Abnormal maternal cardiac function precedes the clinical manifestation of fetal growth restriction

Maternal Hemodynamics from Preconception to Delivery: Research and Potential Diagnostic and Therapeutic Implications: Position Statement by Italian Association of Pre-Eclampsia 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..

Expert review: preeclampsia Type I and Type II

Pregnancy involves an interplay between maternal and fetal factors affecting changes to maternal anatomy and physiology to support the developing fetus and ensure the well-being of both the mother and offspring. A century of research has provided evidence of the imperative role of the placenta in the development of preeclampsia. Recently, a growing body of evidence has supported the adaptations of the maternal cardiovascular system during normal pregnancy and its maladaptation in preeclampsia. Debate surrounds the roles of the placenta vs the maternal cardiovascular system in the pathophysiology of preeclampsia. We proposed an integrated model of the maternal cardiac-placental-fetal array and the development of preeclampsia, which reconciles the disease phenotypes and their proposed origins, whether placenta-dominant or maternal cardiovascular system-dominant. These phenotypes are sufficiently diverse to define 2 distinct types: preeclampsia Type I and Type II. Type I preeclampsia may present earlier, characterized by placental dysfunction or malperfusion, shallow trophoblast invasion, inadequate spiral artery conversion, profound syncytiotrophoblast stress, elevated soluble fms-like tyrosine kinase-1 levels, reduced placental growth factor levels, high peripheral vascular resistance, and low cardiac output. Type I is more often accompanied by fetal growth restriction, and low placental growth factor levels have a measurable impact on maternal cardiac remodeling and function. Type II preeclampsia typically occurs in the later stages of pregnancy and entails an evolving maternal cardiovascular intolerance to the demands of pregnancy, with a moderately dysfunctional placenta and inadequate blood supply. The soluble fms-like tyrosine kinase-1-placental growth factor ratio may be normal or slightly disturbed, peripheral vascular resistance is low, and cardiac output is high, but these adaptations still fail to meet demand. Emergent placental dysfunction, coupled with an increasing inability to meet demand, more often appears with fetal macrosomia, multiple pregnancies, or prolonged pregnancy. Support for the notion of 2 types of preeclampsia observable on the molecular level is provided by single-cell transcriptomic survey of gene expression patterns across different cell classes. This revealed widespread dysregulation of gene expression across all cell types, and significant imbalance in fms-like tyrosine kinase-1 (FLT1) and placental growth factor, particularly marked in the syncytium of early preeclampsia cases. Classification of preeclampsia into Type I and Type II can inform future research to develop targeted screening, prevention, and treatment approaches.

Maternal hemodynamic profile during pregnancy and in the post-partum in hypertensive disorders of pregnancy and fetal growth restriction

BACKGROUND

Maternal cardiovascular changes, occurring since the beginning of pregnancy, are necessary for normal placentation and regular evolution of pregnancy.

OBJECTIVE

This study aimed to compare the hemodynamic profiles and cardiac remodeling of women with hypertensive disorders of pregnancy and either appropriate for gestational age fetuses or growth-restricted fetuses, women with normotensive pregnancies complicated by fetal growth restriction, and women with uncomplicated pregnancies, during pregnancy and the postpartum period.

STUDY DESIGN

A prospective longitudinal case-control design was used for this study. Over the study period, 220 eligible women with singleton pregnancies were selected for the analysis and divided into 4 groups: (1) hypertensive disorders of pregnancy with appropriate for gestational age fetuses; (2) hypertensive disorders of pregnancy with fetal growth restriction; (3) normotensive fetal growth restriction; and (4) controls. Ultrasound fetal biometry and fetoplacental Doppler velocimetry were performed at recruitment. Maternal hemodynamic assessment using transthoracic echocardiography was performed at the time of recruitment by a dedicated cardiologist blinded to maternal clinical data. The same assessments were performed in 104 patients at 32 weeks (interquartile range, 24-40) after delivery by the same cardiologist.

RESULTS

During pregnancy, women in the hypertensive-disorders-of-pregnancy-fetal-growth-restriction group showed significantly lower cardiac output and increased compared with those in the control group. These values were associated with concentric remodeling of the left ventricle owing to relatively increased wall thickness, which was not accompanied by an increase in left ventricular mass. Isolated fetal growth restriction presented similar but less important hemodynamic changes; however, there was no change in relative wall thickness. At postpartum follow-up, the hemodynamic parameters of women in the hypertensive-disorders-of-pregnancy-fetal-growth-restriction and isolated-fetal-growth-restriction groups reverted to values similar to those of the control group. Only 8.3% of women in these groups experienced hypertension even in the postpartum period, and asymptomatic stage-B cardiac failure was observed for 17% at echocardiography. In the group of women with hypertensive disorders of pregnancy and appropriate for gestational age fetuses, cardiac output increased as in normal pregnancies, but total vascular resistance was significantly higher; hypertension then occurred, along with ventricular concentric hypertrophy and diastolic dysfunction. At postpartum follow-up, women in the hypertensive-disorders-of-pregnancy-appropriate-for-gestational-age-fetus group showed significantly higher mean arterial pressure, total vascular resistance, and left ventricular mass compared with those in the control group. Persistent hypertension and asymptomatic stage-B cardiac failure were observed in 39.1% and 13% of women in the former group, respectively.

CONCLUSION

Pregnancies with hypertensive disorders of pregnancy and fetal growth restriction and normotensive pregnancies with fetal growth restriction were associated with the hemodynamic profile of lower heart rate and cardiac output, most likely because of abnormal adaptation to pregnancy, as confirmed by abnormal changes from pregnancy to the postpartum period. The heart rates and cardiac output of women in the hypertensive-disorders-of-pregnancy-appropriate-for-gestational-age-fetus group showed changes opposite to those observed in the hypertensive-disorders-of-pregnancy-fetal-growth-restriction and fetal-growth-restriction groups. Obesity and other metabolic risk factors, significantly prevalent in women in the hypertensive-disorders-of-pregnancy-appropriate-for-gestational-age-fetus group, predispose to hypertension and cardiovascular diseases during pregnancy and the postpartum period, potentially offering a window for personalized prevention. Such preventive strategies could differ in women with hypertensive disorders of pregnancy and fetal growth restriction characterized by poor early placental development.

An update on maternal cardiac hemodynamics in fetal growth restriction and pre-eclampsia

Pre-eclampsia and fetal growth restriction (FGR) have been long related to primary placental dysfunction, caused by abnormal trophoblast invasion. Nevertheless, emerging evidence has led to a new hypothesis for the origin of pre-eclampsia and FGR. Suboptimal maternal cardiovascular adaptation has been shown to result in uteroplacental hypoperfusion, ultimately leading to placental hypoxic damage with secondary dysfunction. In this review, we summarize current evidence on maternal cardiac hemodynamics in FGR and pre-eclampsia. We also discuss the different approaches for antihypertensive treatment according to the hemodynamic phenotype observed in pre-eclampsia and FGR.

Maternal Right Ventricular and Left Atrial Function in Uncomplicated Twin Pregnancies: A Longitudinal Study

Objective: The knowledge regarding maternal cardiovascular hemodynamic adaptation in twin pregnancies is incomplete. We performed a longitudinal investigation of maternal right ventricular (RV) and left atrial (LA) function in a cohort of uncomplicated twin pregnancies compared to singleton pregnancies. Study design: Healthy women with uncomplicated twin pregnancies were prospectively enrolled and assessed by transthoracic echocardiography at 10−15 weeks’ (w) gestation (T1), 19-26 w gestation (T2), and 30−38 w gestation (T3). Subjects with uneventful singleton pregnancies were selected as controls at the same gestational ages. Cardiac findings were compared to those of women with uneventful singleton gestations. RV systolic and diastolic functions were assessed by conventional echocardiography (FAC, TAPSE, sPAP, E, A, DT) and tissue Doppler imaging (TDI) (E’, A’, S’, IVA, IVCT, IVRT, ET, MPI), and LA dimensions were calculated. Speckle-tracking imaging was also applied to evaluate RV global longitudinal strain and LA 2D strains (at LV end-systole (LAS) and at atrial contraction (LAA)). Results: Overall, 30 uncomplicated twin and 30 uncomplicated singleton pregnancies were included. Regarding maternal RV function in twins, all the parameters (FAC, TAPSE, sPAP, E, A, E/A, DT, E/E’, IVA, IVCT, MPI and 2D longitudinal strain) were almost stable throughout gestation, with the exception of the TDI findings (E’ decreased from T1 to T3 (p = 0.03), while E’/A’ increased from T1 to T2 and then decreased (p = 0.01); A’ and basal S’ increased (p = 0.04 and p = 0.03, respectively), while IVRT and ET significantly decreased (p = 0.009 and p = 0.007, respectively)). These findings were similar to those found for singleton pregnancies. LA dimensions significantly increased throughout gestation in both twins and singletons (p < 0.001), without intergroup difference. LA strains did not vary during either twin or singleton pregnancies, except for LAA in T1, which was higher among twins than among singletons. Conclusion: Maternal RV and LA function in uncomplicated twin pregnancies does not seem to undergo more significant changes than in singletons, being characterized by similar findings in RV systolic and diastolic functions, as well as LA dimensions and strains.

Maternal Left Ventricular Function in Uncomplicated Twin Pregnancies: A Speckle-Tracking Imaging Longitudinal Study

Objective: The knowledge of maternal cardiovascular hemodynamic adaptation in twin pregnancies is incomplete. We aimed to longitudinally investigate maternal left ventricular (LV) function in uncomplicated twin pregnancies. Methods: 30 healthy and uncomplicated twin pregnant women and 30 controls with normal singleton pregnancies were prospectively enrolled to undergo transthoracic echocardiography at 10–15 week’s gestation (w) (T1), 19–26 w (T2) and 30–38 w (T3). LV dimensions and volumes, as well as LV ejection fraction (LVEF), mass (LVM) and diastolic parameters (at transmitral pulsed wave Doppler and mitral annular plane tissue Doppler), were calculated. Speckle-tracking imaging was also applied to evaluate LV global longitudinal (GLS), radial and circumferential 2D strains. Results: During twin pregnancy, maternal LV dimensions, volumes and LVM had an increasing trend from T1 to T3, similar to singletons, while LVEF remained stable. There was LV remodeling/hypertrophy in 50% of women at T2 and T3 in both groups. Diastolic function had a worsening trend from T1 to T3 with no differences between twins and singletons, except for higher LV filling pressure (i.e., E/E′) at T2 in twins. Two-dimensional strains did not vary during gestation in either group, except for a linear trend to increase (i.e., worsen) GLS in singletons. Radial and circumferential 2D strains were impaired in about half of the women at each trimester, while GLS was altered in one-fourth/one-third of them in both groups. Conclusion: Maternal LV geometry, dimensions and function are significantly impaired during twin pregnancies, in particular in the second half of gestation, with no significant differences compared to singletons.

Non-invasive Maternal Hemodynamic Assessment to Classify High-Risk Pregnancies Complicated by Fetal Growth Restriction

Objectives

To verify whether the use of the temporal criterion of 32 weeks’ gestation is effective in identifying maternal hemodynamic differences between early- and late-onset fetal growth restriction (FGR), and to test the statistical performance of a classificatory algorithm for FGR.

Materials and methods

A prospective multicenter study conducted at three centers over 17 months. Singleton pregnant women with a diagnosis of FGR based on the international Delphi survey consensus at ≥ 20 weeks of gestation were included. FGR was classified as early-onset if diagnosed &lt;32 weeks’ gestation and as late-onset if ≥32 weeks. Hemodynamic assessment was performed by USCOM-1A at the time of FGR diagnosis. Comparisons between early- and late-onset FGR among the entire study cohort, FGR associated with hypertensive disorders of pregnancy (HDP-FGR), and isolated FGR (i-FGR) were performed. In addition, HDP-FGR cases were compared to i-FGR, regardless of the temporal cut-off of 32 weeks’ gestation. Finally, a classificatory analysis based on the Random Forest model was performed to identify significant variables with the ability to differentiate FGR phenotypes.

Results

During the study period, 146 pregnant women fulfilled the inclusion criteria. In 44 cases, FGR was not confirmed at birth, thus limiting the final study population to 102 patients. In 49 (48.1%) women, FGR was associated to HDP. Fifty-nine (57.8%) cases were classified as early-onset. Comparison of the maternal hemodynamics between early- and late-onset FGR did not show any difference. Similarly, non-significant findings were observed in sensitivity analyses performed for HDP-FGR and for i-FGR. In turn, comparison between pregnant women with FGR and hypertension and women with i-FGR, independently of the gestational age at FGR diagnosis, revealed substantial differences, with the former showing higher vascular peripheral resistances and lower cardiac output, among other significant parameters. The classificatory analysis identified both phenotypic and hemodynamic variables as relevant in distinguishing HDP-FGR from i-FGR (p=0.009).

Conclusions

Our data show that HDP, rather than gestational age at FGR diagnosis, allows to appreciate specific maternal hemodynamic patterns and to accurately distinguish two different FGR phenotypes. In addition, maternal hemodynamics, alongside phenotypic characteristics, play a central role in classifying these high-risk pregnancies.

Preeclampsia has two phenotypes which require different treatment strategies

The opinion on the mechanisms underlying the pathogenesis of preeclampsia still divides scientists and clinicians. This common complication of pregnancy has long been viewed as a disorder linked primarily to placental dysfunction, which is caused by abnormal trophoblast invasion, however, evidence from the previous two decades has triggered and supported a major shift in viewing preeclampsia as a condition that is caused by inherent maternal cardiovascular dysfunction, perhaps entirely independent of the placenta. In fact, abnormalities in the arterial and cardiac functions are evident from the early subclinical stages of preeclampsia and even before conception. Moving away from simply observing the peripheral blood pressure changes, studies on the central hemodynamics reveal two different mechanisms of cardiovascular dysfunction thought to be reflective of the early-onset and late-onset phenotypes of preeclampsia. More recent evidence identified that the underlying cardiovascular dysfunction in these phenotypes can be categorized according to the presence of coexisting fetal growth restriction instead of according to the gestational period at onset, the former being far more common at early gestational ages. The purpose of this review is to summarize the hemodynamic research observations for the two phenotypes of preeclampsia. We delineate the physiological hemodynamic changes that occur in normal pregnancy and those that are observed with the pathologic processes associated with preeclampsia. From this, we propose how the two phenotypes of preeclampsia could be managed to mitigate or redress the hemodynamic dysfunction, and we consider the implications for future research based on the current evidence. Maternal hemodynamic modifications throughout pregnancy can be recorded with simple-to-use, noninvasive devices in obstetrical settings, which require only basic training. This review includes a brief overview of the methodologies and techniques used to study hemodynamics and arterial function, specifically the noninvasive techniques that have been utilized in preeclampsia research.

Cardiovascular Disease in Pregnancy

Cardiovascular disease remains a major contributor to rising maternal morbidity and mortality. Both the pregnant woman and fetus are exposed to many potential complications as a result of the physiologic changes of pregnancy. These changes can exacerbate existing cardiac disease, as well as lead to the development of de novo issues during gestation, delivery, and the postnatal period. For women with preexisting cardiac disease, including congenital malformations, valvular disease, coronary artery disease, and aortopathies, it is crucial that they receive multidisciplinary evaluation, counseling, and optimization before conception, as well as close monitoring and medication management during pregnancy. Close monitoring is also essential for patients who develop cardiovascular complications such as preeclampsia, cardiomyopathy, congestive heart failure, coronary events, and arrhythmias during pregnancy. In addition, concerning disparities in maternal morbidity and mortality exist across many dimensions, in part because of the lack of uniformity of care in different treatment settings. Establishment of multidisciplinary cardio-obstetric teams including representatives from cardiology, anesthesia, obstetrics, maternal-fetal medicine, and specialized nursing has proven instrumental to delivering evidence-based and equitable care to high-risk patients. Multidisciplinary teams should work to guide these patients through the preconception, antepartum, delivery, and postpartum phases to ensure appropriate care for weeks to years after pregnancy.

Fetal Growth Restriction: Does an Integrated Maternal Hemodynamic-Placental Model Fit Better?

In recent years, a growing interest has arisen regarding the possible relationship between adverse pregnancy outcomes (APOs) and inadequate maternal hemodynamic adaptations to the pregnancy. A possible association between "placental syndromes," such as preeclampsia (PE) and fetal growth restriction (FGR), and subsequent maternal cardiovascular diseases (CVD) later in life has been reported. The two subtypes of FGR show different pathogenetic and clinical features. Defective placentation, due to a poor trophoblastic invasion of the maternal spiral arteries, is believed to play a central role in the pathogenesis of early-onset PE and FGR. Since placental functioning is dependent on the maternal cardiovascular system, a pre-existent or subsequent cardiovascular impairment may play a key role in the pathogenesis of early-onset FGR. Late FGR does not seem to be determined by a primary abnormal placentation in the first trimester. The pathological pathway of late-onset FGR may be due to a primary maternal cardiovascular maladaptation: CV system shows a flat profile and remains similar to those of non-pregnant women. Since the second trimester, when the placenta is already developed and increases its functional request, a hypovolemic state could lead to placental hypoperfusion and to an altered maturation of the placental villous tree and therefore to an altered fetal growth. Thus, this review focalizes on the possible relationship between maternal cardiac function and placentation in the development of both early and late-onset FGR. A better understanding of maternal hemodynamics in pregnancies complicated by FGR could bring various benefits in clinical practice, improving screening and therapeutic tools.

Maternal cardiac adaptation and fetal growth

BACKGROUND

Pregnancies with small-for-gestational-age fetuses are at increased risk of adverse maternal-fetal outcomes. Previous studies examining the relationship between maternal hemodynamics and fetal growth were mainly focused on high-risk pregnancies and those with fetuses with extreme birthweights, such as less than the 3rd or 10th percentile and assumed a similar growth pattern in fetuses above the 10th percentile throughout gestation.

OBJECTIVE

This study aimed to evaluate the trends in maternal cardiac function, fetal growth, and oxygenation with advancing gestational age in a routine obstetrical population and all ranges of birthweight percentiles.

STUDY DESIGN

This was a prospective, longitudinal study assessing maternal cardiac output and peripheral vascular resistance by bioreactance at 11⁺⁰ to 13⁺⁶, 19⁺⁰ to 24⁺⁰, 30⁺⁰ to 34⁺⁰, and 35⁺⁰ to 37⁺⁰ weeks' gestation, sonographic estimated fetal weight in the last 3 visits and the ratio of the middle cerebral artery by umbilical artery pulsatility indices or cerebroplacental ratio in the last 2 visits. Women were divided into the following 5 groups according to birthweight percentile: group 1, <10th percentile (n=261); group 2, 10 to 19.9 percentile (n=180); group 3, 20 to 29.9 percentile (n=189); group 4, 30 to 69.9 percentile (n=651); and group 5, ≥70th percentile (n=508). The multilevel linear mixed-effects model was performed to compare the repeated measures of hemodynamic variables and z scores of the estimated fetal weight and cerebroplacental ratio.

RESULTS

In visit 2, compared with visit 1, in all groups, cardiac output increased, and peripheral vascular resistance decreased. At visit 3, groups 1, 2, and 3, compared with 4 and 5, demonstrated an abrupt decrease in cardiac output and increase in peripheral vascular resistance. From visit 2, group 1 had a constant decline in estimated fetal weight, coinciding with the steepest decline in maternal cardiac output and rise in peripheral vascular resistance. In contrast, in groups 4 and 5, the estimated fetal weight had a stable or accelerative pattern, coinciding with the greatest increase in cardiac output and lowest peripheral vascular resistance. Groups 2 and 3 showed a stable growth pattern with intermediate cardiac output and peripheral vascular resistance. Increasing birthweight was associated with higher cerebroplacental ratio. Groups 3, 4, and 5 had stable cerebroplacental ratio across visits 3 and 4, whereas groups 1 and 2 demonstrated a significant decline (P<.001).

CONCLUSION

In a general obstetrical population, maternal cardiac adaptation at 32 weeks' gestation parallels the pattern of fetal growth and oxygenation; babies with birthweight<20th percentile have progressive decline in fetal cerebroplacental ratio, decline in maternal cardiac output, and increase in peripheral vascular resistance.

Prorenin periconceptionally and in pregnancy: Does it have a physiological role?

Pregnancy demands major cardiovascular, renal and endocrine changes to provide an adequate blood supply for the growing fetus. The renin-angiotensin-aldosterone system plays a key role in this adaptation process. One of its components, prorenin, is released in significant amounts from the ovary and uteroplacental unit. This review describes the sources of prorenin in the periconception period and in pregnancy, including its modulation by in-vitro fertilization protocols, and discusses its potential effects, among others focusing on preeclampsia. It ends with discussing the long-term consequences, even in later life, of inappropriate renin-angiotensin-aldosterone system activity in pregnancy and offers directions for future research. Ultimately, a full understanding of the role of prorenin periconceptionally and during pregnancy will help to develop tools to diagnose and/or prevent reproductive complications.

Distinction between SGA and FGR by means of fetal umbilical vein flow and maternal hemodynamics

OBJECTIVES

To improve identification of fetal growth restriction (FGR) by means of umbilical venous flow (QUV) and maternal hemodynamics, including systemic vascular resistance (SVR) and cardiac output (CO), in order to distinguish between FGR and SGA.

METHODS

We enrolled 68 pregnancies (36 SGA, 8 early FGR and 24 late FGR) who underwent a complete fetal hemodynamic examination including QUV and a noninvasive maternal hemodynamics assessment by means of USCOM.

RESULTS

In comparison with SGA, QUV and corrected for estimated fetal weight QUV (cQUV) were significantly lower in early and late-FGR. In addition, maternal CO was lower in early and late-FGR, while SVR was lower only in early-onset FGR. According to ROC analysis, cQUV centile (AUC 0.92, 0.72) was the best parameter for the prediction of SGA before and after 32 weeks, followed by SVR and CO. For all parameters, the prediction was always better in the case of early-onset FGR <32 weeks.

CONCLUSIONS

UV flow and maternal hemodynamics examination are useful tools to accurately discern between SGA and FGR.

Prorenin periconceptionally and in pregnancy: Does it have a physiological role?

Pregnancy demands major cardiovascular, renal and endocrine changes to provide an adequate blood supply for the growing fetus. The renin-angiotensin-aldosterone system plays a key role in this adaptation process. One of its components, prorenin, is released in significant amounts from the ovary and uteroplacental unit. This review describes the sources of prorenin in the periconception period and in pregnancy, including its modulation by in-vitro fertilization protocols, and discusses its potential effects, among others focusing on preeclampsia. It ends with discussing the long-term consequences, even in later life, of inappropriate renin-angiotensin-aldosterone system activity in pregnancy and offers directions for future research. Ultimately, a full understanding of the role of prorenin periconceptionally and during pregnancy will help to develop tools to diagnose and/or prevent reproductive complications.

Hemodynamic findings in normotensive women with small-for-gestational-age and growth-restricted fetuses

INTRODUCTION

Fetal growth restriction (FGR) in most instances is a consequence of primary placental dysfunction due to inadequate trophoblastic invasion. Maternal cardiac maladaptation to pregnancy has been proposed as a possible determinant of placental insufficiency and impaired fetal growth. This study aimed to compare the maternal hemodynamic parameters between normotensive women with small-for-gestational-age (SGA) and FGR fetuses and to evaluate their correlation with neonatal outcome.

MATERIAL AND METHODS

An observational cohort study including singleton pregnancies referred to our tertiary care center due to fetal smallness. At the time of diagnosis, fetuses were classified as SGA or FGR according to the Delphi consensus criteria, and pregnant women underwent hemodynamic assessment using a cardiac output monitor. A group of women with singleton uncomplicated pregnancies ar ≥35 weeks of gestation were recruited as controls. Cardiac output, systemic vascular resistance, stroke volume, and heart rate were measured and compared among the three groups (controls vs FGR vs SGA). The correlation between antenatal findings and neonatal outcome was also evaluated by multivariate logistic regression analysis.

RESULTS

A total of 51 women with fetal smallness were assessed at 34.8 ± 2.6 weeks. SGA and FGR were diagnosed in 22 and 29 cases, respectively. The control group included 61 women assessed at 36.5 ± 0.8 weeks of gestation. Women with FGR had a lower cardiac output Z-score (respectively, -1.3 ± 1.2 vs -0.4 ± 0.8 vs -0.2 ± 1.0; P < .001) and a higher systemic vascular resistance Z-score (respectively, 1.2 ± 1.2 vs 0.2 ± 1.1 vs -0.02 ± 1.2; P < .001) compared with both SGA and controls, whereas no difference in the hemodynamic parameters was found between women with SGA and controls. The incidence of neonatal intensive care unit admission did not differ between SGA and FGR fetuses (18.2% vs 41.4%; P = .13), but FGR fetuses had a longer hospitalization compared with SGA fetuses (14.2 ± 17.7 vs 4.5 ± 1.6 days; P = .02). Multivariate analysis showed that the cardiac output Z-score at diagnosis (P = .012) and the birthweight Z-score (P = .007) were independent predictors of the length of neonatal hospitalization.

CONCLUSIONS

Different maternal hemodynamic profiles characterize women with SGA or FGR fetuses. Furthermore, a negative correlation was found between the maternal cardiac output and the length of neonatal hospitalization.

Hemodynamic maladaptation and left ventricular dysfunction in chronic hypertensive patients at the beginning of gestation and pregnancy complications: a case control study

OBJECTIVE

The aim of this study was to evaluate early pregnancy differences in maternal hemodynamics, cardiac geometry and function, between chronic hypertensive (CH) patients with and without the development of feto-maternal complications later in pregnancy.

METHODS

We performed a case-control study on nulliparous CH treated patients. From a group of CH patients referred to our outpatient clinic at 4-6 weeks for a clinical evaluation the first consecutive 30 patients with subsequent complications (superimposed PE, abruptio placentae, uncontrolled severe hypertension with delivery <34 weeks, HELLP syndrome, FGR, perinatal death) were enrolled; the first 2 CH women with uneventful pregnancy referred after the case were enrolled as controls for a total of 60 patients. All patients were shifted to alpha-methyl dopa at the beginning of pregnancy and were submitted to an echocardiographic evaluation to assess the maternal hemodynamics, cardiac geometry, diastolic and systolic function.

RESULTS

Patients developing complications had a lower early pregnancy heart rate (73 ± 11 vs. 82 ± 11 bpm), cardiac output (5.23 ± 1.2 vs. 6.5 ± 1.3 L/min, p<.01) and cardiac index (3.0 ± 0.7 vs. 3.6 ± 0.7 L/min/m², p<.01); higher total vascular resistance (1554 ± 305 vs. 1248 ± 243 d.s.cm^-5, p<.01) and total vascular resistance index (2666 ± 519 vs. 2335 ± 431, d.s.cm^-5/m², p<.01); higher left ventricular mass index (42.1 ± 8.6 vs. 36.9 ± 8.3 g/m², p<.01) and relative wall thickness (0.40 ± 0.05 vs. 0.36 ± 0.05, p<.01) of the left ventricle, resulting in a higher prevalence of altered cardiac geometry vs. uneventful CH controls. Diastolic and systolic dysfunction were also present with a higher E/e' ratio (10.50 ± 3.56 vs. 7.22 ± 1.91, p<.01) and a lower stress corrected midwall mechanics (89 ± 21 vs. 100 ± 22, p=.02) of the left ventricle.

CONCLUSION

CH treated patients developing maternal and/or fetal complications show early pregnancy altered cardiac geometry, diastolic and systolic dysfunction, and impaired hemodynamics with a high resistance circulation.

Pregnancy complications in chronic hypertensive patients are linked to pre-pregnancy maternal cardiac function and structure

BACKGROUND

Chronic hypertension complicates around 3% of all pregnancies and is associated with an increased risk for pregnancy complications such as superimposed preeclampsia, fetal growth restriction, preterm delivery, and stillbirth, reaching a rate of complications of up to 25-28%.

OBJECTIVE

We performed an echocardiographic study to evaluate pre-pregnancy cardiac geometry and function, along with the hemodynamic features of treated chronic hypertension patients, searching for a possible correlation with the development of feto-maternal complications and with pre-pregnancy therapy.

MATERIALS AND METHODS

This was a prospective observational cohort study of 192 consecutive patients receiving treatment for chronic hypertension (calcium channel blockers, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, β-blockers, α1-adrenoceptor antagonists, and/or diuretics). Patients underwent echocardiography before pregnancy, assessing left ventricular morphology and function, cardiac output, and total vascular resistance. Pre-pregnancy therapy was noted, patients were shifted to α-methyldopa right before pregnancy, and were followed until delivery, noting major early (<34weeks' gestation) and late (≥34 weeks' gestation) complications. Comparisons among the 3 groups (ie, those with no complications, early complications, and late complications) were performed with 1-way analysis of variance with Student-Newman-Keuls correction for multiple comparisons. The Mann-Whitney U test was used for non-normally distributed data. Comparison of proportions was used as appropriate. Receiver operating characteristic curve analysis was used to identify cutoff values of diastolic dysfunction in this population using the E/e' ratio, and separate cutoff of values for total vascular resistance for the prediction of early and late complications of pregnancy. Binary univariate and multivariate logistic regression as well as Cox proportional hazards regression were used to evaluate the possible correlation among angiotensin-converting enzyme inhibitor/angiotensin receptor blocker and/or calcium channel blocker pre-pregnancy therapy, cardiovascular features, and the risk for subsequent early and late complications of pregnancy.

RESULTS

Of 192 patients, 141 had no complications, and 51 had a complicated pregnancy (24 had early complications and 27 had late complications). Concentric geometry was more frequent in those women with early versus late and no complications (50% vs 13.5% and 11.1%, respectively; P < .05), whereas eccentric hypertrophy was more represented in women with late versus early and no complications (32% versus 12.5% and 1.4%, respectively; P < .05). The receiver operating characteristic curve showed an E/e' ratio value >7.65 (sensitivity, 59.6%; specificity, 68.6%) as a predictor of subsequent complications of pregnancy, whereas total vascular resistance <1048 (sensitivity, 83.7%; specificity, 55.6%) was predictive for late complications and total vascular resistance >1498 (sensitivity, 87.5%; specificity, 78.0%) for the early complications of pregnancy. Univariate analysis showed that the following parameters were predictive for complications of pregnancy: altered geometry of the left ventricle (odds ratio, 5.94; 95% confidence interval, 2.90-12.19), diastolic dysfunction (odds ratio, 3.22; 95% confidence interval, 1.63-6.37), altered total vascular resistance (odds ratio, 3.52; 95% confidence interval, 1.78-6.97), and pre-pregnancy therapy without calcium channel blockers/angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (odds ratio, 2.73; 95% confidence interval, 1.37-5.42). These parameters, except for altered total vascular resistance, were independent predictors in the multivariate analysis corrected for body mass index, heart rate, parity, and mean arterial pressure.

CONCLUSION

Chronic hypertension patients with pre-pregnancy cardiac remodeling and dysfunction more often develop early and late complications of pregnancy. Pre-pregnancy therapy for chronic hypertension patients with calcium channel blockers and/or angiotensin-converting enzyme inhibitors/angiotensin receptor blockers may positively influence cardiac profiles and the outcome of a future pregnancy with a reduced rate of complications.

Are maternal hemodynamic indices markers of fetal growth restriction in pregnancies with a small-for-gestational-age fetus?

OBJECTIVE

Pregnancies complicated by fetal growth restriction (FGR) have a worse outcome than those with a small-for-gestational-age (SGA) fetus. There is increasing evidence of a maternal cardiovascular role in the pathophysiology of FGR. We aimed to compare maternal hemodynamic indices between pregnancies complicated by FGR and those delivering a SGA neonate, using a non-invasive device.

METHODS

This was a prospective study of normotensive pregnancies complicated by FGR (defined as estimated fetal weight (EFW) < 3^rd centile or Doppler evidence of impaired placental-fetal blood flow), those with a SGA fetus (defined as EFW < 10^th centile) and control pregnancies with an appropriately grown fetus. Assessment of maternal hemodynamics (heart rate (HR), cardiac output (CO), mean arterial pressure (MAP), systemic vascular resistance (SVR) and stroke volume) was performed using a non-invasive device (USCOM-1A®). Uterine artery (UtA) pulsatility index (PI) was measured using transabdominal ultrasound. Hemodynamic variables that are affected by gestational age and maternal characteristics were corrected for using device-specific reference ranges. Comparison between groups was performed using the chi-square test or the Mann-Whitney U-test, as appropriate.

RESULTS

A total of 102 FGR, 64 SGA and 401 control pregnancies, with a median gestational age of 36 weeks, were included in the analysis. Women with a pregnancy complicated by FGR and those with a SGA fetus were shorter and weighed less than did controls. Compared with controls, the FGR group had significantly lower median maternal HR (80 beats per min (bpm) vs 85 bpm; P = 0.001) and CO multiples of the median (MoM; 0.91 vs 0.98; P = 0.003), and higher median maternal MAP (90 mmHg vs 87 mmHg; P = 0.040), SVR MoM (1.2 vs 1.0; P < 0.001) and UtA-PI MoM (1.1 vs 0.96; P < 0.001), but there was no significant difference in stroke volume MoM (1.0 vs 0.98; P = 0.647). Compared with the SGA group, the FGR group had a significantly lower median HR (80 bpm vs 87 bpm; P = 0.022), and higher median maternal MAP (90 mmHg vs 85 mmHg; P = 0.025), SVR MoM (1.2 vs 1.0; P = 0.002) and UtA-PI MoM (1.1 vs 0.98; P = 0.005), but there was no significant difference in CO MoM (0.91 vs 0.96; P = 0.092) or stroke volume MoM (1.0 vs 1.0; P = 0.806). There were no significant differences in adjusted maternal hemodynamic indices between the SGA group and controls.

CONCLUSION

Pregnancies complicated by FGR presented with impaired maternal hemodynamic function, as evidenced by lower HR and CO, as well as higher MAP, SVR and UtA resistance. Pregnancies delivering a SGA neonate, without evidence of FGR, had normal maternal hemodynamic function. Maternal hemodynamic indices may therefore be of value in distinguishing FGR from SGA pregnancies. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Effect of sildenafil on maternal hemodynamics in pregnancies complicated by severe early-onset fetal growth restriction: planned subgroup analysis from a multicenter randomized placebo-controlled double-blind trial

OBJECTIVES

Fetal growth restriction (FGR) is associated with maternal cardiovascular changes. Sildenafil, a phosphodiesterase type-5 inhibitor, potentiates the actions of nitric oxide, and it has been suggested that it alters maternal hemodynamics, potentially improving placental perfusion. Recently, the Dutch STRIDER trial was stopped prematurely owing to excess neonatal mortality secondary to pulmonary hypertension. The main aim of this study was to investigate the effect of sildenafil on maternal hemodynamics in pregnancies with severe early-onset FGR.

METHODS

This was a cardiovascular substudy within a UK multicenter, placebo-controlled trial, in which 135 women with a singleton pregnancy and severe early-onset FGR (defined as a combination of estimated fetal weight or abdominal circumference below the 10^th centile and absent/reversed end-diastolic flow in the umbilical artery on Doppler velocimetry, diagnosed between 22 + 0 and 29 + 6 weeks' gestation) were assigned randomly to receive either 25 mg sildenafil three times daily or placebo until 32 + 0 weeks' gestation or delivery. Maternal blood pressure (BP), heart rate (HR), augmentation index, pulse wave velocity (PWV), cardiac output, stroke volume (SV) and total peripheral resistance were recorded before randomization, 1-2 h and 48-72 h post-randomization, and 24-48 h postnatally. For continuous data, analysis was performed using repeated measures ANOVA methods including terms for timepoint, treatment allocation and their interaction.

RESULTS

Included were 134 women assigned randomly to sildenafil (n = 69) or placebo (n = 65) who had maternal BP and HR recorded at baseline. At 1-2 h post-randomization, compared with baseline values, sildenafil increased maternal HR by 4 bpm more than did placebo (mean difference, 5.00 bpm (95% CI, 1.00-12.00 bpm) vs 1.25 bpm (95% CI, -5.38 to 7.88 bpm); P = 0.004) and reduced systolic BP by 1 mmHg more (mean difference, -4.13 mmHg (95% CI, -9.94 to 1.44 mmHg) vs -2.75 mmHg (95% CI, -7.50 to 5.25 mmHg); P = 0.048). Even after adjusting for maternal mean arterial pressure, sildenafil reduced aortic PWV by 0.60 m/s more than did placebo (mean difference, -0.90 m/s (95% CI, -1.31 to -0.51 m/s) vs -0.26 m/s (95% CI, -0.75 to 0.59 m/s); P = 0.001). Sildenafil was associated with a non-significantly greater decrease in SV index after 1-2 h post-randomization than was placebo (mean difference, -5.50 mL/m² (95% CI, -11.00 to -0.50 mL/m² ) vs 0.00 mL/m² (95% CI, -5.00 to 4.00 mL/m² ); P = 0.056).

CONCLUSIONS

Sildenafil in a dose of 25 mg three times daily increases HR, reduces BP and reduces arterial stiffness in pregnancies complicated by severe early-onset FGR. These changes are short term, modest and consistent with the anticipated vasodilatory effect. They have no short- or long-term clinical impact on the mother. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Multivariable evaluation of maternal hemodynamic profile in pregnancy complicated by fetal growth restriction: prospective study

OBJECTIVE

To evaluate the association between fetal growth restriction (FGR) and maternal hemodynamic parameters using multivariable analysis, adjusting for major confounding factors, such as hypertensive disorders of pregnancy (pre-eclampsia and gestational hypertension).

METHODS

A prospective cohort study was conducted between January 2013 and April 2016. Two cohorts of patients were recruited, between 24 and 39 weeks of gestation, in a high-risk outpatient setting. These cohorts comprised 49 appropriate-for-gestational-age singleton fetuses and 93 that were FGR (abdominal circumference (AC) at recruitment in the second half of pregnancy ≤ 10th percentile with a previous normal AC at 20-22 weeks). Maternal echocardiography was performed at the time of enrolment and included hemodynamic parameters of systolic and diastolic function and cardiac remodeling indices. Data were analyzed using a multivariable generalized linear model to estimate the association of FGR with maternal hemodynamic parameters after adjusting for significant confounding factors.

RESULTS

In the multivariable analysis, after adjustment for hypertensive disorders of pregnancy and smoking, FGR was associated with a 14% increase in maternal total vascular resistance, 16% reduction in cardiac output, 13% reduction in left ventricular mass and 11% reduction in heart rate; similar results were observed for the corresponding indexed parameters. Hypertensive disorders of pregnancy in the absence of FGR were associated with a 25% increase in total vascular resistance, 16% increase in left ventricular mass and 14% reduction in diastolic function; similar results were observed for the corresponding indexed parameters.

CONCLUSION

FGR is significantly and independently associated with several maternal hemodynamic parameters, even after adjustment for major confounding factors, such as hypertensive disorders of pregnancy. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Maternal hemodynamics in screen-positive and screen-negative women of the ASPRE trial

OBJECTIVE

To compare maternal hemodynamics and perinatal outcome, in pregnancies that do not develop pre-eclampsia (PE) or deliver a small-for-gestational-age (SGA) neonate, between those identified at 11-13 weeks' gestation as being screen positive or negative for preterm PE, by a combination of maternal factors, mean arterial pressure, uterine artery pulsatility index, serum placental growth factor and pregnancy associated plasma protein-A.

METHODS

This was a prospective longitudinal cohort study of maternal cardiovascular function, assessed using a bioreactance method, in women undergoing first-trimester screening for PE. Maternal hemodynamics and perinatal outcome were compared between screen-positive and screen-negative women who did not have a medical comorbidity, did not develop PE or pregnancy-induced hypertension and delivered at term a live neonate with birth weight between the 5^th and 95^th percentiles. A multilevel linear mixed-effects model was used to compare the repeated measures of cardiac variables, controlling for maternal characteristics.

RESULTS

The screen-negative group (n = 926) had normal cardiac function changes across gestation, whereas the screen-positive group (n = 170) demonstrated static or reduced cardiac output and stroke volume and higher mean arterial pressure and peripheral vascular resistance with advancing gestation. In the screen-positive group, compared with screen-negative women, birth-weight Z-score was shifted toward lower values, with prevalence of delivery of a neonate below the 35^th , 30^th or 25^th percentile being about 70% higher, and the rate of operative delivery for fetal distress in labor also being higher.

CONCLUSION

Women who were screen positive for impaired placentation, even though they did not develop PE or deliver a SGA neonate, had pathological cardiac adaptation in pregnancy and increased risk of adverse perinatal outcome. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Methods and considerations concerning cardiac output measurement in pregnant women: recommendations of the International Working Group on Maternal Hemodynamics

Cardiac output (CO), along with blood pressure and vascular resistance, is one of the most important parameters of maternal hemodynamic function. Substantial changes in CO occur in normal pregnancy and in most obstetric complications. With the development of several non-invasive techniques for the measurement of CO, there is a growing interest in the determination of this parameter in pregnancy. These techniques were initially developed for use in critical-care settings and were subsequently adopted in obstetrics, often without appropriate validation for use in pregnancy. In this article, methods and devices for the measurement of CO are described and compared, and recommendations are formulated for their use in pregnancy, with the aim of standardizing the assessment of CO and peripheral vascular resistance in clinical practice and research studies on maternal hemodynamics. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Low Volume Circulation in Normotensive Women Pregnant with Neonates Small for Gestational Age

BACKGROUND

Pregnancies complicated with small for gestational age (SGA) neonates are reported with maternal circulatory maladaptations.

OBJECTIVES

We aimed to understand the pathophysiology of the maternal circulation in normotensive SGA pregnancies and to point out the trimestral differences from those with appropriate-to-large (non-SGA [NGA]) neonates.

METHODS

An observational study was conducted in 3 trimestral cohorts of normotensive pregnancies, categorized after birth according to neonatal birth weight percentile (BW%) as SGA (BW% ≤10, n = 158) or NGA (BW% > 10, n = 1,038). Standardized electrocardiogram-Doppler ultrasound, impedance cardiography, and bio-impedance were used to assess the maternal heart, arteries, veins, and fluid.

RESULTS

Diastolic blood pressure and mean arterial pressure were not significantly different, unless in the third trimester. In SGA compared to NGA pregnancies, total peripheral resistance (TPR) was higher and total arterial compliance, cardiac output (CO), and total body water (TBW) were lower throughout pregnancy. Venous return-enhancing functions were activated. In NGA but not SGA pregnancies, a positive correlation was found between BW% and CO + TBW and a negative correlation between BW% and TPR.

CONCLUSIONS

SGA pregnancies are characterized by lower maternal body fluid volume and CO, while normal blood pressures are maintained via increased TPR already from the first trimester onwards. Pregnancy-induced hemodynamic changes are superimposed on these characteristics.

Maternal hemodynamics, fetal biometry and Doppler indices in pregnancies followed up for suspected fetal growth restriction

OBJECTIVES

To assess whether, in a cohort of patients with a small-for-gestational-age (SGA) fetus with estimated fetal weight ≤ 10^th percentile, maternal hemodynamics, fetal biometry and Doppler indices at presentation can predict the subsequent development of an abnormal fetal Doppler index or delivery of a baby with birth weight < 3^rd percentile.

METHODS

This was a prospective observational cohort study conducted at a specialist clinic for the management of pregnancies with a SGA fetus at King's College Hospital, London, UK. The study population comprised 86 singleton pregnancies with a SGA fetus, presenting at a median gestational age of 32 (range, 26-35) weeks. We measured maternal cardiac function using a non-invasive transthoracic bioreactance monitor, as well as mean arterial pressure, fetal biometry, and umbilical artery (UA), fetal middle cerebral artery (MCA) and uterine artery (UtA) pulsatility indices (PI), and the deepest vertical pool of amniotic fluid. Z-scores of these variables were calculated based on reported reference ranges and the values were compared between pregnancies with evidence of an abnormal fetal Doppler index at presentation (Group 1), those that had developed an abnormal Doppler index at a subsequent visit (Group 2) and those that did not develop an abnormal Doppler index throughout pregnancy (Group 3). Abnormal fetal Doppler was defined as UA-PI > 95^th percentile and/or MCA-PI < 5^th percentile. Differences in measured variables at presentation were also compared between pregnancies delivering a baby with birth weight < 3^rd percentile and those delivering a baby with birth weight ≥ 3^rd percentile. Multivariate logistic regression analysis was used to determine significant predictors of birth weight < 3^rd percentile and evolution from normal to abnormal fetal Doppler.

RESULTS

In the study population, 14 (16%) cases were in Group 1, 19 (22%) in Group 2 and 53 (62%) in Group 3. Birth weight was < 3^rd percentile in 39 (45%) cases and ≥ 3^rd percentile in 47 (55%). There was decreased cardiac output and stroke volume and increased peripheral vascular resistance compared with a normal population, and the deviations from normal were most marked in Group 1. Pregnancies with birth weight < 3^rd percentile, compared with those with birth weight ≥ 3^rd percentile, had greater deviations from normal in fetal biometry, maternal cardiac output, stroke volume, heart rate, peripheral vascular resistance and UtA-PI. Multivariate logistic regression analysis demonstrated that, in the prediction of birth weight < 3^rd percentile, maternal hemodynamic profile provided significant improvement to the prediction provided by maternal demographics, fetal biometry, UtA-PI, UA-PI and MCA-PI (difference between areas under receiver-operating characteristics curves, 0.18 (95% CI, 0.06-0.29); P = 0.002). In contrast, there was no significant independent contribution from maternal hemodynamics in the prediction of the subsequent development of abnormal fetal Doppler.

CONCLUSIONS

In pregnancies with a SGA fetus, there is decreased maternal cardiac output and stroke volume and increased peripheral vascular resistance, and the deviations from normal are most marked in cases of redistribution in the fetal circulation and reduced amniotic fluid volume. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Restricted physical activity in pregnancy reduces maternal vascular resistance and improves fetal growth

OBJECTIVES

To test the efficacy of maternal activity restriction for reducing peripheral vascular resistance in normotensive pregnant women with raised total vascular resistance (TVR) and to evaluate its effect on fetal growth.

METHODS

This was a prospective case-control study of 30 women enrolled between 27 and 29 weeks' gestation. All patients met the following criteria: normal blood pressure before and during pregnancy, TVR between 1300 and 1400 dynes × s/cm⁵ at enrolment, normal fetal Doppler parameters at enrolment and abdominal circumference between the 10^th and 25^th centiles. Patients were assigned to activity restriction (activity-restriction group; n = 15) or no treatment (control group; n = 15) and were assessed after 4 weeks for TVR and fetal growth.

RESULTS

TVR at enrolment and estimated fetal weight centile were similar in the activity-restriction group vs controls (1358 ± 26 vs 1353 ± 30 dynes × s/cm⁵ ; 18^th  ± 4 vs 19^th  ± 4 centile; P = NS). After 4 weeks, the activity-restriction group compared with controls showed significantly lower TVR (1165 ± 159 vs 1314 ± 190 dynes × s/cm⁵ ; P < 0.05), which was associated with higher estimated fetal weight centile (25^th  ± 5 vs 20^th  ± 5 centile; P < 0.05). TVR was lower and estimated fetal weight centile higher for the activity-restriction group after 4 weeks compared with at enrolment.

CONCLUSIONS

In normotensive pregnant women with raised TVR, maternal activity restriction appears to be effective in reducing TVR and therefore enhancing fetal growth. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Early onset fetal growth restriction

Fetal growth restriction (FGR) diagnosed before 32 weeks is identified by fetal smallness associated with Doppler abnormalities and is associated with significant perinatal morbidity and mortality and maternal complications. Recent studies have provided new insights into pathophysiology, management options and postnatal outcomes of FGR. In this paper we review the available evidence regarding diagnosis, management and prognosis of fetuses diagnosed with FGR before 32 weeks of gestation.

Maternal cardiac function at 35-37 weeks' gestation: relationship with birth weight

OBJECTIVE

To evaluate the relationship between maternal cardiovascular parameters and neonatal birth weight and examine the potential value of these parameters in improving the prediction of small-for-gestational-age (SGA) and large-for-gestational-age (LGA) neonates provided by maternal characteristics and medical history.

METHODS

In 2835 singleton pregnancies maternal characteristics and medical history were recorded and maternal cardiovascular parameters were measured. The observed measurements of cardiovascular parameters were expressed as multiples of the normal median (MoM) values after adjustment for those characteristics found to provide a substantial contribution to their measurement. Regression analysis was used to determine the significance of association between the normalized values of the cardiovascular parameters with birth-weight Z-score. Multivariable logistic regression analysis was then used to determine if the maternal factors, fetal biometry and maternal cardiovascular parameters had a significant contribution to predicting SGA and LGA neonates. The performance of screening was determined by the area under receiver-operating characteristics curves (AUC).

RESULTS

In the study population there were significant positive associations between maternal cardiac output and heart rate with neonatal birth-weight Z-score, and significant negative associations between total peripheral resistance and mean arterial pressure (MAP) with neonatal birth-weight Z-score. In pregnancies delivering SGA neonates (n = 249 (8.8%)), cardiac output and heart rate were lower and total peripheral resistance and MAP were higher, whereas in pregnancies delivering LGA neonates (n = 292 (10.3%)) cardiac output and heart rate were higher and total peripheral resistance and MAP were lower. The performance of screening for delivery of SGA neonates achieved by maternal characteristics and fetal biometry was not improved by the measurement of maternal cardiovascular parameters. There was a small but significant improvement in the performance of screening for delivery of LGA neonates by maternal factors and fetal biometry with the addition of maternal heart rate (comparison of AUC, P = 0.0095).

CONCLUSIONS

There are significant associations between maternal cardiac output, heart rate, total peripheral resistance and MAP and neonatal birth-weight Z-score; such findings reflect the close relationship between maternal cardiac function and fetal demands. However, assessment of these parameters at 35-37 weeks' gestation is unlikely to improve substantially the performance of screening for SGA or LGA neonates provided by a combination of maternal factors and fetal biometry. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Pregnancy-driven cardiovascular maternal miR-29 plasticity in obesity

BACKGROUND

Obesity in pregnancy (MO) is a risk factor for maternal and/or fetal cardiovascular system disorders. This study evaluated maternal CVS expression of microRNA-29 family and its target molecules in MO to test the hypotheses: CVS miR-29 concentrations are increased in pregnancy and decreased in MO.

METHODS

Non-pregnant (n=4), pregnant obese (POb, n=4), and pregnant non-obese (PnOb, n=4) baboons (Papio spp.) were studied. Maternal left ventricle (LV), left atrium (LA), and aortic arch (AA) were collected at the end of gestation. Expression of MiR-29 and elastin (ELN) mRNA were quantified.

RESULTS

LA miR-29 (a, c) expression was highest in PnOb. In the LV, miR-29b expression trended lower (P=.059) for PnOb animals. ELN mRNA expression correlated positively with miR-29b expression in AA (r=.76, P=.03).

CONCLUSION

Maternal obesity diminishes miR-29 adaptation to pregnancy. Pharmacologic, tissue-specific targeting of miRNA-29 may represent a strategy for prevention and treatment of MO complications.

Early onset fetal growth restriction

Fetal growth restriction remains a challenging entity with significant variations in clinical practice around the world. The different etiopathogenesis of early and late fetal growth restriction with their distinct progression of fetal severity and outcomes, compounded by doctors and patient anxiety adds to the quandary involving its management. This review summarises the literature around diagnosing and monitoring early onset fetal growth restriction (early onset FGR) with special emphasis on optimal timing of delivery as guided by recent research advances.

G-Protein-coupled receptors as potential drug candidates in preeclampsia: targeting the relaxin/insulin-like family peptide receptor 1 for treatment and prevention

BACKGROUND

Important roles for G-protein-coupled receptors (GPCRs) have been identified in the maternal physiological adaptations to pregnancy and in the pathogenesis of preeclampsia. On this basis, GPCRs are potential therapeutic targets for preeclampsia.

OBJECTIVES AND RATIONALE

In this review, vasopressin and apelin are initially considered in this context before the focus on the hormone relaxin and its cognate receptor, the relaxin/insulin-like family peptide receptor 1 (RXFP1). Based on both compelling scientific rationale and a promising safety profile, the relaxin ligand-receptor system is comprehensively evaluated as a potential therapeutic endpoint in preeclampsia.

SEARCH METHODS

The published literature relating to the topic was searched through January 2016 using PubMed.

OUTCOMES

Relaxin is a peptide hormone secreted by the corpus luteum; it circulates in the luteal phase and during pregnancy. Activation of RXFP1 is vasodilatory; thus, relaxin supplementation is expected to at least partly restore the fundamental vasodilatory changes of normal pregnancy, thereby alleviating maternal organ hypoperfusion, which is a major pathogenic manifestation of severe preeclampsia. Specifically, by exploiting its pleiotropic hemodynamic attributes in preeclampsia, relaxin administration is predicted to (i) reverse robust arterial myogenic constriction; (ii) blunt systemic and renal vasoconstriction in response to activation of the angiotensin II receptor, type 1; (iii) mollify the action of endogenous vasoconstrictors on uterine spiral arteries with failed remodeling and retained smooth muscle; (iv) increase arterial compliance; (v) enhance insulin-mediated glucose disposal by promoting skeletal muscle vasodilation and (vi) mobilize and activate bone marrow-derived angiogenic progenitor cells, thereby repairing injured endothelium and improving maternal vascularity in organs such as breast, uterus, pancreas, skin and fat. By exploiting its pleiotropic molecular attributes in preeclampsia, relaxin supplementation is expected to (i) enhance endothelial nitric oxide synthesis and bioactivity, as well as directly reduce vascular smooth muscle cytosolic calcium, thus promoting vasodilation; (ii) improve the local angiogenic balance by augmenting arterial vascular endothelial and placental growth factor (VEGF and PLGF) activities; (iii) ameliorate vascular inflammation; (iv) enhance placental peroxisome proliferator-activated receptor gamma, coactivator 1 alpha (PCG1α) expression, and hence, peroxisome proliferator-activated receptor gamma (PPAR-γ) activity and (v) confer cytotrophoblast and endothelial cytoprotection. Insofar as impaired endometrial maturation (decidualization) predisposes to the development of preeclampsia, relaxin administration in the late secretory phase and during early pregnancy would be anticipated to improve decidualization, and hence trophoblast invasion and spiral artery remodeling, thereby reducing the risk of preeclampsia. Relaxin has a favorable safety profile both in the non-pregnant condition and during pregnancy.

WIDER IMPLICATIONS

There is a strong scientific rationale for RXFP1 activation in severe preeclampsia by administration of relaxin, relaxin analogs or small molecule mimetics, in order to mollify the disease pathogenesis for safe prolongation of pregnancy, thus allowing time for more complete fetal maturation, which is a primary therapeutic endpoint in treating the disease. In light of recent data implicating deficient or defective decidualization as a potential etiological factor in preeclampsia and the capacity of relaxin to promote endometrial maturation, the prophylactic application of relaxin to reduce the risk of preeclampsia is a plausible therapeutic approach to consider. Finally, given its pleiotropic and beneficial attributes particularly in the cardiovascular system, relaxin, although traditionally considered as a 'pregnancy' hormone, is likely to prove salutary for several disease indications in the non-pregnant population.

Persistent Maternal Cardiac Dysfunction After Preeclampsia Identifies Patients at Risk for Recurrent Preeclampsia

The purpose of our study was to assess cardiac function in nonpregnant women with previous early preeclampsia before a second pregnancy to highlight the cardiovascular pattern, which may take a risk for recurrent preeclampsia. Seventy-five normotensive patients with previous preeclampsia and 147 controls with a previous uneventful pregnancy were enrolled in a case-control study and submitted to echocardiographic examination in the nonpregnant state 12 to 18 months after the first delivery. All patients included in the study had pregnancy within 24 months from the echocardiographic examination and were followed until term. Twenty-two (29%) of the 75 patients developed recurrent preeclampsia. In the nonpregnant state, patients with recurrent preeclampsia compared with controls and nonrecurrent preeclampsia had lower stroke volume (63 ± 14 mL versus 73 ± 12 mL and 70 ± 11 mL, P<0.05), cardiac output (4.6 ± 1.2 L versus 5.3 ± 0.9 L and 5.2 ± 1.0 L, P<0.05), higher E/E' ratio (11.02 ± 3.43 versus 7.34 ± 2.11 versus 9.03 ± 3.43, P<0.05), and higher total vascular resistance (1638 ± 261 dyne · s(-1) · cm(-5) versus 1341 ± 270 dyne · s(-1) · cm(-5) and 1383 ± 261 dyne · s(-1) · cm(-5), P<0.05). Left ventricular mass index was higher in both recurrent and nonrecurrent preeclampsia compared with controls (30.0 ± 6.3 g/m(2.7) and 30.4 ± 6.8 g/m(2.7) versus 24.8 ± 5.0 g/m(2.7), P<0.05). Signs of diastolic dysfunction and different left ventricular characteristics are present in the nonpregnant state before a second pregnancy with recurrent preeclampsia. Previous preeclamptic patients with nonrecurrent preeclampsia show left ventricular structural and functional features intermediate with respect to controls and recurrent preeclampsia.

Maternal functional hemodynamics in the second half of pregnancy: a longitudinal study

Objective

Cardiovascular response to passive leg raising (PLR) is useful in assessing preload reserve, but it has not been studied longitudinally during pregnancy. We aimed to investigate gestational age associated serial changes in maternal functional hemodynamics and establish longitudinal reference ranges for the second half of pregnancy.

Materials and Methods

This was a prospective longitudinal study on 98 healthy pregnant women who were examined 3–5 times during 20–40 weeks of gestation (a total of 441 observations). Maternal cardiac function and systemic hemodynamics were assessed at baseline and 90 seconds after PLR using impedance cardiography (ICG). The main outcome measures were gestational age specific changes in ICG-derived variables of maternal cardiovascular function and functional hemodynamic response to PLR.

Results

Hemodynamic response to PLR varied during pregnancy. PLR led to an insignificant increase in stroke volume during 20⁺⁰ to 31⁺⁶ weeks, but later in gestation the stroke volume was slightly lower at PLR compared to baseline. PLR caused no significant change in cardiac output between 20⁺⁰ and 23⁺⁶ weeks and a significant decrease after 24⁺⁰ weeks. A decrease in heart rate, mean arterial pressure, and cardiac contractility was observed during PLR throughout the second half of pregnancy. Systemic vascular resistance was reduced by PLR up to 32⁺⁰ weeks, but increased slightly thereafter.

Conclusion

Healthy pregnant women appear to have limited preload reserve and reduced cardiac contractility, especially in the third trimester, which makes them vulnerable to fluid overload and cardiac failure.

Hepatic hemodynamics and fetal growth: a relationship of interest for further research

BACKGROUND

It is well known that hepatic hemodynamics is an important physiologic mechanism in the regulation of cardiac output (CO). It has been reported that maternal cardiac output relates to neonatal weight at birth.

AIMS

In this study, we assessed the correlation between maternal hepatic vein Doppler flow parameters, cardiac output and neonatal birth weight.

METHODS

Healthy women with uncomplicated second or third trimester pregnancy attending the outpatient antenatal clinic of Ziekenhuis Oost-Limburg in Genk (Belgium), had a standardized combined electrocardiogram-Doppler ultrasound with Impedance Cardiography, for measurement of Hepatic Vein Impedance Index (HVI  =  [maximum velocity - minimum velocity]/maximum velocity), venous pulse transit time (VPTT  =  time interval between corresponding ECG and Doppler wave characteristics) and cardiac output (heart rate x stroke volume). After delivery, a population-specific birth weight chart, established from a cohort of 27000 neonates born in the index hospital, was used to define customized birth weight percentiles (BW%). Correlations between HVI, VPTT, CO and BW% were calculated using Spearman's ρ, linear regression analysis and R2 goodness of fit in SPSS 22.0.

RESULTS

A total of 73 women were included. There was a negative correlation between HVI and VPTT (ρ = -0.719, p < 0.001). Both HVI and VPTT correlated with CO (ρ = -0.403, p < 0.001 and ρ = 0.332, p < 0.004 resp.) and with BW% (ρ =  -0.341, p < 0.003 and ρ = 0.296, p < 0.011 resp.).

CONCLUSION

Our data illustrate that the known contribution of hepatic hemodynamics in the regulation of cardiac output is also true for women with uncomplicated pregnancies. Our study is the first to illustrate a potential link between maternal hepatic hemodynamics and neonatal birth weight. Whether this link is purely associative or whether hepatic vascular physiology has a direct impact on fetal growth is to be evaluated in more extensive clinical and experimental research.

Uteroplacental blood flow, cardiac function, and pregnancy outcome in women with congenital heart disease

BACKGROUND

Pregnant women with congenital heart disease (CHD) are susceptible to cardiovascular, obstetric, and offspring complications. In women with CHD, cardiac dysfunction may compromise uteroplacental flow and contribute to the increased incidence of obstetric and offspring events.

METHODS AND RESULTS

We performed a prospective multicenter cohort study of pregnant women with CHD and healthy pregnant women. We compared clinical, laboratory, echocardiographic, and uteroplacental Doppler flow (UDF) parameters at 20 and 32 weeks gestation, and pregnancy outcome. We related cardiovascular parameters to UDF parameters and pregnancy outcome in women with CHD. We included 209 women with CHD and 70 healthy women. Cardiovascular parameters (N-terminal pro-B-type natriuretic peptide, left and right ventricular function) differed between both groups. UDF parameters were impaired in CHD women (umbilical artery pulsatility and resistance index at 32 weeks in CHD versus healthy women, P=0.0085 and P=0.017). The following cardiovascular parameters prepregnancy and at 20 weeks gestation were associated with UDF (umbilical artery resistance index) at 32 weeks at multivariable analysis: (1) right ventricular function (tricuspid annular plane systolic excursion) (P=0.002), (2) high N-terminal pro-B-type natriuretic peptide (P=0.085), (3) systemic (P=0.001), and (4) pulmonary (P=0.045) atrioventricular valve regurgitation. Women with CHD had more obstetric (58.9% versus 32.9%, P<0.0001) and offspring events (35.4% versus 18.6%, P=0.008) than healthy women. Impaired UDF was associated with adverse obstetric and offspring outcome.

CONCLUSIONS

UDF parameters are abnormal in pregnant women with CHD. Cardiovascular function is associated with an abnormal pattern of UDF. Compromised UDF may be a key factor in the high incidence of offspring and obstetric complications in this population.

Corpus luteal contribution to maternal pregnancy physiology and outcomes in assisted reproductive technologies

Investigations in the rat model of pregnancy indicate an important role for the corpus luteal (CL) hormone relaxin in the maternal circulatory and osmoregulatory changes in pregnancy, which are epitomized by profound vasodilation and modest hypoosmolality, respectively. In a pilot study of infertile women who became pregnant through donor eggs, in vitro fertilization, and embryo transfer, the gestational rise in glomerular filtration and fall in plasma osmolality were markedly subdued. Because these women were infertile, they lacked a CL and circulating relaxin (and possibly other vasoactive CL hormones). Based on these findings in pregnant rats and women, we hypothesize that infertile women conceiving through donor eggs will have overall subdued circulatory changes (e.g., attenuated reduction in systemic vascular resistance and subdued increase in cardiac output) particularly during early pregnancy when CL hormones predominate before the full development and maturation of the placenta. In contrast, infertile women conceiving by autologous eggs retrieved after ovarian stimulation and fresh embryo transfer may have a relatively hyperdynamic circulation due to the presence of many CL (up to 20 or more) and higher circulating levels of vasodilatory ovarian hormones such as relaxin. Emerging evidence suggests that women undergoing Assisted Reproductive Technologies (ART) have increased risk for adverse pregnancy outcomes such as preeclampsia and small for gestational-age babies. This increased risk may be partly caused by the maternal milieu, which is not physiological in ART pregnancies due to the abnormal status of the CL.

Medical treatment of early-onset mild gestational hypertension reduces total peripheral vascular resistance and influences maternal and fetal complications

OBJECTIVE

Complications in early-onset mild gestational hypertension (GH) are better predicted by total peripheral vascular resistance (TPVR) > 1350 dyne than by blood pressure. We therefore aimed to assess the possible reduction of severe complications by lowering TPVR with nitric oxide (NO) donors, oral fluids and standard antihypertensive therapy in women with early-onset mild GH.

METHODS

A group of 400 patients with early-onset (20-27 weeks' gestation) mild GH (systolic and diastolic blood pressure < 170/110 mmHg) and TPVR > 1350 dyne were enrolled in a prospective non-randomized trial with sequential allocation: 100 patients were treated with nifedipine (Group A); 100 with nifedipine and NO donors (Group B); 100 with nifedipine and oral fluids (Group C); and 100 with nifedipine, NO donors and oral fluids (Group D). TPVR was checked 1 month after initiation of therapy, and the number of patients with severe maternal and fetal complications was recorded in each group. The relationship between reduction in TPVR and the frequency of severe complications was assessed.

RESULTS

Severe complications developed in 51% of patients in Group A, 48% in Group B, 53% in Group C and 35% in Group D, the frequency in Group D being significantly lower than that in the other treatment groups (P < 0.05). A reduction in TPVR of < 15% predicted the occurrence of severe complications with sensitivity 95.2% and specificity 88.3%. In Group D a reduction in TPVR of ≥ 15% was more probable (odds ratio (OR) = 2.03; 95% CI, 1.15-3.60; P < 0.015) and severe complications were less probable (OR = 0.52; 95% CI, 0.29-0.91; P < 0.023).

CONCLUSION

In women with early-onset mild GH, combined treatment with NO donors, oral fluids and nifedipine optimally reduces TPVR and seems to reduce maternal and fetal complications.

GPCRs as potential therapeutic targets in preeclampsia

Preeclampsia is an important obstetric complication that arises in 5% of women after the 20(th) week of gestation, for which there is no specific therapy and no cure. Although much of the recent investigation in this field has focused on soluble forms of the angiogenic membrane receptor tyrosine kinase Flt1 and the transforming growth factor β co-receptor Endoglin, there is significant clinical potential for several GPCR targets and their agonists or antagonists in preeclampsia. In this review, we discuss several of the most promising candidates in this category, including calcitonin receptor-like receptor / receptor activity modifying protein 1 complexes, the angiotensin AT1, 2 and Mas receptors, and the relaxin receptor RXFP1. We also address some of the controversies surrounding the roles and therapeutic potential of these GPCRs and their (ant)agonists in preeclampsia.

Left ventricular midwall mechanics at 24 weeks' gestation in high-risk normotensive pregnant women: relationship to placenta-related complications of pregnancy

OBJECTIVES

Most studies during pregnancy have assessed maternal left ventricular (LV) function by load-dependent indices, assessing only chamber function. The aim of this study was to assess afterload-adjusted LV myocardial and chamber systolic function at 24 weeks' gestation and 6 months postpartum in high-risk normotensive pregnant women.

METHODS

A group of 118 high-risk women with bilateral notching of the uterine arteries underwent an echocardiographic examination to evaluate midwall mechanics (midwall shortening (mFS%) and stress-corrected midwall shortening (SCmFS%)) of the LV at 24 weeks' gestation and 6 months postpartum. Patients were followed until delivery and pregnancies were classified retrospectively as uneventful (uncomplicated outcome) or complicated. A control group of 54 low-risk women with uneventful pregnancies without bilateral notching was also enrolled.

RESULTS

The pregnancy was uneventful in 74 (62.7%) women, whereas 44 (37.3%) developed complications. At 24 weeks' gestation, mFS% and SCmFS% were greater in the uncomplicated-outcome compared with the complicated-outcome group (25.9 ± 4.8 vs 18.8 ± 5.0%, P < 0.001 and 107.9 ± 18.4 vs 77.9 ± 20.7%, P < 0.001, respectively). At 6 months postpartum, SCmFS% remained greater in the uncomplicated-outcome compared with the complicated-outcome group (100.4 ± 21.6 vs 87.8 ± 19.1, P < 0.05). In the uncomplicated-outcome group, SCmFS% was higher during pregnancy than it was postpartum, whereas in the complicated-outcome group, it was lower during pregnancy than it was postpartum (P < 0.05).

CONCLUSIONS

Maternal cardiac midwall mechanics appear to be enhanced (SCmFS% increased compared with controls) during pregnancy compared with postpartum in high-risk patients with uncomplicated pregnancy, whereas midwall mechanics are depressed both during pregnancy and postpartum in patients with pregnancy complications.

Echocardiographic assessment of cardiovascular hemodynamics in preeclampsia

OBJECTIVE

To assess maternal cardiovascular function using echocardiography in normal and preeclamptic women in the third trimester of pregnancy.

METHODS

40 subjects, 20 with preeclampsia and 20 normotensive controls with >34 weeks gestation and singleton pregnancy were recruited. Baseline characteristics, maternal and fetal outcome were studied with systolic and diastolic parameters on echocardiography.

RESULTS

The following parameters were higher in preeclamptic subjects as compared to normotensive controls-mean cardiac output (66.85 ± 4.56 ml/min vs. 56.1 ± 1.77 ml/min); mean LV diastolic mass (131.15 ± 16.85 vs. 104.90 ± 23.17 g); systolic mass (88.5 ± 7.34 vs. 83.33 ± 23.84 g); total vascular resistance (1396.85 ± 150.2 vs. 1204.5 ± 71.182 dyne, s cm(5)). Women with preeclampsia delivered smaller babies (2410 ± 426.16 g) as compared to normotensive controls (2895 ± 276.20 g). Student 't' test was used as a test of significance.

CONCLUSION

Women with preeclampsia have significant systolic and diastolic dysfunction compared to normotensive controls. Blood pressure monitoring alone is insufficient to identify effectively, risk of cardiovascular complications in these subjects.

Maternal cardiac function in complicated twin pregnancy: a longitudinal study

OBJECTIVE

To evaluate longitudinally a cohort of twin pregnancies and to assess whether the occurrence of adverse pregnancy outcome may be related to specific maternal cardiac findings.

METHODS

Women with twin pregnancies were enrolled prospectively and underwent serial maternal echocardiography at 20-23 weeks, 26-29 weeks and 30-33 weeks of gestation. Patients were excluded if delivery took place prior to 34 weeks. Cardiac findings were compared between patients with uneventful pregnancy outcome and those who developed one of the following complications: pre-eclampsia or gestational hypertension; small-for-gestational age (SGA) neonates (birth weight of one or both twins < 5(th) centile for gestational age).

RESULTS

A group of 28 twin gestations was obtained for analysis, including eight complicated cases. At each visit, mean ± SD cardiac output (CO) was significantly higher in uncomplicated than complicated twin pregnancies (6.55 ± 0.82 vs 4.99 ± 0.67 L/min, P < 0.001 at 20-23 weeks; 7.31 ± 0.74 vs 5.66 ± 1.17 L/min, P < 0.001 at 26-29 weeks; 7.50 ± 0.89 vs 5.32 ± 0.74 L/min, P < 0.001 at 30-33 weeks), as was stroke volume (83.4 ± 12.2 vs 64.5 ± 9.2 mL, P = 0.001 at 20-23 weeks; 84.4 ± 15.6 vs 64.5 ± 12.0 mL, P = 0.003 at 26-29 weeks; 85.0 ± 19.2 vs 65.6 ± 10.7 mL, P = 0.013 at 30-33 weeks), whereas total vascular resistance (TVR) was lower (1005 ± 137 vs 1406 ± 159 dynes × s/cm(5) , P < 0.001 at 20-23 weeks; 924 ± 100 vs 1249 ± 231 dynes × s/cm(5) , P < 0.001 at 26-29 weeks; 929 ± 96 vs 1400 ± 244 dynes × s/cm(5) , P < 0.001 at 30-33 weeks). Moreover, CO, blood pressure (BP), heart rate (HR) and TVR remained stable throughout the assessed pregnancy interval in women developing a complication, whereas significant changes (rise in CO, HR and BP; fall in TVR) were noted in the uncomplicated group.

CONCLUSIONS

Maternal cardiac function in twin pregnancies complicated by pre-eclampsia or SGA neonates apparently does not undergo the profound longitudinal changes that occur in uneventful twin pregnancies.

Early and late preeclampsia: two different maternal hemodynamic states in the latent phase of the disease

Because early and late preeclampsia (PE) are thought to be different disease entities, we compared maternal cardiac function at 24 weeks gestation in a group of normotensive asymptomatic patients with subsequent development of early (<34 weeks gestation) and late (>or=34 weeks gestation) PE (blood pressure >140/90+proteinuria >300 mg/dL) to detect possible early differences in the hemodynamic state. A group of 1345 nulliparous normotensive asymptomatic women underwent at 24 weeks gestation uterine artery Doppler evaluation and maternal echocardiography calculating total vascular resistance. In the subsequent follow-up 107 patients showed PE: 32 patients had late and 75 had early PE. Five of 32 patients with late PE and 45 of 75 patients with early PE had bilateral notching of the uterine artery at 24 weeks (15.6% versus 60.0%; P<0.05). Total vascular resistance was 1605+/-248 versus 739+/-244 dyn . s . cm(-5), and cardiac output was 4.49+/-1.09 versus 8.96+/-1.83 L in early versus late PE (P<0.001). Prepregnancy body mass index was higher in late versus early PE (28+/-6 versus 24+/-2 kg/m(2); P<0.001). Early and late PE appear to develop from different hemodynamic states. Late PE appears to be more frequent in patients with high body mass index and low total vascular resistance; earlier forms of PE appear to be more frequent in patients with lower BMI and with bilateral notching of the uterine artery. These findings support the hypothesis of different hemodynamics and origins for early PE (placental mediated, linked to defective trophoblast invasion with high percentage of altered uterine artery Doppler) and late PE (linked to constitutional factors such as high body mass index).

Maternal cardiac output between 11 and 13 weeks of gestation in the prediction of preeclampsia and small for gestational age

OBJECTIVE

To investigate maternal cardiac output in the first trimester as a predictor of preeclampsia and delivery of small for gestational age (SGA) infants.

METHODS

In women attending for routine care between 11(+0) and 13(+6) weeks of gestation, we recorded maternal variables and measured cardiac output by echocardiography. We compared cardiac output in those that developed preeclampsia (n=83), pregnancy-induced hypertension (PIH) (n=87), or SGA (n=532) with those unaffected by preeclampsia, PIH, or SGA (n=3,591). Regression analysis was used to first determine which of the factors among the maternal variables were significant predictors of cardiac output in the unaffected group and, secondly, to predict each complication by a combination of maternal variables and cardiac output.

RESULTS

In the unaffected group, cardiac output increased with gestation and maternal weight and decreased with maternal age. Cardiac output was higher in parous women, in cigarette smokers, in those taking antihypertensive or beta-mimetic medications, and in those conceiving after in vitro fertilization, and lower in women of Afro-Caribbean origin. Compared with the unaffected group, cardiac output was significantly higher in the preeclampsia and PIH groups and lower in the SGA group. In screening by cardiac output and maternal variables, for a 10% false-positive rate, the detection rates were 43.4% for all preeclampsia, 52% for preeclampsia without SGA, 23.3% for PIH, and 23.9% for SGA.

CONCLUSION

In pregnancies complicated by preeclampsia, PIH, and SGA, alterations in maternal cardiac output predate the clinical onset of the disorders by several months. Maternal cardiac output in the first trimester is increased in women who develop preeclampsia and decreased in women who deliver SGA infants.

LEVEL OF EVIDENCE

II.

Total vascular resistance and left ventricular morphology as screening tools for complications in pregnancy

We evaluated the predictive value of elevated total vascular resistance on the outcome of pregnancy in normotensive high-risk primigravidas with bilateral notching of the uterine artery Doppler. A total of 526 high-risk primigravidas referred to the obstetrics outpatient clinic of Tor Vergata University with bilateral notching of the uterine artery at 20 to 22 weeks' gestation were submitted to a maternal echocardiographic examination and uterine artery Doppler evaluation at 24 weeks' gestation. Blood pressure was recorded at the time of the examination, total vascular resistance was calculated, and the geometric pattern of the left ventricle was assessed. Patients were followed until the end of pregnancy to detect fetal/maternal adverse outcomes (gestational hypertension, preeclampsia, abruptio placentae, fetal growth restriction, perinatal death, etc). A total of 111 of the 526 pregnancies showed a bilateral notch at 24 weeks' gestation, and 97 had an adverse outcome (18.44%). The best independent predictor for maternal and fetal complications was total vascular resistance (odds ratio: 91.25; 95% CI: 39.64 to 210.05; P<0.001). The cutoff value was 1400 dynes x s x cm(-5), with a sensitivity and a specificity of 89% and 94%, respectively. A high relative wall thickness of the left ventricle (>0.37; odds ratio: 2.47; 95% CI: 1.12 to 5.44) and a hypertrophized ventricle (left ventricular mass >130 g; odds ratio: 2.52; 95% CI: 1.12 to 5.64) were also independent predictors (P<0.05). Echocardiography might identify at 24 weeks' gestation patients who subsequently develop maternal and fetal complications through the assessment of maternal hemodynamics and left ventricular geometry.