Preeclampsia as a Form of Type 5 Cardiorenal Syndrome: An Underrecognized Entity in Women's Cardiovascular Health

Adverse Pregnancy Outcomes and Long-Term Risk of Heart Failure in Women: National Cohort and Co-Sibling Study

BACKGROUND

Adverse pregnancy outcomes, such as preterm delivery and hypertensive disorders of pregnancy, may be associated with higher future risks of heart failure (HF). However, the comparative effects of different adverse pregnancy outcomes on long-term risk of HF, and their potential causality, are unclear.

OBJECTIVES

The authors sought to examine 5 major adverse pregnancy outcomes in relation to long-term risk of HF in a large population-based cohort.

METHODS

A national cohort study was conducted of all 2,201,638 women with a singleton delivery in Sweden in 1973-2015, followed up for HF identified from nationwide outpatient and inpatient diagnoses through 2018. Cox regression was used to compute HRs for HF associated with preterm delivery, small for gestational age, preeclampsia, other hypertensive disorders of pregnancy, and gestational diabetes, while adjusting for other adverse pregnancy outcomes and maternal factors. Co-sibling analyses assessed for potential confounding by shared familial (genetic or environmental) factors.

RESULTS

In 48 million person-years of follow-up, 667,774 women (30%) experienced an adverse pregnancy outcome, and 19,922 women (0.9%) were diagnosed with HF (median age, 61 years). All 5 adverse pregnancy outcomes were independently associated with long-term increased risk of HF. With up to 46 years of follow-up after delivery, adjusted HRs for HF associated with specific adverse pregnancy outcomes were: gestational diabetes, 2.19 (95% CI: 1.95-2.45); preterm delivery, 1.68 (95% CI: 1.61-1.75); other hypertensive disorders, 1.68 (95% CI: 1.48-1.90); preeclampsia, 1.59 (95% CI: 1.53-1.66); and small for gestational age, 1.35 (95% CI: 1.31-1.40). All HRs remained significantly elevated (1.3- to 3.0-fold) even 30 to 46 years after delivery. These findings were only partially explained by shared familial factors. Women with multiple adverse pregnancy outcomes had further increases in risk (eg, up to 46 years after delivery, adjusted HRs associated with 1, 2, or ≥3 adverse pregnancy outcomes were 1.51 [95% CI: 1.47-1.56], 2.31 [95% CI: 2.19-2.45], and 3.18 [95% CI: 2.85-3.56], respectively).

CONCLUSIONS

In this large national cohort, women who experienced any of 5 major adverse pregnancy outcomes had increased risk for HF up to 46 years later. Women with adverse pregnancy outcomes need early preventive actions and long-term clinical care to reduce the risk of HF.

Association between preterm delivery and the risk of maternal renal disease: A systematic review and meta‑analysis

The present systematic review and meta-analysis aimed to generate high-quality evidence on the association between preterm delivery (PTD) and subsequent risk of renal disease in the mother. A literature search was conducted on PubMed, Embase, CENTRAL and Scopus until the 15th of May 2023 for studies reporting an adjusted association between PTD and the risk of maternal renal disease. A total of seven studies were eligible. The pooled analysis found that women with PTD had a statistically significant increased risk of chronic kidney disease in the long term [hazard ratio (HR): 1.82 95% confidence interval (CI): 1.38, 2.40; I2=85%]. Similarly, the meta-analysis also found a statistically significant increased risk of end-stage renal disease (ESRD) amongst women with PTD as compared with those without PTD (HR: 2.22 95% CI: 1.95, 2.53; I2=0%). Overall, the pooled analysis showed a significantly higher incidence of renal disorders with PTD (HR: 1.98; 95% CI: 1.57, 2.50; I2=88%). The results were unchanged on sensitivity analysis. Women with PTD could be at increased risk of future chronic kidney disease and ESRD. The small number of studies and retrospective nature of data are important limitations. Further studies are needed to supplement the available evidence.

Adverse pregnancy outcomes and long-term risk of chronic kidney disease in women: national cohort and co-sibling study

BACKGROUND

Women with adverse pregnancy outcomes may have higher subsequent risk of chronic kidney disease, but the long-term independent risks and potential causality are unclear.

OBJECTIVE

This study aimed to determine long-term risks of chronic kidney disease associated with 5 major adverse pregnancy outcomes in a large population-based cohort, and to assess for familial confounding using co-sibling analyses.

STUDY DESIGN

A national cohort study was conducted of all 2,201,279 women with a singleton delivery in Sweden from 1973 to 2015, followed up for chronic kidney disease identified from nationwide diagnoses through 2018. Cox regression was used to compute hazard ratios for chronic kidney disease associated with preterm delivery, small for gestational age, preeclampsia, other hypertensive disorders, and gestational diabetes, adjusting for other adverse pregnancy outcomes and maternal factors. Co-sibling analyses assessed for potential confounding by shared familial (genetic or environmental) factors.

RESULTS

In 56 million person-years of follow-up, 11,572 (0.5%) women were diagnosed with chronic kidney disease (median age, 61 years). All 5 adverse pregnancy outcomes were independently associated with increased chronic kidney disease risk. Within 10 years following delivery, adjusted hazard ratios associated with specific adverse pregnancy outcomes were: 7.12 for other hypertensive disorders (95% confidence interval, 5.88-8.62), 4.38 for preeclampsia (3.72-5.16), 3.50 for preterm delivery (2.95-4.15), 3.15 for gestational diabetes (2.53-3.92), and 1.22 for small for gestational age (1.02-1.44). All hazard ratios remained significantly elevated even 30 to 46 years after delivery (gestational diabetes, 3.32 [95% confidence interval, 2.96-3.72]; other hypertensive disorders, 2.44 [1.91-3.11]; preeclampsia, 2.03 [1.90-2.16]; preterm delivery, 1.56 [1.44-1.68]; and small for gestational age, 1.24 [1.16-1.31]). These findings were only partially (0%-45%) explained by shared familial factors. Women with multiple adverse pregnancy outcomes had further increases in risk.

CONCLUSION

In this large national cohort, women who experienced any of 5 major adverse pregnancy outcomes had increased risk for chronic kidney disease up to 46 years later. Women with adverse pregnancy outcomes need early preventive actions and long-term monitoring to reduce risk of chronic kidney disease.

Diagnosing Arterial Stiffness in Pregnancy and Its Implications in the Cardio-Renal-Metabolic Chain

Cardio-renal and metabolic modifications during gestation are crucial determinants of foetal and maternal health in the short and long term. The cardio-renal metabolic syndrome is a vicious circle that starts in the presence of risk factors such as obesity, hypertension, diabetes, kidney disease and ageing, all predisposing to a status dominated by increased arterial stiffness and alteration of the vascular wall, which eventually damages the target organs, such as the heart and kidneys. The literature is scarce regarding cardio-renal metabolic syndrome in pregnancy cohorts. The present paper exposes the current state of the art and emphasises the most important findings of this entity, particularly in pregnant women. The early assessment of arterial function can lead to proper and individualised measures for women predisposed to hypertension, pre-eclampsia, eclampsia, and diabetes mellitus. This review focuses on available information regarding the assessment of arterial function during gestation, possible cut-off values, the possible predictive role for future events and modalities to reverse or control its dysfunction, a fact of crucial importance with excellent outcomes at meagre costs.

Effects of Probiotic Supplementation during Pregnancy on the Future Maternal Risk of Metabolic Syndrome

Probiotics are live microorganisms that induce health benefits in the host. Taking probiotics is generally safe and well tolerated by pregnant women and their children. Consumption of probiotics can result in both prophylactic and therapeutic effects. In healthy adult humans, the gut microbiome is stable at the level of the dominant taxa: Bacteroidetes, Firmicutes and Actinobacteria, and has a higher presence of Verrucomicrobia. During pregnancy, an increase in the number of Proteobacteria and Actinobacteria phyla and a decrease in the beneficial species Roseburia intestinalis and Faecalibacterium prausnitzii are observed. Pregnancy is a "window" to the mother's future health. The aim of this paper is to review studies assessing the potentially beneficial effects of probiotics in preventing the development of diseases that appear during pregnancy, which are currently considered as risk factors for the development of metabolic syndrome, and consequently, reducing the risk of developing maternal metabolic syndrome in the future. The use of probiotics in gestational diabetes mellitus, preeclampsia and excessive gestational weight gain is reviewed. Probiotics are a relatively new intervention that can prevent the development of these disorders during pregnancy, and thus, would reduce the risk of metabolic syndrome resulting from these disorders in the mother's future.

Preeclampsia and Fetal Congenital Heart Defects

Endothelial dysfunction, impaired implantation and placental insufficiency have been identified as mechanisms behind the development of pre-eclampsia, resulting in angiogenic factors' alteration. Angiogenic imbalance is also associated with congenital heart defects, and this common physiologic pathway may explain the association between them and pre-eclampsia. This review aims to understand the physiology shared by these two entities and whether women with pre-eclampsia have an increased risk of fetal congenital heart defects (or the opposite). The present research has highlighted multiple vasculogenic pathways associated with heart defects and preeclampsia, but also epigenetic and environmental factors, contributing both. It is also known that fetuses with a prenatal diagnosis of congenital heart disease have an increased risk of several comorbidities, including intrauterine growth restriction. Moreover, the impact of pre-eclampsia goes beyond pregnancy as it increases the risk for following pregnancies and for diseases later in life in both offspring and mothers. Given the morbidity and mortality associated with these conditions, it is of foremost importance to understand how they are related and its causative mechanisms. This knowledge may allow earlier diagnosis, an adequate surveillance or even the implementation of preventive strategies.

Serum catestatin level is increased in women with preeclampsia

Catestatin can inhibit catecholamine release from chromaffin cells and adrenergic neurons. Catestatin can also have a strong vasodilator effect. This may be useful in understanding the pathophysiology of preeclampsia and its treatment. In this study, we investigated the serum catestatin levels in pregnant women with and without preeclampsia. Fifty consecutive women with mild preeclampsia, 50 consecutive women with severe preeclampsia, and 100 consecutive pregnant women with a gestational age-matched (±1 week) uncomplicated pregnancy were evaluated in a cross-sectional study. Mean serum catestatin was significantly increased in the preeclampsia group compared to the control group (290.7 ± 95.5 pg/mL vs. 182.8 ± 72.0 pg/mL). Mean serum catestatin was comparable in mild and severe preeclampsia groups (282.7 ± 97.9 pg/mL vs. 298.7 ± 93.4 pg/mL, p = .431). Serum catestatin levels had positive correlations with systolic and diastolic blood pressure, urea, uric acid, and creatinine. In conclusion, serum catestatin levels are increased in preeclamptic pregnancies compared to gestational age-matched controls.IMPACT STATEMENTWhat is already known on this subject? The role of autonomic nervous system dysregulation in the pathophysiology of preeclampsia is known. The most obvious part of this dysregulation is the sympathetic nervous system activation. The adrenal medulla is one of the locations of the sympathetic nervous system in the body.What do the results of this study add? Serum catestatin levels were found to be correlated with clinical and laboratory data of preeclampsia. This highlights the importance of chromaffin cell secretions in the adrenal medulla in preeclampsia.What are the implications of these findings for clinical practice and/or further research? This study will help understand the role of the adrenal medulla in the autonomic nervous system dysregulation in preeclampsia. Also, control of serum catestatin levels may support the treatment of hypertension in preeclampsia.

The Fourth Trimester: Pregnancy as a Predictor of Cardiovascular Disease

Pregnancy identifies women who may be at a greater risk of cardiovascular disease (CVD), based on the development of adverse pregnancy outcomes (APOs), and may identify women who may benefit from atherosclerotic CVD (ASCVD) risk reduction efforts. APOs are common and although they are separate diagnoses, all these disorders seem to share an underlying pathogenesis. What is not clear is whether the APO itself initiates a pathway that results in CVD or whether the APO uncovers a woman's predisposition to CVD. Regardless, APOs have immediate risks to maternal and foetal health, in addition to longer-term CVD consequences. CVD risk assessment and stratification in women remains complex and, historically, has underestimated risk, especially in young women. Further research is needed into the role of ASCVD risk assessment and the effect of aggressive ASCVD risk modification on CVD outcomes in women with a history of APOs.

Hypertensive disorders of pregnancy and the risk of chronic kidney disease: A Swedish registry-based cohort study

BACKGROUND

Hypertensive disorders of pregnancy (HDP) (preeclampsia, gestational hypertension) are associated with an increased risk of end-stage kidney disease (ESKD). Evidence for associations between HDP and chronic kidney disease (CKD) is more limited and inconsistent. The underlying causes of CKD are wide-ranging, and HDP may have differential associations with various aetiologies of CKD. We aimed to measure associations between HDP and maternal CKD in women who have had at least one live birth and to identify whether the risk differs by CKD aetiology.

METHODS AND FINDINGS

Using data from the Swedish Medical Birth Register (MBR), singleton live births from 1973 to 2012 were identified and linked to data from the Swedish Renal Register (SRR) and National Patient Register (NPR; up to 2013). Preeclampsia was the main exposure of interest and was treated as a time-dependent variable. Gestational hypertension was also investigated as a secondary exposure. The primary outcome was maternal CKD, and this was classified into 5 subtypes: hypertensive, diabetic, glomerular/proteinuric, tubulointerstitial, and other/nonspecific CKD. Cox proportional hazard regression models were used, adjusting for maternal age, country of origin, education level, antenatal BMI, smoking during pregnancy, gestational diabetes, and parity. Women with pre-pregnancy comorbidities were excluded. The final sample consisted of 1,924,409 women who had 3,726,554 singleton live births. The mean (±SD) age of women at first delivery was 27.0 (±5.1) years. Median follow-up was 20.7 (interquartile range [IQR] 9.9-30.0) years. A total of 90,917 women (4.7%) were diagnosed with preeclampsia, 43,964 (2.3%) had gestational hypertension, and 18,477 (0.9%) developed CKD. Preeclampsia was associated with a higher risk of developing CKD during follow-up (adjusted hazard ratio [aHR] 1.92, 95% CI 1.83-2.03, p < 0.001). This risk differed by CKD subtype and was higher for hypertensive CKD (aHR 3.72, 95% CI 3.05-4.53, p < 0.001), diabetic CKD (aHR 3.94, 95% CI 3.38-4.60, p < 0.001), and glomerular/proteinuric CKD (aHR 2.06, 95% CI 1.88-2.26, p < 0.001). More modest associations were observed between preeclampsia and tubulointerstitial CKD (aHR 1.44, 95% CI 1.24-1.68, p < 0.001) or other/nonspecific CKD (aHR 1.51, 95% CI 1.38-1.65, p < 0.001). The risk of CKD was increased after preterm preeclampsia, recurrent preeclampsia, or preeclampsia complicated by pre-pregnancy obesity. Women who had gestational hypertension also had increased risk of developing CKD (aHR 1.49, 95% CI 1.38-1.61, p < 0.001). This association was strongest for hypertensive CKD (aHR 3.13, 95% CI 2.47-3.97, p < 0.001). Limitations of the study are the possibility that cases of CKD were underdiagnosed in the national registers, and some women may have been too young to have developed symptomatic CKD despite the long follow-up time. Underreporting of postpartum hypertension is also possible.

CONCLUSIONS

In this study, we found that HDP are associated with increased risk of maternal CKD, particularly hypertensive or diabetic forms of CKD. The risk is higher after preterm preeclampsia, recurrent preeclampsia, or preeclampsia complicated by pre-pregnancy obesity. Women who experience HDP may benefit from future systematic renal monitoring.

Adverse Pregnancy Outcomes and Long-term Maternal Kidney Disease: A Systematic Review and Meta-analysis

IMPORTANCE

Adverse pregnancy outcomes, such as hypertensive disorders of pregnancy, gestational diabetes, and preterm delivery, are associated with increased risk of maternal cardiovascular disease. Little is known about whether adverse pregnancy outcomes are associated with increased risk of maternal chronic kidney disease (CKD) and end-stage kidney disease (ESKD).

OBJECTIVE

To review and synthesize the published literature on adverse pregnancy outcomes (hypertensive disorders of pregnancy, gestational diabetes, and preterm delivery) and subsequent maternal CKD and ESKD.

DATA SOURCES

PubMed, Embase, and Web of Science were searched from inception to July 31, 2019, for cohort and case-control studies of adverse pregnancy outcomes and maternal CKD and ESKD.

STUDY SELECTION

Selected studies included the following: a population of pregnant women, exposure to an adverse pregnancy outcome of interest, and at least 1 primary outcome (CKD or ESKD) or secondary outcome (hospitalization or death due to kidney disease). Adverse pregnancy outcomes included exposure to hypertensive disorders of pregnancy (preeclampsia, gestational hypertension, or chronic hypertension), preterm delivery (<37 weeks), and gestational diabetes. Three reviewers were involved in study selection. Of 5656 studies retrieved, 23 were eligible for inclusion.

DATA EXTRACTION AND SYNTHESIS

The Meta-analyses of Observational Studies in Epidemiology (MOOSE) guidelines were followed throughout. Three reviewers extracted data and appraised study quality. Random-effects meta-analyses were used to calculate overall pooled estimates using the generic inverse variance method.

MAIN OUTCOMES AND MEASURES

Primary outcomes included CKD and ESKD diagnosis, defined using established clinical criteria (estimated glomerular filtration rate or albuminuria values) or hospital records. The protocol for this systematic review was registered on PROSPERO (CRD42018110891).

RESULTS

Of 23 studies included (5 769 891 participants), 5 studies reported effect estimates for more than 1 adverse pregnancy outcome. Preeclampsia was associated with significantly increased risk of CKD (pooled adjusted risk ratio [aRR], 2.11; 95% CI, 1.72-2.59), ESKD (aRR, 4.90; 95% CI, 3.56-6.74), and kidney-related hospitalization (aRR, 2.65; 95% CI, 1.03-6.77). Gestational hypertension was associated with increased risk of CKD (aRR, 1.49; 95% CI, 1.11-2.01) and ESKD (aRR, 3.64; 95% CI, 2.34-5.66). Preterm preeclampsia was associated with increased risk of ESKD (aRR, 5.66; 95% CI, 3.06-10.48); this association with ESKD persisted for women who had preterm deliveries without preeclampsia (aRR, 2.09; 95% CI, 1.64-2.66). Gestational diabetes was associated with increased risk of CKD among black women (aRR, 1.78; 95% CI, 1.18-2.70), but not white women (aRR, 0.81; 95% CI, 0.58-1.13).

CONCLUSIONS AND RELEVANCE

In this meta-analysis, exposure to adverse pregnancy outcomes, including hypertensive disorders of pregnancy, gestational diabetes, and preterm delivery, was associated with higher risk of long-term kidney disease. The risk of ESKD was highest among women who experienced preeclampsia. A systematic approach may be warranted to identify women at increased risk of kidney disease, particularly after hypertensive disorders of pregnancy, and to optimize their long-term follow-up.

Effects of preeclampsia and eclampsia on maternal metabolic and biochemical outcomes in later life: a systematic review and meta-analysis

OBJECTIVE

To evaluate the association between preeclampsia (PE) and eclampsia (E) on subsequent metabolic and biochemical outcomes.

METHODS

Systematic review and meta-analysis of observational studies. We searched five engines until November 2018 for studies evaluating the effects of PE/E on metabolic and biochemical outcomes after delivery. PE was defined as presence of hypertension and proteinuria at >20 weeks of pregnancy; controls did not have PE/E. Primary outcomes were blood pressure (BP), body mass index (BMI), metabolic syndrome (MetS), blood lipids and glucose levels. Random effects models were used for meta-analyses, and effects reported as risk difference (RD) or mean difference (MD) and their 95% confidence interval (CI). Subgroup analyses by time of follow up, publication year, and confounder adjustment were performed.

RESULTS

We evaluated 41 cohorts including 3300 PE/E and 13,967 normotensive controls. Women were followed up from 3 months after delivery up to 32 years postpartum. In comparison to controls, PE/E significantly increased systolic BP (MD = 8.3 mmHg, 95%CI 6.8 to 9.7), diastolic BP (MD = 6.8 mmHg, 95%CI 5.6 to 8.0), BMI (MD = 2.0 kg/m²; 95%CI 1.6 to 2.4), waist (MD = 4.3 cm, 95%CI 3.1 to 5.5), waist-to-hip ratio (MD = 0.02, 95%CI 0.01 to 0.03), weight (MD = 5.1 kg, 95%CI 2.2 to 7.9), total cholesterol (MD = 4.6 mg/dL, CI 1.5 to 7.7), LDL (MD = 4.6 mg/dL; 95%CI 0.2 to 8.9), triglycerides (MD = 7.7 mg/dL, 95%CI 3.6 to 11.7), glucose (MD = 2.6 mg/dL, 95%CI 1.2 to 4.0), insulin (MD = 19.1 pmol/L, 95%CI 11.9 to 26.2), HOMA-IR index (MD = 0.7, 95%CI 0.2 to 1.2), C reactive protein (MD = 0.05 mg/dL, 95%CI 0.01 to 0.09), and the risks of hypertension (RD = 0.24, 95%CI 0.15 to 0.33) and MetS (RD = 0.11, 95%CI 0.08 to 0.15). Also, PE/E reduced HDL levels (MD = -2.15 mg/dL, 95%CI -3.46 to -0.85). Heterogeneity of effects was high for most outcomes. Risk of bias was moderate across studies. Subgroup analyses showed similar effects as main analyses.

CONCLUSION

Women who had PE/E have worse metabolic and biochemical profile than those without PE/E in an intermediate to long term follow up period.

Autonomic Dysfunction in Preeclampsia: A Systematic Review

Background: Preeclampsia (PE) is a major obstetric complication that leads to severe maternal and fetal morbidity. Early detection of preeclampsia can reduce the severity of complications and improve clinical outcomes. It is believed that the autonomic nervous system (ANS) is involved in the pathogenesis of PE. We aimed to review the current literature on the prevalence and nature of ANS dysfunction in women with PE and the possible prognostic value of ANS testing in the early detection of PE.

Methods: Literature search was performed using Medline (1966–2018), EMBase (1947–2018), Google Scholar (1970–2018), BIOSIS (1926–2018), Web of science (1900–2018); CINAHL (1937–2018); Cochrane Library, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials (CENTRAL) and Cochrane Methodology Register (1999–2018). Additionally, the reference lists of articles included were screened.

Results: A total of 26 studies were included in the present review presenting data of 1,854 pregnant women. Among these women, 453 were diagnosed with PE, 93.6% (424/453) of which displayed autonomic dysfunction. ANS function was assessed by cardiovascular reflex tests (n = 9), heart rate variability (n = 11), cardiac baroreflex gain (n = 5), muscle sympathetic nerve activity (MSNA) (n = 3), and biomarkers of sympathetic activity (n = 4). Overall, 21 studies (80.8%) reported at least one of the following abnormalities in ANS function in women diagnosed with PE compared to healthy pregnant control women: reduced parasympathetic activity (n = 16/21, 76%), increased sympathetic activity (n = 12/20, 60%), or reduced baroreflex gain (n = 4/5, 80%). Some of these studies indicated that pressor and orthostatic stress test may be useful in early pregnancy to help estimate the risk of developing PE. However, autonomic function tests seem not to be able to differentiate between mild and severe PE.

Conclusions: Current evidence suggests that autonomic dysfunction is highly prevalent in pre-eclamptic women. Among autonomic functions, cardiovascular reflexes appear to be predominantly affected, seen as reduced cardiac parasympathetic activity and elevated cardiac sympathetic activity. The diagnostic value of autonomic testing in the prediction and monitoring of autonomic failure in pre-eclamptic women remains to be determined.

A systematic review and meta-analysis indicates long-term risk of chronic and end-stage kidney disease after preeclampsia

Preeclampsia is a pregnancy-related syndrome of variable severity, classically characterized by acute kidney involvement, with hypertension and/or proteinuria and reduced kidney function. Once considered a self-limited disease healed by delivery, it is now acknowledged that preeclampsia can affect cardiovascular and kidney health in the long term. The entity of risk has not been established and consequently follow-up policies have not been defined. Here we undertook a systematic review to gain better insights into the need for post-preeclampsia follow-up. Articles published between January 2000 and March 2018 were selected, dealing with at least 20 preeclampsia patients, with follow-up of 4 years or more (MEDLINE, Embase, and Cochrane Library). No quality selection or language restriction was performed. Of the 10,510 titles and abstracts originally considered, 21 papers were selected, providing information on 110,803 cases with and 2,680,929 controls without preeclampsia, with partial overlap between studies on the same databases. Heterogeneity was high, and a random meta-analytic model selected. The increase in risk of end stage renal disease after preeclampsia was significant (meta-analytic risk ratios (95% confidence interval) 6.35 (2.73-14.79)); the risk of albuminuria and chronic kidney disease increased but statistical significance was not reached (4.31 (0.95-19.58) and 2.03 (0.58-7.32), respectively). Translating meta-analytic risk into the number of patients who need follow-up to detect one adverse event, 310 patients with preeclampsia are needed to identify one woman with end stage renal disease or four to identify one woman with albuminuria. Heterogeneity in definitions, insufficient follow-up and incomplete recruitment may account for discrepancies. Thus, preeclampsia significantly increases the risk of end stage renal disease. However, there is lack of sufficient data to show a relationship between preeclampsia, albuminuria and chronic kidney disease, underlining the need for further prospective studies.

Adverse pregnancy outcomes and long-term risk of maternal renal disease: a systematic review and meta-analysis protocol

INTRODUCTION

Adverse pregnancy outcomes, such as hypertensive disorders of pregnancy (HDP), gestational diabetes (GDM) and preterm birth have been linked to maternal cardiovascular disease in later life. Pre-eclampsia (PE) is associated with an increased risk of postpartum microalbuminuria, but there is no clear consensus on whether HDP increases the risk of maternal chronic kidney disease (CKD) and end-stage kidney disease (ESKD). Similarly, it is uncertain whether GDM, preterm birth and delivery of low birth-weight infants independently predict the risk of maternal renal disease in later life. The aims of this proposed systematic review and meta-analysis are to summarise the available evidence examining the association between adverse outcomes of pregnancy (HDP, GDM, preterm birth, delivery of low birth-weight infant) and later maternal renal disease and to synthesise the results of relevant studies.

METHODS AND ANALYSIS

A systematic search of PubMed, EMBASE and Web of Science will be undertaken using a detailed prespecified search strategy. Two authors will independently review the titles and abstracts of all studies, perform data extraction and appraise the quality of included studies using a bias classification tool. Original case-control and cohort studies published in English will be considered for inclusion. Primary outcomes of interest will be CKD and ESKD; secondary outcomes will be hospitalisation for renal disease and deaths from renal disease. Meta-analyses will be performed to calculate the overall pooled estimates using the generic inverse variance method. The systematic review will follow the Meta-analyses Of Observational Studies in Epidemiology guidelines.

ETHICS AND DISSEMINATION

This systematic review and meta-analysis will be based on published data, and thus there is no requirement for ethics approval. The results will be shared through publication in a peer reviewed journal and through presentations at academic conferences.

PROSPERO REGISTRATION NUMBER

CRD42018110891.

Sympathetic nervous system control of vascular function and blood pressure during pregnancy and preeclampsia

: Proper vascular tone and blood pressure regulation during pregnancy are important for immediate and long-term cardiovascular health of the mother and her offspring. Preeclampsia is clinically defined as new-onset maternal hypertension accompanied by cardiovascular, renal, and/or neural abnormalities presenting in the second half of pregnancy. There is strong evidence to support that preeclampsia is mediated by attenuations in uteroplacental vascular remodeling and increases in vasoconstriction with subsequent placental ischemia/reperfusion-induced release of hypertensive substances into the maternal circulation. These include antiangiogenic and pro-inflammatory factors. There is also evidence implicating increased sympathetic nervous system activity (SNA) in this maternal disorder, but this mostly includes data correlating severity of disease with catecholamine levels and elevated muscle SNA. These measurements have not confirmed a causative role for SNA in the pathogenesis of preeclampsia. Therefore, studies are needed to provide a comprehensive understanding of SNA and its control of vascular function and blood pressure regulation during normal pregnancy in order to set the stage for exploring the mechanisms mediating the exaggerated SNA and signaling during preeclampsia. This review examines the role of SNA in control of uteroplacental vascular tone and blood pressure regulation during normal pregnancy. Furthermore, it is proposed that over-activation of the SNA contributes to altered uteroplacental vascular tone and perfusion leading to placental ischemic events and modulates the systemic vasoconstriction and hypertensive responses to soluble placenta ischemic factors. Recognizing the integrative role and importance of SNA in the pathophysiology of preeclampsia will advance our understanding of this maternal disorder.