Infertility, Miscarriage, Stillbirth, and the Risk of Stroke Among Women: A Systematic Review and Meta-Analysis

Miscarriage and stillbirth in relation to risk of cardiovascular diseases: A systematic review and meta-analysis

INTRODUCTION

The relationship between pregnancy loss and the risk of cardiovascular diseases (CVDs) remains a matter of debate. Our intention in conducting this meta-analysis was to analyze the relationship between miscarriage and stillbirth and risk of CVDs.

METHODS

PubMed, Embase, and Web of Science were systematically searched up to May 30, 2023 for all relevant studies. The random-effects model was applied to estimate the pooled relative risks (RRs) and 95% confidence intervals (95% CIs). We evaluated RR estimates for the risk of CVDs with each additional miscarriage and stillbirth through generalized least squares regression.

RESULTS

Twenty-three articles were incorporated into the meta-analysis. For women with a history of miscarriage, the pooled RRs for the risk of total CVDs, coronary heart disease (CHD), stroke, and total CVD deaths were 1.16 (95 % CI 1.10-1.22), 1.26 (1.12-1.41), 1.13 (1.03-1.24), and 1.20 (1.01-1.42), respectively. For women with a history of stillbirth, the pooled RRs for the risk of total CVDs, CHD, stroke, and total CVD deaths were 1.60 (1.34-1.89), 1.30 (1.12-1.50), 1.37 (1.06-1.78), and 1.95 (1.05-3.63), respectively. With each additional miscarriage, the risk increased for total CVDs (1.08, 1.04-1.13), CHD (1.08, 1.04-1.13), and stroke (1.05, 1.00-1.10). With each additional stillbirth, the risk increased for total CVDs (1.11, 1.03-1.21) and CHD (1.13, 1.07-1.19).

CONCLUSION

This meta-analysis indicates that both miscarriages and stillbirths are related to a higher risk of total CVDs, CHD, stroke, and total CVD deaths. The risk of total CVDs and CHD increased with the number of miscarriages or stillbirths.

Causal associations of male infertility with stroke: a two-sample Mendelian randomization study

Background

Stroke is a devastating global health issue, with high mortality and disability rates. The increasing prevalence of male infertility among reproductive-aged men has become a growing concern worldwide. However, the relationship between male infertility and stroke incidence remains uncertain. This study aimed to address this knowledge gap by employing a Mendelian randomization (MR) approach.

Method

Utilizing genetic instrumental variables derived from a genome-wide association study (GWAS) on male infertility and stroke, a two-sample MR design was implemented. Five different analysis methods, with inverse-variance weighted as the primary approach, were used to examine the genetic causal associations between male infertility and various stroke subtypes. Heterogeneity analysis, pleiotropy tests, and leave-one-out validation were conducted to assess heterogeneity, evaluate pleiotropy, and ensure the robustness of the findings.

Result

The results indicate a potential lower risk of small vessel stroke associated with male infertility (odds ratio, 95% confidence interval: 0.82, 0.68 to 0.99, p=0.044), although no significant impact on other stroke subtypes was observed. The study exhibited low heterogeneity and no apparent pleiotropy; however, the stability of the results was not optimal.

Conclusion

Male infertility might potentially confer a protective effect against small vessel stroke risk. Caution is warranted due to potential confounding factors. Additional studies are necessary to confirm these findings and provide further validation.

Measuring EQ-5D-5L utility values in parents who have experienced perinatal death

BACKGROUND

Policymakers use clinical and cost-effectiveness evidence to support decisions about health service commissioning. In England, the National Institute for Health and Care Excellence (NICE) recommend that in cost-effectiveness analyses "effectiveness" is measured as quality-adjusted life years (QALYs), derived from health utility values. The impact of perinatal death (stillbirth/neonatal death) on parents' health utility is currently unknown. This knowledge would improve the robustness of cost-effectiveness evidence for policymakers.

OBJECTIVE

This study aimed to estimate the impact of perinatal death on parents' health utility.

METHODS

An online survey conducted with mothers and fathers in England who experienced a perinatal death. Participants reported how long ago their baby died and whether they/their partner subsequently became pregnant again. They were asked to rate their health on the EQ-5D-5L instrument (generic health measure). EQ-5D-5L responses were used to calculate health utility values. These were compared with age-matched values for the general population to estimate a utility shortfall (i.e. health loss) associated with perinatal death.

RESULTS

There were 256 survey respondents with a median age of 40 years (IQR 26-40). Median time since death was 27 months (IQR 8-71). The mean utility value of the sample was 0.774 (95% CI 0.752-0.796). Utility values in the sample were 13% lower than general population values (p < 0.05). Over 10 years, this equated to a loss of 1.1 QALYs. This reduction in health utility was driven by anxiety and depression.

CONCLUSIONS

Perinatal death has important and long-lasting health impacts on parents. Mental health support following perinatal bereavement is especially important.

2024 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2024 AHA Statistical Update is the product of a full year's worth of effort in 2023 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. The AHA strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional global data, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Impact of adverse pregnancy outcomes on brain vascular health and cognition

A State of the Art lecture titled "Impact of Adverse Pregnancy Outcomes on Brain Vascular Health and Cognition" was presented at the International Society on Thrombosis and Haemostasis Congress in 2023. Adverse pregnancy outcomes, encompassing conditions such as gestational hypertension, eclampsia, preeclampsia, preterm birth, fetal growth restriction, stillbirth, and gestational diabetes, may form part of an underrecognized pathway from early adulthood reproductive health factors to later-life vascular cognitive impairment and dementia in women. Adverse pregnancy outcomes are caused by dysregulated vascular and metabolic adaptations during pregnancy, and these pathophysiological changes may persist after delivery. Adverse pregnancy outcomes may contribute to the increased risk of cognitive impairment and dementia directly through vascular and metabolic dysregulation and subsequent development of cardiovascular diseases, or other biological processes may be at play, such as shared maternal risk factors. Extensive epidemiologic evidence has shown that many cognitive impairment and dementia cases may be prevented or delayed by strategies targeting midlife cardiovascular health. Despite the recognized importance of adverse pregnancy outcomes for cardiovascular health, the literature on associated long-term health outcomes is limited. In this State of the Art review article, we summarize the current epidemiologic evidence on the relationship between adverse pregnancy outcomes and cognitive impairment and dementia and provide an overview of the potential pathophysiological mechanisms. Finally, we summarize relevant new data on this topic presented during the 2023 International Society on Thrombosis and Haemostasis Congress.

Future risk of metabolic syndrome after recurrent pregnancy loss: a cohort study using UK Biobank

OBJECTIVE

To evaluate the risk of metabolic syndrome (MS) after recurrent pregnancy loss (RPL) using UK Biobank data. A history of pregnancy loss is associated with the development of cardiovascular diseases in the future. However, the association between RPL and subsequent MS is poorly understood. Therefore, we aimed to check the risk of MS after RPL.

DESIGN

The study population was divided into 2 groups according to reproductive history: women with a history of RPL and women without a history of RPL. Recurrent pregnancy loss was defined as 2 or more spontaneous miscarriages, and MS was defined as at least 3 of the following: abdominal obesity, hypertriglyceridemia, low high-density lipoprotein cholesterol levels, high-blood pressure, and hyperglycemia.

SETTING

UK Biobank resource.

PATIENTS

The UK Biobank is a prospective cohort study that enrolled individuals aged between 40 and 69 years whose medical and reproductive histories were retrieved at enrollment. In this cohort, only women with a history of at least one pregnancy were selected.

INTERVENTIONS

Recurrent pregnancy loss.

MAIN OUTCOME MEASURES

The primary outcome was the prevalence of MS. The secondary outcomes were 5 diagnostic components of MS.

RESULTS

We analyzed 228,674 women, including 15,702 with a history of RPL and 212,972 without a history of RPL. Women with a history of RPL have a higher prevalence of MS between the ages of 40 and 60 years (33.0% vs. 31.5%). After adjusting for covariates (age, race, number of live births, early menopause, smoking, alcohol consumption, and physical activity), the increased risk of MS after RPL remained significant (adjusted odds ratio, 1.10; 95% confidence interval, 1.06-1.15). Furthermore, in the analysis of the 5 diagnostic components of MS, a history of RPL significantly increased the risk of abdominal obesity, hypertriglyceridemia, low high-density lipoprotein cholesterol levels, and hyperglycemia.

CONCLUSION

Middle-aged women with a history of RPL have an increased risk of MS.

Risk of Stroke Hospitalization After Infertility Treatment

Importance

Stroke accounts for 7% of pregnancy-related deaths in the US. As the use of infertility treatment is increasing, many studies have sought to characterize the association of infertility treatment with the risk of stroke with mixed results.

Objective

To evaluate the risk of hospitalization from hemorrhagic and ischemic strokes in patients who underwent infertility treatment.

Design, Setting, and Participants

This population-based, retrospective cohort study used data abstracted from the Nationwide Readmissions Database, which stores data from all-payer hospital inpatient stays from 28 states across the US, from 2010 and 2018. Eligible participants included individuals aged 15 to 54 who had a hospital delivery from January to November in a given calendar year, and any subsequent hospitalizations from January to December in the same calendar year of delivery during the study period. Statistical analysis was performed between November 2022 and April 2023.

Exposure

Hospital delivery after infertility treatment (ie, intrauterine insemination, assisted reproductive technology, fertility preservation procedures, or use of a gestational carrier) or after spontaneous conception.

Main Outcomes and Measures

The primary outcome was hospitalization for nonfatal stroke (either ischemic or hemorrhagic stroke) within the first calendar year after delivery. Secondary outcomes included risk of stroke hospitalization at less than 30 days, less than 60 days, less than 90 days, and less than 180 days post partum. Cox proportional hazards regression models were used to estimate associations, which were expressed as hazard ratios (HRs), adjusted for confounders. Effect size estimates were corrected for biases due to exposure misclassification, selection, and unmeasured confounding through a probabilistic bias analysis.

Results

Of 31 339 991 patients, 287 813 (0.9%; median [IQR] age, 32.1 [28.5-35.8] years) underwent infertility treatment and 31 052 178 (99.1%; median [IQR] age, 27.7 [23.1-32.0] years) delivered after spontaneous conception. The rate of stroke hospitalization within 12 months of delivery was 37 hospitalizations per 100 000 people (105 patients) among those who received infertility treatment and 29 hospitalizations per 100 000 people (9027 patients) among those who delivered after spontaneous conception (rate difference, 8 hospitalizations per 100 000 people; 95% CI, -6 to 21 hospitalizations per 100 000 people; HR, 1.66; 95% CI, 1.17 to 2.35). The risk of hospitalization for hemorrhagic stroke (adjusted HR, 2.02; 95% CI, 1.13 to 3.61) was greater than that for ischemic stroke (adjusted HR, 1.55; 95% CI, 1.01 to 2.39). The risk of stroke hospitalization increased as the time between delivery and hospitalization for stroke increased, particularly for hemorrhagic strokes. In general, these associations became larger for hemorrhagic stroke and smaller for ischemic stroke following correction for biases.

Conclusions and Relevance

In this cohort study, infertility treatment was associated with an increased risk of stroke-related hospitalization within 12 months of delivery; this risk was evident as early as 30 days after delivery. Timely follow-up in the immediate days post partum and continued long-term follow-up should be considered to mitigate stroke risk.

Obstetric and Gynecologic Disorders and the Nervous System

OBJECTIVE

This article discusses obstetric and gynecologic associations with common neurologic disorders.

LATEST DEVELOPMENTS

Neurologic complications of obstetric and gynecologic disorders can arise throughout the lifespan. Caution should be exercised when prescribing fingolimod and natalizumab to patients with multiple sclerosis who are of childbearing potential because of the risk of disease rebound when they are discontinued. OnabotulinumtoxinA is considered safe in pregnancy and lactation based on long-term observational data. Hypertensive disorders of pregnancy are associated with higher subsequent cerebrovascular risk, likely via multiple mechanisms.

ESSENTIAL POINTS

Neurologic disorders may present in a variety of obstetric and gynecologic contexts, with meaningful implications for recognition and treatment. These interactions must be considered when treating women with neurologic conditions.

Infertility and Risk of Cardiovascular Disease: A Prospective Cohort Study

Background Certain symptoms associated with infertility are associated with cardiovascular disease, including menstrual cycle irregularity, early menopause, and obesity; however, few studies have investigated the association between infertility and cardiovascular disease risk. Methods and Results Participants in the NHSII (Nurses' Health Study II) who reported infertility (12 months of trying to conceive without success, including women who subsequently conceived) or who were gravid, with no infertility were followed from 1989 until 2017 for development of incident, physician-diagnosed coronary heart disease (CHD) (myocardial infarction, coronary artery bypass grafting, angioplasty, stent) and stroke. Time-varying Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% CIs and were adjusted a priori for potential confounding variables. Among 103 729 participants, 27.6% reported having ever experienced infertility. Compared with gravid women who had not reported infertility, women with a history of infertility had greater risk of CHD (HR, 1.13 [95% CI, 1.01-1.26]) but not stroke (HR, 0.91 [95% CI, 0.77-1.07]). The association between history of infertility and CHD was strongest among women who reported infertility at an earlier age (HR for infertility first reported at ≤25 years, 1.26 [95% CI, 1.09-1.46]; HR at 26-30 years, 1.08 [95% CI, 0.93-1.25]; HR at >30 years, 0.91 [95% CI, 0.70-1.19]). When we investigated specific infertility diagnoses, elevated risk of CHD was observed among women whose infertility was attributed to an ovulatory disorder (HR, 1.28 [95% CI, 1.05-1.55]) or endometriosis (HR, 1.42 [95% CI, 1.09-1.85]). Conclusions Women with infertility may be at an increased risk of CHD. Risk differed by age at first infertility diagnosis and was restricted to ovulatory- and endometriosis-related infertility.

Miscarriage, stillbirth and the risk of diabetes in women: A systematic review and meta-analysis

AIMS

Whether women with a history of miscarriage or stillbirth have an increased risk of diabetes is inconclusive. We aimed to systematically assess the association between them.

METHODS

We searched PubMed, Web of Science and Scopus through November 2022. Random-effect model for meta-analysis was applied to calculate pooled odds ratios and corresponding 95 % confidence intervals (CIs) when heterogeneity was > 40 %.

RESULTS

Thirteen cohort studies and eight case-control studies with a total of 529,990 participants were included. Women ever experiencing a miscarriage had a 1.15-fold risk of non-gestational diabetes (95% CI: 1.02-1.28) and a 1.62-fold risk of gestational diabetes (95% CI: 1.32-1.98) compared to those never experiencing a miscarriage. Of them, women with three or more miscarriages had a 1.99-fold risk of non-gestational diabetes (95% CI: 1.36-2.91). The risk of non-gestational diabetes among women ever experiencing a stillbirth was 1.21 times compared with those never experiencing a stillbirth (95% CI: 1.03-1.41). Pooled results did not support a stable association between stillbirth and gestational diabetes risk (odds ratio:1.91, 95% CI: 1.00-3.64).

CONCLUSIONS

A history of miscarriage or stillbirth was associated with an increased risk of diabetes in women. Future studies are needed to explore whether prediabetic metabolic conditions contribute to this association.

Sex and Gender Bias as a Mechanistic Determinant of Cardiovascular Disease Outcomes

Defined as a prejudice either for or against something, biases at the provider, patient, and societal level all contribute to differences in cardiovascular disease recognition and treatment, resulting in outcome disparities between sexes and genders. Provider bias in the under-recognition of female-predominant cardiovascular disease and risks might result in underscreened and undertreated patients. Furthermore, therapies for female-predominant phenotypes including nonobstructive coronary artery disease and heart failure with preserved ejection fraction are less well researched, contributing to undertreated female patients. Conversely, women are less likely to seek urgent medical attention, potentially related to societal bias to put others first, which contributes to diagnostic delays. Furthermore, women are less likely to have discussions around risk factors for coronary artery disease compared with men, partially because they are less likely to consider themselves at risk for heart disease. Provider bias in interpreting a greater number of presenting symptoms, some of which have been labelled as "atypical," can lead to mislabelling presentations as noncardiovascular. Furthermore, providers might avoid discussions around certain therapies including thrombolysis for stroke, and cardiac resynchronization therapy in heart failure, because it is incorrectly assumed that women are not interested in pursuing options deemed more invasive. To mitigate bias, organizations should aim to increase the visibility and involvement of women in research, health promotion, and clinical and leadership endeavours. More research needs to be done to identify effective interventions to mitigate sex and gender bias and the resultant cardiovascular outcome discrepancies.

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 between pregnancy and pregnancy loss with COPD in Chinese women: The China Kadoorie Biobank study

Background

Chronic obstructive pulmonary disease (COPD) is an inflammatory lung disease characterized by airflow blockage. Pregnancy and pregnancy loss may be related to an elevated risk of COPD, although studies have yet to report on this association. Hence, this study aims to investigate the association between pregnancy and pregnancy loss with the risk of COPD among Chinese women.

Methods

Data on 302,510 female participants from the China Kadoorie Biobank were utilized for this study. Multivariable logistic regression, stratified by sociodemographic and lifestyle factors, was employed to obtain the odds ratio (ORs) and 95% confidence intervals (CIs) for the association between pregnancy and pregnancy loss with COPD.

Results

Pregnancy loss was significantly associated with increased risk of COPD (OR 1.19, 95% CI 1.13-1.25), specifically, spontaneous (OR 1.19, 95% CI 1.11-1.29) and induced abortion (OR 1.18, 95% CI 1.12-1.25). Stillbirth, however, was not significantly associated with the risk of COPD (OR 1.09, 95% CI 0.99-1.20). Increasing number of pregnancy losses was associated with increasing risk of COPD (one pregnancy loss: OR 1.14, 95% CI 1.07-1.21, two or more pregnancy loss: OR 1.25, 95% CI 1.17-1.32, and each additional pregnancy loss: OR 1.06, 95% CI 1.03-1.09). A single pregnancy was significantly associated with reduced risk of COPD (OR 0.75, 95% CI 0.59-0.97), although each additional pregnancy was significantly associated with increased risk of COPD (OR 1.03, 95% CI 1.01-1.04).

Conclusion

Pregnancy loss, in particular, spontaneous and induced abortions are associated with increased risk of COPD among Chinese women. A single pregnancy, however, demonstrated protective effects.

Infertility, recurrent pregnancy loss, and risk of stroke: pooled analysis of individual patient data of 618 851 women

OBJECTIVE

To examine the associations of infertility, recurrent miscarriage, and stillbirth with the risk of first non-fatal and fatal stroke, further stratified by stroke subtypes.

DESIGN

Individual participant pooled analysis of eight prospective cohort studies.

SETTING

Cohort studies across seven countries (Australia, China, Japan, Netherlands, Sweden, the United Kingdom, and the United States) participating in the InterLACE (International Collaboration for a Life Course Approach to Reproductive Health and Chronic Disease Events) consortium, which was established in June 2012.

PARTICIPANTS

618 851 women aged 32.0-73.0 years at baseline with data on infertility, miscarriage, or stillbirth, at least one outcome event (non-fatal or fatal stroke), and information on covariates were included; 93 119 women were excluded. Of the participants, 275 863 had data on non-fatal and fatal stroke, 54 716 only had data on non-fatal stroke, and 288 272 only had data on fatal stroke.

MAIN OUTCOME AND MEASURES

Non-fatal strokes were identified through self-reported questionnaires, linked hospital data, or national patient registers. Fatal strokes were identified through death registry data.

RESULTS

The median follow-up for non-fatal stroke and fatal stroke was 13.0 years (interquartile range 12.0-14.0) and 9.4 years (7.6-13.0), respectively. A first non-fatal stroke was experienced by 9265 (2.8%) women and 4003 (0.7%) experienced a fatal stroke. Hazard ratios for non-fatal or fatal stroke were stratified by hypertension and adjusted for race or ethnicity, body mass index, smoking status, education level, and study. Infertility was associated with an increased risk of non-fatal stroke (hazard ratio 1.14, 95% confidence interval 1.08 to 1.20). Recurrent miscarriage (at least three) was associated with higher risk of non-fatal and fatal stroke (1.35, 1.27 to 1.44, and 1.82, 1.58 to 2.10, respectively). Women with stillbirth were at 31% higher risk of non-fatal stroke (1.31, 1.10 to 1.57) and women with recurrent stillbirth were at 26% higher risk of fatal stroke (1.26, 1.15 to 1.39). The increased risk of stroke (non-fatal or fatal) associated with infertility or recurrent stillbirths was mainly driven by a single stroke subtype (non-fatal ischaemic stroke and fatal haemorrhagic stroke), while the increased risk of stroke (non-fatal or fatal) associated with recurrent miscarriages was driven by both subtypes.

CONCLUSION

A history of recurrent miscarriages and death or loss of a baby before or during birth could be considered a female specific risk factor for stroke, with differences in risk according to stroke subtypes. These findings could contribute to improved monitoring and stroke prevention for women with such a history.

Reply to Kielb et al. Untapped Potential for Female Patients? Comment on "Lucà et al. Update on Management of Cardiovascular Diseases in Women. J. Clin. Med. 2022, 11, 1176"

We would like to thank the authors of this letter for their comments [...].

Current Resources for Evidence-Based Practice, May 2022

An extensive review of new resources to support the provision of evidence-based care for women and infants. The current column includes a discussion of the roles of researchers and clinicians in fostering evidence-based practice, diagnostic test accuracy in suspected preeclampsia, and the effectiveness of decision-making tools in patients with pre-pregnancy morbidities.