Reproductive factors and risk of mortality in the European Prospective Investigation into Cancer and Nutrition; a cohort study

Review of mendelian randomization studies on age at natural menopause

Menopause marks the end of the reproductive phase of life. Based on epidemiological studies, abnormal age at natural menopause (ANM) is thought to contribute to a number of adverse outcomes, such as osteoporosis, cardiovascular disease, and cancer. However, the causality of these associations remains unclear. A powerful epidemiological method known as Mendelian randomization (MR) can be used to clarify the causality between ANM and other diseases or traits. The present review describes MR studies that included ANM as an exposure, outcome and mediator. The findings of MR analyses on ANM have revealed that higher body mass index, poor educational level, early age at menarche, early age at first live birth, early age at first sexual intercourse, and autoimmune thyroid disease appear to be involved in early ANM etiology. The etiology of late ANM appears to be influenced by higher free thyroxine 4 and methylene tetrahydrofolate reductase gene mutations. Furthermore, early ANM has been found to be causally associated with an increased risk of osteoporosis, fracture, type 2 diabetes mellitus, glycosylated hemoglobin, and the homeostasis model of insulin resistance level. In addition, late ANM has been found to be causally associated with an increased systolic blood pressure, higher risk of breast cancer, endometrial cancer, endometrioid ovarian carcinoma, lung cancer, longevity, airflow obstruction, and lower risk of Parkinson's disease. ANM is also a mediator for breast cancer caused by birth weight and childhood body size. However, due to the different instrumental variables used, some results of studies are inconsistent. Future studies with more valid genetic variants are needed for traits with discrepancies between MRs or between MR and other types of epidemiological studies.

Premature Menopause and All-Cause Mortality and Life Span Among Women Older Than 40 Years in the NHANES I Epidemiologic Follow-Up Study: Propensity Score Matching Analysis

Objective: Findings from studies of the long-term effect of premature menopause on risks of all-cause mortality in women are equivocal. We used the approach of propensity score matching to examine the causal association of premature menopause with all-cause mortality and life span among women older than 40 years. Methods: The data were from the National Health and Nutrition Examination Survey I Epidemiologic Follow-up Study. We calculated the propensity score of premature menopause using a logistic regression model, then matched premature menopause with nonpremature menopause according to the score and the ratio of 1:1. We estimated mortality hazard ratios (HRs) and 95% confidence intervals (CIs) using Cox proportional hazard models. We also analyzed and plotted the relationship between age at menopause and reproductive life span with all-cause mortality and life span. Results: The mean age of 1,210 women was 55.4 ± 10.8 years at baseline. The unadjusted and adjusted HRs of all-cause mortality for women with premature menopause were 1.46 (95% CI: 1.08-1.96) and 1.53 (95% CI: 1.13-2.08), respectively, compared to nonpremature menopause. Nonlinear associations were found between age at menopause, reproductive life span, all-cause mortality, and life span. Menopausal age <37.5 years of age or reproductive life span <24 years increased the risk of all-cause mortality. Women with menopausal age <39 years of age or reproductive life span <24 years had a lower mean life span than the overall average of 76 years. Conclusions: Premature menopause significantly increased all-cause mortality risk and shortened life span in women. As women's age at menopause or reproductive life span increases, their overall life span also tends to increase.

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

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

Hormonal and Reproductive Factors in Relation to Cardiovascular Events in Women with Early Rheumatoid Arthritis

Hormonal and reproductive factors affect the risk for cardiovascular events (CVE) in the general population. Although the risk of CVE is increased in rheumatoid arthritis (RA), the knowledge about the impact of hormonal factors for CVE in RA is sparse. Female postmenopausal patients ≤80 years with early RA were consecutively included in this observational study (n = 803) between 1 January 1996 until 31 December 2017. Questionnaires regarding hormonal factors were distributed from the index date. Data regarding CVE were obtained from the Swedish National Health Register and Cause of Death Register. Associations between CVE and hormonal factors were analyzed using Cox proportional hazard regression. Of the postmenopausal women, 64 women had a CVE after RA onset. The time period from menopause to RA onset was significantly longer for CVE cases with higher proportion of postmenopausal women. In Cox proportional hazard regression models, years from last childbirth and multiparity were associated with higher CVE risk. Adjustments for traditional risk factors did not affect the results except for hypertension. RA onset after menopause and a longer duration from menopause until onset increased the CVE risk. Multiparity was associated with higher CVE risk whilst oral contraceptives decreased the risk. These results can contribute to identification of high-risk patients for CVE beyond traditional risk factors.

Breastfeeding duration and subsequent risk of mortality among US women: A prospective cohort study

BACKGROUND

Breastfeeding has been associated with a reduced maternal long-term risk of chronic diseases, but its association with mortality is poorly known.

METHODS

We included 166,708 female United States (US) nurses from the Nurses' Health Study (1986-2016) and the Nurses' Health Study II (1989-2019) who experienced at least one pregnancy lasting at least six months across their reproductive lifespan. Hazard ratios and 95% confidence intervals (CI) for mortality according to lifetime breastfeeding duration were estimated with time-dependent Cox proportional hazards regression models.

FINDINGS

During 4,705,160 person-years of follow-up, 36,634 deaths were documented in both cohorts, including 9880 from cancer and 7709 from cardiovascular disease (CVD). Lifetime total breastfeeding duration was associated with a lower subsequent risk of all-cause mortality in a non-linear manner (p-value for non-linearity=0.0007). The pooled multivariable-adjusted hazard ratios of all-cause mortality were 0.95 (95% CI: 0.92 to 0.98), 0.94 (95% CI: 0.91 to 0.98), 0.93 (95% CI: 0.90 to 0.97), and 0.93 (95% CI: 0.89 to 0.97), respectively, for women reporting lifetime total breastfeeding duration of 4-6, 7-11, 12-23, and ≥24 months, compared to women who breastfed for ≤3 months over their reproductive lifespan. Cause-specific analysis showed a similar pattern of non-linear inverse associations between lifetime total breastfeeding duration and CVD and cancer mortality (both p-values for non-linearity <0.01). There was no evidence of interactions between breastfeeding duration and pre-pregnancy lifestyle factors on mortality risk.

INTERPRETATION

Parous women with longer lifetime breastfeeding duration had a modestly lower risk of mortality.

FUNDING

The National Institutes of Health grants.

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.

Prognostic factors for cancer-specific survival in 220 patients with breast cancer: A single center experience

OBJECTIVES

Hospital-based breast cancer survival studies are scarce in western Iran. Furthermore, the relationship between breast cancer survival and clinical parameters has been extensively studied, but many of the findings come from developing countries. This paper aims to estimate the survival of hospital-based breast cancer patients and its predictor factors.

METHOD

This retrospective analysis was conducted on 578 patients with primary breast cancer who underwent surgery between 2004 and 2020. Information was collected from medical reports by the Hospital information system in Imam Reza Hospital, Kermanshah, Iran. One-, 2-, 5-, and 10-year breast cancer-specific survival has been calculated using the Kaplan-Meier process. Crude and adjusted Hazard Ratios (HR) were calculated using the Cox proportional regression model.

RESULT

One-, 2-, and 5-year overall breast cancer survival were 219 (99.54%), 196 (89.09%), 159 (72.27%), and 70 (31.81%), respectively. Univariate analysis of breast cancer patients with tumor-related variables revealed that factors such as age, menopause status, lymph node metastasis, number of lymph nodes, organ metastasis, and stage of disease were significantly associated with disease-specific survival (p < .05). Multivariate analysis demonstrated that metastasis (HR = 41.77, 95% CI: 15.3-114.15) and lymph node metastasis (HR = 5.26, 95% CI: 1.9-14.6) were significantly related to survival.

CONCLUSION

The findings demonstrate that survival is relatively low and is consistent with late-stage disease diagnosis. It is believed that this is due to a poor level of awareness, lack of screening programs, and subsequent late access to treatment.

Breastfeeding Is Associated With a Reduced Maternal Cardiovascular Risk: Systematic Review and Meta-Analysis Involving Data From 8 Studies and 1 192 700 Parous Women

Background

Breastfeeding has been robustly linked to reduced maternal risk of breast cancer, ovarian cancer, and type 2 diabetes. We herein systematically reviewed the published evidence on the association of breastfeeding with maternal risk of cardiovascular disease (CVD) outcomes.

Methods and Results

Our systematic search of PubMed and Web of Science of articles published up to April 16, 2021, identified 8 relevant prospective studies involving 1 192 700 parous women (weighted mean age: 51.3 years at study entry, 24.6 years at first birth; weighted mean number of births: 2.3). A total of 982 566 women (82%) reported having ever breastfed (weighted mean lifetime duration of breastfeeding: 15.6 months). During a weighted median follow‐up of 10.3 years, 54 226 CVD, 26 913 coronary heart disease, 30 843 stroke, and 10 766 fatal CVD events were recorded. In a random‐effects meta‐analysis, the pooled multivariable‐adjusted hazard ratios comparing parous women who ever breastfed to those who never breastfed were 0.89 for CVD (95% CI, 0.83–0.95; I²=79.4%), 0.86 for coronary heart disease (95% CI, 0.78–0.95; I²=79.7%), 0.88 for stroke (95% CI, 0.79–0.99; I²=79.6%), and 0.83 for fatal CVD (95% CI, 0.76–0.92; I²=47.7%). The quality of the evidence assessed with the Grading of Recommendations Assessment, Development, and Evaluation tool ranged from very low to moderate, which was mainly driven by high between‐studies heterogeneity. Strengths of associations did not differ by mean age at study entry, median follow‐up duration, mean parity, level of adjustment, study quality, or geographical region. A progressive risk reduction of all CVD outcomes with lifetime durations of breastfeeding from 0 up to 12 months was found, with some uncertainty about shapes of associations for longer durations.

Conclusions

Breastfeeding was associated with reduced maternal risk of CVD outcomes.

Adverse childhood experiences are associated with increased risk of hysterectomy and bilateral oophorectomy: A national retrospective cohort study of women in England

Objective

To examine the associations between adverse childhood experiences (ACE) and the risk of hysterectomy and bilateral oophorectomy in a national sample of women in England.

Design

Retrospective cohort study.

Setting

A stratified random sample of households across England.

Population

2648 women aged ≥55 years in 2007 from the English Longitudinal Study of Ageing (ELSA) were included in the bilateral oophorectomy analyses and 2622 in the hysterectomy analyses.

Methods

Logistic and multinomial logistic regression analyses of the associations between categories of the ACE summary score (0, 1, 2, ≥3 ACE), eight individual ACE, and hysterectomy and bilateral oophorectomy.

Results

615 women had undergone hysterectomy and 259 women bilateral oophorectomy. We found graded associations between the summary ACE score and risk of hysterectomy and bilateral oophorectomy. In the fully adjusted model, compared with women with no ACE, those with ≥3 ACE had double the odds of hysterectomy (odds ratio [OR] 2.01, 95% confidence interval [CI] 1.30–3.11) and more than double the odds of bilateral oophorectomy (OR 2.61, 95% CI 1.54–4.42). The exclusion of women with cancer history made the associations stronger, especially in women who underwent hysterectomy at age <40 years or bilateral oophorectomy at age ≤44 years. Several individual ACE were positively associated with both outcomes.

Conclusions

ACE are associated with increased risk of hysterectomy and bilateral oophorectomy. Individual‐level covariates did not explain these associations. Our findings highlight the importance of a life course approach to understanding surgical menopause and add to our knowledge of the societal and public health impact of ACE.

Tweetable abstract

Adverse childhood experiences are associated with increased risk of hysterectomy and bilateral oophorectomy in a national sample of women in England.

Adverse childhood experiences are associated with increased risk of hysterectomy and bilateral oophorectomy in a national sample of women in England.

Linked article: This article is commented on by Walter A. Rocca, pp. 1491–1492 in this issue. To view this minicommentary visit https://doi.org/10.1111/1471-0528.17105.

Menarche characteristics in association with total and cause-specific mortality: a prospective cohort study of Mexican teachers

PURPOSE

We evaluated the relation between age at menarche and time to menstrual regularity with all-cause and cause specific mortality in a cohort of Mexican women.

METHODS

We followed 113,540 women from the Mexican Teachers' Cohort. After a mean follow-up time of 9.2 years, 1,355 deaths were identified. We estimated hazard ratios from Cox regression models for total mortality and a competitive risk models for cause-specific mortality adjusting for year of birth and childhood factors.

RESULTS

Women with extreme age of menarche were at increased risk of all-cause mortality (HR [95% CI]: <11 years 1.50 [1.20, 1.87]; 14 years 1.19 [0.97, 1.43]) relative to those with menarche at 13 years. Extreme ages at menarche had higher risk of mortality for diabetes (HR: <11 years 1.66 [0.90, 3.05]; 14 years 1.47 [0.90, 2.40]), breast cancer (HR: <11 years 1.34 [0.56, 3.20]), and other cancer (HR:<11 years 1.65 [1.10, 2.48]) compared to menarche at 13 years. Women who took three or more years to achieve menstrual regularity had a higher risk of all-cause mortality compared to those who took less (HR: 1.27 [1.01, 1.58]).

CONCLUSIONS

Extreme ages at menarche and longer time to reach menstrual regularity were associated with an increased rate of all-cause and cause-specific mortality.

Protocol for the WARM Hearts study: examining cardiovascular disease risk in middle-aged and older women - a prospective, observational cohort study

INTRODUCTION

Cardiovascular disease (CVD) is a leading cause of death in women. Novel approaches to detect early signs of elevated CVD risk in women are needed. Enhancement of traditional CVD risk assessment approaches through the addition of procedures to assess physical function or frailty as well as novel biomarkers of cardiovascular, gut and muscle health could improve early identification. The Women's Advanced Risk-assessment in Manitoba (WARM) Hearts study will examine the use of novel non-invasive assessments and biomarkers to identify women who are at elevated risk for adverse cardiovascular events.

METHODS AND ANALYSIS

One thousand women 55 years of age or older will be recruited and screened by the WARM Hearts observational, cohort study. The two screening appointments will include assessments of medical history, gender variables, body composition, cognition, frailty status, functional fitness, physical activity levels, nutritional status, quality of life questionnaires, sleep behaviour, resting blood pressure (BP), BP response to moderate-intensity exercise, a non-invasive measure of arterial stiffness and heart rate variability. Blood sample analysis will be used to assess lipid and novel biomarker profiles and stool samples will support the characterisation of gut microbiota. The incidence of the adverse cardiovascular outcomes will be assessed 5 years after screening to compare WARM Hearts approaches to the Framingham Risk Score, the current clinical standard of assessing CVD risk in Canada.

ETHICS AND DISSEMINATION

The University of Manitoba Health Research Ethics Board (7 October 2019) and the St Boniface Hospital Research Review Committee (7 October 2019) approved the trial (Ethics Number HS22576 (H2019:063)). Recruitment started 10 October 2020. Data gathered from the WARM Hearts study will be published in peer-reviewed journals and presented at national and international conferences. Knowledge translation strategies will be created to share our findings with stakeholders who are positioned to implement evidence-informed CVD risk assessment programming.

TRIAL REGISTRATION NUMBER

NCT03938155.

The risk of developing a meningioma during and after pregnancy

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

Reproductive risk factors for angiographic obstructive coronary artery disease among postmenopausal women

OBJECTIVE

Reproductive factors are female-specific coronary artery disease (CAD) risk factors. However, the importance of reproductive factors in angiographic obstructive CAD in postmenopausal women remains uncertain. This study aimed to compare reproductive factors between postmenopausal women with no apparent CAD, nonobstructive CAD, and obstructive CAD and identify reproductive risk factors for obstructive CAD.

METHODS

In this hospital-based cross-sectional study, 1,474 postmenopausal women, admitted with chest pain and referred for invasive coronary angiography were enrolled between April 2013 and October 2018.

RESULTS

Adjusted odds ratio (95% CI) for obstructive CAD were 1.81 (1.03-3.17) for multigravidity (three or more pregnancies), 1.77 (1.14-2.76) for early menopause (≤40 y old), and 1.72 (1.26-2.35) for short reproductive life span (≤30 y). Each additional year in age at menopause or reproductive life span was associated with a 4% reduction in obstructive CAD risk in postmenopausal women (odds ratio, 0.96; 95% CI, 0.94-0.99; P = 0.011). The other reproductive factors, including parity, age at first birth, spontaneous abortion, induced abortion, stillbirth, hypertensive disorders of pregnancy, gestational diabetes mellitus, and age at menarche, were not correlated with obstructive CAD risk in postmenopausal women.

CONCLUSIONS

Multigravidity (three or more pregnancies), early menopause, and a shorter reproductive life span were independent risk factors of angiographic obstructive CAD among postmenopausal women, which suggested that pregnancy and ovarian function may be important for the early identification and prevention of increased risk of female angiographic obstructive CAD.

Evaluating Health Literacy among Adolescent and Young Adult Pregnant Women from a Low-Income Area of Northeast Brazil

Adequate health literacy is important for strong health outcomes during pregnancy, particularly among mothers with high risk of adverse outcomes related to pregnancy and childbirth. Understanding the health literacy of young pregnant women in low-income settings could support strategies to reduce adverse outcomes in this population. This exploratory study assessed the health literacy of young pregnant adolescents and young adults from a rural area in Northeast Brazil and associated factors such as socioeconomic conditions, adequacy of prenatal care, and social support from family and friends. In this cross-sectional study, 41 pregnant adolescents (13–18 years) and 45 pregnant adults (23–28 years) from the Rio Grande do Norte state, Brazil, were assessed regarding health literacy through the Short Assessment of Health Literacy for Portuguese-Speaking Adults (SAHLPA, score from 0–18, inadequate if <15). Income sufficiency, self-perceived school performance, compliance with recommendations for adequate prenatal care, and social support were also assessed. A linear regression analysis was conducted to evaluate the variables associated with the SAHLPA score. Ninety-five percent of the adolescents and 53.3% of the adults (p < 0.001) presented inadequate health literacy. Adolescent age (β − 3.5, p < 0.001), poorer self-perceived school performance (β − 2.8, p < 0.001), and insufficient income for basic needs (β − 2.8, p = 0.014) were associated with worse SAHLPA scores. Adolescent mothers have higher rates of inadequate health literacy in this population. Policies are needed to improve access to health information for young populations from rural low-income areas.

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

Background

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

Methods

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

Results

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

Conclusion

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

Duration of estrogen exposure during reproductive years, age at menarche and age at menopause, and risk of cardiovascular disease events, all-cause and cardiovascular mortality: a systematic review and meta-analysis

BACKGROUND

Little is known about the estrogen exposure measurement and mutual effect of age at menarche and age at menopause in the risk of cardiovascular disease (CVD) events.

OBJECTIVES

To evaluate estrogen exposure measurement and describe mutual effect of age at menarche and age at menopause in the risk of CVD events.

SEARCH STRATEGY

Systematic review of literature in PubMed, Embase and Web of Science for studies published up to 28 June 2020.

SELECTION CRITERIA

Observational studies related to estrogen exposure measurement, including mutual effect of age at menarche and age at menopause and risk of CVD events.

DATA COLLECTION AND ANALYSIS

Synthesis of evidence was conducted by reviewing individual estimates, followed by meta-analysis. The study received no external funding.

MAIN RESULTS

A total of 75 studies were included in synthesis of evidence, of which 17 studies were included in meta-analysis. Reproductive lifespan (age at menopause - age at menarche), endogenous estrogen exposure and total estrogen exposure were used for estrogen exposure measurement. Reproductive lifespan was by far the most commonly used method for estrogen exposure measurement. A shorter reproductive lifespan was associated with a higher risk of CVD events; the pooled relative risk (95% CI) was 1.31 (1.25-1.36) for stroke events. Robust epidemiological studies with measurement of estrogen exposure and associated health risk would strengthen the evidence.

CONCLUSIONS

Reproductive lifespan was the most commonly used method for estrogen exposure measurement in epidemiological studies. A shorter reproductive lifespan was associated with a higher risk of CVD events, particularly stroke.

TWEETABLE ABSTRACT

A systematic review and meta-analysis found that women with a shorter reproductive lifespan have a higher risk of stroke events.

Hysterectomy with and without oophorectomy and all-cause and cause-specific mortality

BACKGROUND

Hysterectomy is one of the most commonly performed gynecologic surgeries, with an estimated 30% of women in Australia undergoing the procedure by age of 70 years. In the United States, about 45% of women undergo hysterectomy in their lifetime. Some studies have suggested that this procedure increases the risk of premature mortality. With many women making the decision to undergo hysterectomy for a benign indication each year, additional research is needed to clarify whether there are long-term health consequences of hysterectomy.

OBJECTIVE

This study aimed to examine the association between hysterectomy for benign indications, with or without removal of the ovaries, and cause-specific and all-cause mortality.

STUDY DESIGN

Our cohort of 666,588 women comprised the female population of Western Australia with linked hospital and health records from 1970 to 2015. Cox regression models were used to assess the association between hysterectomy and all-cause, cardiovascular disease, cancer, and other mortality by oophorectomy type (categorized as none, unilateral, and bilateral), with no hysterectomy or oophorectomy as the reference group. We repeated these analyses using hysterectomy without oophorectomy as the reference group. We also investigated whether associations varied by age at the time of surgery, although small sample size precluded this analysis in women who underwent hysterectomy with unilateral salpingo-oophorectomy. In our main analysis, women who underwent hysterectomy or oophorectomy as part of cancer treatment were retained in the analysis and considered unexposed to that surgery. For a sensitivity analysis, we censored procedures performed for cancer.

RESULTS

Compared with no surgery, hysterectomy without oophorectomy before 35 years was associated with an increase in all-cause mortality (hazard ratio, 1.29; 95% confidence interval, 1.19-1.40); for surgery after 35 years of age, there was an inverse association (35-44 years: hazard ratio, 0.93; 95% confidence interval, 0.89-0.97). Similarly, hysterectomy with bilateral salpingo-oophorectomy before 45 years of age was associated with increased all-cause mortality (35-44 years: hazard ratio, 1.15; 95% confidence interval, 1.04-1.27), but decreased mortality rates after 45 years of age. In our sensitivity analysis, censoring gynecologic surgeries for cancer resulted in many cancer-related deaths being excluded for women who did not have surgery for benign indications and thus increased the hazard ratios for the associations between both hysterectomy without oophorectomy and hysterectomy with bilateral salpingo-oophorectomy and risk of all-cause and cancer-specific mortality. The sensitivity analysis therefore potentially biased the results in favor of no surgery.

CONCLUSION

Among women having surgery for benign indications, hysterectomy without oophorectomy performed before 35 years of age and hysterectomy with bilateral salpingo-oophorectomy performed before 45 years of age were associated with an increase in all-cause mortality. These procedures are not associated with poorer long-term survival when performed at older ages.

Improving Breastfeeding by Empowering Mothers in Vietnam: A Randomised Controlled Trial of a Mobile App

Breastfeeding provides benefits to the infant and mother; however, the rates of breastfeeding, particularly exclusive breastfeeding, remain below optimal levels in many Asian countries. The aim of this study is to review the benefits of breastfeeding to mothers and infants and current rates of breastfeeding in Vietnam, and to evaluate the effectiveness of a mobile application on exclusive breastfeeding among mothers in Vietnam. A two-arm, parallel triple-blinded randomised controlled trial will be conducted among 1000 mothers in Hanoi City, Vietnam, during 2020-2021. Eligible participants are pregnant women who will seek antenatal care from health facilities at 24-36 weeks of gestation and plan to deliver at two participating hospitals, own a smartphone, and carry a singleton foetus. Permuted-block randomisation method stratified by maternal age, education and parity will be used to ensure an equal number of participants in each group. A smartphone app will be developed to deliver breastfeeding and non-breastfeeding information to the intervention and control group, respectively. Data will be collected at baseline, before hospital discharge, and at 1, 4, and 6 months postpartum. This study envisages demonstrating whether a smartphone-based intervention can be effective at improving breastfeeding in Vietnam. Trials registration: ACTRN12619000531112.

Breastfeeding and Cardiovascular Disease Hospitalization and Mortality in Parous Women: Evidence From a Large Australian Cohort Study

Background

Few studies have investigated the longitudinal association between breastfeeding and maternal cardiovascular disease (CVD) outcomes. This study examined the association between breastfeeding and CVD hospitalization and mortality in a large Australian cohort.

Methods and Results

Baseline questionnaire data (2006–2009) from a sample of 100 864 parous women aged ≥45 years from New South Wales, Australia, were linked to hospitalization and death data until June 2014 and December 2013, respectively. Analysis was restricted to women without self‐reported medically diagnosed CVD at baseline or without past CVD hospitalization 6 years before study entry. Never versus ever breastfeeding and average breastfeeding duration per child, derived from self‐reported lifetime breastfeeding duration and number of children, and categorized as never breastfed, <6, >6 to 12, or >12 months/child, were assessed. Cox proportional hazards models were used to explore the association between breastfeeding and CVD outcomes. Covariates included sociodemographic characteristics, lifestyle risk factors, and medical and reproductive history. There were 3428 (3.4%) first CVD‐related hospital admissions and 418 (0.4%) deaths during a mean follow‐up time of 6.1 years for CVD hospitalization and 5.7 years for CVD mortality. Ever breastfeeding was associated with lower risk of CVD hospitalization (adjusted hazard ratio [95% CI]: 0.86 [0.78, 0.96]; P=0.005) and CVD mortality (adjusted hazard ratio [95% CI]: 0.66 [0.49, 0.89]; P=0.006) compared with never breastfeeding. Breastfeeding ≤12 months/child was significantly associated with lower risk of CVD hospitalization.

Conclusions

Breastfeeding is associated with lower maternal risk of CVD hospitalization and mortality in middle‐aged and older Australian women. Breastfeeding may offer long‐term maternal cardiovascular health benefits.

Pregnancy and Lactation: Risk or Protective Factors for Breast Cancer?

Pregnancy and lactation represent the most effective protective elements against breast cancer; counter-intuitively breast cancer incidence shows a small but noticeable increase up to 5 years after delivery. The cumulative effect is however favourable and women show a reduction in breast cancer risk which is proportional to the total duration of lactation and to the number of full-term pregnancies.

Age at menarche and risk of all-cause and cardiovascular mortality: a systematic review and dose-response meta-analysis

OBJECTIVE

The evidence between age at menarche and mortality risk is controversial. We aimed to quantify the dose-response association of age at menarche and risk of all-cause and cardiovascular disease (CVD) mortality based on cohort studies.

METHODS

PubMed, EMBASE, Web of Science, and Scopus databases were searched up to March 15, 2018 for relevant articles. Random-effects models and restricted cubic splines were used for this meta-analysis.

RESULTS

Twelve cohort studies, with 79,363 deaths and 2,341,769 participants, met the inclusion criteria. With each 1-year increase in menarche age, the relative risk (RR) was reduced for all-cause mortality (RR: 0.977, 95% confidence interval [CI]: 0.970-0.984), CVD mortality (RR: 0.993, 95% CI: 0.975-1.011), ischemic heart disease (IHD) mortality (RR: 0.969, 95% CI: 0.947-0.993), and stroke mortality (RR: 0.983, 95% CI: 0.954-1.012). We found a nonlinear dose-response association (Pnonlinearity = 0.001) between age at menarche and all-cause mortality, with the lowest risk observed at menarche age 15 years (RR: 0.849 95% CI: 0.800-0.901), but no evidence of a nonlinear association between menarche age and CVD mortality (Pnonlinearity = 0.543), IHD mortality (Pnonlinearity = 0.310), or stroke mortality (Pnonlinearity = 0.824).

CONCLUSIONS

Age at menarche is inversely associated with all-cause and IHD mortality.

Ages at menarche and menopause, and mortality among postmenopausal women

OBJECTIVES

Although both age at menarche and age at menopause may independently affect the risk of cardiovascular diseases and all-cause mortality, their joint association with mortality is less clear. The objectives of this study were to address the relationship between ages at menarche and at menopause with mortality among postmenopausal women.

STUDY DESIGN

The study included 75,359 U.S. postmenopausal women aged 50-78 years from the Prostate, Lung, Colorectal, and Ovarian (PLCO) cohort. Information on ages at menarche and menopause was self-reported and collected at baseline, by questionnaire.

MAIN OUTCOME MEASURES

All-cause, cardiovascular and cancer mortality.

RESULTS

After a median follow-up of 13 years, we identified 7826 deaths among 75,359 women in the PLCO cohort. Compared with women with an age at menarche of 12-13 years and an age at menopause of 45-54 years, the adjusted hazard ratios (95% confidence interval) for all-cause mortality for women with early menarche (≤11 years) and menopause (≤44 years) and those with late menarche (≥14 years) and menopause (≥55 years) were 1.20 (1.09, 1.32) and 0.82 (0.71, 0.96), respectively. This association remained significant in a sensitivity analysis that excluded women who did not undergo natural menopause. The indexes for the additive effect of the combined association showed no excess risk due to an interaction.

CONCLUSIONS

Early menarche and early menopause seemed to have an exactly additive effect on all-cause mortality. The findings suggest that it is important to evaluate ages at both menarche and menopause rather than to consider either variable on its own in assessing the risk of mortality.

Age at Menarche and Risk of Cardiovascular Disease Outcomes: Findings From the National Heart Lung and Blood Institute-Sponsored Women's Ischemia Syndrome Evaluation

Background

Previous studies have reported an association between the timing of menarche and cardiovascular disease (CVD). However, emerging studies have not examined the timing of menarche in relation to role of estrogen over a lifetime and major adverse cardiac events (MACE).

Methods and Results

A total of 648 women without surgical menopause undergoing coronary angiography for suspected ischemia in the WISE (Women's Ischemia Syndrome Evaluation) study were evaluated at baseline and followed for 6 years (median) to assess major adverse CVD outcomes. MACE was defined as the first occurrence of all‐cause death, nonfatal myocardial infarction, nonfatal stroke, or heart failure hospitalization. Age at menarche was self‐reported and categorized (≤10, 11, 12, 13, 14, ≥15 years) with age 12 as reference. Total estrogen time and supra–total estrogen time were calculated. Cox regression analysis was performed adjusting for CVD risk factors. Baseline age was 57.9 ± 12 years (mean ± SD), body mass index was 29.5 ± 6.5 kg/m², total estrogen time was 32.2 ± 8.9 years, and supra–total estrogen time was 41.4 ± 8.8 years. MACE occurred in 172 (27%), and its adjusted regression model was J‐shaped. Compared with women with menarche at age 12 years, the adjusted MACE hazard ratio for menarche at ≤10 years was 4.53 (95% CI 2.13‐9.63); and at ≥15 years risk for MACE was 2.58 (95% CI, 1.28‐5.21).

Conclusions

History of early or late menarche was associated with a higher risk for adverse CVD outcomes. These findings highlight age at menarche as a potential screening tool for women at risk of adverse CVD events.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00000554.

Female reproductive factors and the likelihood of reaching the age of 90 years. The Netherlands Cohort Study

OBJECTIVES

The aim of this study was to prospectively assess the relationship between several reproductive factors in women and the likelihood of reaching the age of 90 years (achieving longevity).

STUDY DESIGN

For this study, data from the oldest birth cohort (1916-17) of the prospective Netherlands Cohort Study (NLCS) were used. These participants filled in a baseline questionnaire in 1986 (at age 68-70 years). Follow-up for vital status information until the age of 90 years (2006-07) was >99.9% complete.

MAIN OUTCOME MEASURES

Multivariable-adjusted Cox regression analyses with a fixed follow-up time were based on 2,697 women with complete exposure and co-variable data to calculate risk ratios (RR) of reaching age 90.

RESULTS

No associations were observed between the likelihood of reaching the age of 90 years, and age at menarche, age at menopause, parity, menstrual lifespan, and oral contraceptive use after adjustment for potential confounders. A later age at first childbirth pointed towards a higher chance of achieving longevity (age ≥30 vs. 20-24; RR,1.17; 95%CI,0.98-1.39). Ever-use of hormone replacement therapy (HRT) was significantly associated with a higher chance of achieving longevity compared with never HRT-users, but only in women who had had an early menopause (<50 years)(RR,1.32; 95% CI, 1.07-1.61).

CONCLUSION

Age at first childbirth, and ever-use of HRT in women with an early menopause (<50 years) were associated with the likelihood of reaching the age of 90 years.

Parity associated with telomere length among US reproductive age women

STUDY QUESTION

Is telomere length related to parity among a nationally representative sample of US reproductive age women?

SUMMARY ANSWER

History of live birth was associated with shorter telomere length.

WHAT IS KNOWN ALREADY

Shorter telomeres have been linked with a range of chronic health conditions and mortality and parity has been associated with health indicators. However, there is a lack of research on how parity relates to telomere length.

STUDY DESIGN, SIZE, DURATION

This nationally representative, cross-sectional study included 1954 women from the National Health and Nutrition Examination Survey, 1999-2002, the only survey period which includes measurement of telomere length.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Women aged 20-44 were included. Parity, defined as number of previous live births, was ascertained by questionnaire. Leukocyte telomere length was measured by polymerase chain reaction and reported as a ratio in relation to standard reference DNA (T/S ratio). The relationship between leukocyte T/S ratio and parity was examined using survey weighted linear regression. Models were adjusted for race/ethnicity, age, BMI, income-to-poverty ratio, education, early age at menarche and smoking status.

MAIN RESULTS AND THE ROLE OF CHANCE

Among reproductive age women in the US, the adjusted mean leukocyte T/S ratio was 4.2% (95% CI: 0.9, 7.3) shorter in parous compared with nulliparous women. Parity was associated with 116 fewer base pairs (95% CI: 26, 204) on average, using estimated coefficients from the adjusted linear regression models and mean covariate values.

LIMITATIONS REASONS FOR CAUTION

This study was cross-sectional and therefore was unable to establish temporality. The dataset lacked information on social factors, stress and fertility status, which may help explain these findings. Only two previous studies have examined this question and our findings should be interpreted with caution.

WIDER IMPLICATIONS OF THE FINDINGS

These findings in a nationally representative sample of US reproductive age women suggest that history of live birth may be associated with accelerated cellular aging. The magnitude of the observed association was greater than that of the impact of smoking or obesity on telomere length, suggesting that parity may have an independent influence on cellular aging and warrant further study.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded in part by the Undergraduate Research Scholars Program at George Mason University. The authors have no conflicts of interest.

TRIAL REGISTRATION NUMBER

NA.

Association of Combined Estrogen-Progestogen and Progestogen-Only Contraceptives with the Development of Cancer

Combined estrogen-progestogen contraceptives (oral contraceptives or OCs) and progestogen-only contraceptives (POCs) are synthetic steroids that bind to steroid hormone receptors, which are widespread throughout the body. They have a profound effect on cellular physiology. Combined OCs have been classified by the International Agency for Research on Cancer (IARC) as Group 1 carcinogens, but their findings have not been updated recently. In order to update the information and better understand the impact that OCs and POCs have on the risk of development of cancers, a comprehensive literature search was undertaken, focusing on more recently published papers. In agreement with the IARC, the recent literature confirms an increased risk of breast cancer and cervical cancer with the use of OCs. The recent literature also confirms the IARC conclusion that OCs decrease the risk of ovarian and endometrial cancers. However, there is little support from recent studies for the IARC conclusion that OCs decrease the risk of colorectal cancer or increase the risk of liver cancer. For liver cancer, this may be due to the recent studies having been performed in areas where hepatitis is endemic. In one large observational study, POCs also appear to increase the overall risk of developing cancer. OCs and POCs appear to increase the overall risk of cancer when carefully performed studies with the least intrinsic bias are considered.

Summary

OCs have been classified as cancer-causing agents, especially leading to increases in breast cancer and cervical cancer. A review of the recent scientific literature was performed to see whether this still appears to be the case. The recent literature supports the cancer-causing role of OCs especially for breast cancer and cervical cancer. Studies also indicate that progesterone-only contraceptives (such as implants and vaginal rings) also can cause cancer. This is especially true for breast cancer and cervical cancer.

Hysterectomy status and all-cause mortality in a 21-year Australian population-based cohort study

BACKGROUND

Hysterectomy is a common surgical procedure, predominantly performed when women are between 30 and 50 years old. One in 3 women in Australia has had a hysterectomy by the time they are 60 years old, and 30% have both ovaries removed at the time of surgery. Given this high prevalence, it is important to understand the long-term effects of hysterectomy. In particular, women who have a hysterectomy/oophorectomy at younger ages are likely to be premenopausal or perimenopausal and may experience greater changes in hormone levels and a shortened reproductive lifespan than women who have a hysterectomy when they are older and postmenopausal. Use of menopausal hormone therapy after surgery may compensate for these hormonal changes. To inform clinical decisions about postsurgery management of women who have a hysterectomy prior to menopause (ie, average age at menopause 50 years), it is useful to compare women with a hysterectomy to women with no hysterectomy and to stratify the hysterectomy status by whether or not women have had a bilateral oophorectomy, or used menopausal hormone therapy.

OBJECTIVE

We sought to investigate whether women who had a hysterectomy with ovarian conservation or a hysterectomy and bilateral oophorectomy before the age of 50 years were at a higher risk of premature all-cause mortality compared to women who did not have this surgery before the age of 50 years. We also sought to explore whether use of menopausal hormone therapy modified these associations.

STUDY DESIGN

Women from the midcohort (born 1946 through 1951) of the Australian Longitudinal Study on Women's Health were included in our study sample (n = 13,541). Women who reported a hysterectomy (with and without both ovaries removed) before the age of 50 years were considered exposure at risk and compared with women who did not report these surgeries before age 50 years. To explore effect modification by use of menopausal hormone therapy we further stratified hysterectomy status by menopausal hormone therapy use. Risk of all-cause mortality was assessed using inverse-probability weighted Cox regression models.

RESULTS

During a median follow-up of 21.5 years, there were 901 (6.7%) deaths in our study sample. Overall, there was no difference in all-cause mortality between women who reported a hysterectomy with ovarian conservation (hazard ratio, 0.86; 95% confidence interval, 0.72-1.02) or women who reported a hysterectomy and bilateral oophorectomy (hazard ratio, 1.02; 95% confidence interval, 0.78-1.34) and women with no hysterectomy. When stratified by menopausal hormone therapy use, women with hysterectomy and ovarian conservation before the age of 50 years were not at higher risk of all-cause mortality compared to no hysterectomy, regardless of menopausal hormone therapy use status. In contrast, among nonusers of menopausal hormone therapy only, women who reported a hysterectomy-bilateral oophorectomy before the age of 50 years were at a higher risk of death compared to women with no hysterectomy (hazard ratio, 1.81; 95% confidence interval, 1.01-3.25).

CONCLUSION

Hysterectomy with ovarian conservation before the age of 50 years did not increase risk of all-cause mortality. Among nonmenopausal hormone therapy users only, hysterectomy and bilateral oophorectomy before the age of 50 years was associated with a higher risk of death.

Effects of pregnancy experience on ovarian senescence and longevity in Hatano rats bred for high- and low-avoidance learning

We investigated the effects of pregnancy experience on ovarian senescence and longevity using two inbred strains of Hatano rats. These strains have been selectively bred for high- and low-avoidance animals (HAA and LAA, respectively), but the HAA line has a slower onset of ovarian senescence and a shorter lifespan compared with the LAA line. The onset of abnormal estrous cycles and survival curves were compared between nulliparous and parous rats in each line. In the HAA line, pregnancy experience did not change the onset of ovarian senescence but increased longevity. This suggests that a pituitary tumor, which is a causal factor for accelerated mortality in this line, developed slowly in parous rats. In the LAA line, pregnancy experience delayed the onset of ovarian senescence and reduced the incidence of mammary tumors but did not increase longevity because of an increased frequency of constipation with megacolon. These data suggest that the effects of pregnancy experience on ovarian senescence and longevity depend on the reproductive characteristics of the rat strains.

ABM Clinical Protocol #7: Model Maternity Policy Supportive of Breastfeeding

A central goal of The Academy of Breastfeeding Medicine is the development of clinical protocols for managing common medical problems that may impact breastfeeding success. These protocols serve only as guidelines for the care of breastfeeding mothers and infants and do not delineate an exclusive course of treatment or serve as standards of medical care. Variations in treatment may be appropriate according to the needs of an individual patient.

Menopause Characteristics, Total Reproductive Years, and Risk of Cardiovascular Disease Among Chinese Women

Supplemental Digital Content is available in the text.

Background—

Previous studies, mostly of Western women, have reported inconsistent findings on the association of menopause characteristics (status, age, and time since menopause) and total reproductive years with risk of cardiovascular disease (CVD).

Methods and Results—

The China Kadoorie Biobank recruited 302 632 women in 2004 to 2008 from 10 regions across China. During 9-year follow-up, 19 393 incident cases of stroke, 18 611 of ischemic heart disease, and 4978 CVD deaths occurred. Cox regression yielded adjusted hazard ratios relating each menopause characteristic and total reproductive years to CVD risk. Among 274 233 women with no prior CVD at baseline, 134 010 were naturally postmenopausal women (mean [SD] age at menopause of 48.6 [4.0] years and total reproductive years 32.7 [4.4]). Compared with premenopausal women, naturally peri- or postmenopausal women were at a higher risk of either fatal or nonfatal CVD. Among women who had had menopause, inverse associations were observed between age at menopause and risks of CVD mortality, incident ischemic heart disease, stroke, and subtypes of stroke, with 1.5% higher risk of CVD death (P<0.001), 0.7% for incident ischemic heart disease (P=0.002), and 0.5% for incident stroke (P=0.02) for every 1 year lower age at menopause. Compared with women who had menopause at age 48 to 50 years, lower age at menopause (ie, <43 years) was associated with 14% higher risk of CVD death and 6% higher risks of both incident ischemic heart disease and stroke. Higher risks of both fatal and nonfatal CVD were also found in women with 5 to 10, 10 to 15, 15 to 20, or >20 years since menopause compared with <5 years since menopause. Total reproductive years were inversely associated with risks of both fatal and nonfatal CVD, with 1.4% lower risk of CVD death per additional reproductive year (P<0.001).

Conclusions—

Women with younger age at menopause, longer time since menopause, or fewer total reproductive years had a higher risk of CVD.

The relation of age at menarche with age at natural menopause: a population study of 336 788 women in Norway

STUDY QUESTION

Is age at menarche associated with age at menopause or with duration of the reproductive period (interval between menarche and menopause)?

SUMMARY ANSWER

The association of age at menarche with age at menopause was weak and non-linear, and the duration of the reproductive period decreased by increasing age at menarche.

WHAT IS KNOWN ALREADY

It remains uncertain whether age at menarche is associated with age at menopause. Some studies report that women with early menarche also have early menopause. Other studies report that women with early menarche have late menopause, or they report no association. The duration of the reproductive period may be an indicator of the cumulative endogenous exposure to estrogens and progestogens during life course and is associated with risk of breast cancer and endometrial cancer.

STUDY DESIGN, SIZE, DURATION

A retrospective cohort study of 336 788 women, aged 48-71 years, in the BreastScreen Norway during the years 2006-2014 was performed.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Information about age at menarche and menopausal status was obtained by self-administered questionnaires. We used time to event approaches to estimate the associations.

MAIN RESULTS AND THE ROLE OF CHANCE

Median age at menopause was 51 years in most menarche groups. Women with menarche at age 16 years or age ≥ 17 years had menopause 1 year later [median: 52 years, interquartile range (IQR): 49-54 years] than women with menarche at age 13 years (median: 51 years, IQR: 49-54 years, reference) (crude hazard ratio (HR) = 0.95; 95% CI: 0.93-0.97 and 0.95; 95% CI: 0.92-0.99, Pnon-linearity < 0.001). The reproductive period decreased with increasing age at menarche (Pnon-linearity < 0.001), and women with menarche at age ≤ 9 years had 9 years longer median reproductive period than women with menarche at age ≥ 17 years (median: 43 versus 34 years). Adjustment for year of birth did not change the HR estimates notably.

LARGE SCALE DATA

Not applicable.

LIMITATIONS, REASONS FOR CAUTION

Information about age at menarche and age at menopause was based on self-reports. Particularly for age at menarche, the long time interval between the event and data collection may have caused imprecise reporting.

WIDER IMPLICATIONS OF THE FINDINGS

Our study suggests that age at menarche is a strong indicator for the duration of women's reproductive period. Our findings should encourage studies of the independent role of duration of the reproductive period on the risk of breast cancer and endometrial cancer, since these cancers have been associated with exposure to estrogens and progestogens.

STUDY FUNDING/COMPETING INTEREST(S)

The present study was funded by the Norwegian Cancer Society [Grant number 6863294-2015]. The authors declare no conflicts of interest.

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

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

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.

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

Background

Cardiovascular disease (CVD) is the principal contributor to the burden of disease and mortality worldwide. Previous studies observed associations between early age at first birth (AFB) and all-cause mortality. AFB may be associated with CVD both through physiological and sociobiological pathways. In this paper, we review the literature on AFB and CVD events and mortality. Additionally, we provide an overview of limitations of the current research and recommendations for future research.

Methods

PubMed and Web of Science databases were searched for observational studies published between 1980-June 2016, investigating associations between AFB and CVD events and mortality. Data were extracted using a pre-defined list.

Results

A total of 20 publications, reporting on 33 associations, were included in the review. Ten studies observed a positive association between early AFB and CVD while two studies observed a positive association between later AFB and CVD. Substantial methodological limitations were observed related to: operationalization of exposure categories, choice of reference category, sample size, follow-up time and possibly over adjustment.

Conclusions

Early AFB is possibly related to CVD. More work, in particular from large cohort studies starting before reproductive age is reached, is needed to better investigate this relationship, and to ascertain causal pathways that may explain observed associations.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-017-4519-x) contains supplementary material, which is available to authorized users.

Breastfeeding and the Risk of Maternal Cardiovascular Disease: A Prospective Study of 300 000 Chinese Women

BACKGROUND

Breastfeeding confers substantial benefits to child health and has also been associated with lower risk of maternal cardiovascular diseases (CVDs) in later life. However, the evidence on the effects of CVD is still inconsistent, especially in East Asians, in whom the frequency and duration of breastfeeding significantly differ from those in the West.

METHODS AND RESULTS

In 2004-2008, the nationwide China Kadoorie Biobank recruited 0.5 million individuals aged 30 to 79 years from 10 diverse regions across China. During 8 years of follow-up, 16 671 incident cases of coronary heart disease and 23 983 cases of stroke were recorded among 289 573 women without prior CVD at baseline. Cox regression yielded adjusted hazard ratios (HRs) and 95% CIs for incident CVD by breastfeeding. Overall, ≈99% of women had given birth, among whom 97% reported a history of breastfeeding, with a median duration of 12 months per child. Compared with parous women who had never breastfed, ever breastfeeding was associated with a significantly lower risk of CVD, with adjusted HRs of 0.91 (95% CI, 0.84-0.99) for coronary heart disease and 0.92 (95% CI, 0.85-0.99) for stroke. Women who had breastfed for ≥24 months had an 18% (HR, 0.82; 0.77-0.87) lower risk of coronary heart disease and a 17% (HR, 0.83; 0.79-0.87) lower risk of stroke compared with women who had never breastfed. Among women who ever breastfed, each additional 6 months of breastfeeding per child was associated with an adjusted HR of 0.96 (95% CI, 0.94-0.98) for coronary heart disease and 0.97 (95% CI, 0.96-0.98) for stroke.

CONCLUSIONS

Among Chinese women, a history of breastfeeding was associated with an ≈10% lower risk of CVD in later life and the magnitude of the inverse association was stronger among those with a longer duration of breastfeeding.

Maternal Age at Childbirth and Parity as Predictors of Longevity Among Women in the United States: The Women's Health Initiative

OBJECTIVES

To examine associations of maternal age at childbirth and parity with survival to age 90 years (longevity).

METHODS

We performed a prospective study among a multiethnic cohort of postmenopausal US women in the Women's Health Initiative recruited from 1993 to 1998 and followed through August 29, 2014. We adjusted associations with longevity for demographic, lifestyle, reproductive, and health-related characteristics.

RESULTS

Among 20 248 women (mean age at baseline, 74.6 years), 10 909 (54%) survived to age 90 years. The odds of longevity were significantly higher in women with later age at first childbirth (adjusted odds ratio = 1.11; 95% confidence interval = 1.02, 1.21 for age 25 years or older vs younger than 25 years; P for trend = .04). Among parous women, the relationship between parity and longevity was significant among White but not Black women. White women with 2 to 4 term pregnancies compared with 1 term pregnancy had higher odds of longevity.

CONCLUSIONS

Reproductive events were associated with longevity among women. Future studies are needed to determine whether factors such as socioeconomic status explain associations between reproductive events and longevity.

Parity, breastfeeding and risk of coronary heart disease: A pan-European case-cohort study

OBJECTIVE

There is uncertainty about the direction and magnitude of the associations between parity, breastfeeding and the risk of coronary heart disease (CHD). We examined the separate and combined associations of parity and breastfeeding practices with the incidence of CHD later in life among women in a large, pan-European cohort study.

METHODS

Data were used from European Prospective Investigation into Cancer and Nutrition (EPIC)-CVD, a case-cohort study nested within the EPIC prospective study of 520,000 participants from 10 countries. Information on reproductive history was available for 14,917 women, including 5138 incident cases of CHD. Using Prentice-weighted Cox regression separately for each country followed by a random-effects meta-analysis, we calculated hazard ratios (HRs) and 95% confidence intervals (CIs) for CHD, after adjustment for age, study centre and several socioeconomic and biological risk factors.

RESULTS

Compared with nulliparous women, the adjusted HR was 1.19 (95% CI: 1.01-1.41) among parous women; HRs were higher among women with more children (e.g., adjusted HR: 1.95 (95% CI: 1.19-3.20) for women with five or more children). Compared with women who did not breastfeed, the adjusted HR was 0.71 (95% CI: 0.52-0.98) among women who breastfed. For childbearing women who never breastfed, the adjusted HR was 1.58 (95% CI: 1.09-2.30) compared with nulliparous women, whereas for childbearing women who breastfed, the adjusted HR was 1.19 (95% CI: 0.99-1.43).

CONCLUSION

Having more children was associated with a higher risk of CHD later in life, whereas breastfeeding was associated with a lower CHD risk. Women who both had children and breastfed did have a non-significantly higher risk of CHD.

Breastfeeding Associated with Reduced Mortality in Women with Breast Cancer

OBJECTIVE

To study whether breastfeeding affects survival from breast cancer.

BACKGROUND

There are few studies on the relationship between breastfeeding, reproductive health, and breast cancer survival. This study is a follow-up of an earlier study showing no convincing associations between breastfeeding and breast cancer prognostic parameters.

METHODS

From a cohort of 629 women with primary breast cancer having undergone surgery between 1988 and 1992, 341 were traced and consequently studied 20 years later regarding breastfeeding and reproductive variables, as well as for prognostic parameters such as the Nottingham histological grade, tumor size, lymph node status, and vascular invasion (VI). Multivariate Cox regression analyses were used.

RESULTS

Increased breast cancer mortality was associated with the Nottingham prognostic index (hazard rate ratio (HR) 4.47; 95% confidence interval (CI) 2.04-9.79), VI (HR 3.44; CI 2.03-5.82), fewer pregnancies (three categories; >2, 1-2, 0) (HR per category 2.04; CI 1.34-3.11), and breastfeeding ≤6 months (HR 2.74; CI 1.41-5.35). The HRs for overall mortality were, as expected, lower for the Nottingham prognostic index (HR 1.28; CI 0.89-1.85) and VI (HR 2.09; CI 1.38-3.17), and they were slightly lower for the number of pregnancies (HR 1.61; CI 1.48-4.59), but notably similar for breastfeeding (HR 3.01;CI 1.92-4.73).

CONCLUSION

A total breastfeeding history >6 months and pregnancy are associated with both greater overall and breast cancer-specific survival for women diagnosed with breast cancer, having lived long enough for other causes of death to contribute substantially to mortality.