Abnormal maternal cardiac function and morphology in pregnancies complicated by intrauterine 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..

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.

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.

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.

Subclinical cardiac performance in obese and overweight women as a potential risk factor of preeclampsia

OBJECTIVES

Failure to increase cardiac output owing to suboptimal cardiac performance in obese women may contribute to placental hypoperfusion, and therefore subsequently to the abnormal placental development. The aim of this study was to evaluate the relationship between left ventricle (LV) function in overweight and obese pregnant women and parameters of blood flow in uterine arteries.

STUDY DESIGN AND MAIN OUTCOME MEASURES

We conducted a prospective cohort study, which included consecutive 87 women with singleton pregnancy - 56 women with normal weight and 31 overweight and obese women. During pregnancy blood pressure, echocardiography and the assessment of blood flow in uterine arteries - pulsatility index (PI) and resistance index (RI) were assessed on two visits (V): V1 between 10 and 14 weeks and V2 between 25 and 30 weeks of gestation. A stepwise logistic regression analysis was performed to determine the independent predictors of upper quartile of RI and PI during V2 in the study population.

RESULTS

The multivariate logistic regression analysis showed that LVCI and LV mass measured on V1 were the only independent predictors of upper quartile of RI during V2, whereas LVCI was the only independent predictor of upper quartile of PI during V2.

CONCLUSIONS

Subclinical left ventricle dysfunction in obese and overweight women, present from the first trimester, may contribute to placental hypoperfusion and higher resistance in uterine arteries later during pregnancy. This may lead in some women to preeclampsia.

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.

Atrial septal aneurysm in pregnancy: echocardiography and obstetric outcomes

Background Atrial septal aneurysm (ASA) is an uncommon cardiac anomaly that increases maternal morbidity during pregnancy. ASA is related to atrial arrhythmia thromboembolism and it may accompany congenital anomalies such as an atrial septal defect (ASD) or patent foramen ovale (PFO). There are no studies examining pregnancy outcomes in pregnant women with ASA. We aimed to investigate the cardiologic parameters and obstetric outcomes of pregnant women diagnosed with ASA. Methods This prospective cohort study analyzed 45 pregnant women diagnosed with ASA, who continued their follow-ups in an obstetric tertiary care center. Results A total of 45 pregnant women were recruited; seven pregnancies ended before the 20th gestational week (six spontaneous abortion, one fetal anomaly), 38 women gave birth. In total, there were 32 term births (≥37 weeks), six preterm births (<37 weeks), two extremely preterm births <28 weeks). Among 38 babies delivered, several obstetrical complications such as oligohydramnios, spontaneous preterm labor, intrauterine growth restriction (IUGR), preeclampsia and gestational diabetes mellitus (GDM) developed in 16 patients, while 22 women ended with term pregnancy without any complications. Deep venous thrombosis (DVT) developed in one patient. Conclusion ASA may have an increased risk for cardiac complications during pregnancy and may also be associated with poor pregnancy outcomes. Increased attention to these entities with more studies is needed in order to determine a potential risk for pregnant women.

Cardiovascular effects of severe late-onset preeclampsia are reversed within six months postpartum

OBJECTIVES

Preeclampsia (PE) is a common pregnancy-related disorder associated with cardiovascular long-term disease. Eighty percent are late-onset PE, occurring after 34 gestational weeks, and can present with severe symptoms. Magnitude and reversibility rate of maternal cardiovascular changes after severe late-onset PE have not been characterized. This study therefore evaluated longitudinal dynamics of maternal cardiovascular changes after severe late-onset PE.

STUDY DESIGN

Six previously normotensive women with severe late-onset PE and eight pregnant controls were included. Severe PE was defined as systolic blood pressure (SBP) ≥ 160 mmHg or diastolic blood pressure (DBP) ≥ 110 mmHg and proteinuria with/without evidence of end-organ dysfunction, or SBP ≥ 140 mmHg or DBP ≥ 90 mmHg with/without proteinuria and with evidence of end-organ dysfunction. Cardiovascular function was assessed by magnetic resonance imaging at 1-3 days, one week and six months postpartum.

RESULTS

Left ventricular mass at 1-3 days postpartum was higher after severe late-onset PE (57 g/m²) compared to after normal pregnancy (48 g/m²; p = 0.01). Pulse wave velocity (PWV) decreased between 1 and 3 days and six months postpartum after PE (6.1 to 5.0 m/s; p = 0.028). There was no difference in PWV 1-3 days postpartum after severe PE compared after normal pregnancy (6.1 versus 5.6 m/s; p = 0.175). Blood pressure normalized within six months in all but one patient.

CONCLUSIONS

Cardiac effects after severe late-onset PE were small and transient. This indicates that left ventricular hypertrophy after severe late-onset PE may be a secondary physiologic response to increased peripheral resistance in PE. Vascular mechanisms rather than persistent cardiac hypertrophy postpartum may be the culprit for increased long-term cardiovascular risk after PE.

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.

Maternal Central Blood Pressure Is Associated with Fetal Middle Cerebral Artery Dopplers

Cardiovascular adaptations to pregnancy involve physiological mechanisms that increase cardiac output, decrease total vascular resistance, and decrease both systolic and diastolic blood pressure (BP). These maternal hemodynamic changes modulate uteroplacental blood flow and fetal-placental Doppler indices. Our objective was to create maternal cardiac profiles of pregnant women using non-invasive measurements of central BP to identify changes in maternal-fetal hemodynamics as a surrogate to fetal status. This was a prospective cohort study of all singleton pregnancies in a perinatal referral center between January and April 2018. Central BP was measured non-invasively using the BP+ device. The BP+ device is a supra-systolic oscillometric central BP device, which measures BP waveforms peripherally and calculates central BP. We compared various BP+ values for peripheral BP with central BP and stratified by gestational age. We investigated the correlations between peripheral BP, central BP, estimated fetal weight (EFW), and the pulsatility indices (PI) of Doppler velocimetry and demonstrate that both central systolic and diastolic BP correlated to peripheral systolic and diastolic BP. Linear regression analysis confirmed that central BP predicts the middle cerebral artery (MCA) PI. The MCA PI correlated with EFW, specifically higher central systolic BP is associated with a lower MCA PI, implying a possible etiology of fetal brain shunting with poor placental perfusion. Future studies using predictors and markers of fetal outcomes from maternal cardiac parameters should consider maternal cardiovascular measurements to peripheral arterial BP.

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.

Effects of low maternal heart rate on fetal growth and birthweight

OBJECTIVE

To evaluate the association between birthweight and maternal heart rate (MHR) or heart rate variability (HRV) under resting conditions at 20-24 gestational weeks and 34 weeks or later (34+ weeks).

METHODS

Data were retrospectively reviewed from the Safe Passage Study, a prospective longitudinal cohort study of alcohol use in pregnancy and birth outcomes in Cape Town, South Africa, between August 2007 and January 2015. Using custom-designed software, MHR and indicators of HRV were obtained from the recorded maternal electrocardiograms and compared with birthweight and z-scores of birthweight adjusted for gestation and gender.

RESULTS

Data from 5655 women were included. MHR increased from 84.6 bpm at 20-24 weeks to 88.3 bpm at 34+ weeks. Increasing MHR from 70-80 to 80-90 and 90-100 bpm at 20-24 weeks was associated with increasing birthweight from 2940 to 2998 and 3032 g, respectively (P<0.05). MHR and HRV contributed 29% to the variability associated with birthweight, whereas maternal body mass index at recruitment contributed 44%. Similar associations were observed for MHR at 34+ weeks.

CONCLUSION

The observed association of low maternal heart rate with birthweight might help to identify pregnancies at risk of poor fetal growth.

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.

Uterine and fetal placental Doppler indices are associated with maternal cardiovascular function

BACKGROUND

The mechanism underlying fetal-placental Doppler index changes in preeclampsia and/or fetal growth restriction are unknown, although both are associated with maternal cardiovascular dysfunction.

OBJECTIVE

We sought to investigate whether there was a relationship between maternal cardiac output and vascular resistance and fetoplacental Doppler findings in healthy and complicated pregnancy.

STUDY DESIGN

Women with healthy pregnancies (n=62), preeclamptic pregnancies (n=13), preeclamptic pregnancies with fetal growth restriction (n=15), or fetal growth restricted pregnancies (n=17) from 24-40 weeks gestation were included. All of them underwent measurement of cardiac output with the use of an inert gas rebreathing technique and derivation of peripheral vascular resistance. Uterine and fetal Doppler indices were recorded; the latter were z scored to account for gestation. Associations were determined by polynomial regression analyses.

RESULTS

Mean uterine artery pulsatility index was higher in fetal growth restriction (1.37; P=.026) and preeclampsia+fetal growth restriction (1.63; P=.001) but not preeclampsia (0.92; P=1) compared with control subjects (0.8). There was a negative relationship between uterine pulsatility index and cardiac output (r²=0.101; P=.025) and umbilical pulsatility index z score and cardiac output (r²=0.078; P=.0015), and there were positive associations between uterine pulsatility index and peripheral vascular resistance (r²=0.150; P=.003) and umbilical pulsatility index z score and peripheral vascular resistance (r²= 0.145; P=.001). There was no significant relationship between cardiac output and peripheral vascular resistance with cerebral Doppler indices.

CONCLUSION

Uterine artery Doppler change is abnormally elevated in fetal growth restriction with and without preeclampsia, but not in preeclampsia, which may explain the limited sensitivity of uterine artery Doppler changes for all these complications when considered in aggregate. Furthermore, impedance within fetoplacental arterial vessels is at least, in part, associated with maternal cardiovascular function. This relationship may have important implications for fetal surveillance and would inform therapeutic options in those pathologic pregnancy conditions currently, and perhaps erroneously, attributed purely to placental maldevelopment. Uterine and fetal placental Doppler indices are associated significantly with maternal cardiovascular function. The classic description of uterine and fetal Doppler changes being initiated by placental maldevelopment is a less plausible explanation for the pathogenesis of the conditions than that relating to maternal cardiovascular changes.

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.

Maternal heart rate patterns under resting conditions in late pregnancy

Objectives:

To describe maternal heart rate patterns observed during antenatal monitoring under resting conditions between the gestational ages of 34 to 38 weeks and to demonstrate its associations with uterine activity.

Methods:

Each participant had five high quality ECG electrodes attached to her anterior abdominal wall which were connected to the Monica AN24 device to collect raw electrical signals from the maternal and fetal ECG and signals of uterine activity. Proprietary software was then used to download the raw data and extract the maternal and fetal heart rate patterns and uterine activity.

Results:

Several distinct maternal heart rate patterns were observed. These included unusually high or low levels of variability, tachycardia, bradycardia, regular and irregular periodic changes and sporadic changes where the heart rate suddenly decreased or increased. Some of the fluctuations, especially decelerations of maternal heart rate, seemed to be associated with uterine activity.

Conclusion:

The clinical implications of these different patterns, for both the mother and fetus, needs to be explored further. There is a need for computerized analyses of the different maternal patterns during different gestational ages to determine its relevance.

Synopsis

Various maternal heart rate patterns under resting conditions in late pregnancy are described.

Gestation-Specific Changes in the Anatomy and Physiology of Healthy Pregnant Women: An Extended Repository of Model Parameters for Physiologically Based Pharmacokinetic Modeling in Pregnancy

BACKGROUND

In the past years, several repositories for anatomical and physiological parameters required for physiologically based pharmacokinetic modeling in pregnant women have been published. While providing a good basis, some important aspects can be further detailed. For example, they did not account for the variability associated with parameters or were lacking key parameters necessary for developing more detailed mechanistic pregnancy physiologically based pharmacokinetic models, such as the composition of pregnancy-specific tissues.

OBJECTIVES

The aim of this meta-analysis was to provide an updated and extended database of anatomical and physiological parameters in healthy pregnant women that also accounts for changes in the variability of a parameter throughout gestation and for the composition of pregnancy-specific tissues.

METHODS

A systematic literature search was carried out to collect study data on pregnancy-related changes of anatomical and physiological parameters. For each parameter, a set of mathematical functions was fitted to the data and to the standard deviation observed among the data. The best performing functions were selected based on numerical and visual diagnostics as well as based on physiological plausibility.

RESULTS

The literature search yielded 473 studies, 302 of which met the criteria to be further analyzed and compiled in a database. In total, the database encompassed 7729 data. Although the availability of quantitative data for some parameters remained limited, mathematical functions could be generated for many important parameters. Gaps were filled based on qualitative knowledge and based on physiologically plausible assumptions.

CONCLUSION

The presented results facilitate the integration of pregnancy-dependent changes in anatomy and physiology into mechanistic population physiologically based pharmacokinetic models. Such models can ultimately provide a valuable tool to investigate the pharmacokinetics during pregnancy in silico and support informed decision making regarding optimal dosing regimens in this vulnerable special population.

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.

Effect of a nitric oxide donor on maternal hemodynamics in fetal growth restriction

OBJECTIVE

To evaluate the effect on maternal cardiovascular parameters of treatment with a nitric oxide (NO) donor and plasma volume expansion in pregnancies complicated by fetal growth restriction (FGR).

METHODS

Twenty-six pregnant women with a diagnosis of FGR were treated with transdermal patches of a NO donor and plasma volume expansion by co-administration of oral fluids. We compared the treated group to a historical control group of untreated FGR patients. Hemodynamic indices were obtained using the UltraSonic Cardiac Output Monitor system.

RESULTS

At diagnosis, the two groups were similar in terms of maternal and hemodynamic characteristics. In the treated group, we found a significant increase in maternal cardiac output and stroke volume and a decrease in systemic vascular resistance after 2 weeks of therapy. No significant differences were found 2 weeks after diagnosis in the untreated group. The treated group delivered infants with higher birth-weight centile than did the untreated control group.

CONCLUSIONS

The combined therapeutic approach of NO donor administration and plasma volume expansion in FGR apparently improves significantly maternal hemodynamic indices. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Maternal hemodynamics: a method to classify hypertensive disorders of pregnancy

BACKGROUND

The classification of hypertensive disorders of pregnancy is based on the time at the onset of hypertension, proteinuria, and other associated complications. Maternal hemodynamic interrogation in hypertensive disorders of pregnancy considers not only the peripheral blood pressure but also the entire cardiovascular system, and it might help to classify the different clinical phenotypes of this syndrome.

OBJECTIVE

This study aimed to examine cardiovascular parameters in a cohort of patients affected by hypertensive disorders of pregnancy according to the clinical phenotypes that prioritize fetoplacental characteristics and not the time at onset of hypertensive disorders of pregnancy.

STUDY DESIGN

At the fetal-maternal medicine unit of Ziekenhuis Oost-Limburg (Genk, Belgium), maternal cardiovascular parameters were obtained through impedance cardiography using a noninvasive continuous cardiac output monitor with the patients placed in a standing position. The patients were classified as pregnant women with hypertensive disorders of pregnancy who delivered appropriate- and small-for-gestational-age fetuses. Normotensive pregnant women with an appropriate-for-gestational-age fetus at delivery were enrolled as the control group. The possible impact of obesity (body mass index ≥30 kg/m²) on maternal hemodynamics was reassessed in the same groups.

RESULTS

Maternal age, parity, body mass index, and blood pressure were not significantly different between the hypertensive disorders of pregnancy/appropriate-for-gestational-age and hypertensive disorders of pregnancy/small-for-gestational-age groups. The mean uterine artery pulsatility index was significantly higher in the hypertensive disorders of pregnancy/small-for-gestational-age group. The cardiac output and cardiac index were significantly lower in the hypertensive disorders of pregnancy/small-for-gestational-age group (cardiac output 6.5 L/min, cardiac index 3.6) than in the hypertensive disorders of pregnancy/appropriate-for-gestational-age group (cardiac output 7.6 L/min, cardiac index 3.9) but not between the hypertensive disorders of pregnancy/appropriate-for-gestational-age and control groups (cardiac output 7.6 L/min, cardiac index 4.0). Total vascular resistance was significantly higher in the hypertensive disorders of pregnancy/small-for-gestational-age group than in the hypertensive disorders of pregnancy/appropriate-for-gestational-age group and the control group. All women with hypertensive disorders of pregnancy showed signs of central arterial dysfunction. The cardiovascular parameters were not influenced by gestational age at the onset of hypertensive disorders of pregnancy, and no difference was observed between the women with appropriate-for-gestational-age fetuses affected by preeclampsia or by gestational hypertension with appropriate-for-gestational-age fetuses. Women in the obese/hypertensive disorders of pregnancy/appropriate-for-gestational-age and obese/hypertensive disorders of pregnancy/small-for-gestational-age groups showed a significant increase in cardiac output, as well as significant changes in other parameters, compared with the nonobese/hypertensive disorders of pregnancy/appropriate-for-gestational-age and nonobese/hypertensive disorders of pregnancy/small-for-gestational-age groups.

CONCLUSION

Significantly low cardiac output and high total vascular resistance characterized the women with hypertensive disorders of pregnancy associated with small for gestational age due to placental insufficiency, independent of the gestational age at the onset of hypertension. The cardiovascular parameters were not significantly different in the women with appropriate-for-gestational-age or small-for-gestational-age fetuses affected by preeclampsia or gestational hypertension. These findings support the view that maternal hemodynamics may be a candidate diagnostic tool to identify hypertensive disorders in pregnancies associated with small-for-gestational-age fetuses. This additional tool matches other reported evidence provided by uterine Doppler velocimetry, low vascular growth factors in the first trimester, and placental pathology. Obesity is associated with a significantly higher cardiac output and outweighs other determinants of hemodynamics in pregnancy; therefore, in future studies on hypertensive disorders, obesity should be studied as an additional disease and not simply as a demographic characteristic.

Echocardiographic Techniques of Deformation Imaging in the Evaluation of Maternal Cardiovascular System in Patients with Complicated Pregnancies

Cardiovascular diseases (CVD) represent the leading cause of maternal mortality and morbidity. Knowledge of CVD in women is constantly evolving and data are emerging that female-specific risk factors as complications of pregnancy are conditions associated with an increased risk for the long-term development of CVD. Echocardiography is a safe and effective imaging technique indicated in symptomatic or asymptomatic pregnant women with congenital heart diseases who require close monitoring of cardiac function. Deformation imaging is an echocardiographic technique used to assess myocardial function by measuring the actual deformation of the myocardium through the cardiac cycle. Speckle-tracking echocardiography (STE) is a two-dimensional (2D) technique which has been found to be more accurate than tissue Doppler to assess both left ventricular (LV) and right ventricular (RV) myocardial function. The use of 2D STE however might present some technical issues due to the tomographic nature of the technique and the motion in the three-dimensional space of the myocardial speckles. This has promoted the use of 3D STE to track the motion of the speckles in the 3D space. This review will focus on the clinical value of the new echocardiographic techniques of deformation imaging used to assess the maternal cardiovascular system in complicated pregnancies.

Relationship between maternal hemodynamics and plasma natriuretic peptide concentrations during pregnancy complicated by preeclampsia and fetal growth restriction

OBJECTIVE

A proper maternal cardiovascular adaptation to the pregnancy plays a key role for promoting an adequate uteroplacental perfusion, for ensuring normal fetal development and for preventing gestational hypertensive complications such as preeclampsia. This study aims to evaluate hemodynamic measurements obtained by noninvasive methods among preclamptic women with and without fetal growth restriction (FGR) and the relationship with plasma levels of natriuretic peptides.

STUDY DESIGN

The study compared 98 pregnant women (n=48 with preeclampsia; n=50 normotensive pregnant women) and 50 nonpregnant normotensive control subjects undergoing anultrasonic cardiac output monitor (USCOM) and plasma assessment of atrial N-terminal pro B-type natriuretic peptide (NT-proBNP). The statistical analysis was carried out by analysis of variance and correlation analysis.

RESULTS

Preeclampsia state is associated with increased vascular resistance (mean 1587±236 vs 978±153 dyn s cm^-3) and lower cardiac output (mean 5.7±1.1 vs 6.78±0.8 l) and this hemodynamic state is associated with higher levels of NT-proBNP (mean 121.2±26.3 vs 42.5±11.4 pg ml^-1); furthermore, we found an inverse correlation between maternal cardiac output and plasma levels of NT-proBNP only if preeclampsia is associated with FGR.

CONCLUSION

The elevated NT-proBNP in preeclampsia may reflect ventricular stress and subclinical cardiac dysfunction worsening if FGR is present. This may have implications for the acute management of the preeclampsia and FGR women and for appropriately timed therapeutic interventions later in life.

Change in maternal cardiac output from preconception to mid-pregnancy is associated with birth weight in healthy pregnancies

OBJECTIVE

Birth weight (BW) is thought to be determined by maternal health and genetic, nutritional and placental factors, the latter being influenced by anatomical development and perfusion. Maternal cardiovascular changes contribute to uteroplacental perfusion; however, they have not yet been investigated in relation to fetal growth or BW. Our aim was to explore the relationship between maternal cardiovascular adaptation, fetal growth and BW in healthy pregnancies.

METHODS

This was a longitudinal prospective study of women planning to conceive a pregnancy. Maternal cardiac output (CO), cardiac index (CI), pulse-wave velocity, aortic augmentation index, central blood pressure and peripheral vascular resistance were assessed prior to pregnancy and at 6, 23 and 33 weeks' gestation. Fetal growth was assessed using serial ultrasound measurements of biometry.

RESULTS

In total, 143 women volunteered to participate and were eligible for study inclusion. A total of 101 women conceived within 18 months and there were 64 live births with normal pregnancy outcome. There were positive correlations between BW and the pregnancy-induced changes in CO (ρ = 0.4, P = 0.004), CI (ρ = 0.3, P = 0.02) and peripheral vascular resistance (ρ = 0.3, P = 0.02). There were significant associations between second-to-third-trimester fetal weight gain and the prepregnancy-to-second-trimester increase in CO (Δ, 0.8 ± 1.2 L/min; ρ = 0.3, P = 0.02) and CI (Δ, 0.4 ± 0.6 L/min/m² ; ρ = 0.3, P = 0.04) and reduction in aortic augmentation index (Δ, -10 ± 9%; ρ = -0.3, P = 0.04).

CONCLUSIONS

In healthy pregnancy, incremental changes in maternal CO in early pregnancy are associated with third-trimester fetal growth and BW. It is plausible that this association is causative as the changes predate third-trimester fetal growth and eventual BW. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

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.

Maternal cardiac deceleration capacity: a novel insight into maternal autonomic function in pregnancies complicated by hypertensive disorders and intrauterine growth restriction

OBJECTIVE

To explore maternal cardiac deceleration capacity (DC), a marker of autonomic function derived from electrocardiographic (ECG) signals, in pregnancies complicated by intrauterine growth restriction (IUGR) and hypertensive disorders of pregnancy (HDP) associated to IUGR (HDP-IUGR) or to appropriate for gestational age fetal growth (HDP-AGAf).

METHODS

Prospective single center case-control study conducted at Buzzi Children's Hospital, Milan. Maternal ECGs were analyzed by Phase Rectified Signal Averaging (PRSA) method to obtain cardiac DC in women with: HDP-IUGR, HDP-AGAf, severe-IUGR, mild-IUGR and uncomplicated pregnancies. IUGR was defined as abdominal circumference <5th centile; severe-IUGR was associated with umbilical artery Doppler pulsatility index >2 standard deviations. Non-parametric tests were adopted.

RESULTS

269 women were recruited. Women with HDP-IUGR (n=35) showed significantly higher cardiac DC compared both to controls (n=141) (p=0.003) and women with HDP-AGAf (n=18) (p=0.01). Women with severe-IUGR (n=14) showed significantly higher DC than controls (p=0.01). Women with mild-IUGR (n=61) as well as women with HDP-AGAf showed no differences in DC compared to controls (both p=0.3).

CONCLUSIONS

Women with pregnancy complicated by severe placental failure, such as HDP-IUGR and severe IUGR, show significant autonomic alterations, as indicated by elevated cardiac DC. On the contrary, pregnancy complications such as HDP-AGAf and mild IUGR show no impact on maternal autonomic balance. We present a new approach to explore maternal autonomic cardiovascular regulation that might reflect the severity of placental vascular insufficiency.

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.

Cardiac output and related haemodynamics during pregnancy: a series of meta-analyses

OBJECTIVE

Cardiac output, a fundamental parameter of cardiovascular function, has consistently been shown to increase across healthy pregnancy; however, the time course and magnitude of adaptation remains equivocal within published literature. The aim of the present meta-analyses was to comprehensively describe the pattern of change in cardiac output during healthy pregnancy.

METHOD

A series of meta-analyses of previously published cardiac output data during healthy, singleton pregnancies was completed. PubMed and Scopus databases were searched for studies published between 1996 and 2014. Included studies reported absolute values during a predetermined gestational age (non-pregnant, late first trimester, early and late second trimester, early and late third trimester, early and late postpartum). Cardiac output was measured through echocardiography, impedance cardiography or inert gas rebreathing. Observational data were meta-analysed at each gestational age using a random-effects model. If reported, related haemodynamic variables were evaluated.

RESULTS

In total, 39 studies were eligible for inclusion, with pooled sample sizes ranging from 259 to 748. Cardiac output increased during pregnancy reaching its peak in the early third trimester, 1.5 L/min (31%) above non-pregnant values. The observed results from this study indicated a non-linear rise to this point. In the early postpartum, cardiac output had returned to non-pregnant values.

CONCLUSION

The present results suggest that cardiac output peaks in the early third trimester, following a non-linear pattern of adaptation; however, this must be confirmed using longitudinal studies. The findings provide new insight into the normal progression of cardiac output during pregnancy.

Maternal subclinical vascular changes in fetal growth restriction with and without pre-eclampsia

OBJECTIVE

To assess maternal vascular structure and function in pregnancies complicated by fetal growth restriction (FGR), in women with and without pre-eclampsia (PE) at the time of FGR diagnosis.

METHODS

We evaluated 124 women with a pregnancy complicated by FGR, of whom 60 had PE and 64 did not, and compared these findings to those of 110 normal women (controls). The group of FGR pregnancies without PE was further subdivided according to gestational age at FGR diagnosis into early onset (< 32 weeks) or late onset (≥ 32 weeks). Maternal carotid intima-media thickness (IMT), blood pressure (BP), carotid artery distensibility (CD), circumferential wall stress (CWS) and inferior vena cava (IVC) collapsibility were assessed by ultrasound at the time of FGR diagnosis.

RESULTS

Compared to controls, cases of FGR with PE showed increased maternal carotid IMT (0.425 (interquartile range (IQR), 0.381-0.486) vs 0.409 (IQR, 0.386-0.439) mm; P = 0.021), BP (mean, 109 (IQR, 101-117) vs 82  (IQR, 77-89) mmHg; P  < 0.001) and CWS (19.7 (IQR, 17.0-22.7) vs 12.2 (IQR, 11.1-13.7) kPa; P < 0.001), and reduced CD (25.3 (IQR, 15.7-35.6) vs 31.9 (IQR, 25.4-41.1) kPa(-1)  × 10(-3) ; P = 0.037) and IVC collapsibility indices (0.07 (IQR, 0.06-1.11) vs 0.10 (IQR, 0.06-0.13); P  =  0.136). Similarly, compared to controls, in cases of FGR without PE maternal carotid IMT (0.436  (IQR, 0.392-0.476) mm; P  = 0.001) and BP (88 (IQR, 81-95) mmHg; P < 0.001) were increased but CD and IVC collapsibility were similar. When analysis was subclassified according to gestational age at diagnosis, IMT and CWS were significantly increased only in early-onset FGR while BP was increased in both groups.

CONCLUSION

Normotensive women with pregnancy complicated by FGR share some subclinical vascular features with those of women with PE, which further reinforces the notion that, at least in a proportion of cases, there is a common placental disease that influences maternal cardiovascular features.

Maternal Cardiovascular Impairment in Pregnancies Complicated by Severe Fetal Growth Restriction

Fetal growth restriction and preeclampsia are both conditions of placental etiology and associated to increased risk for the long-term development of cardiovascular disease in the mother. At presentation, preeclampsia is associated with maternal global diastolic dysfunction, which is determined, at least in part, by increased afterload and myocardial stiffness. The aim of this study is to test the hypothesis that women with normotensive fetal growth-restricted pregnancies also exhibit global diastolic dysfunction. This was a prospective case-control study conducted over a 3-year period involving 29 preterm fetal growth-restricted pregnancies, 25 preeclamptic with fetal growth restriction pregnancies, and 58 matched control pregnancies. Women were assessed by conventional echocardiography and tissue Doppler imaging at diagnosis of the complication and followed-up at 12 weeks postpartum. Fetal growth-restricted pregnancies are characterized by a lower cardiac index and higher total vascular resistance index than expected for gestation. Compared with controls, fetal growth-restricted pregnancy was associated with significantly increased prevalence ( P <0.001) of asymptomatic left ventricular diastolic dysfunction (28% versus 4%) and widespread impaired myocardial relaxation (59% versus 21%). Unlike preeclampsia, cardiac geometry and intrinsic myocardial contractility were preserved in fetal growth-restricted pregnancy. Fetal growth-restricted pregnancies are characterized by a low output, high resistance circulatory state, as well as a higher prevalence of asymptomatic global diastolic dysfunction and poor cardiac reserve. These findings may explain the increased long-term cardiovascular risk in these women who have had fetal growth-restricted pregnancies. Further studies are needed to clarify the postnatal natural history of cardiac dysfunction in these women.

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.

Maternal cardiac function in normal twin pregnancy: a longitudinal study

OBJECTIVE

To investigate maternal cardiac function in a cohort of uncomplicated twin gestations assessed longitudinally.

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 any of these complications occurred after recruitment: delivery < 34 weeks; pre-eclampsia or gestational hypertension; small-for-gestational age neonates (birth weight of one or both twins < 5(th) centile for gestational age). Cardiac findings were compared with those obtained at the same gestational age periods in a group of singleton gestations.

RESULTS

A group of 20 uncomplicated twin gestations was obtained for analysis and 10 singleton pregnancies were then selected as controls. At each visit, mean ± SD cardiac output (CO) was significantly higher in twins than in singletons (6.55 ± 0.82 vs 5.62 ± 0.82 L/min, P = 0.007 at 20-23 weeks; 7.31 ± 0.74 vs 6.39 ± 0.74 L/min, P = 0.003 at 26-29 weeks; 7.50 ± 0.89 vs 6.68 ± 0.65 L/min, P = 0.015 at 30-33 weeks), whereas total vascular resistance (TVR) was lower (1005 ± 137 vs 1179 ± 199 dynes × s/cm(5) , P = 0.009 at 20-23 weeks; 924 ± 100 vs 1070 ± 138 dynes × s/cm(5), P = 0.003 at 26-29 weeks; 929 ± 96 vs 1031 ± 122 dynes × s/cm(5), P = 0.018 at 30-33 weeks). In both twins and singletons, CO showed a significant increase while TVR decreased significantly throughout the assessed pregnancy time period.

CONCLUSION

In twin gestation, maternal cardiac function apparently undergoes more profound changes compared with in singleton gestation, as testified by higher CO and lower TVR values at each stage of pregnancy starting from the mid-trimester.

Prevalence of maternal cardiac defects in women with high-resistance uterine artery Doppler indices

OBJECTIVES

To compare the prevalence of previously undiagnosed cardiac structural abnormalities in pregnant women with normal- and high-resistance midtrimester uterine artery Doppler indices.

METHODS

Maternal transthoracic echocardiography was undertaken in asymptomatic pregnant women after uterine artery Doppler screening for pre-eclampsia at 21-23 weeks' gestation. Women with a mean uterine artery pulsatility index above the 90(th) centile (1.25) for the local population (multiethnic, socially diverse and migrant) were considered to have high-resistance uteroplacental blood flow indices. The prevalence of newly diagnosed cardiac structural defects in these women was recorded.

RESULTS

A total of 491 women underwent echocardiography, of whom 205 had high-resistance uterine artery blood flow indices. There were nine previously undiagnosed, functionally significant cardiac defects in the high-resistance uterine artery blood flow group and only one, functionally insignificant cardiac defect in the normal-resistance group (P = 0.005; relative risk = 12.6, 95% confidence interval, 1.60-98.34). Multiple regression analysis demonstrated that both uterine artery Doppler indices (P = 0.024) and ethnicity (P = 0.048) contributed independently towards a higher prevalence of cardiac defects.

CONCLUSIONS

The prevalence of previously undiagnosed maternal cardiac structural abnormalities is significantly increased in women with high midtrimester uterine artery Doppler resistance indices. This observation has important consequences for the current and long-term medical care provided to these patients. Detailed maternal cardiac assessment with echocardiography may be required in migrant women with high uterine artery Doppler indices.

Comparison of pregnancy outcomes in women with repaired versus unrepaired atrial septal defect

OBJECTIVE

To compare the risks of complications during pregnancy in women with repaired and unrepaired atrial septal defects (ASDs) without associated complex cardiac lesions.

DESIGN

A retrospective multicentre study.

SETTING

Tertiary centres in the Netherlands and Belgium.

POPULATION

Women with ASD without associated complex cardiac lesions.

METHODS

Women were identified using two congenital heart disease registries. One hundred women were identified who had 243 pregnancies, including 49 miscarriages and six terminations of pregnancy. Detailed information on each completed pregnancy (n = 188; unrepaired ASD, n = 133; repaired ASD, n = 55) was obtained using medical records and telephone interviews. In addition, data from the Generation R database (a prospective cohort study; n = 9667) were used to determine the background risk (control group).

MAIN OUTCOME MEASURES

Adjusted odds ratios (AORs) for cardiac, obstetric and neonatal events controlled for multiple pregnancies per woman using general estimating equation analysis.

RESULTS

Women with an unrepaired ASD had a higher risk of neonatal events (AOR = 2.99, 95% confidence interval [CI] 1.14-7.89, P = 0.027) than women with a repaired ASD. The risk of cardiac and obstetric complications was comparable between women with unrepaired and repaired ASDs. Compared with the general population, women with an unrepaired ASD had higher risks of pre-eclampsia (AOR = 3.54, 95% CI 1.26-9.98, P = 0.017), small-for-gestational-age births (AOR = 1.95, 95% CI 1.15-3.30, P = 0.013) and fetal mortality (AOR = 5.55, 95% CI 1.77-17.4, P = 0.003). By contrast, no differences were observed when comparing women with a repaired ASD versus controls.

CONCLUSIONS

Women with an unrepaired ASD are at increased risk of neonatal events in comparison with women with a repaired ASD. Compared with the general population, women with an unrepaired ASD are at increased risk of pre-eclampsia, small-for-gestational-age births and fetal mortality.

Hemodynamic Adaptation during Pregnancy in Chronic Hypertension

OBJECTIVE

To assess hemodynamic and NT-proANP changes in women with chronic hypertension during pregnancy.

METHODS

Stroke volume index (SI), heart rate (HR), cardiac output index (CI), systemic vascular resistance index (SVRI), pulse wave velocity (PWV), and left cardiac work index (LCWI) were measured using whole-body impedance cardiography. Systolic blood pressure (SAP), mean arterial pressure (MAP), diastolic blood pressure (DAP), and pulse pressure (PP) were also measured. Arterial compliance was defined as the SI-to-PP ratio (SI/PP). Hemodynamic parameters and NT-proANP concentrations were assessed during the early and late second trimester, the third trimester, and after delivery in 20 women with essential hypertension and 30 normotensive women.

RESULTS

Arterial blood pressure, SVRI, and PWV remained higher during the whole study period in chronic hypertensive compared with healthy pregnancies. In the early second trimester, women with chronic hypertension had significantly lower SI and NT-proANP concentrations than did normotensive women.

CONCLUSION

The hemodynamics of chronic hypertension during pregnancy are characterized by persistent high vascular resistance. Lower SI and NT-proANP values found in chronic hypertensive pregnancies during the early second trimester may suggest a reduced intravascular volume increase during pregnancy.

Maternal cardiac function in normotensive and pre-eclamptic intrauterine growth restriction

OBJECTIVES

To compare maternal cardiac function between pregnancies complicated by normotensive and pre-eclamptic intrauterine growth restriction (IUGR).

METHODS

Two-dimensional Doppler echocardiography and Doppler tissue imaging (DTI) were used to examine 19 pregnant women with IUGR and 17 with pre-eclampsia complicated by IUGR at 20-38 weeks of gestation. Indices were converted into differences in SDs from the expected normal mean for gestation (Z-scores) and compared.

RESULTS

With respect to normal pregnancy, in the normotensive IUGR compared with the pre-eclamptic IUGR group, there were similar reductions in maternal cardiac output (Z-score, - 1.71 vs. - 1.37, P = 0.26) and heart rate (Z-score, - 3.67 vs. - 9.43, P = 0.1) and a similar increase in total vascular resistance (Z-score, 2.91 vs. 3.93, P = 0.05). There was also a greater decrease in stroke volume (Z-score, - 1.72 vs. - 0.69, P = 0.01), a smaller increase in mean arterial pressure (Z-score, 0.73 vs. 2.94, P < 0.01) and a smaller decrease in DTI systolic velocity at the lateral mitral margin (Z-score, - 0.4 vs. - 1.42, P = 0.02). In terms of diastolic function, there was a smaller transmitral late diastolic velocity (Z-score, 0.04 vs. 0.93, P = 0.03) and a greater DTI early diastolic velocity at the lateral mitral margin (Z-score, - 0.17 vs. - 1.6, P < 0.01).

CONCLUSIONS

In normotensive IUGR and pre-eclamptic IUGR there is a similar alteration in maternal left ventricular systolic function, but there is greater impairment in maternal diastolic function in pre-eclamptic IUGR.

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).

Could birthweight prediction models be improved by adding fetal subcutaneous tissue thickness?

AIM

The aims of the study were to: (i) compare the accuracy of standard ultrasonic algorithms in the estimation of fetal weight and; (ii) test two new algorithms in order to improve the global performance of birthweight prediction by adding fetal subcutaneous tissue thickness.

METHODS

We enrolled 398 patients who were between 34 and 42 weeks' gestation. Routine ultrasonographic biometric parameters as well as subcutaneous tissue thickness ultrasound parameters were measured. Correlation matrices between ultrasound parameters, in order to evaluate the degree of multicollinearity between these parameters, were assessed to develop a stepwise multiple regression birthweight predictive model.

RESULTS

Contributions of single ultrasound measurements in predicting birthweight were examined, by fitting Log-transformed birthweight versus single ultrasound measurements. We found that the mid-thigh tissue area was able to significantly improve the performance of the birthweight prediction process when added to the other standard ultrasound measurements. We derived two new algorithms which appeared to be better at predicting birthweight. Furthermore there was a lower minimum absolute estimation error noted when compared to other reported formulae.

CONCLUSIONS

Our algorithms showed that the addition of the mid-thigh tissue evaluation in birthweight prediction was valuable in comparison to birthweight prediction models which are based on routine ultrasound parameters.

Perinatal changes of circulating N-terminal pro B-type natriuretic peptide (NT-proBNP) in normal and intrauterine-growth-restricted pregnancies

OBJECTIVE

To investigate changes in NT-proBNP in intrauterine-growth-restricted (IUGR) and appropriate-for-gestational-age (AGA) pregnancies.

METHODS

NT-proBNP levels were measured in 40 mothers (MS), umbilical cords (UC), and their 20 IUGR/ 20 AGA neonates on day 1 (N1) and day 4 (N4).

RESULTS

UC, N1, and N4 NT-proBNP was lower in IUGR pregnancies (p <or= 0.049). In both groups, NT-proBNP levels were similar in MS and higher in N1 (p <or= 0.001). In AGA, MS NT-proBNP correlated positively with UC.

CONCLUSIONS

Fetal and neonatal NT-proBNP levels are lower in IUGR compared with AGA, probably due to blood flow redistribution in IUGR and NT-proBNP placental transport in AGA. NT-proBNP levels peak on N1.

Maternal and fetal hemodynamic effects induced by nitric oxide donors and plasma volume expansion in pregnancies with gestational hypertension complicated by intrauterine growth restriction with absent end-diastolic flow in the umbilical artery

OBJECTIVE

To evaluate the effect of plasma volume expansion (PVE) and nitric oxide (NO) donors, in addition to antihypertensive therapy for gestational hypertensive pregnancies complicated by intrauterine growth restriction (IUGR) with absent end-diastolic flow (AEDF) in the umbilical artery (UA).

METHODS

This was a case-control study into which 32 gestational hypertensive pregnancies with IUGR and AEDF were enrolled. Sixteen of these were treated with antihypertensive drugs, NO donors and PVE (Group A), and 16, matched for maternal age, gestational age and fetal conditions, were treated with antihypertensive drugs only (Group B). All patients underwent fetal and uteroplacental assessment and maternal echocardiography to evaluate total vascular resistance (TVR) and cardiac output before and 5-14 days after initiation of treatment.

RESULTS

After 5-14 days of treatment, the maternal TVR in Group A fell from 2170 +/- 248 to 1377 +/- 110 dynes.s.cm(-5) (P < 0.01), and that in Group B fell from 2090 +/- 260 to 1824 +/- 126 dynes.s.cm(-5) (P < 0.01), with the reduction being greater in Group A than in Group B (P < 0.01). There was a significant increase in cardiac output in Group A after 5-14 days of treatment vs. baseline (6.19 +/- 0.77 vs. 4.32 +/- 0.66, P < 0.001), and, after treatment, cardiac output was significantly greater in Group A than it was in Group B (6.19 +/- 0.77 vs. 4.70 +/- 0.44, P < 0.001). Reappearance of end-diastolic flow in the UA occurred in 14/16 patients in Group A but in no patients in Group B (87.5% vs. 0%, P < 0.05). The interval between detection of UA-AEDF and delivery was 28 +/- 16 days in Group A and 11 +/- 6 days in Group B (P < 0.05).

CONCLUSION

Administration of NO donors and PVE in gestational hypertensive pregnancies affected by IUGR and UA-AEDF appears to improve both maternal and fetal hemodynamics, inducing prolongation of gestation.

Maternal cardiovascular function in pregnancies complicated by intrauterine growth restriction

OBJECTIVE

To investigate maternal cardiovascular function in pregnancies complicated by intrauterine growth restriction (IUGR).

METHODS

Maternal echocardiography and ambulatory blood pressure monitoring were performed in pregnancies complicated by IUGR (n = 12) and controls (n = 12), all of whom were normotensive at enrollment.

RESULTS

Compared to controls, maternal blood pressure (P = 0.016) and total vascular resistance (P = 0.008) were higher in IUGR pregnancies. Heart rate was lower (P = 0.003), as was systolic function expressed by midwall fractional shortening (P = 0.04). No significant differences between the two groups were observed for left atrial or left ventricular dimensions, nor for left ventricular geometry. Assessment of diastolic function by means of transmitral Doppler flow measurements revealed a significantly longer isovolumetric relaxation time in pregnancies with IUGR (P = 0.006).

CONCLUSIONS

In normotensive pregnancies complicated by IUGR, as compared to controls, there is decreased diastolic and systolic maternal cardiac function, and a higher blood pressure.