The risk of cardiovascular disease in women after miscarriage, stillbirth, and therapeutic abortion: a protocol for a systematic review and meta-analysis

Metabolic disorders mediate the relation of miscarriage with cardiovascular diseases

AIMS

The extent to which the contribution of pregnancy loss to cardiovascular diseases (CVDs) can be explained by metabolic disorders is poorly elucidated but holds insights for reducing long-term cardiovascular risk. The aim of this study is to investigate the mediating effects of hypertension, diabetes mellitus (DM), and lipoprotein metabolism disorders on the association of miscarriage and stillbirth with coronary heart disease (CHD), stroke, heart failure, atrial fibrillation, and composite outcomes.

METHODS AND RESULTS

A total of 163 283 ever-gravid women (age 55.3 ± 7.9 years) from the UK Biobank cohort without established metabolic disorders and CVDs were included and followed from 2007 to 2010 baseline until December 2020. Causal mediation analyses were used to estimate the proportion mediated. Hypertension mediated 11.1% (95% confidence interval, 3.7-18.5%) of the association between a history of miscarriage and incident CHD. Approximately, 9.5% (4.1-14.8%) of the effect of recurrent miscarriages on incident CHD was via hypertension, 8.4% (2.5-14.3%) of the effect was via lipoprotein metabolism disorders, 1.7% (0.5-2.9%) of the effect was via DM, and 10.7% (0.2-21.1%) of the effect of recurrent miscarriages on incident stroke was via hypertension. Hypertension mediated the largest proportion of effect for the atherosclerotic cardiovascular event (15.5% for a history of miscarriage and 9.4% for recurrent miscarriages), followed by lipoprotein metabolism disorders and DM.

CONCLUSION

Hypertension, DM, and lipoprotein metabolism disorders mediated the association between miscarriage and various cardiovascular outcomes in later life. In particular, hypertension mediated a large proportion of the relationship between miscarriage and atherosclerotic CVD.

Cardiovascular complications following medical termination of pregnancy: An updated review

BACKGROUND

Around 1 million cases of medical termination of pregnancy (MTP) take place yearly in the United States of America with around 2 percent of this population developing complications. The cardiovascular (CVD) complications occurring post MTP or after stillbirth is not very well described.

AIM

To help the reader better understand, prepare, and manage these complications by reviewing various cardiac comorbidities seen after MTP.

METHODS

We performed a literature search in PubMed, Medline, RCA, and google scholar, using the search terms "abortions" or "medical/legal termination of pregnancy" and "cardiac complications" or "cardiovascular complications".

RESULTS

The most common complications described in the literature following MTP were infective endocarditis (IE) (n = 16), takotsubo cardiomyopathy (TTC) (n = 7), arrhythmias (n = 5), and sudden coronary artery dissection (SCAD) (n = 4). The most common valve involved in IE was the tricuspid valve in 69% (n = 10). The most observed causative organism was group B Streptococcus in 81% (n = 12). The most common type of TTC was apical type in 57% (n = 4). Out of five patients developing arrhythmia, bradycardia was the most common and was seen in 60% (3/5) of the patients. All four cases of SCAD-P type presented as acute coronary syndrome 10-14 d post termination of pregnancy with predominant involvement of the right coronary artery. Mortality was only reported following IE in 6.25%. Clinical recovery was reported consistently after optimal medical management following all these complications.

CONCLUSION

In conclusion, the occurrence of CVD complications following pregnancy termination is infrequently documented in the existing literature. In this review, the most common CVD complication following MTP was noted to be IE and TTC.

Is There a Relationship between Adverse Pregnancy Outcomes and Future Development of Atherosclerosis?

Cardiovascular disease is one of the main death causes globally. Effective cardiovascular risk management requires a thorough understanding of the mechanisms underlying the disorder. Establishing early markers of the disease allows a timely intervention and prevention of further atherosclerosis development. Multiple studies confirm the correlation between pregnancy disorders and cardiovascular disease in the postpartum period. Moreover, over 30% of women experience adverse pregnancy outcomes. Thus, the examination of the links between these conditions and atherosclerotic cardiovascular disease may help to identify gender-specific risk factors. In this review, we will explore the association between several adverse pregnancy outcome conditions and atherosclerosis. The current analysis is based on the data from several recent studies on the mechanisms behind gestational diabetes, hypertensive disorders of pregnancy, miscarriages, and stillbirths and their implications for the female cardiovascular system.

The risk of cardiovascular diseases after miscarriage, stillbirth, and induced abortion: a systematic review and meta-analysis

Aims

Miscarriage and stillbirth have been included in cardiovascular disease (CVD) risk guidelines, however heterogeneity in exposures and outcomes and the absence of reviews assessing induced abortion, prevented comprehensive assessment. We aimed to perform a systematic review and meta-analysis of the risk of cardiovascular diseases for women with prior pregnancy loss (miscarriage, stillbirth, and induced abortion).

Methods and results

Observational studies reporting risk of CVD, coronary heart disease (CHD), and stroke in women with pregnancy loss were selected after searching MEDLINE, Scopus, CINAHL, Web of Knowledge, and Cochrane Library (to January 2020). Data were extracted, and study quality were assessed using the Newcastle-Ottawa Scale. Pooled relative risk (RR) and 95% confidence intervals (CIs) were calculated using inverse variance weighted random-effects meta-analysis.Twenty-two studies involving 4 337 683 women were identified. Seven studies were good quality, seven were fair and eight were poor. Recurrent miscarriage was associated with a higher CHD risk (RR = 1.37, 95% CI: 1.12-1.66). One or more stillbirths was associated with a higher CVD (RR = 1.41, 95% CI: 1.09-1.82), CHD (RR = 1.51, 95% CI: 1.04-1.29), and stroke risk (RR = 1.33, 95% CI: 1.03-1.71). Recurrent stillbirth was associated with a higher CHD risk (RR = 1.28, 95% CI: 1.18-1.39). One or more abortions was associated with a higher CVD (RR = 1.04, 95% CI: 1.02-1.07), as was recurrent abortion (RR = 1.09, 95% CI: 1.05-1.13).

Conclusion

Women with previous pregnancy loss are at a higher CVD, CHD, and stroke risk. Early identification and risk factor management is recommended. Further research is needed to understand CVD risk after abortion.

Pregnancy Complications and Risk of Cardiovascular Disease Later in Life: A Nationwide Cohort Study

Background

The aim of this study was to investigate the associations between pregnancy complications and cardiovascular mortality and hospitalizations of cardiovascular disease (CVD) after adjustment for major confounding.

Methods and Results

In a nationwide register‐based cohort study, women with singleton births between 1973 and 2014 were included from the Swedish Medical Birth Register. Outcomes of mortality and hospitalizations of CVD were collected from the Cause of Death Register and the National Inpatient Register. The cohort was followed from the date of the first delivery until death or end of follow‐up, whichever occurred first. The pregnancy complications studied were preeclampsia or eclampsia, gestational hypertension, gestational diabetes, preterm birth, small for gestational age, and stillbirth. Among the 2 134 239 women (mean age at first pregnancy, 27.0 [SD, 5.1] and mean parity 1.96 [SD, 0.9]), 19.1% (N=407 597) had 1 of the studied pregnancy complications. All pregnancy complications were associated with all‐cause and cardiovascular mortality and hospitalization for CVD (ischemic heart disease, ischemic stroke, and peripheral artery disease) after adjustment for major confounding in a Cox proportional hazard regression model. The adjusted hazard ratio for cardiovascular mortality was 1.84 (95% CI, 1.38–2.44) for preterm birth and 3.14 (95% CI, 1.81–5.44) for stillbirth.

Conclusions

In this large cohort study, pregnancy complications were associated with all‐cause mortality, cardiovascular mortality, and hospitalizations for CVD, also after adjusting for confounding, including overweight, smoking, and comorbidities. The study highlights that less established pregnancy complications such as preterm birth and stillbirth are also associated with cardiovascular mortality and CVD.