Maternal functional hemodynamics in uncomplicated twin pregnancies: A longitudinal study using impedance cardiography

Abstract

Introduction Longitudinal studies of maternal hemodynamics in twin pregnancy are scarce and preload reserve in twin pregnancies has not been studied. Thus, we aimed to investigate serial changes in maternal systemic hemodynamics from the first to third trimester, and cardiovascular response to passive leg raising to evaluate preload reserve using impedance cardiography in a cohort of uncomplicated twin pregnancies. Material and methods This was a prospective longitudinal study of 50 twin pregnancies. Maternal hemodynamics was assessed at baseline and 120 seconds after passive leg raising using impedance cardiography, at five time points during gestation. Women were excluded from the analysis if there were pregnancy complications or fewer than three of five planned assessments were available. Results Data from 37 uncomplicated twin pregnancies were available for analysis. Mean arterial pressure slightly decreased until 17 weeks’ gestation, then increased. Systemic vascular resistance was constant in the first half of pregnancy before rising steadily thereafter, whereas the cardiac output increased from the first trimester, peaked by the end of the second trimester and then decreased in the third trimester. The change in stroke volume and cardiac output following passive leg raising during pregnancy ranged from −2.2% to 1.6% and from −3.7% to 3.2%, respectively. Although passive leg raising caused no significant changes in systemic vascular resistance, cardiac output or heart rate, mean arterial pressure decreased in the first and second trimesters. Conclusions In uncomplicated twin pregnancies, maternal cardiovascular adaptation is evident from the first trimester. Twin pregnancies show a reduced preload reserve in the second half of gestation.

Morphofunctional cardiac changes in singleton and twin pregnancies: a longitudinal cohort study

“…Consistent with their findings, our results showed that e' was similar to that in singleton pregnancy but s', which is the contractility in the longitudinal direction, was lower than that in singleton pregnancy until PP2 [17]. Moreover, Orabona et al reported a reduction in preload reserve in twin pregnancy [18]. Considering that the circulating blood volume was higher in twin pregnancies than in singleton pregnancies [1], this result was caused by the fact that the volume load during pregnancy exceeded the physiological limit of reversible adaptation.…”

“…However, this trend was not observed in women with twin pregnancies because of the limited sample size and because catecholamine production from postoperative pain affected BNP, considering that 95% of women had undergone cesarean section [34]. We found two reports of hemodynamic comparison between monochorionic and dichorionic twin pregnancies [18,35]. Ghi et al reported that monochorionic twin pregnancies had lower cardiac output, higher systemic vascular resistance, and higher E/A than dichorionic twin pregnancies [35], but our study found no differences in echocardiographic parameters and cardiac biomarkers between monochorionic and dichorionic twin pregnancies (Table 5), as in the results of Orland et al [18].…”

“…In Pritchard's classical study [1], the circulating blood volume in singleton and twin pregnancies increased by 1570 and 1960 mL, respectively. As a result, the echocardiographic findings [13][14][15][16][17] and blood levels of cardiac biomarkers, such as B-type natriuretic peptide (BNP), Nterminal precursor protein BNP fragment (NT-proBNP), and high-sensitivity troponin I (hs-TnI), are significantly different between women with singleton and twin pregnancies [18,19]. Kuleva et al [16] revealed a higher cardiac output in twin pregnancies than in singleton pregnancies.…”

Morphofunctional Cardiac Changes in Singleton and Twin Pregnancies: A Longitudinal Cohort Study

“…In Pritchard's classical study [1], the circulating blood volume in singleton and twin pregnancies increased by 1570 and 1960 mL, respectively. As a result, the echocardiographic ndings [13][14][15][16][17] and blood levels of cardiac biomarkers, such as B-type natriuretic peptide (BNP), N-terminal precursor protein BNP fragment (NT-proBNP), and high-sensitivity troponin I (hs-TnI), are signi cantly different between women with singleton and twin pregnancies [18,19]. Kuleva et al [16] revealed a higher cardiac output in twin pregnancies than in singleton pregnancies.…”

Perinatal Cardiovascular Evaluation in Dorper Sheep: Echocardiographic Description and Behavior of the Heart Rate Variability on the Field

“…Pregnancy induces significant alterations in the maternal cardiovascular and hemodynamic systems, including increases in the cardiac output (CO), and reductions in arterial blood pressure (ABP) and vascular resistance, as well as a systemic vascular dilation [1]. The renin-angiotensin-aldosterone system (RAAS) is activated to increase the circulatory volume [2], since the volume of blood increases during pregnancy due to increases in the volume of plasma and, to a lesser degree, in the volume of red blood cells [3].…”