Physiological adaptation of endothelial function to pregnancy: systematic review and meta-analysis

The Role of Endothelial Dysfunction in the Pathogenesis of Pregnancy-Related Pathological Conditions: A Review

In the recent decades, endothelial dysfunction (ED) has been recognized as a significant contributing factor in the pathogenesis of many pathological conditions. In interaction with atherosclerosis, hypercholesterolemia, and hypertension, ED plays a crucial role in the pathogenesis of coronary artery disease, chronic renal disease, and microvascular complications in diabetes mellitus. Although ED plays a significant role in the pathogenesis of several pregnancy-related disorders such as preeclampsia, HELLP syndrome, fetal growth restriction, and gestational diabetes mellitus, the exact pathogenetic mechanisms are still a matter of debate. The increased prevalence of these entities in patients with preexisting vascular diseases highlights the essential pathological role of the preexisting ED in these patients. The abnormal uteroplacental circulation and the release of soluble factors from the ischemic placenta into the maternal bloodstream are the main causes of the maternal ED underlying the characteristic preeclamptic phenotype. Besides the increased risk for maternal and fetal poor outcomes, the preexisting ED also increases the risk of development of future cardiovascular diseases in these patients. This study aimed to look deeper into the role of ED in the pathogenesis of several pregnancy-related hypertensive and liver diseases. Hopefully, it could contribute to improvement of the awareness, knowledge, and management of these conditions and also to the reduction of the adverse outcomes and additional long-term cardiovascular complications.

VASCULAR AND RENAL MECHANISMS OF PREECLAMPSIA

Preeclampsia (PE) is a multisystem obstetric disorder that affects 2-10% of pregnancies worldwide and it is a leading cause of maternal and fetal morbidity and mortality. The etiology of PE development is not clearly delineated, but since delivery of the fetus and placenta often leads to symptom resolution in the most cases of PE, it is hypothesized that the placenta is the inciting factor of the disease. Current management strategies for PE focus on treating the maternal symptoms to stabilize the mother in an attempt to prolong the pregnancy. However, the efficacy of this management strategy is limited. Therefore, identification of novel therapeutic targets and strategies is needed. Here, we provide a comprehensive overview of the current state of knowledge regarding mechanisms of vascular and renal pathophysiology during PE and discuss potential therapeutic targets directed at improving maternal vascular and renal function.

Clinical value of flow-mediated dilatation of brachial artery in hypertensive disorders complicating pregnancy

Hypertensive disorders complicating pregnancy (HDCP) are common pregnancy-related disorders. In this study, we aimed to study the clinical value of flow-mediated dilation (FMD) in HDCP and its association with endothelial dysfunction and HDCP-related factors. 160 HDCP patients and 120 healthy pregnancies were enrolled in the study. The expressions of endothelial function markers and FMD were determined. In addition, their correlations in HDCP patients were also analyzed using Pearson's correlation analysis. FMD value decreased gradually from normal pregnancy to severe PE. The levels of plasma nitric oxidase (NO) were significantly lower in the HDCP group than those in the control group, while the levels of plasma endothelin-1 (ET-1) were increased dramatically in the HDCP group. Moreover, the levels of placental growth factor (PLGF) in HDCP women were significantly lower, while the soluble FMS-like tyrosine kinase 1 (sFLt-1) levels were markedly higher than those in control. In addition, the FMD value was correlated with the levels of plasma NO, ET-1, PLGF and sFlt1. It was also found that lower levels of FMD correspond to endothelial dysfunction and abnormal concentrations of PLGF and sFlt-1. The FMD value was associated with endothelial function indicators and could be a strong and non-invasive measure to predict HDCP. The association between the FMD values and endothelial function indicators in HDCP could be helpful for the prediction of pregnant hypertension more accurately.

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.

The Assessment of Maternal and Fetal Intima-Media Thickness in Perinatology

Intima-media thickness (IMT) measurement is a non-invasive method of arterial wall assessment. An increased IMT is a common manifestation of atherosclerosis associated with endothelial dysfunction. In the course of pregnancy, various maternal organs, including the endothelium, are prepared for their new role. However, several pre-gestational conditions involving endothelial dysfunction, such as diabetes, chronic hypertension, and obesity, may impair the adaptation to pregnancy, whereas vascular changes may also affect fetal development, thus, influencing the fetal IMT. In the conducted studies, a correlation was found between an increased fetal abdominal aorta IMT (aIMT) and placental dysfunctions, which may subsequently impact both the mother and the fetus, and contribute to gestational hypertension, preeclampsia (PE), and fetal growth restriction (FGR). In fact, data indicate that following the delivery, the endothelial dysfunction persists and influences the future health of the mother and the newborn. Hypertensive disorders in pregnancy increase the maternal risk of chronic hypertension, obesity, and vascular events. Moreover, individuals born from pregnancies complicated by preeclampsia or fetal growth restriction are at high risk of obesity, diabetes, hypertension, and cardiovascular disease. Therefore, understanding the pathomechanism underlying an increased aIMT in preeclampsia and FGR, as well as subsequent placental dysfunctions, is essential for developing targeted therapies. This review summarizes recent publications regarding IMT and demonstrates how IMT measurements affect predicting perinatal complications.

Vascular Dysfunction in Preeclampsia

Preeclampsia is a life-threatening pregnancy-associated cardiovascular disorder characterized by hypertension and proteinuria at 20 weeks of gestation. Though its exact underlying cause is not precisely defined and likely heterogenous, a plethora of research indicates that in some women with preeclampsia, both maternal and placental vascular dysfunction plays a role in the pathogenesis and can persist into the postpartum period. Potential abnormalities include impaired placentation, incomplete spiral artery remodeling, and endothelial damage, which are further propagated by immune factors, mitochondrial stress, and an imbalance of pro- and antiangiogenic substances. While the field has progressed, current gaps in knowledge include detailed initial molecular mechanisms and effective treatment options. Newfound evidence indicates that vasopressin is an early mediator and biomarker of the disorder, and promising future therapeutic avenues include mitigating mitochondrial dysfunction, excess oxidative stress, and the resulting inflammatory state. In this review, we provide a detailed overview of vascular defects present during preeclampsia and connect well-established notions to newer discoveries at the molecular, cellular, and whole-organism levels.

Comparison of brachial artery flow-mediated dilatation, uterine artery Doppler, and umbilical artery Doppler measurements in obese and normal pregnant women

OBJECTIVE

In this study, we aimed to compare vascular function at trimesters 1, 2, and 3 between obese and normal pregnant women through brachial artery flow-mediated dilatation (FMD), uterine artery Doppler, and umbilical artery Doppler measurements.

METHODS

Pregnant women between the ages of 18 and 40 who presented to our clinic were included. Brachial artery FMD, uterine and umbilical artery Doppler, and clinical parameters of 40 obese pregnant women from each trimester between 11 and 14 weeks, 24 and 28 weeks, 37 and 40 weeks and control pregnant group in the same number and gestational week were examined.

RESULTS

In all three trimesters, the FMD value was lower in obese pregnant women compared to normal women with adequate weight (p < 0.001). In obese pregnant women, lower FMD values were observed in the second trimester compared to other trimesters (p = 0.011) Cut-off value of FMD below 14.35 in obese pregnant women was found to be associated with gestational diabetes mellitus. Uterine artery Doppler in obese pregnant women started to increase from the second trimester compared to normal women with adequate weight.

CONCLUSION

Obese pregnant women have endovascular dysfunction compared to normal pregnant women and this becomes evident from the second trimester.

l-Citrulline supplementation during pregnancy improves perinatal and postpartum maternal vascular function in a mouse model of preeclampsia

Preeclampsia is a spontaneously occurring pregnancy complication diagnosed by new-onset hypertension and end-organ dysfunction with or without proteinuria. This pregnancy-specific syndrome contributes to maternal morbidity and mortality and can have detrimental effects on fetal outcomes. Preeclampsia is also linked to increased risk of maternal cardiovascular disease throughout life. Despite intense investigation of this disorder, few treatment options are available. The aim of this study was to investigate the potential therapeutic effects of maternal l-citrulline supplementation on pregnancy-specific vascular dysfunction in the male C57BL/6J × female C57BL/6J C1q-/- preeclampsia-like mouse model. l-Citrulline is a nonessential amino acid that is converted to l-arginine to promote smooth muscle and blood vessel relaxation and improve nitric oxide (NO)-mediated vascular function. To model a preeclampsia-like pregnancy, female C57BL/6J mice were mated to C1q-/- male mice, and a subset of dams was supplemented with l-citrulline throughout pregnancy. Blood pressure, systemic vascular glycocalyx, and ex vivo vascular function were investigated in late pregnancy, and postpartum at 6 and 10 mo of age. Main findings show that l-citrulline reduced blood pressure, increased vascular glycocalyx volume, and rescued ex-vivo vascular function at gestation day 17.5 in this preeclampsia-like model. The vascular benefit of l-citrulline also extended postpartum, with improved vascular function and glycocalyx measures at 6 and 10 mo of age. l-Citrulline-mediated vascular improvements appear, in part, attributable to NO pathway signaling. Taken together, l-citrulline supplementation during pregnancy appears to have beneficial effects on maternal vascular health, which may have translational implications for improved maternal cardiovascular health.

Prenatal exercise and cardiovascular health (PEACH) study: The remote effect of aerobic exercise training on conduit artery and resistance vessel function

We assessed the impact of a structured lower-limb aerobic exercise training intervention during pregnancy on brachial artery endothelial function, shear rate and patterns, and forearm blood flow and reactive hyperemia. Twenty-seven pregnant women were recruited and randomized into either a control group (n=11; 31.0 ± 0.7 years), or an exercise intervention group (n=16; 32.6 ± 0.9 years; NCT02948439). The exercise group completed 40 minutes of aerobic exercise (50-70% heart rate reserve) 3-4 times per week, between the second and third trimester of pregnancy. Endothelial function was assessed using flow-mediated dilation (FMD, normalized for shear stress) pre- (16-20 weeks) and post-intervention (34-36 weeks). The exercise training group experienced an attenuated increase in mean arterial pressure (MAP) relative to the control group (∆MAP exercise: +2± 2 mmHg vs. control: +7±3 mmHg; p=0.044) from pre- to post-intervention. % FMD change corrected for shear stress was not different between groups (p=0.460); however, the post occlusion mean flow rate (exercise: 437±32 mL/min vs. control: 364±35 mL/min; p=0.001) and post occlusion anterograde flow rate (exercise: 438±32 mL/min vs. control: 364±46 mL/min;p=0.001) were larger for the exercise training group compared to controls, post-intervention. Although endothelial function was not different between groups, we observed an increase in microcirculatory dilatory capacity, as suggested by the augmented reactive hyperemia in the exercise training group. Novelty: • Endothelial function was not altered with exercise training during pregnancy. • Exercise training did contribute to improved cardiovascular outcomes, which may have been associated with augmented reactive hyperaemia, indicative of increased microcirculatory dilatory capacity.

Role of arterial impairment in preeclampsia: should the paradigm shift?

Preeclampsia is a worldwide pregnancy complication with serious short- and long-term maternal and neonatal consequences. Our understanding of preeclampsia pathophysiology has significantly evolved over the last decades with the recognition that impaired arterial function and structure may occur early in the course of pregnancy, preceding the clinic-humoral syndrome and driving long-term cardiovascular disease risk in the future of these patients. Although an early abnormal placentation may be the inciting event for a large proportion of cases, there is growing evidence that challenges the placental hypothesis in all affected women, since placental histopathology lesions thought to be characteristic are neither sensitive nor specific markers for the disorder. Recent hemodynamic investigations and studies on left ventricular function and structure in women with preeclampsia further challenge this universal paradigm and propose that placental dysfunction could be secondary to a maternal cardiovascular maladaptation to pregnancy in certain patients. Supporting this hypothesis, certain vascular features, which are characteristically enhanced in normal pregnancy allowing a healthy vascular adaptation, are absent in preeclampsia and comparable to the nonpregnant population. However, arterial biomechanics in preeclampsia may only not cope with hemodynamic demands of pregnancy but also impose additional detrimental loads to the maternal heart ("impaired left-ventricle-aorta coupling") and transmit pressure and flow disturbances into the fetoplacental circulation ("impaired large arteries-microcirculation coupling"). In this review, we analyze the major role of the arterial dysfunction in the cardiovascular maladaptation hypothesis of preeclampsia, shed light on its potential etiopathogenic link, and discuss the complementary nature of the placental and cardiovascular theories.

Low-dose acetylsalicylic acid does not modify maternal vascular reactivity in nulliparas

OBJECTIVE

To assess if the low-dose acetylsalicylic acid (ASA) would be capable of modifying endothelial function throughout pregnancy in nulliparous patients.

METHODS

A double-blind, randomized clinical trial with 277 were included. A total of 139 were orally administered 100 mg/day of ASA, and 138 received placebo. Endothelial function was assessed by flow-mediated dilation (FMD) in the brachial artery before the start of medication (11-14 weeks) and 20-24 and 30-34 weeks of gestation. The intervention was maintained until 34 weeks. The Mann-Whitney U test was used to compare the placebo and ASA groups. The comparison of FMD during pregnancy was performed using the Friedman test.

RESULTS

The groups (ASA and placebo) were similar regarding to age, weight, height, and body mass index (BMI) (p > .005). The comparison of values of FMD (%) between placebo vs. ASA at 11 and 14 weeks (8.9 vs. 9.7%, p: .253), 20 and 24 weeks (8.8 vs. 10.7%, p: .152), and 30 and 34 weeks (10.7 vs. 9.8%, p: .314) did not show significant changes throughout pregnancy. We observed a significant prevalence of PE in the placebo regarding to ASA group [14 (10.2%) vs. 8 (5.8%), p: .171].

CONCLUSION

Acetylsalicylic acid did not modify the endothelial function assessed by FMD of the brachial artery during pregnancy in nulliparous women.

Cardiac output and peripheral vascular resistance during normotensive and hypertensive pregnancy - a systematic review and meta-analysis

BACKGROUND

In-depth insight into haemodynamic changes during normotensive pregnancy may help identify women at risk for gestational hypertensive complications.

OBJECTIVES

To determine the magnitude of changes in cardiac output and its determinants stroke volume and heart rate, and total peripheral vascular resistance during singleton normotensive and hypertensive pregnancies.

SEARCH STRATEGY

PubMed (NCBI) and Embase (Ovid) databases were searched from their inception up to November 2019.

SELECTION CRITERIA

Studies reporting original measurements of haemodynamic parameters during pregnancy together with a non-pregnant reference measurement. Studies including women using antihypertensive medication were excluded.

DATA COLLECTION AND ANALYSIS

Pooled mean differences between pregnant and non-pregnant women, and absolute values of haemodynamic parameters were calculated for predefined gestational intervals using a random-effects model in normotensive and hypertensive pregnancy. Meta-regression analysis was used to analyse group differences in adjustments and absolute values during pregnancy.

MAIN RESULTS

In normotensive pregnancies, cardiac output increased from the first weeks on, reaching its highest level early in the third trimester (mean difference, 1.41 l·min¹ ; 95% CI 1.18-1.63 l·min^-1 ). In parallel, vascular resistance decreased progressively until its nadir in the early third trimester (mean difference, -331 dyn·sec^-1 ·cm^-5 ; 95% CI -384 to -277 dyn·sec^-1 ·cm^-5 ) and then increased slightly at term. In hypertensive pregnancies, the initial cardiac output increase was higher and vascular resistance did not change throughout gestation compared with reference values.

CONCLUSIONS

Hemodynamic changes in women who eventually develop hypertensive complications are substantially different. Serial monitoring and plotting against developed normograms can identify women at risk and may allow timely intervention.

TWEETABLE ABSTRACT

Monitoring haemodynamic changes in pregnancy helps identify women at risk for hypertensive complications.

Effects of nifedipine on endothelial function, assessed by flow-mediated vasodilatation in pregnant patients

OBJECTIVES

To evaluate the endothelial function, through flow-mediated vasodilation parameters from brachial artery test in women receiving nifedipine for acute tocolysis with threatened preterm delivery.

METHODS

In a prospective study in a university-affiliated hospital, each participant served as herself control. We evaluated various parameters of endothelial function in 22 patients between 27 and 33 weeks of gestation with a diagnosis of threatened preterm delivery (TPTD) before and after 48 h of nifedipine treatment. Each patient received 80 mg nifedipine per day. The assessment tool was Brachial artery reactivity test (BART). Primary outcome was flow mediated vasodilation (FMD).

RESULTS

The average participant's age was 27 ± 4.5 years, median gestational age of 28.5 weeks, BMI, kg/m² (mean ± SD) 28.4 ± 3.3. Systolic blood pressure (mmHg) and diastolic blood pressure (mmHg) decreased from 108 ± 6 to 104 ± 5, p < .001 and from 66 ± 4 to 63 ± 4, p < .001, respectively. FMD (%) significantly decrease from 10.8 ± 6.1 to 7.2 ± 4.7, p = .03 prior to and after nifedipine treatment. The basal brachial artery diameter (mm) at rest was (3.19 ± 0.38 versus 3.39 ± 0.49, p = .28) before versus after nifedipine. The largest brachial artery diameter (mm) was (3.54 ± 0.35 versus 3.58 ± 0.44, p = .76) before versus after nifedipine.

CONCLUSIONS

Our results suggest unfavorable changes in FMD probably as a result of nifedipine used for acute tocolysis. Future prospective studies should try to evaluate the safety of acute and maintenance tocolytic therapy with nifedipine on endothelial function in pregnant women.

Female Sex Hormone Effects on the Vasculature: Considering the Validity of Restricting Study Inclusion to Low-Hormone Phases

Many studies of vascular function limit the testing of premenopausal female participants to periods when female sex hormones, either endogenous or exogenous, are at their lowest concentration. This practice, when not part of the specific research question, may limit data surrounding the predominant physiological state of premenopausal females and pose a threat to external validity. In this Perspective, we briefly review the literature on the effect of female sex hormones on vascular function and discuss when limiting experimental testing to a certain phase of the menstrual cycle (MC) or oral contraceptive (OC) use may be appropriate. The goal of this Perspective is to open a dialog that may enhance data validity and the overall understanding of vascular function in premenopausal females.

Spiral artery blood flow during pregnancy: a systematic review and meta-analysis

Background

Downstream remodeling of the spiral arteries (SpA) decreases utero-placental resistance drastically, allowing sustained and increased blood flow to the placenta under all circumstances. We systematically evaluated available reports to visualize adaptation of spiral arteries throughout pregnancy by ultra-sonographic measurements and evaluated when this process is completed.

Methods

A systematic review and meta-analysis of spiral artery flow (pulsatility index (PI), resistance index (RI) and peak systolic velocity (PSV)) was performed. English written articles were obtained from Pubmed, EMBASE and Cochrane Library and included articles were assessed on quality and risk of bias. Weighted means of Doppler indices were calculated using a random-effects model.

Results

In healthy pregnancies, PI and RI decreased from 0.80 (95% CI: 0.70–0.89) and 0.50 (95% CI: 0.47–0.54) in the first trimester to 0.50 (95% CI: 0.45–0.55, p < 0.001) and 0.39 (95% CI: 0.37–0.42, p < 0.001) in the second trimester and to 0.49 (95% CI: 0.44–0.53, p = 0.752) and 0.36 (95% CI: 0.35–0.38, p = 0.037) in the third trimester, respectively. In parallel, PSV altered from 0.22 m/s (95% CI: 0.13–0.30 m/s) to 0.28 m/s (95% CI: 0.17–0.40 m/s, p = 0.377) and to 0.25 m/s (95% CI: 0.20–0.30 m/s, p = 0.560) in the three trimesters. In absence of second and third trimester Doppler data in complicated gestation, only a difference in PI was observed between complicated and healthy pregnancies during the first trimester (1.49 vs 0.80, p < 0.001). Although individual studies have identified differences in PI between SpA located in the central part of the placental bed versus those located at its periphery, this meta-analysis could not confirm this (p = 0.349).

Conclusions

This review and meta-analysis concludes that an observed decrease of SpA PI and RI from the first towards the second trimester parallels the physiological trophoblast invasion converting SpA during early gestation, a process completed in the midst of the second trimester. Higher PI was found in SpA of complicated pregnancies compared to healthy pregnancies, possibly reflecting suboptimal utero-placental circulation. Longitudinal studies examining comprehensively the predictive value of spiral artery Doppler for complicated pregnancies are yet to be carried out.

Hemodynamic Complications in Pregnancy: Preeclampsia and Beyond

Normal pregnancy is a complex and dynamic process that requires significant adaptation from the maternal system. Failure of this adaptive process in pregnancy contributes to many pregnancy related disorders, including the hypertensive disorders of pregnancy. This article discusses placental development and how abnormalities in the process of vascular remodeling contribute to the multisystem maternal and fetal disease that is preeclampsia and fetal growth restriction. We review some of the consequences of this condition on the mother and fetus, aspects of the clinical management of preeclampsia and how it can influence both mother and infant in the postnatal period and beyond.

Evaluation of Vascular Reactivity of Maternal Vascular Adaptations of Pregnancy With Quantitative MRI: Pilot Study

BACKGROUND

Abnormal maternal vascular function during pregnancy stemming from systemic endothelial dysfunction (EDF) has a central role in the pathophysiology of preeclampsia (PE).

PURPOSE

To utilize quantitative MRI to investigate changes in physiological measures of vascular reactivity during normal pregnancy, and to explore EDF associated with preeclampsia.

STUDY TYPE

Prospective.

POPULATION

Healthy pregnant (HP) (n = 14, mean GA = 26 ± 7 weeks) and nonpregnant women (NP; n = 14); newly postpartum (PP <48 hours) women with severe PE (PP-PE; n = 4) and normotensive pregnancy (PP-HP; n = 5).

FIELD STRENGTH/SEQUENCE

1.5T/3T. RF spoiled multiecho gradient-recalled echo, 1D phase-contrast MRI, time-of-flight.

ASSESSMENT

The micro- and macrovascular function (vasodilatory capacity of arterioles and conduit arteries, respectively) of the femoral vascular bed was evaluated with MRI-based venous oximetry, arterial velocimetry, and luminal flow-mediated dilation quantification, during cuff-induced reactive hyperemia. Aortic arch pulse-wave velocity (aPWV) was quantified to assess arterial stiffness using an ungated 1D technique.

STATISTICAL TESTS

Two-tailed unpaired t-tests were performed to address our two, primary a priori comparisons, HP vs. NP, and PP-PE vs. PP-HP. Given the pilot nature of this study, adjustments for multiple comparisons were not performed.

RESULTS

In HP, microvascular function was attenuated compared to NP by a significant increase in the washout time (10 ± 2 vs. 8 ± 2 sec; P < 0.05) and reduced upslope (2.1 ± 0.5 vs. 3.2 ± 0.8%HbO₂ /s; P < 0.05), time of forward flow (28 ± 5 vs. 33 ± 6 sec, P < 0.05), and hyperemic index (11 ± 3 vs. 16 ± 4 cm/s² ; P < 0.05), but luminal flow-mediated dilatation (FMD_L )was comparable between HP and NP. PP-PE exhibited significant vascular dysfunction compared to PP-HP, as evidenced by differences in upslope (2.2 ± 0.6 vs. 1.3 ± 0.2%HbO₂ /s, P < 0.05), overshoot (16 ± 5 vs. 7 ± 3%HbO₂ , P < 0.05), time of forward flow (28 ± 6 vs. 15 ± 7 s, P < 0.05), and aPWV (7 ± 1 vs. 8 ± 1 m/s, P < 0.05).

DATA CONCLUSION

Attenuated vascular reactivity during pregnancy suggests that the systemic vasodilatory state partially depletes nitric oxide bioavailability. Preliminary data support the potential for MRI to identify vascular dysfunction in vivo that underlies PE. Level of Evidence 2 Technical Efficacy Stage 1 J. MAGN. RESON. IMAGING 2021;53:447-455.

Arterial Function in Healthy Pregnant Women vs. Non-Pregnant Women-A 10-Year Study

INTRODUCTION

Maternal age for the first pregnancy is increasing and so, the prevalence of cardiovascular risk factors in pregnancy is also increasing. Heart disease is the main reason for maternal death during pregnancy in developed countries. Arterial stiffness is an independent risk factor for atherosclerosis and a predictor of cardiovascular morbidity and mortality. The most widespread parameters for detecting subclinical atherosclerosis are augmentation index (AIx) and pulse wave velocity (PWV). The objective of this prospective study was to assess the differences between arterial function in pregnant vs. non-pregnant women of the same age, and its changes throughout the gestation period.

MATERIALS AND METHODS

Between 2010-2019, 887 patients were enrolled into 2 groups: pregnant (N1 = 471) and non-pregnant (N2 = 416). Data about their anthropometric characteristics, arterial function (for group 1 in all three trimesters and 6 weeks post-partum), smoking status and physical activity were collected.

RESULTS

There were statistically significant differences (p < α, α = 0.05) between the two groups regarding the body mass index, brachial AIx, systolic, diastolic and central blood pressure, and pulse pressure values. In the first group, there was a decrease of both brachial AIx and PWV in the second and third trimester, followed by a post-partum increase; better outcomes were noticed in physically active women.

CONCLUSIONS

Arterial function modifies during pregnancy and these alterations differ according to the trimester of gestation. Further research is needed to establish the cut-off values for this category. Pregnant women can have better outcomes through physical activity.

Suboptimal health pregnant women are associated with increased oxidative stress and unbalanced pro- and antiangiogenic growth mediators: a cross-sectional study in a Ghanaian population

Optimal oxidative stress (OS) is important throughout pregnancy; however, an increased OS may alter placental angiogenesis culminating in an imbalanced of angiogenic growth mediators (AGMs). Suboptimal Health Status (SHS), a physical state between health and disease, may be associated with increased OS and unbalanced AGMs. In this study, we explored the association between SHS, biomarkers of OS (BOS) and AGMs among normotensive pregnant women (NTN-PW) in a Ghanaian Suboptimal Health Cohort Study (GHOACS). This comparative GHOACS recruited 593 NTN-PW from the Komfo Anokye Teaching Hospital, Ghana. SHS was measured using a Suboptimal Health Status Questionnaire-25 (SHSQ-25). Along with the subjective SHS measure, objective BOS: 8-hydroxy-2-deoxyguanosine (8-OHdG), 8-epiprostaglandinF2 alpha (8-epi-PGF2α), total antioxidant capacity (TAC), and AGMs: vascular endothelial growth factor-A (VEGF-A), soluble fms-like tyrosine kinase receptor 1 (sFlt-1), placental growth factor (PIGF) and soluble endoglin (sEng) were evaluated. Compared to optimal health NTN-PW, levels of PlGF, VEGF-A and TAC were significantly (p < 0.05) reduced and negatively associated with SHS whilst sEng, sFlt-1, 8-epiPGF2α, 8-OHdG, and combined ratios of sFlt-1/PlGF, 8-epiPGF2α/PlGF, 8-OHdG/PlGF, and sEng/PlGF were significantly increased and positively associated with SHS. The first quartile for PIGF (2.79-fold) and VEGF-A (5.35-fold), and the fourth quartile for sEng (4.31-fold), sFlt-1 (1.84-fold), 8-epiPGF2α (2.23-fold), 8-OHdG (1.90-fold) and urinary 8-OHdG (1.95-fold) were independently associated with SHS (p < 0.05). SHS is associated with increased OS and unbalanced AGMs. Early identification of SHS-related OS and unbalanced AGMs may inform clinicians of the need for therapeutic options.

Progesterone Predisposes Females to Obesity-Associated Leptin-Mediated Endothelial Dysfunction via Upregulating Endothelial MR (Mineralocorticoid Receptor) Expression

Compelling clinical evidence indicates that obesity and its associated metabolic abnormalities supersede the protective effects of female sex-hormones and predisposes premenopausal women to cardiovascular disease. The underlying mechanisms remain poorly defined; however, recent studies have implicated overactivation of the aldosterone-MR (mineralocorticoid receptor) axis as a cause of sex-specific cardiovascular risk in obese females. Experimental evidence indicates that the MR on endothelial cells contributes to obesity-associated, leptin-induced endothelial dysfunction in female experimental models, however, the vascular-specific mechanisms via which females are predisposed to heightened endothelial MR activation remain unknown. Therefore, we hypothesized that endogenous expression of endothelial MR is higher in females than males, which predisposes them to obesity-associated, leptin-mediated endothelial dysfunction. We found that endothelial MR expression is higher in blood vessels from female mice and humans compared with those of males, and further, that PrR (progesterone receptor) activation in endothelial cells is the driving mechanism for sex-dependent increases in endothelial MR expression in females. In addition, we show that genetic deletion of either the endothelial MR or PrR in female mice prevents leptin-induced endothelial dysfunction, providing direct evidence that interaction between the PrR and MR mediates obesity-associated endothelial impairment in females. Collectively, these novel findings suggest that progesterone drives sex-differences in endothelial MR expression and predisposes female mice to leptin-induced endothelial dysfunction, which indicates that MR antagonists may be a promising sex-specific therapy to reduce the risk of cardiovascular diseases in obese premenopausal women.

Intake of antioxidants nutrients by pregnant womem: Associated factors

ABSTRACT Objective To evaluate the intake of antioxidant nutrients by pregnant women being cared for in the Brazilian public health system and associated factors. Methods A cross-sectional study was carried out with pregnant women cared for in the public health system in the city of Maceió, Brazil, in 2014, including 385 pregnant women and their newborns, and the collection of maternal information (socioeconomic, personal, prenatal, dietary and anthropometric data), and after the babies’ birth (gestational age, birth weight and length). Food intake was assessed by two 24-hour dietary reminders per pregnant woman with subsequent adjustments by the Estimated Average Requirement method. Data were processed and Pearson’s correlation was used to evaluate associations, considering p<0.05 as significant. Results A total of 388 pregnant women with a mean age of 24.06±5.92 years were studied, with inadequate intake and high variation of the following antioxidants: vitamin A (83.2%/62.7%), vitamin C (50.5%/75.7%), vitamin E (76.5%/60.2%), Selenium (60.8%/50.3%), Copper (98.5%/42.8%) and Zinc (79.6%/43.4%), respectively. Additionally, the following associations were observed: the intake of vitamin A (p=0.02), Copper (p=0.01), and Selenium (p=0.01) with the maternal Body Mass Index; the intake of vitamin A (0.04) and Selenium (p=0.02) with the birth weight; and between vitamin A (p=0.04) with the birth length. Conclusion The low intake of antioxidant nutrients by pregnant women is a reality, being associated to the maternal Body Mass Index and the birth weight and length of the newborn.

Mechanisms and Clinical Significance of Endothelial Dysfunction in High-Risk Pregnancies

The maternal cardiovascular system undergoes critical anatomic and functional adaptations to achieve a successful pregnancy outcome which, if disrupted, can result in complications that significantly affect maternal and fetal health. Complications that involve the maternal cardiovascular system are among the most common disorders of pregnancy, including gestational hypertension, preeclampsia, gestational diabetes, and impaired fetal growth. As a central feature, maternal endothelial dysfunction is hypothesized to play a predominant role in mediating the pathogenesis of these high-risk pregnancies, and as such, might proceed and precipitate the clinical presentation of these pregnancy disorders. Improving or normalizing maternal endothelial function in high-risk pregnancies might be an effective therapeutic strategy to ameliorate maternal and fetal clinical outcomes.