Maternal arterial stiffness and fetal cardiovascular physiology in diabetic pregnancy

Arterial stiffness in gestational diabetes: Latest insights

Increased arterial stiffness is a known cardiovascular risk factor, associated with hypertension and acute coronary events. Gestational diabetes (GDM) is associated with the development of placental-mediated disorders and future cardiovascular morbidity, raising the possibility of an association with increased arterial stiffness (AS). Several studies have now investigated this association through the assessment of pulse wave velocity and augmentation index. In the current review, we present the latest evidence regarding the changes in arterial stiffness in pregnancies complicated by GDM, before the onset of clinical disease, during its course, and after its resolution. We also review the evidence that AS could influence the need for different treatments for GDM, and the impact that the treatments, and in particular, metformin, could have on arterial stiffness.

Maternal Hemodynamics from Preconception to Delivery: Research and Potential Diagnostic and Therapeutic Implications: Position Statement by Italian Association of Preeclampsia and Italian Society of Perinatal Medicine

OBJECTIVE

 The Italian Association of Preeclampsia (AIPE) and the Italian Society of Perinatal Medicine (SIMP) developed clinical questions on maternal hemodynamics state of the art.

STUDY DESIGN

 AIPE and SIMP experts were divided in small groups and were invited to propose an overview of the existing literature on specific topics related to the clinical questions proposed, developing, wherever possible, clinical and/or research recommendations based on available evidence, expert opinion, and clinical importance. Draft recommendations with a clinical rationale were submitted to 8th AIPE and SIMP Consensus Expert Panel for consideration and approval, with at least 75% agreement required for individual recommendations to be included in the final version.

RESULTS

 More and more evidence in literature underlines the relationship between maternal and fetal hemodynamics, as well as the relationship between maternal cardiovascular profile and fetal-maternal adverse outcomes such as fetal growth restriction and hypertensive disorders of pregnancy. Experts agreed on proposing a classification of pregnancy hypertension, complications, and cardiovascular states based on three different hemodynamic profiles depending on total peripheral vascular resistance values: hypodynamic (>1,300 dynes·s·cm-5), normo-dynamic, and hyperdynamic (<800 dynes·s·cm-5) circulation. This differentiation implies different therapeutical strategies, based drugs' characteristics, and maternal cardiovascular profile. Finally, the cardiovascular characteristics of the women may be useful for a rational approach to an appropriate follow-up, due to the increased cardiovascular risk later in life.

CONCLUSION

 Although the evidence might not be conclusive, given the lack of large randomized trials, maternal hemodynamics might have great importance in helping clinicians in understanding the pathophysiology and chose a rational treatment of patients with or at risk for pregnancy complications.

KEY POINTS

· Altered maternal hemodynamics is associated to fetal growth restriction.. · Altered maternal hemodynamics is associated to complicated hypertensive disorders of pregnancy.. · Maternal hemodynamics might help choosing a rational treatment during hypertensive disorders..

Reference-range of arterial stiffness by cardio-ankle vascular index in normal pregnancy

OBJECTIVE

To establish the arterial stiffness, represented by the cardio-ankle vascular index (CAVI) at various gestational ages among low-risk pregnant women. The second objective is to construct the reference range of mean arterial pressure and maternal heart rate during pregnancy.

METHODS

This cross-sectional study was conducted on low risk pregnant Thai women, meeting the following inclusion criteria: 1) singleton pregnant women aged 18 years old or over; 2) gestational age between 11 and 40 weeks; 3) low-risk pregnancy without any underlying medical diseases; and 4) known final pregnancy outcomes. Pregnancy-induced hypertension, gestational diabetes and fetal growth restriction were excluded. The mean CAVI, mean arterial pressure (MAP), and heart rate were measured at each gestational age.

RESULTS

A total of 329 measurements for each parameter were available for analysis. CAVI was significantly correlated with gestational age with the best fitted model: CAVI = 6.952 - 0.076(GA) + 0.001(GA)2; SD = 0.742 (R2 = 0.049; p-value < 0.001). The maternal age and pre-pregnancy BMI were correlated with CAVI. CAVI gradually increased with maternal age and decreased with increasing body mass index (BMI). The MAP and heart rate of normal pregnancy in each gestation were conducted.

CONCLUSION

The reference range of CAVI in normal pregnancies as a function of gestational age and the model for predicting CAVI based on multiple regression analysis are constructed and presented. These reference ranges may be useful in predicting risk of cardiovascular disorders during pregnancy.

Doppler Indices of the Uterine, Umbilical and Fetal Middle Cerebral Artery in Diabetic versus Non-Diabetic Pregnancy: Systematic Review and Meta-Analysis

Background and Objectives: The aim of this study was to assess the differences in Doppler indices of the uterine (Ut), umbilical (UA), and middle cerebral artery (MCA) in diabetic versus non-diabetic pregnancies by conducting a comprehensive systematic review of the literature with a meta-analysis. Materials and Methods: PubMed, Web of Science, and SCOPUS were searched for studies that measured the pulsatility index (PI), resistance index (RI), and systolic/diastolic ratio index (S/D ratio) of the umbilical artery, middle cerebral artery, and uterine artery in diabetic versus non-diabetic pregnancies. Two reviewers independently evaluated the eligibility of studies, abstracted data, and performed quality assessments according to standardized protocols. The standardized mean difference (SMD) was used as a measure of effect size. Heterogeneity was assessed using the I2 statistic. Publication bias was evaluated by means of funnel plots. Results: A total of 62 publications were included in the qualitative and 43 in quantitative analysis. The UA-RI, UtA-PI, and UtA-S/D ratios were increased in diabetic compared with non-diabetic pregnancies. Subgroup analysis showed that levels of UtA-PI were significantly higher during the third, but not during the first trimester of pregnancy in diabetic versus non-diabetic pregnancies. No differences were found for the UA-PI, UA-S/D ratio, MCA-PI, MCA-RI, MCA-S/D ratio, or UtA-RI between diabetic and non-diabetic pregnancies. Conclusions: This meta-analysis revealed the presence of hemodynamic changes in uterine and umbilical arteries, but not in the middle cerebral artery in pregnancies complicated by diabetes.

Comparison of Central Aortic Pressure between Women with Preeclampsia and Normotensive Postpartum Women from an Urban Region of Western Mexico

Background and Objectives: Central aortic pressure (CAP) can be measured through noninvasive methods, and CAP wave analysis can provide information about arterial stiffness. The objective of this study was to compare CAP in women with preeclampsia and normotensive postpartum women from an urban region in western Mexico. Materials and Methods: We recruited 78 women in immediate puerperium, including 39 with preeclampsia and 39 with normotension, who received delivery care in our hospital between September 2017 and January 2018. Pulse wave analysis was used to assess central hemodynamics as well as arterial stiffness with an oscillometric device. For this purpose, the measurement of the wave of the left radial artery was obtained with a wrist applanation tonometer and the ascending aortic pressure wave was generated using the accompanying software (V 1.1, Omron, Japan). Additionally, the systolic CAP, diastolic pressure, pulse pressure, heart rate, and rise rate adjusted for a heart rate of 75 bpm were determined. The radial pulse wave was calibrated using the diastolic and mean arterial pressures obtained from the left brachial artery. For all the statistical analyses, we considered p < 0.05 to be significant. Results: The results were as follows: a systolic CAP of 125.40 (SD 15.46) vs. 112.10 (SD 10.12) with p < 0.0001 for women with and without preeclampsia, respectively. Systolic CAP was significantly elevated in women with preeclampsia and could indicate an elevated risk of cardiovascular disease. Conclusion: CAP is an important parameter that can be measured in this group of patients and is significantly elevated in women with postpartum preeclampsia, even when the brachial blood pressure is normal.

Third Trimester Myocardial Performance Index in Fetuses from Women with Hyperglycemia in Pregnancy: A Systematic Review and Meta-Analysis

INTRODUCTION

 The myocardial performance index (MPI) has been proposed to evaluate cardiac dysfunction in newborns from diabetic mothers. Although MPI is routinely assessed in newborns, its role in the evaluation of fetuses from women with hyperglycemia in pregnancy (HIP) is still under evaluation. We aimed to evaluate the differences in third trimester fetal MPI in pregnant women with hyperglycemia compared to healthy controls.

MATERIALS AND METHODS

 Seven electronic databases were searched for all studies assessing women with HIP who underwent evaluation of fetal left MPI during pregnancy compared to a control group. The summary measures were reported as mean differences (MD) in the mean fetal left MPI between women with HIP and healthy controls, with a 95 % confidence interval (CI). A post hoc subgroup analysis based on the type of HIP - pregestational diabetes, GDM, or gestational impaired glucose tolerance (GIGT) - was performed as an additional analysis.

RESULTS

 14 studies assessing 1326 fetuses (580 from women with HIP and 746 from controls) were included. Women with HIP had a significantly higher mean left fetal MPI compared to controls (MD 0.08; 95 %CI: 0.05 to 0.11; p < 0.00 001). Subgroup analysis according to the type of HIP concurred with the overall analysis for women with DM (MD 0.07; 95 %CI: 0.01 to 0.13; p = 0.02) and for women with GDM (MD 0.012; 95 %CI: 0.07 to 0.17; p < 0.00 001) but not for women with GIGT (MD -0.01, 95 % CI -0.28 to 0.27; p = 0.96).

CONCLUSION

 Fetal left MPI is increased in pregnancies with HIP appearing as a potential marker of cardiac dysfunction.

The Impact of Maternal Preeclampsia and Hyperglycemia on the Cardiovascular Health of the Offspring: A Systematic Review and Meta-analysis

OBJECTIVES

The objective of this review was to assess the impact of maternal preeclampsia or hyperglycemia on the body composition and cardiovascular health in the offspring.

STUDY DESIGN

We conducted a systematic review utilizing PubMed, EBSCO, CINAHLPlus, Cochrane Library, and Web of Science to include all studies assessing the impact of preeclampsia/eclampsia and/or gestational/pregestational diabetes mellitus on the health of the offspring (children <10 years of age). The health measures included anthropometry, cardiac dimensions and function, and vascular function. We performed a meta-analysis using Review Manager software and computed net risk ratio (RR) with 95% confidence interval (CI) for dichotomous data and mean difference (MD) with 95% CI for continuous data.

RESULTS

There were 6,376 studies in total, of which 45 were included in the review and 40 in the meta-analysis. The results demonstrated higher birth weight (MD: 0.12 kg; 95% CI: 0.06-0.18) and systolic and diastolic blood pressure (BP; MD: 5.98 mm Hg; 95% CI: 5.64-6.32 and MD: 3.27 mm Hg; 95% CI: 0.65-5.89, respectively) in the offspring of mothers with gestational diabetes compared to controls. In contrast, the offspring of mothers with preeclampsia had lower birth weight (MD: -0.41 kg; 95% CI: -0.7 to -0.11); however, they had increased systolic (MD: 2.2 mm Hg; 95% CI: 1.28-3.12) and diastolic BP (MD: 1.41 mm Hg; 95% CI: 0.3-2.52) compared to controls. There is lack of data to conduct a meta-analysis of cardiac morphology, functional, and vascular imaging parameters.

CONCLUSION

These findings suggest that the in-utero milieu can have a permanent impact on the body composition and vascular health of the offspring. Future work warrants multicenter prospective studies to understand the mechanism and the actual effect of exposure to maternal hyperglycemia and high BP on the cardiovascular health of the offspring and long-term outcomes.

KEY POINTS

· Adverse in-utero exposures may have an impact on cardiovascular risk in children.. · Maternal hyperglycemia/preeclampsia lead to changes in birthweight and BP.. · Limited echocardiographic and vascular imaging data in these cohorts necessitates future work..

Pregestational Diabetes and Congenital Heart Defects

Studies have consistently shown a significant increase in the risk of congenital heart defects in the offspring of diabetic mothers compared with those of nondiabetic pregnancies. Evidence points that all types of pregestational diabetes have the capacity of generating cardiac malformations in a more accentuated manner than in gestational diabetes, and there seems to be an increased risk for all congenital heart defects phenotypes in the presence of maternal diabetes. Currently, the application of some therapies is under study in an attempt to reduce the risks inherent to diabetic pregnancies; however, it has not yet been possible to fully prove their effectiveness. The present review aims to better understand the mechanisms that govern the association between pregestational diabetes and congenital heart defects and how maternal diabetes interferes with fetal cardiac development, as there is still a long way to go in the investigation of this complex process.

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.

Maternal hemodynamic changes in gestational diabetes: a prospective case-control study

PURPOSE

The aim of the study is to compare maternal hemodynamic adaptations in gestational diabetes (GDM) versus healthy pregnancies.

METHODS

A prospective case-control study was conducted, comparing 69 singleton pregnancies with GDM and 128 controls, recruited between September 2018 and April 2019 in Maternal-Fetal Medicine Unit, Careggi University Hospital, Florence, Italy. Hemodynamic assessment by UltraSonic Cardiac Output Monitor (USCOM) was performed in both groups in four gestational age intervals: 17-20 weeks (only in early GDM cases), 26-30 weeks, 32-35 weeks and 36-39 weeks. We evaluated six hemodynamic parameters comparing GDM cases versus controls: cardiac output (CO), cardiac index (CI), stroke volume (SV), total vascular resistance (TVR), inotropy index (INO) and potential to kinetic energy ratio (PKR).

RESULTS

GDM group had significantly lower values of CO and SV than controls from the early third trimester (26-30 weeks) until term (p < 0.001). CI is significantly lower in GDM women already at the first evaluation (p = 0.002), whereas TVR and PKR were significantly higher in GDM (p < 0.001). GDM women showed also lower INO values than controls in all assessments.

CONCLUSIONS

A hemodynamic maternal maladaptation to pregnancy can be detected in GDM women. The effect of hyperglycemia on vascular system or a poor pre-pregnancy cardiovascular (CV) reserve could explain this hemodynamic maladaptation. The abnormal CV response to pregnancy in GDM women may reveal a predisposition to develop CV disease later in life and might help in identifying patients who need a CV follow-up.

The cardio-ankle vascular index as a predictor of adverse pregnancy outcomes

OBJECTIVE

To assess the association between maternal hemodynamic parameters; cardio-ankle vascular index (CAVI), representing arterial stiffness; mean arterial pressure (MAP), uterine artery pulsatility index (Ut-PI), and adverse pregnancy outcomes including preeclampsia (PE), fetal growth restriction (FGR), and gestational diabetes mellitus (GDM).

METHODS

A prospective cohort study was conducted on low-risk pregnancies. All were serially measured for the mean CAVI, MAP, and Ut-PI for four times at gestational age (GA) 11-14, 18-22, 28-32, and after 36 weeks. Also, the women were followed up for pregnancy outcomes, focusing on PE, FGR, and GDM.

RESULTS

Of 335 recruited cases meeting the inclusion criteria, 16 cases developed PE, 24 cases had FGR, and 83 cases had GDM. Compared to the non-PE group, women developing PE had a significant increase in CAVI at 18-22, 28-32, and after 36 weeks (P-value = 0.021, 0.003, and <0.001, respectively), a significant increase in MAP at all of the four periods (P-value < 0.001, for all periods), and a significant increase in Ut-PI during GA 18-22 weeks (P-value = 0.021). In pregnancies with FGR, there was a significant increase of CAVI at GA 18-22, 28-32 and after 36 weeks (P-value = 0.012, 0.015, and 0.004, respectively), an increase in Ut-PI in all gestational periods (P-value < 0.05) but no changes of MAP throughout pregnancy. In GDM, the three parameters were not significantly different from those in the non-GDM group in all of the four periods. CAVI could predict PE and FGR with AUC of 0.655-0.835 and 0.673-0.760, respectively. CAVI added predictive values when combined with MAP or Ut-PI.

CONCLUSION

Increased CAVI, like MAP and Ut-PI, can be used as a predictor of PE and FGR but not GDM. Also, it has an added predictive value when combined with MAP or Ut-PI.

Persistent Aortic Stiffness and Left Ventricular Hypertrophy in Children of Diabetic Mothers

Background

Fetuses of diabetic mothers develop left ventricular (LV) hypertrophy and are at increased long-term risk of cardiovascular disease. In our previous longitudinal study from midgestation to late infancy we showed persistence of LV hypertrophy and increased aortic stiffness compared with infants of healthy mothers, the latter of which correlated with third trimester maternal hemoglobin A1c. In the present study, we reexamined the same cohort in early childhood to determine if these cardiovascular abnormalities persisted.

Methods

Height, weight, and right arm blood pressure were recorded. A full functional and structural echocardiogram was performed with offline analysis of LV posterior wall and interventricular septal diastolic thickness (IVSd), systolic and diastolic function, and aortic pulse wave velocity. Vascular reactivity was assessed using digital thermal monitoring. Participants also completed a physical activity questionnaire.

Results

Twenty-five children of diabetic mothers (CDMs) and 20 children from healthy pregnancies (mean age, 5.6 ± 1.7 and 5.3 ± 1.3 years, respectively; P = not significant) were assessed. Compared with controls, IVSd z score was increased in CDMs (1.2 ± 0.6 vs 0.5 ± 0.3, respectively; P = 0.006), with one-fifth having a z score of more than +2.0. Aortic pulse wave velocity was increased in CDMs (3.2 ± 0.6 m/s vs 2.2 ± 0.4 m/s; P = 0.001), and correlated with IVSd z score (R² = 0.81; P = 0.001) and third trimester maternal A1c (R² = 0.65; P < 0.0001). Body surface area, height, weight, blood pressure, vascular reactivity, and physical activity scores did not differ between groups. Our longitudinal analysis showed that individuals with greater IVSd, and aortic stiffness in utero, early and late infancy also tended to have greater measures in early childhood (P < 0.001 and P < 0.0001, respectively).

Conclusions

CDMs show persistently increased interventricular septal thickness and aortic stiffness in early childhood.

Arterial function in hypertensive pregnant women. Is arterial stiffness a marker for the outcomes in pregnancy?

AIMS

Hypertension (HTN) in pregnancy is a major cause of maternal, foetal and neonatal morbimortality in both developing and developed countries. Arterial stiffness is a predictor of cardiovascular events and can be assessed through augmentation index (AIx) and pulse wave velocity (PWV). This study was intended to analyse the arterial stiffness in three categories, hypertensive pregnant women vs. healthy women (both pregnant and non-pregnant).

MAIN METHODS

Between 2018 and 2019, 150 women were prospectively included into three homogenous groups, of equal sizes (N = 50): pregnant women with HTN (group 1), pregnant women without HTN (group 2), and non-pregnant women (group 3). We assessed pregnant women 3 times (in all three trimesters) and six weeks postpartum, and the women from the control group once.

KEY FINDINGS

Significant differences (p < 0.001) of the hemodynamic and arterial stiffness parameters and of the heart rate (HR) (p = 0.006) were observed between groups 1 and 2. Women with pregnancy-induced HTN had different values of arterial function parameters long time before the first signs of high blood pressure (BP) occurred. Also, body mass index (BMI) had a deleterious effect in all patients, but especially in pregnant HTN women. Significant differences (p < 0.001) between groups 2 and 3 were observed regarding the BP and aortic PWV (PWVao) and, as well, significant differences (p < 0.05) between BMI, aortic systolic BP (p = 0.02), brachial AIx (p = 0.01) and pulse pressure (PP) (p = 0.049) values.

SIGNIFICANCE

The current study emphasizes the importance of the assessment of arterial function parameters and BMI as markers for future BP values and outcomes throughout gestation.

Cardiac maladaptation in obese pregnant women at term

OBJECTIVE

Obesity is an increasing problem worldwide, with well recognized detrimental effects on cardiovascular health; however, very little is known about the effect of obesity on cardiovascular adaptation to pregnancy. The aim of the present study was to compare biventricular cardiac function at term between obese pregnant women and pregnant women with normal body weight, utilizing conventional echocardiography and speckle-tracking assessment.

METHODS

This was a prospective case-control study of 40 obese, but otherwise healthy, pregnant women with a body mass index (BMI) of ≥ 35 kg/m² and 40 healthy pregnant women with a BMI of ≤ 30 kg/m² . All women underwent a comprehensive echocardiographic examination and speckle-tracking assessment at term.

RESULTS

Obese pregnant women, compared with controls, had significantly higher systolic blood pressure (117 vs 109 mmHg; P = 0.002), cardiac output (6.73 vs 4.90 L/min; P < 0.001), left ventricular (LV) mass index (74 vs 64 g/m² ; P < 0.001) and relative wall thickness (0.43 vs 0.37; P < 0.001). Diastolic dysfunction was present in five (12.5%) controls and 16 (40%) obese women (P = 0.004). In obese women, compared with controls, LV global longitudinal strain (-15.59 vs -17.61%; P < 0.001), LV endocardial (-17.30 vs -19.84%; P < 0.001) and epicardial (-13.10 vs -15.73%; P < 0.001) global longitudinal strain as well as LV early diastolic strain rate (1.05 vs 1.24 /s; P = 0.006) were all significantly reduced. No differences were observed in the degree of LV twist and torsion between the two groups.

CONCLUSIONS

Morbidly obese, but otherwise healthy, pregnant women at term had significant LV hypertrophy with evidence of diastolic dysfunction and impaired deformation indices compared with pregnant women of normal weight. These findings are likely to represent a maladaptive response of the heart to volume overload in obese pregnancy. The impact of theses changes on pregnancy outcome and long-term maternal outcome is unclear. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.