Age at first birth and risk of later-life cardiovascular disease: a systematic review of the literature, its limitation, and recommendations for future research

Parity, infertility, age at first birth, and risk of atrial fibrillation: data from the HUNT study

AIMS

Although parity, infertility, and age at first birth are important for later development of cardiovascular disease, research on their association with atrial fibrillation (AF) is limited.

METHODS AND RESULTS

We linked data from the population-based HUNT study and the Medical Birth Registry of Norway (MBRN) and validated medical records from local hospitals. A total of 24 015 women aged 45 years or older were followed for verified incident AF. Parity and age at first birth were retrieved from the MBRN or from self-reported questionnaires in the HUNT study. A history of infertility was self-reported on the HUNT questionnaire. Cox proportional hazards models were used to calculate hazard ratios (HRs) for the multivariable-adjusted associations of parity, infertility, and age at first birth with risk of AF. During a median follow-up of 12.8 years, 1448 (6.0%) participants developed AF. Women with higher parity (four or more births vs. two births) were at 21% higher risk of AF [HR 1.21, 95% confidence interval (CI) 1.05-1.39]. A history of infertility was also associated with the risk of AF (HR 1.20, 95% CI 1.02-1.42). Among parous women, younger age at first birth (<20 vs. 20-29 years) was associated with a 20% higher risk of AF (HR 1.20, 95% CI 1.03-1.40).

CONCLUSION

Women with four or more births, or a history of infertility, or younger age at first birth have approximately a 20% higher risk of AF among women over 45 years old.

The legal and medical consequences of child marriage

The Marriage and Civil Partnership (Minimum Age) Act 2022 came into force in England on 27 February 2023 and made both registered and unregistered marriages involving people under 18 illegal in England and Wales. This means that such marriages which take place outside England and Wales will not be recognised and those who organised them, including parents, will have committed a criminal offence.This review considers issues related to families where such marriages have happened, including their impact on the health of the victim and any resulting children. It touches on religious and societal issues and the need for targeted and appropriate education.

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.

Childhood adversity and accelerated reproductive events: a systematic review and meta-analysis

OBJECTIVE

Accelerated female reproductive events represent the early onset of reproductive events involving puberty, menarche, pregnancy loss, first sexual intercourse, first birth, parity, and menopause. This study aimed to explore the association between childhood adversity and accelerated female reproductive events.

DATA SOURCES

PubMed, Web of Science, and Embase were systematically searched from September 22, 2022 to September 23, 2022.

STUDY ELIGIBILITY CRITERIA

Observational cohort, cross-sectional, and case-control studies in human populations were included if they reported the time of reproductive events for female individuals with experience of childhood adversity and were published in English.

METHODS

Two reviewers independently screened studies, obtained data, and assessed study quality, and conflicts were resolved by a third reviewer. Dichotomous outcomes were evaluated using meta-analysis, and pooled odds ratios and 95% confidence intervals were generated using random-effects models. Moderation analysis and meta-regression were used to investigate heterogeneity.

RESULTS

In total, 21 cohort studies, 9 cross-sectional studies, and 3 case-control studies were identified. Overall, female individuals with childhood adversity were nearly 2 times more likely to report accelerated reproductive events than those with no adversity exposure (odds ratio, 1.91; 95% confidence interval, 1.33-2.76; I2=99.6%; P<.001). Moderation analysis indicated that effect sizes for the types of childhood adversity ranged from an odds ratio of 1.61 (95% confidence interval, 1.23-2.09) for low socioeconomic status to 2.13 (95% confidence interval, 1.14-3.99) for dysfunctional family dynamics. Among the 7 groups based on different reproductive events, including early onset of puberty, early menarche, early sexual initiation, teenage childbirth, preterm birth, pregnancy loss, and early menopause, early sexual initiation had a nonsignificant correlation with childhood adversity (odds ratio, 2.70; 95% confidence interval, 0.88-8.30; I2=99.9%; P<.001). Considerable heterogeneity (I2>75%) between estimates was observed for over half of the outcomes. Age, study type, and method of data collection could explain 35.9% of the variance.

CONCLUSION

The literature tentatively corroborates that female individuals who reported adverse events in childhood are more likely to experience accelerated reproductive events. This association is especially strong for exposure to abuse and dysfunctional family dynamics. However, the heterogeneity among studies was high, requiring caution in interpreting the findings and highlighting the need for further evaluation of the types and timing of childhood events that influence accelerated female reproductive events.

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.

Child Marriage and Cardiovascular Risk: An Application of the Non-laboratory Framingham Risk Score

INTRODUCTION

Child marriage, defined as marriage before the age of 18 years, is a precocious transition from adolescence to adulthood, which may take a long-term toll on health.

AIM

This study aims to assess whether child marriage was associated with added risk of adverse cardiovascular outcomes in a nationally representative sample of Indian adults.

METHODS

Applying the non-laboratory-based Framingham algorithm to data on 336,953 women aged 30-49 years and 49,617 men aged 30-54 years, we estimated individual's predicted heart age (PHA). Comparing the PHA with chronological age (CA), we categorized individuals in four groups: (i) low PHA: PHA < CA, (ii) equal PHA: PHA = CA (reference category), (iii) high PHA: PHA > CA by at most 4 years, and (iv) very high PHA: PHA > CA by 5 + years. We estimated multivariable multinomial logistic regressions to obtain relative risks of respective categories for the child marriage indicator.

RESULTS

We found that women who were married in childhood had 1.06 (95% CI 1.01-1.10) and 1.22 (95% CI 1.16-1.27) times higher adjusted risks of having high and very high PHA, respectively, compared to women who were married as adults. For men, no differential risks were found between those who were married as children and as adults. These results were generally robust across various socioeconomic sub-groups.

CONCLUSIONS

These findings add to the relatively new and evolving strand of literature that examines the role of child marriage on later life chronic health outcomes and provide important insights for public health policies aimed at improving women's health and wellbeing.

WITHDRAWN: Cardiovascular disease in individuals with a history of out-of-home care: a Swedish national cohort study

The authors have withdrawn their manuscript owing to errors apparent in the results. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.

Association of age at first sexual intercourse and lifetime number of sexual partners with cardiovascular diseases: a bi-directional Mendelian randomization study

Background

Limited studies have explored the association between sexual factors [age at first sexual intercourse (AFS) and lifetime number of sexual partners (LNSP)] and cardiovascular diseases (CVDs), leaving the causality inconclusive.

Methods

We performed a bi-directional Mendelian randomization (MR) study to investigate the causality between sexual factors and CVDs, including coronary artery disease, myocardial infarction, atrial fibrillation (AF), heart failure (HF), and ischemic stroke (IS). Single-nucleotide polymorphisms (SNPs) for sexual factors were extracted from the UK Biobank. Statistics for each CVD were derived from two different databases. MR estimates were calculated per outcome database and were combined through meta-analysis. Several complementary sensitivity analyses were also performed.

Results

The primary analysis suggested that AFS was causally associated with the risk of CVDs; the odds ratios (ORs) ranged from 0.686 [95% confidence interval (CI), 0.611-0.770] for HF to 0.798 (95% CI, 0.719-0.886) for AF. However, the association between AFS and IS (OR, 0.844; 95% CI, 0.632-1.126) was not consistent in the meta-analysis after excluding SNPs related to confounders. Moreover, non-significant associations were found between LNSP and CVDs. Reverse direction MR analysis showed that CVDs were not associated with sexual factors.

Conclusions

Genetic evidence suggested that AFS was causally associated with the risk of CVDs except for IS, whereas non-significant association of LNSP with CVDs was detected. Further investigation into AFS could be warranted in preventing the progression of CVDs.

Association between number of children and incident heart disease and stroke in parents - results from the Survey of Health, Ageing and Retirement in Europe (SHARE)

BACKGROUND

In former studies, parity was associated with adverse cardiovascular outcomes in parents. This study aims to extend the limited existing data regarding the association between the number of children and heart disease and/or stroke in a large longitudinal study in different European countries in both men and women.

METHODS

For 42 075 subjects (18 080 men, 23 995 women; median age 58 years (interquartile range: 53 to 65)) from 19 European countries and Israel in the Survey of Health, Ageing and Retirement in Europe (SHARE), odds ratios (OR) for the association between number of children and incident self-reported heart disease and/or stroke (HDS) were estimated using logistic regression analyses. Persons with one or two children were used as reference. The final model was adjusted for baseline age, sex, education, region, and marital status. All analyses were stratified by sex.

RESULTS

Women with seven or more children had the highest OR for the association between the number of children and incident HDS (OR = 2.12 [95% CI: 1.51 to 2.98]), while men with six children showed the highest OR (OR = 1.62 [1.13 to 2.33]). Stratified by education, across all education levels, men and women with five or more children had the highest ORs for this association. The highest OR was observed in both women and men in the group with primary education (OR = 1.66 [1.29 to 2.15] and OR = 1.60 [1.19 to 2.14], respectively). Stratified by region, both men and women with five or more children showed the highest ORs in Southern Europe (OR = 2.07 [1.52 to 2.82] and OR = 1.75 [1.25 to 2.44], respectively).

CONCLUSION

In this long-term follow-up study in various countries in Europe and Israel we found a positive association between number of children and incident HDS. This association was more pronounced in lower educated subjects and showed regional variations.

The association of female reproductive factors with risk of metabolic syndrome in women from NHANES 1999-2018

BACKGROUND

Female reproductive factors such as age at first birth (AFB), age at last birth (ALB), number of pregnancies and live births play an essential role in women's health. However, few epidemiological studies have evaluated the association between female reproductive factors and metabolic syndrome (MetS). We therefore conducted a cross-sectional study to investigate the association between MetS risk and female reproductive factors.

METHODS

We investigated the relationship between AFB, ALB, number of pregnancies and live births and the incidence of MetS using publicly available data from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2018. Weighted multivariable logistic regression analysis, restricted cubic spline (RCS) model, and subgroup analysis were used to evaluate the association between AFB and ALB and the risk of MetS in women. In addition, the relationship between the number of pregnancies, live births and MetS risk was also explored.

RESULTS

A total of 15,404 women were included in the study, and 5,983 (38.8%) had MetS. RCS models showed an N-shaped relationship between AFB and MetS risk, whereas ALB, number of pregnancies, and live births were linearly associated with MetS. Weighted multivariable logistic regression analysis showed that the number of live births was associated with MetS risk, with ORs of 1.18 (95% CI: 1.04, 1.35) for women with ≥ 5 deliveries compared to women with ≤ 2 births.

CONCLUSIONS

AFB was associated with the risk of MetS in an N-shaped curve in women. In addition, women with high live births have a higher incidence of MetS.

Association between age at first birth and postpartum depression: A two-sample mendelian randomization analysis

Background

Previous observational research has documented an association between age at first childbirth (AFB) and postpartum depression (PPD). However, the causal relationship remains unclear. This study aimed to assess the causal effects of AFB on PPD using a two-sample Mendelian randomization (MR) analysis.

Methods

Three sets of instrumental variables were obtained from the United Kingdom Biobank (UK Biobank), Neale Lab consortium and a meta-analysis of genome-wide association studies (GWAS). Single-nucleotide polymorphisms (SNPs) associated with the PPD phenotype were obtained from the Finngen consortium, which included 13,657 cases and 236,178 controls. Inverse variance weighted (IVW), weighted median, weighted mode, and MR-Egger methods to evaluate causal effects. Heterogeneity was assessed using Cochran's Q test and funnel plots. Horizontal pleiotropy and sensitivity were assessed using the MR-Egger intercept test and "leave-one-out" analysis, respectively. Further meta-analysis was performed to validate the robustness of this relationship. Additionally, the potential mediating effects of risk factors associated with PPD were analyzed.

Results

Strong causal effects between AFB and PPD was found in both IVW and weighted median methods, which was further supported by meta-analysis (IVW, odds ratio [OR] 0.59 [95% confidence interval (CI) 0.36-0.96, p = 0.03]; weighted median, OR 0.59 [95% CI 0.37-0.95, p = 0.03]). The power of the MR supports the robustness of the findings. Heterogeneity or horizontal pleiotropy was not observed. Major depressive disorders, family income levels, and marital stress were identified as potential mediating factors in the causal relationships.

Conclusion

Results of MR analysis supported the causal effect of increased AFB in reducing the risk for PPD.

Adolescent childbirth and mobility disability among women ages 15-49: an analysis of population health surveys from 14 low-income and middle-income countries

OBJECTIVES

Adolescent childbirth is associated with older adult adverse health outcomes that negatively affect mobility function, but these associations have not been studied globally in large samples of reproductive-age women. This study examines the association between age at first childbirth and mobility disability in national surveys from low-income and middle-income countries, and hypotheses that adolescent childbirth is associated with mobility disability.

DESIGN

Cross-sectional analysis.

SETTING

Population health surveys from 2013 to 2018 containing mobility disability measures among ever-pregnant women ages 15-49. These included 13 Demographic Health Surveys from Haiti, Pakistan, Uganda, Cambodia, Colombia, South Africa, Timor-Leste, Albania, Gambia, Maldives, Peru, Senegal and Yemen and 1 Maternal Health Survey from Ghana.

PARTICIPANTS

The sample included 157 988 women ages 15-49 years.

PRIMARY OUTCOME MEASURE

Adolescent childbirth was defined as 10-19 years of age. Poisson regression models were used to estimate prevalence ratios (PRs) of mobility disability among women who first gave birth during adolescence and in adult life (ages 20-45 years) in each country and across the whole sample. Countries were also analysed according to the use of standard and non-standard mobility disability measures. Covariates included current age, urban/rural residence, education and household wealth.

RESULTS

Prevalence of adolescent childbirth (17.5%-66.2%) and mobility disability (0.32%-21.45%) varied widely across countries. Adolescent childbirth was significantly (p<0.05) associated with greater mobility disability in six of eight countries using standard disability measures. Among the six countries that did not use standard disability measures, none showed a statistically significant association between adolescent childbirth and mobility disability. Considering the whole sample and adjusting for all covariates, women who gave birth during adolescence had greater prevalence of mobility disability (pooled PR 1.19, 95% CI 1.06-1.31).

CONCLUSIONS

This analysis suggests a moderate and consistent association of adolescent childbearing with subsequent mobility disability.

Maternal age at birth of last child and cardiovascular disease mortality later in life among a national cohort of postmenopausal women from the United States

Maternal age at last birth of child is increasing in the United States, and it has been reported to influence future chronic diseases. In this study of nationally-representative sample of postmenopausal women, there was no conclusive association between maternal age at last birth of child and cardiovascular disease mortality later in life.

Objective

Maternal age at last birth (ALB) of child is increasing in the United States, and it has been reported to influence future chronic diseases. However, the relationship of ALB and cardiovascular disease (CVD) events later in life has not been widely studied. We evaluated the association of ALB with CVD mortality.

Methods

Data were from 7,971 parous postmenopausal women older than 45 years who participated in the US National Health and Nutritional Examination Survey from 1999 to 2018 and had mortality follow-up data through to December 31, 2019. ALB was self-reported, whereas CVD mortality was assessed using International Classification of Diseases codes. Cox regression was used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI).

Results

The mean age of participants was 63 ± 9.8 years, with 9.5% being non-Hispanic Black, 9.7% being Hispanic women, and 21% reporting ALB ≥35 years. During a median follow-up of 8.1 years, 443 participants died from CVD. In age-adjusted models, CVD mortality was elevated for women with ALB of <25 years (HR, 1.68; 95% CI, 1.23-2.29) and ALB of ≥35 years (HR, 1.37; 95% CI, 1.00-1.88). However, after additional adjustment for race and ethnicity, foreign born, education, marital status, poverty income ratio, parity, smoking status, age at menarche, oral contraceptive pills use and family history of myocardial infarction, these estimates were attenuated resulting in no association between ALB and CVD mortality.

Conclusions

In this study of nationally representative sample of postmenopausal women, there was no conclusive association between maternal ALB and CVD mortality later in life.

Coronary artery restenosis and target lesion revascularisation in women by pregnancy history

BACKGROUND

Women's pregnancy history is associated with incident risk of coronary artery disease with some evidence also suggesting a relevance for prognosis following treatment.

OBJECTIVES

To study the associations between maternal history of preterm delivery, a history of small for gestational age infant, parity and age at first delivery with clinical restenosis after percutaneous coronary intervention (PCI).

METHODS

In this prospective cohort study, we included 6027 women <65 years undergoing their first PCI 2006-2017, merging clinical register data on PCI procedures in Sweden with comprehensive registry data on deliveries since 1973. We used proportional hazards regression to study the association between aspects of pregnancy history and clinical restenosis in per-segment analyses, and with target lesion revascularisation (TLR) in per-patient analyses. We adjusted models for procedural-related and patient-related predictors of restenosis.

RESULTS

During 15 981 segment-years of follow-up, 343 (3.7%) events of clinical restenosis occurred. We found no strong evidence of associations between the studied aspects of pregnancy history and clinical restenosis following PCI. For example, the restenosis HR for a history of preterm delivery in the fully adjusted model was 1.09 (95% CI 0.77 to 1.55) and the TLR HR was 1.18 (95% CI 0.91 to 1.52).

CONCLUSION

Risk of restenosis following treatment with PCI did not differ by the studied aspects of pregnancy history, including preterm delivery, in young and middle-aged women. Larger studies are needed to obtain more precise estimates.

Maternal age at childbirth and the risk of attention-deficit/hyperactivity disorder and learning disability in offspring

Background

Studies have shown that young maternal age at childbirth can increase the risk of attention-deficit/hyperactivity disorder (ADHD) in offspring, but a study of the U.S. population has not been reported. Moreover, there is no reported research on young and advanced maternal age at childbirth and whether it can contribute to the risk of learning disability (LD) in offspring.

Methods

This study evaluated the association between young and advanced maternal age at childbirth and offspring risk of ADHD and LD in the U.S. population. Using data from 8,098 participants included in the National Health and Nutrition Examination Survey (NHANES) conducted in 1999-2004, we analyzed the association between maternal age at childbirth and ADHD and LD risk in offspring. Odds ratios (ORs) and 95% confidence intervals (CIs) for maternal age at childbirth in association with ADHD and LD risk in offspring were estimated using multivariate logistic regression models after adjustment for age, sex, race, body mass index (BMI), poverty income ratio, smoking status during pregnancy, and NHANES cycle. Restricted cubic spline (RCS) models were used to evaluate potential non-linear relationships. Sensitivity analyses were performed to ensure the reliability of the results.

Results

Among all participants, the offspring of subjects with a maternal age at childbirth of 18-24 years had an increased risk of ADHD (OR = 1.34, 95% CI: 1.01, 1.79) and LD (OR = 1.36, 95% CI: 1.06, 1.79) or either ADHD or LD (OR = 1.48, 95% CI: 1.20, 1.81). Additionally, compared with subjects with a maternal age at childbirth of 25-29 years, subjects with a maternal age at childbirth of 35-39 years had lower odds of having offspring with ADHD (OR = 0.60, 95% CI: 0.36, 1.00) and higher odds of having offspring with LD (OR = 1.34, 95% CI: 1.01, 1.78). The relationship between maternal age at childbirth and LD risk presented a U-shaped curve.

Conclusions

These results provide epidemiological evidence showing that young and advanced maternal age at childbirth are associated with ADHD and LD risk.

Is first pregnancy age associated with hypertension in the Chinese rural women population?

Introduction

The purpose of this study was to investigate the relationship between first pregnancy age and hypertension later in the life of women from Chinese rural areas.

Methods

In total, 13,493 women were enrolled in the Henan Rural Cohort study. Logistic regression and linear regression were used to evaluate the association between first pregnancy age and hypertension and blood pressure indicators [including systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP)]. The restricted cubic spline was used to examine the dose-response relationship between the first pregnancy age and hypertension or blood pressure indicators.

Results

After adjusting for potential confounders, each 1-year increase in first pregnancy age was associated with a 0.221 mmHg increase in SBP values, a 0.153 mmHg increase in DBP values, and a 0.176 mmHg decrease in MAP values (all P < 0.05). The β of SBP, DBP, and MAP showed a trend of first increasing and then decreasing with increasing first pregnancy age and there was no statistical significance after first pregnancy age beyond 33 years on SBP, DBP, and MAP, respectively. A 1-year increment in first pregnancy age was associated with a 2.9% [OR (95% CI): 1.029 (1.010, 1.048)] higher odds of prevalent hypertension. The odds of hypertension increased sharply and then eventually leveled off with an increment of first pregnancy age after adjusting for potential confounders.

Conclusion

First pregnancy age might increase the risk of hypertension later in life and might be an independent risk factor for hypertension in women.

Women's reproductive traits and ischemic stroke: a two-sample Mendelian randomization study

OBJECTIVE

We conducted a Mendelian randomization (MR) study to disentangle causal associations between women's reproductive behaviors and ischemic stroke (IS) and investigate the roles of two modifiable risk factors (body mass index (BMI) and educational attainment (EA)) in these associations.

METHODS

Using summary-level data from large-scale genome-wide association studies, we performed univariable MR to examine whether there is genetic evidence that women's reproductive traits are causally associated with IS and its subtypes. Multivariable MR and MR mediation analysis were used to investigate whether BMI and EA are common mechanisms or mediators for these associations. A set of sensitivity analyses were conducted to test valid MR assumptions.

RESULTS

We observed consistent and statistically significant associations across female and sex-combined analyses for earlier age at first birth (AFB) and age at first sexual intercourse (AFS) with a higher risk of IS and large-artery atherosclerotic stroke (LAS) risk in the primary analysis. The odds ratios of IS per 1 SD increase in genetically predicted early AFB and AFS were 0.93 (95% CI, 0.86-0.99; p = 0.046) and 0.83 (95% CI, 0.70-0.97, p = 0.020), respectively. Further analyses indicated that BMI played a shared role in AFS and IS/LAS while EA played a shared role in AFS/AFB and IS/LAS as well as a mediator in the path from AFS to IS/LAS.

INTERPRETATION

These findings may inform prevention strategies and interventions directed toward relative women's reproductive behaviors and IS. Future studies are warranted to explore other factors related to EA which are responsible for these causalities.

Association of age at first birth and risk of non-alcoholic fatty liver disease in women: evidence from the NHANES

BACKGROUND

Numerous studies have suggested that age at first birth (AFB) is inversely associated with metabolic diseases, but positively associated with liver cancer in women. Non-alcoholic fatty liver disease (NAFLD) is a canonical example of metabolic dysfunction and inflammation-based liver disease, while the association between AFB and the risk of NAFLD remains unclear. We aimed to investigate the association between AFB and the odds of NAFLD in women.

METHODS

Women older than 20 years at the time of the survey were analyzed using National Health and Nutrition Examination Survey (NHANES) data from 1999 to 2018 in the US. AFB was obtained with self-administered questionnaires. NAFLD was diagnosed as fatty liver index (FLI) ≥ 60. Odds ratios (ORs) and 95% confidence intervals (CI) were estimated using logistic regression models.

RESULTS

Of the 12,188 women included in this study, 5670 (46.5%) had NAFLD. Compared to individuals with AFB of 30-32 years old (reference group), the fully adjusted ORs and 95% CI in women with AFB < 18, 18-20, 21-23, and 24-26 years were 1.52 (95% CI 1.14, 2.03), 1.60 (95% CI 1.21, 2.11), 1.40 (95% CI 1.06, 1.84), and 1.33 (95% CI 1.01-1.76), respectively. Yet there was no significant difference between AFB of 27-29, 33-35, or > 35 years compared to the reference group.

CONCLUSIONS

Women with younger AFB have higher odds of NAFLD in later life. Policymakers should consider focusing on those with earlier AFB for screening and prevention of NAFLD.

High Prevalence of Asymptomatic Intracranial Atherosclerosis in Elder Women With Tubal Ligation: Result From a Community-Based Study in Shandong, China

Background

In addition to traditional cardiovascular risk factors, gender-specific factors may also contribute to intracranial atherosclerosis. This study aimed to comprehensively investigate the association between asymptomatic intracranial atherosclerosis (aICAS) and menstrual or reproductive history (MRH), namely, menstruation, pregnancy, childbirth, menopause, and contraception.

Methods

Participants in this study were selected from the Kongcun town aICAS study. MRH was collected through structured case report forms, in which menarche age, menstrual regularity, dysmenorrhea, number of pregnancies, number of childbirths, age of first pregnancy, breastfeeding, menopause, menopause age, and contraceptive methods were all involved. All characteristics were compared by chi-squared and nonparametric tests as applicable. Logistic regression model and sensitivity analysis were used to analyze the association between aICAS and MRH.

Results

A total of 1,052 female participants were involved in this study, of which 5.7% had moderate to severe aICAS. Tubal ligation was significantly associated with aICAS in univariate analysis [crude odds ratio (OR), 2.85; 95% CI, 1.22–6.62; P = 0.015]. This association was still significant among female participants over 60 years old after multivariate adjustment (adjusted OR, 4.36; 95% CI, 1.55–12.24; P = 0.005). Sensitivity analysis showed a similar result (adjusted OR, 3.76; 95% CI, 1.24–11.41; P = 0.020). Menopause lost significant association with aICAS after multivariate adjustment (adjusted OR, 1.68; 95% CI, 0.66–4.24; P = 0.275). No other MRH factors were found to be associated with aICAS.

Conclusion

Tubal ligation may be associated with a higher prevalence of aICAS in Chinese elderly women. This provides a new perspective to study the epidemiological characteristics of ICAS.

Adverse Pregnancy Outcomes and Cardiovascular Disease Risk: Unique Opportunities for Cardiovascular Disease Prevention in Women: A Scientific Statement From the American Heart Association

This statement summarizes evidence that adverse pregnancy outcomes (APOs) such as hypertensive disorders of pregnancy, preterm delivery, gestational diabetes, small-for-gestational-age delivery, placental abruption, and pregnancy loss increase a woman's risk of developing cardiovascular disease (CVD) risk factors and of developing subsequent CVD (including fatal and nonfatal coronary heart disease, stroke, peripheral vascular disease, and heart failure). This statement highlights the importance of recognizing APOs when CVD risk is evaluated in women, although their value in reclassifying risk may not be established. A history of APOs is a prompt for more vigorous primordial prevention of CVD risk factors and primary prevention of CVD. Adopting a heart-healthy diet and increasing physical activity among women with APOs, starting in the postpartum setting and continuing across the life span, are important lifestyle interventions to decrease CVD risk. Lactation and breastfeeding may lower a woman's later cardiometabolic risk. Black and Asian women experience a higher proportion APOs, with more severe clinical presentation and worse outcomes, than White women. More studies on APOs and CVD in non-White women are needed to better understand and address these health disparities. Future studies of aspirin, statins, and metformin may better inform our recommendations for pharmacotherapy in primary CVD prevention among women who have had an APO. Several opportunities exist for health care systems to improve transitions of care for women with APOs and to implement strategies to reduce their long-term CVD risk. One proposed strategy includes incorporation of the concept of a fourth trimester into clinical recommendations and health care policy.

Association between the reproductive health of young women and cardiovascular disease in later life: umbrella review

OBJECTIVE

To consolidate evidence from systematic reviews and meta-analyses investigating the association between reproductive factors in women of reproductive age and their subsequent risk of cardiovascular disease.

DESIGN

Umbrella review.

DATA SOURCES

Medline, Embase, and Cochrane databases for systematic reviews and meta-analyses from inception until 31 August 2019.

REVIEW METHODS

Two independent reviewers undertook screening, data extraction, and quality appraisal. The population was women of reproductive age. Exposures were fertility related factors and adverse pregnancy outcomes. Outcome was cardiovascular diseases in women, including ischaemic heart disease, heart failure, peripheral arterial disease, and stroke.

RESULTS

32 reviews were included, evaluating multiple risk factors over an average follow-up period of 7-10 years. All except three reviews were of moderate quality. A narrative evidence synthesis with forest plots and tabular presentations was performed. Associations for composite cardiovascular disease were: twofold for pre-eclampsia, stillbirth, and preterm birth; 1.5-1.9-fold for gestational hypertension, placental abruption, gestational diabetes, and premature ovarian insufficiency; and less than 1.5-fold for early menarche, polycystic ovary syndrome, ever parity, and early menopause. A longer length of breastfeeding was associated with a reduced risk of cardiovascular disease. The associations for ischaemic heart disease were twofold or greater for pre-eclampsia, recurrent pre-eclampsia, gestational diabetes, and preterm birth; 1.5-1.9-fold for current use of combined oral contraceptives (oestrogen and progesterone), recurrent miscarriage, premature ovarian insufficiency, and early menopause; and less than 1.5-fold for miscarriage, polycystic ovary syndrome, and menopausal symptoms. For stroke outcomes, the associations were twofold or more for current use of any oral contraceptive (combined oral contraceptives or progesterone only pill), pre-eclampsia, and recurrent pre-eclampsia; 1.5-1.9-fold for current use of combined oral contraceptives, gestational diabetes, and preterm birth; and less than 1.5-fold for polycystic ovary syndrome. The association for heart failure was fourfold for pre-eclampsia. No association was found between cardiovascular disease outcomes and current use of progesterone only contraceptives, use of non-oral hormonal contraceptive agents, or fertility treatment.

CONCLUSIONS

From menarche to menopause, reproductive factors were associated with cardiovascular disease in women. In this review, presenting absolute numbers on the scale of the problem was not feasible; however, if these associations are causal, they could account for a large proportion of unexplained risk of cardiovascular disease in women, and the risk might be modifiable. Identifying reproductive risk factors at an early stage in the life of women might facilitate the initiation of strategies to modify potential risks. Policy makers should consider incorporating reproductive risk factors as part of the assessment of cardiovascular risk in clinical guidelines.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019120076.

Association between gravidity and risk of metabolic syndrome: Results of Tabari cohort study

BACKGROUND AND AIMS

The purpose of the present study was to investigate the association of gravidity and age at first pregnancy with metabolic syndrome in a large-scale, population-based cohort study in Iran.

METHODS

The present secondary analysis was conducted on a subset of the population (5739 women with at least one pregnancy) enrolled in the Tabari cohort study. Reproductive history was collected using a structured questionnaire. The relationship of gravidity and age at first pregnancy with metabolic syndrome and its components was analyzed using the logistic regression model.

RESULTS

The results showed that after adjustment for confounding variables, the odds of having metabolic syndrome was not significantly associated with age at first pregnancy (P = 0.269) and gravidity (P = 0.504). However, there was an association between hypertension and age at first pregnancy (OR = 0.32, 95% CI = 0.12-0.82; P = 0.03). Additionally, waist circumference was also associated with gravidity (OR = 2.17, 95% CI = 1.37-3.35).

CONCLUSION

As the findings indicated, age at first pregnancy and gravidity were not associated with the odds of having metabolic syndrome. However, a relationship was found between first pregnancy at the age of >35 years and the decreased risk of hypertension. Gravidity was also found to be a dose-dependent risk factor for increased waist circumference.

Association between age at first childbirth and type 2 diabetes in Chinese women

AIMS/INTRODUCTION

The present study aims to explore the relationship between age at first childbirth and developing type 2 diabetes, and analyze potential modifiers of its relationship.

MATERIALS AND METHODS

The data were obtained from the baseline survey of a large-scale cohort study in 10 diverse areas of China. Multivariate logistic regressions were used to analyze the association between developing type 2 diabetes and the age at first childbirth. Adjustments were made in each model on sociodemographic, socioeconomic and reproductive covariates. Subgroup analyses were further carried out to investigate the effects of reproductive factors, body mass index at 25 years of age and hypertension on the above-mentioned association.

RESULTS

Women who have their first child at age <20 years (odds ratio [OR] 1.33, 95% confidence interval [CI] 1.22-1.44) and between the ages of 20 and 24 years (OR 1.16, 95% CI 1.10-1.23) were more likely to be diagnosed with type 2 diabetes compared with those who have their first child between the ages of 25 and 29 years; equal to or more than three parities (OR 1.44, 95% CI 1.30-1.60), premenopausal status (OR 1.58, 95% CI 0.99-2.54), overweight at age 25 years (OR 1.62, 95% CI 1.37-1.93) and hypertension (OR 1.37, 95% CI 1.22-1.53) are all conditions found to increase the odds of developing type 2 diabetes in those who have their their first child at an early age (<20 years).

CONCLUSIONS

The study concluded that having the first child at an early age is associated with an increased likelihood of developing type 2 diabetes later in life; reproductive factors, overweight at age 25 years and status of hypotension could modify such an association.

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.

Fertility trajectories and later-life depression among parents in England

We examine pathways between indicators of fertility tempo/quantum and depressive symptoms among parents aged 55+ with at least two children, using three waves of the English Longitudinal Study of Ageing. Using standard regression approaches and path analysis within the structural equation framework, we also investigate whether fertility trajectories mediated the association between childhood disadvantage and later-life depression. Results provide limited support for direct influences of fertility trajectories on depression, but indicate indirect linkages for both women and men. Associations are mediated by partnership history, social support, wealth, later-life smoking, and functional limitation. Associations between childhood disadvantage and later-life depression are partially mediated by fertility stressors. Results confirm the influence of life course experiences on depression at older ages and demonstrate the interlinked role of family and other life course pathways on later-life well-being.

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.

Symptoms of urinary incontinence and pelvic organ prolapse and physical performance in middle-aged women from Northeast Brazil: a cross-sectional study

Background

Reproductive history and urogynecological disorders have been associated with limitations in physical function. However, little is known about the relationship between symptoms of urinary incontinence and pelvic organ prolapse, and physical performance. Therefore, the purpose of this study was to examine whether symptoms of urinary incontinence and pelvic organ prolapse are independently associated factors with indicators of lower physical performance in middle-aged women from Northeast Brazil.

Methods

This is a cross-sectional study of 381 women between 40 to 65 years old living in Parnamirim, Northeast Brazil. Physical performance was assessed by gait speed, chair stand and standing balance tests. Urinary incontinence and pelvic organ prolapse were self-reported. Multiple linear regression analyses were performed to model the effect of self-reported urinary incontinence and pelvic organ prolapse on each physical performance measure, adjusted for covariates (age, family income, education, body mass index, parity).

Results

In the analysis adjusted for confounders, women reporting urinary incontinence spent, on average, half a second longer to perform the chair stand test (β = 0.505 95% CI: 0.034: 0.976). Those reporting pelvic organ prolapse shortened the balance time with eyes open by 2.5 s on average (β = − 2.556; CI: − 4.769: − 0.343).

Conclusions

Symptoms of pelvic organ prolapse and urinary incontinence are associated to worse physical performance in middle-aged women. These seemingly small changes in physical performance levels are of clinical importance, since these conditions may influence women’s physical ability, with implications for other tasks important to daily functioning and should be addressed by health policies targeting women’s health and functionality.

Association between reproductive factors and carotid atherosclerosis in post-menopausal women

OBJECTIVES

Assessment of cardiovascular risk in women is specific and hormonal factors should be considered to avoid its underestimation. So far, studies on this issue are lacking and the impact of reproductive factors on cardiovascular risk has yet to be determined. We study the association between reproductive factors and carotid atherosclerosis, a non-invasive marker of cardiovascular diseases, in post-menopause.

STUDY DESIGN

In this cross-sectional study, data were analyzed from post-menopausal women with at least one cardiovascular risk factor followed through a dedicated healthcare pathway at the Lille University Hospital between January 1st, 2013 and December 31st, 2016.

MAIN OUTCOME AND MEASURES

The primary outcome was the presence of plaque or stenosis at carotid ultrasound.

RESULTS

We included 370 post-menopausal women with a mean age of 63.4 ± 0.5 years. Carotid atherosclerosis was found in 161 (43,3%) women. Women with 3 or more children had higher odds of having carotid atherosclerosis than women with fewer than 3 children after adjustment for age, OR 1,69 [CI 95% 1,09-2,61], p = 0,019, and after further adjustment for anthropometric measures, traditional cardiovascular risk factors and pregnancy-related complications: OR 1,65 [CI 95% 1,05-2,62], p = 0,031. No other reproductive factor was significantly associated with carotid atherosclerosis.

CONCLUSIONS

A higher parity was associated with higher odds of carotid atherosclerosis independently of age, traditional risk factors, anthropometric measures and gestational diseases among post-menopausal women at risk of cardiovascular diseases. This suggests the importance of considering the number of children when assessing cardiovascular risk in women.

Data gaps in adolescent fertility surveillance in middle-income countries in Latin America and South Eastern Europe: Barriers to evidence-based health promotion

Adolescent health is a major global priority. Yet, as recently described by the World Health Organization (WHO), increased recognition of the importance of adolescent health rarely transforms into action. One challenge is lack of data, particularly on adolescent fertility. Adolescent pregnancy and childbirth are widespread and affect lifetime health and social outcomes of women, men, and families. Other important components of adolescent fertility include abortion, miscarriage, and stillbirth. Access to reliable, consistently-collected data to understand the scope and complexity of adolescent fertility is critical for designing strong research, developing meaningful policies, building effective programs, and evaluating success in these domains. Vital surveillance data can be challenging to obtain in general, and particularly in low- and middle-income countries and other under-resourced settings (including rural and indigenous communities in high-income countries). Definitions also vary, making comparisons over time and across locations challenging. Informed by the Adolescence and Motherhood Research project in Brazil and considering relevance to the Southern Eastern European (SEE) context, this article focuses on challenges in surveillance data for adolescent fertility for middle-income countries. Specifically, we review the literature to: (1) discuss the importance of understanding adolescent fertility generally, and (2) highlight relevant challenges and complexity in collecting adolescent fertility data, then we (3) consider implications of data gaps on this topic for selected middle-income countries in Latin America and SEE, and (4) propose next steps to improve adolescent fertility data for evidence-based health promotion in the middle-income country context.

Parity and risk of maternal cardiovascular disease: A dose-response meta-analysis of cohort studies

BACKGROUND

Parity has been reported to play an important role in the development of cardiovascular disease; however, the results are still controversial. We aimed to conduct a meta-analysis of cohort studies to assess quantitatively the association between parity and cardiovascular disease risk.

METHODS

PubMed and Web of Science databases were searched to 1 June 2018, supplemented by manual searches of the bibliographies of retrieved articles. And multivariate-adjusted relative risks were pooled by using random-effects models. Restricted cubic spline analysis with four knots was used to explore the relationship of parity and the risk of cardiovascular disease.

RESULTS

Ten cohort studies involving 150,512 incident cases of cardiovascular disease among 3,089,929 participants were included in the meta-analysis. A significant association between parity and cardiovascular disease risk was observed while comparing parity with nulliparity, with a summarised relative risk of 1.14 (95% confidence interval (CI) 1.09-1.18; I² = 62.0%, P = 0.002). In the dose-response analysis, we observed a potential non-linear J-shaped dose-response relationship between the number of parity and cardiovascular disease risk, the summary risk estimates for an increase of one live birth was 1.04 (95% CI 1.02-1.05), with significant heterogeneity ( I² = 89.6%). In addition, the similar J-shaped associations between parturition number and cardiovascular disease, ischaemic heart disease or stroke risk were also observed.

CONCLUSIONS

Our findings suggest that ever parity is related to cardiovascular disease risk and there is an association between the number of pregnancies and the risk of cardiovascular disease. Since the number of included studies was limited, further studies are warranted to confirm our findings.

Maternal nutrition and the developmental origins of osteoporosis in offspring: Potential mechanisms and clinical implications

Osteoporosis, the most frequent metabolic disorder of bone, is a complex disease with a multifactorial origin that is influenced by genes and environments. However, the pathogenesis of osteoporosis has not been fully elucidated. The theory of "Developmental Origins of Health and Disease" indicates that early life environment exposure determines the risks of cardiometabolic diseases in adulthood. However, investigations into the effects of maternal nutrition and nutrition exposure during early life on the development of osteoporosis are limited. Recently, emerging evidence has strongly suggested that maternal nutrition has long-term influences on bone metabolism in offspring, and epigenetic modifications maybe the underlying mechanisms of this process. This review aimed to address maternal nutrition and its implications for the developmental origins of osteoporosis in offspring. It is novel in providing a theoretical basis for the early prevention of osteoporosis. Impact statement Our review aimed to address maternal nutrition and its implications for the developmental origins of osteoporosis in offspring, that can novelly provide a theoretical basis for the early prevention of osteoporosis.

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.