND AND AIMS

Reproductive factors are associated with later life CVD in women (e.g., age at first birth, preeclampsia, gestational diabetes), but studies have focused largely on premenopausal women. We examined the relationship of reproductive factors with subclinical CVD burden in late midlife women.

METHODS

We included 964 parous women from the Study of Women's Health Across the Nation (SWAN), who completed a reproductive history questionnaire at the 13th SWAN visit (2011-2012), and a carotid ultrasound and brachial-ankle pulse wave velocity (baPWV) assessment. The primary outcomes were carotid intima-media thickness, plaque, and baPWV; our secondary outcome was a composite subclinical CVD index created using these measures. Linear and logistic regression was performed to examine associations with individual subclinical CVD measures, and multinomial logistic regression was used in analyses of the composite index. Models adjusted for socio-demographics and cardiovascular risk factors.

RESULTS

Mean age at subclinical CVD assessment was 60.2 years (SD ± 2.7). History of gestational hypertension/preeclampsia was associated with greater carotid IMT (β: 0.038, p = 0.004). Earlier age at first birth was associated with subclinical CVD, but not when accounting for CVD risk factors. History of gestational diabetes was associated with greater baPWV, but not related to our composite index.

CONCLUSIONS

Pregnancy history is an important marker of subclinical CVD in late midlife and may impact the vasculature through distinct pathways. Future studies are necessary to evaluate racial/ethnic differences in the observed associations and to assess the benefit of a composite subclinical CVD index for earlier CVD risk modification in midlife women.

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.

•

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.

Maternal age and cardiovascular and metabolic disease outcomes: a retrospective cohort study using data from population-based electronic medical records

Objective: To evaluate whether a woman's age at first birth is associated with cardiovascular risk and metabolic health outcomes (cardiometabolic outcomes) by age 45.Methods: This is a retrospective, population-based cohort study that uses electronic health record data from the largest health fund in Israel. Women aged 34-39 at baseline (2004-2006) free of chronic diseases were identified as nulliparous at baseline and were followed up to 10 years (through 2016). The cohort was divided into three groups based on their age at first birth: younger parturients (ages 35-39), older parturients (ages 40-44), and never had children. The percentage of adverse pregnancy events and cardiometabolic outcomes at age 45 were compared across these three groups as well as to women in the general population. Cardiovascular risk and metabolic health outcomes were defined as: Type 2 diabetes, obesity, hypertension, cardiovascular disease, and Framingham risk score.Methods and results: Out of a group of 126,121 women aged 34-39 at baseline, 9979 were nulliparous and free of comorbidities. Over the course of the follow-up, there were 952 younger parturients and 673 older parturients who had their first birth, and 8354 women who remained persistent nulliparous. While older parturients had more adverse pregnancy events, there was no difference in rates of cardiometabolic outcomes between the two parturient groups, and they both had lower rates than the persistent nulliparous and the general population.Conclusions: Parturients free of major chronic diseases who give birth at a later age do not have increased cardiometabolic outcomes in midlife as compared to a general population of women in a large retrospective cohort. Our results may support clinicians when counseling healthy women who are seeking advice regarding delaying their first pregnancy without a tradeoff on health outcomes.

Women's reproductive factors and incident cardiovascular disease in the UK Biobank

BACKGROUND

Studies have suggested that women's reproductive factors are associated with the risk of cardiovascular disease (CVD); however, findings are mixed. We assessed the relationship between reproductive factors and incident CVD in the UK Biobank.

METHODS

Between 2006 and 2010, the UK Biobank recruited over 500 000 participants aged 40-69 years across the UK. During 7 years of follow-up, 9054 incident cases of CVD (34% women), 5782 cases of coronary heart disease (CHD) (28% women), and 3489 cases of stroke (43% women) were recorded among 267 440 women and 215 088 men without a history of CVD at baseline. Cox regression models yielded adjusted hazard ratios (HRs) for CVD, CHD and stroke associated with reproductive factors.

RESULTS

Adjusted HRs (95% CI) for CVD were 1.10 (1.01 to 1.30) for early menarche (<12 years), 0.97 (0.96 to 0.98) for each year increase in age at first birth, 1.04 (1.00 to 1.09) for each miscarriage, 1.14 (1.02 to 1.28) for each stillbirth, and 1.33 (1.19 to 1.49) for early menopause (<47 years). Hysterectomy without oophorectomy or with previous oophorectomy had adjusted HRs of 1.16 (1.06 to 1.28) and 2.30 (1.20 to 4.43) for CVD. Each additional child was associated with a HR for CVD of 1.03 (1.00 to 1.06) in women and 1.03 (1.02 to 1.05) in men.

CONCLUSIONS

Early menarche, early menopause, earlier age at first birth, and a history of miscarriage, stillbirth or hysterectomy were each independently associated with a higher risk of CVD in later life. The relationship between the number of children and incident CVD was similar for men and women.

Adolescent Childbirth Is Associated With Greater Framingham Risk Scores for Cardiovascular Disease Among Participants of the IMIAS (International Mobility in Aging Study)

BACKGROUND

Previous studies observe associations between lifetime parity and cardiovascular disease, but relatively fewer investigate age at first childbirth (AFB). Herein, we examine the association of AFB with a summary cardiovascular risk measure (Framingham Risk Score [FRS]).

METHODS AND RESULTS

As part of the IMIAS (International Mobility in Aging Study), data were collected in 2012 among 1047 women, aged 65 to 74 years, from Canada, Albania, Colombia, and Brazil. FRSs were calculated to describe cardiovascular risk profiles, and linear regression analyses were performed, adjusting for early life and socioeconomic variables. Women with an AFB of <20 years were compared with women with an AFB of 20 to 24, 25 to 29, and ≥30 years, as well as nulliparous women. We also compared FRS between combinations of AFB and parity categories: nulliparous women, parity 1 to 3 combined with AFB <20 years, parity ≥4 with AFB <20 years, parity 1 to 3 with AFB ≥20 years, and parity ≥4 with AFB ≥20 years. Women with an AFB of <20 years had a higher mean FRS compared with all other AFB groups. Compared with the lowest AFB risk group (25-29 years), women with an AFB of <20 years had a 5.8-point higher mean FRS (95% confidence interval, 3.4-8.3 points). Nulliparous women presented the lowest mean FRS in all analyses. The analysis comparing combinations of AFB and parity categories showed no meaningful differences in FRS between women who had 1 to 3 childbirths and those who had ≥4 childbirths within the stratum of AFB <20 years, and in the stratum of AFB ≥20 years.

CONCLUSIONS

Our analyses suggest that nulliparity and AFB, rather than increasing parity, drive the association with cardiovascular disease risk.