Arterial stiffness throughout pregnancy: Arteriograph device-specific reference ranges based on a low-risk population

Do maternal haemodynamics have a causal influence on treatment for gestational diabetes?

BACKGROUND

Arterial stiffening is believed to contribute to the worsening of insulin resistance, and factors which are associated with needing pharmacological treatment of gestational diabetes (GDM), such as maternal obesity or advanced age, are associated with impaired cardiovascular adaptation to pregnancy. In this observational study, we aimed to investigate causal relationships between maternal haemodynamics and treatment requirement amongst women with GDM.

METHODS

We assessed maternal haemodynamics in women with GDM, comparing those who remained on dietary treatment with those who required pharmacological management. Maternal haemodynamics were assessed using the Arteriograph® (TensioMed Ltd, Budapest, Hungary) and the NICOM® non-invasive bio-reactance method (Cheetah Medical, Portland, Oregon, USA). A graphical causal inference technique was used for statistical analysis.

RESULTS

120 women with GDM were included in the analysis. Maternal booking BMI was identified as having a causative influence on treatment requirement, with each unit increase in BMI increasing the odds of needing metformin and/or insulin therapy by 12% [OR 1.12 (1.02 - 1.22)]. The raw values of maternal heart rate (87.6 ± 11.7 vs. 92.9 ± 11.90 bpm, p = 0.014) and PWV (7.8 ± 1.04 vs. 8.4 ± 1.61 m/s, p = 0.029) were both significantly higher amongst the women requiring pharmacological management, though these relationships did not remain significant in causal logistic regression.

CONCLUSIONS

Maternal BMI at booking has a causal, rather than simply associational, relationship on the need for pharmacological treatment of GDM. No significant causal relationships were found between maternal haemodynamics and the need for pharmacological treatment.

The Impact of COVID-19 during Pregnancy on Maternal Hemodynamic Function, Angiogenic Markers and Neonatal Outcome

Infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) in pregnancy are associated with the development of preeclampsia and fetal growth restriction (FGR). Recently, preeclampsia was linked to impaired maternal hemodynamic function. This retrospective study evaluated singleton pregnancies with COVID-19 during pregnancy and healthy pregnant controls matched for gestational age from November 2020 to March 2022. Non-invasive assessment of maternal hemodynamics by continuous wave Doppler ultrasound measurements (USCOM-1A® Monitor) and oscillometric arterial stiffness (Arteriograph) was performed. Overall, 69 pregnant women were included-23 women after COVID-19 during pregnancy and 46 healthy controls. While two women (8.7%) were admitted to the hospital due to COVID-19-related symptoms, none required intensive care unit admission or non-invasive/invasive ventilation. There were no statistically significant differences in the majority of hemodynamic parameters between the two cohorts. The prevalence of FGR was significantly higher in the COVID-19 during pregnancy group (9.5% vs. healthy controls: 0.0%; p = 0.036), especially in nulliparous women. No difference in angiogenic markers and neonatal outcomes were observed between pregnant women after COVID-19 and healthy controls. In conclusion, no significant differences in hemodynamic parameters or neonatal outcome were observed in women with COVID-19 during pregnancy. However, an increased prevalence of FGR could be described.

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.

Alterations in Vessel Hemodynamics Across Uncomplicated Pregnancy

Pregnancy is marked by the onset of rapid hemodynamic alterations in order to accommodate the needs of the developing fetus. Arterial stiffness is an independent predictor of cardiovascular events and mortality, and its measurement in clinical practice has been recommended. It follows a U-shaped curve in uncomplicated pregnancy, decreasing to a nadir in mid-pregnancy and rising at term. Systemic vasodilation occurs due to elevated nitric oxide, prostacyclin, endothelium-derived hyperpolarizing factor, estrogen, progesterone, and relaxin. Vascular resistance decreases to a nadir in mid-pregnancy, while endothelial function is enhanced starting in the first trimester. Plasma volume increases by about 50%, and total red blood cell mass increases by up to 40%. Cardiac output increases by up to 45%, at first due primarily to elevated stroke volume, then mainly due to increased heart rate. Along with echocardiography, cardiac magnetic resonance imaging is safe for use in pregnancy. It may assess cardiac function more accurately than echocardiography, and may be indicated in specific clinical cases. Moreover, blood pressure decreases to a nadir in mid-pregnancy and rises to near preconception values postpartum. An appreciation of the vascular changes occurring in healthy pregnancy can aid in the prediction and diagnosis of pregnancy complications, such as preeclampsia and other hypertensive disorders of pregnancy, and inform treatment. In particular, noninvasive arterial stiffness/hemodynamics assessment provides unique clinical information beyond blood pressure and traditional maternal characteristics, and can signal a need for further testing, or be used in combination with other tests to predict or diagnose complications of pregnancy.

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.