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

Maternal vascular dysfunction in gestational diabetes is associated with birth of small neonates

AIMS

The study aimed to evaluate maternal hemodynamic and vascular changes in women with small-for-gestational age(SGA) and large-for-gestational age(LGA) fetuses in the presence and absence of gestational diabetes mellitus(GDM).

MATERIALS

Women at 35+0 to 36+6 weeks' gestation with and without GDM were included. Maternal demographics, ultrasound for fetal growth, Doppler studies of uterine and ophthalmic arteries, carotid-femoral pulse-wave velocity(PWV), augmentation index, cardiac output, and total peripheral resistance(TPR) were recorded. Multinomial logistic regression was used.

RESULTS

Of 11,132 women, 1,228(11.0%) developed GDM. In GDM pregnancies, 158(12.8%) delivered SGA and 136(11.1%) delivered LGA neonates, while non-GDM pregnancies had 1,051(10.6%) SGA and 806(8.1%) LGA neonates. In GDM and non-GDM women, SGA groups had the highest uterine artery pulsatility index(PI) percentiles, PWV and ophthalmic artery peak systolic velocity ratio. PWV was higher in the GDM SGA group compared to non-GDM SGA group. Cardiac output was lower in SGA groups when compared to the AGA group. In women with GDM, TPR, ophthalmic artery PSV ratio and uterine artery PI percentile had a positive association with the development of SGA.

CONCLUSIONS

Women with GDM and vascular dysfunction have higher risk to deliver SGA neonates. Maternal hemodynamic and vascular maladaptation could potentially explain the development of SGA in women with GDM.

At mid-gestation, markers of placental function rather than maternal cardiac function are stronger determinants of birthweight

BACKGROUND

The role of maternal cardiac and hemodynamic assessment during normal and complicated pregnancies has gained attention during the last few years. Some researchers suggested that the manifestation of complications in pregnancy suffering from impaired placentation is mainly driven by preexisting cardiac changes, identifiable at an early stage by echocardiographic and hemodynamic assessment. It is therefore of great importance to determine the link between placental perfusion and maternal cardiac function and hemodynamics. Also, the impact of maternal cardiac function on birth weight has not been thoroughly studied.

OBJECTIVE

To elucidate the possible association of maternal cardiovascular indices with placental perfusion at mid-gestation and birthweight.

STUDY DESIGN

Prospective study on women with singleton pregnancies attending Kings' College Hospital, London, UK for a routine hospital visit at 19 to 24 weeks of gestation. We recorded maternal characteristics and medical history, measured mean arterial pressure, heart rate, uterine artery pulsatility index, umbilical artery pulsatility index, middle cerebral artery pulsatility index, and serum placental growth factor. We also performed maternal echocardiogram to assess cardiac output and peripheral vascular resistance as well as indices of diastolic and systolic cardiac function. Multivariable regression modeling was used.

RESULTS

Our cohort included 4006 women. Higher uterine artery pulsatility index values were associated with lower mean arterial pressure, heart rate, and left ventricular systolic function, after adjustment for maternal characteristics and subsequent development of hypertensive disorders of pregnancy and gestational diabetes mellitus. In a multivariable approach that explained 17.9% of the variance of the birthweight, we found that some cardiovascular indices provided small but significant contribution to the model after accounting for maternal factors and development of hypertensive disorders of pregnancy and gestational diabetes mellitus, uterine artery pulsatility index, and placental growth factor.

CONCLUSION

The findings of our study indicate a weak but significant association between maternal cardiovascular indices with placental perfusion at mid-gestation and birthweight. Our data would not support routine maternal cardiovascular assessment for predicting birthweight.

Maternal vascular indices at 36 weeks' gestation in pregnancy with small or growth-restricted fetus

OBJECTIVE

To compare maternal vascular indices and hemodynamic parameters at 35-37 weeks' gestation in pregnancies complicated by delivery of a small-for-gestational-age (SGA) or growth-restricted (FGR) neonate.

METHODS

This was a prospective observational study of women with a singleton pregnancy attending for a routine hospital visit at 35 + 0 to 36 + 6 weeks' gestation. The visit included recording of maternal demographic characteristics, medical history, vascular indices and hemodynamic parameters, which were obtained using a non-invasive operator-independent device and included pulse-wave velocity, augmentation index, cardiac output, stroke volume, central systolic and diastolic blood pressure, total peripheral resistance and heart rate. Women with hypertensive disorders of pregnancy were excluded. SGA was diagnosed if birth weight was < 10th percentile. FGR was diagnosed if, in addition to birth weight < 10th percentile, at the 35-37-week scan, uterine artery or umbilical artery pulsatility index (PI) was > 95th percentile or fetal middle cerebral artery PI was < 5th percentile.

RESULTS

Among the 6413 women included in the study, there were 605 (9.4%) cases of SGA, 133 (2.1%) cases of FGR and 5675 (88.5%) cases that were unaffected by SGA or FGR. Women with SGA or FGR, compared to unaffected pregnancies, had increased peripheral vascular resistance and reduced cardiac output. Central systolic and diastolic blood pressure were increased in the FGR group compared with the unaffected group. Aortic stiffness, as assessed by pulse-wave velocity, and augmentation index did not differ between affected and unaffected pregnancies. In the FGR group, compared with the SGA group, central systolic and diastolic blood pressure were higher, whereas heart rate was lower.

CONCLUSIONS

SGA and FGR pregnancies exhibit deranged maternal hemodynamic responses compared with unaffected pregnancies. Pregnancies with FGR have higher central blood pressure compared to those with SGA, but it remains unclear whether these differences are driven by the size of the fetus or pathological fetal growth. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Alterations in maternal cardiovascular parameters and their impact on uterine and fetal circulation in hypertensive pregnancies and fetal growth restriction

Objective

To examine potential alterations in maternal cardiovascular parameters in hypertensive pregnancies with or without fetal growth restriction (FGR) in comparison to uncomplicated normotensive pregnancies, and to determine the correlation between maternal cardiovascular parameters and changes in umbilical and uterine artery circulation.

Materials and methods

This study enrolled 73 pregnant women starting from the 20th week of gestation, categorized into three groups: hypertensive conditions (pregnancy-induced hypertension, preeclampsia or eclampsia, n = 30), hypertensive conditions with FGR (n = 8) and a control group of healthy normotensive pregnant women (n = 35). All participants underwent echocardiography to assess cardiac output and calculate peripheral vascular resistance. Additionally, fetal biometric measurements and Doppler ultrasound examinations of the uterine and umbilical artery were performed. The results were standardized into gestational age-adjusted z-scores.

Results

The mean pulsatility index (PI) of the uterine artery (1.36, p < 0.001) and umbilical artery PI z-scores (1.32, p < 0.001) showed significant increases in the hypertensive conditions + FGR group. Maternal cardiac output z-scores were notably lower in both the hypertensive + FGR group (-2.62, p = 0.001) and the hypertensive group (-2.49, p < 0.001). Peripheral vascular resistance was significantly elevated in the hypertensive + FGR group (7.43, p < 0.001) and the hypertensive group (6.06, p < 0.001). There was a positive correlation between maternal peripheral vascular resistance and uterine artery PI (R2 = 0.172; p = 0.0004), and a negative correlation between cardiac output and uterine artery PI (R2 = 0.067; p = 0.031). However, significant correlation between maternal cardiovascular parameters and umbilical artery PI was not identified.

Conclusions

Maternal cardiac output exhibits a significant decrease whereas peripheral vascular resistance increases in hypertensive pregnancies, irrespective of the presence of FGR. Both uterine and umbilical artery PI notably increase when hypertensive pregnancies are accompanied by FGR. A positive correlation exists between maternal peripheral vascular resistance and uterine artery PI, as well as a negative correlation between maternal cardiac output and uterine artery PI. However, changes in maternal cardiovascular parameters do not exhibit significant correlations with umbilical artery PI.

Maternal cardiovascular function in midgestation is related to placental angiogenesis

OBJECTIVE

To investigate whether angiogenic markers of placental function are associated with maternal cardiac function and hemodynamic responses at 19-23 weeks' gestation, controlling for maternal risk factors and pregnancy complications.

METHODS

This was a prospective study of women with singleton pregnancy attending King's College Hospital, London, UK, for a routine hospital visit at 19-23 weeks' gestation. We recorded maternal characteristics and measured mean arterial pressure (MAP), maternal heart rate, serum placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1). We also performed maternal echocardiography to assess cardiac output and peripheral vascular resistance as well as indices of diastolic and systolic function.

RESULTS

Our cohort included 4006 women. Lower PlGF values were significantly associated with higher MAP (P < 0.0001), lower maternal heart rate (P < 0.0001), lower mitral valve s' mean velocity (P = 0.027) and higher left atrial area (P = 0.022) after adjustment for maternal characteristics and pregnancy complications. sFlt-1 was associated positively with relative wall thickness (P = 0.012), whereas sFlt-1/PlGF ratio was associated negatively with mitral valve A (P = 0.006) and positively with left atrial area (P = 0.015) and MAP (P = 0.004). The magnitude of these associations was similar in the subgroup of women without any risk factors based on their obstetric and medical history.

CONCLUSIONS

A continuous association of moderate strength between angiogenic factors and subclinical maternal cardiac function alterations is present in midgestation, independently of pre-existing maternal risk factors and pregnancy complications. Impaired placental function appears to be related to mild systolic and diastolic dysfunction and cardiac remodeling. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Prediction model of preeclampsia using machine learning based methods: a population based cohort study in China

Introduction

Preeclampsia is a disease with an unknown pathogenesis and is one of the leading causes of maternal and perinatal morbidity. At present, early identification of high-risk groups for preeclampsia and timely intervention with aspirin is an effective preventive method against preeclampsia. This study aims to develop a robust and effective preeclampsia prediction model with good performance by machine learning algorithms based on maternal characteristics, biophysical and biochemical markers at 11-13 + 6 weeks' gestation, providing an effective tool for early screening and prediction of preeclampsia.

Methods

This study included 5116 singleton pregnant women who underwent PE screening and fetal aneuploidy from a prospective cohort longitudinal study in China. Maternal characteristics (such as maternal age, height, pre-pregnancy weight), past medical history, mean arterial pressure, uterine artery pulsatility index, pregnancy-associated plasma protein A, and placental growth factor were collected as the covariates for the preeclampsia prediction model. Five classification algorithms including Logistic Regression, Extra Trees Classifier, Voting Classifier, Gaussian Process Classifier and Stacking Classifier were applied for the prediction model development. Five-fold cross-validation with an 8:2 train-test split was applied for model validation.

Results

We ultimately included 49 cases of preterm preeclampsia and 161 cases of term preeclampsia from the 4644 pregnant women data in the final analysis. Compared with other prediction algorithms, the AUC and detection rate at 10% FPR of the Voting Classifier algorithm showed better performance in the prediction of preterm preeclampsia (AUC=0.884, DR at 10%FPR=0.625) under all covariates included. However, its performance was similar to that of other model algorithms in all PE and term PE prediction. In the prediction of all preeclampsia, the contribution of PLGF was higher than PAPP-A (11.9% VS 8.7%), while the situation was opposite in the prediction of preterm preeclampsia (7.2% VS 16.5%). The performance for preeclampsia or preterm preeclampsia using machine learning algorithms was similar to that achieved by the fetal medicine foundation competing risk model under the same predictive factors (AUCs of 0.797 and 0.856 for PE and preterm PE, respectively).

Conclusions

Our models provide an accessible tool for large-scale population screening and prediction of preeclampsia, which helps reduce the disease burden and improve maternal and fetal outcomes.

Evaluation of utero-placental vascularization using contrast-enhanced ultrasound: Early first trimester maternal perfusion of the intervillous space is confirmed

INTRODUCTION

The objective was to confirm and semiquantify the maternal perfusion of the intervillous space between 8 and 13 + 6 gestational weeks (GW).

METHODS

We conducted a prospective, multicenter, and nonrandomized open study. Women undergoing voluntary termination of pregnancy at three different gestational ages (Group 8 GW: 8 to 8 + 6 GW, Group 11GW: 11 to 11 + 6 GW and Group 13GW: 13 to 13 + 6 GW) were included, with 14 subjects per group. Women presenting with a personal risk of preeclampsia and/or intrauterine growth restriction were excluded. Contrast-enhanced ultrasound (CEUS) was performed with an intravenous bolus administration of 2.4 mL of microbubbles. The region of interest (ROI) was the entire placenta. The perfusion curves and kinetic parameters, including wash-in perfusion index, peak enhancement and mean transit time, were calculated.

RESULTS

Of the 42 women initially included, interpretable perfusion curves could be obtained for 33. Regardless of the gestational age, contrast was observed in the entire placenta. No significant difference in perfusion parameters was observed between groups. There was an association between signal intensity and both maternal heart frequency and placental location. Signal intensity was decreased when the heart frequency increased (p < 0.05) and when the placenta was in a nonanterior position (p > 0.005).

DISCUSSION

We confirmed the presence of maternal perfusion of the intervillous space as early as 8 GW. No significant increase in perfusion parameters was observed between 8 and 13 + 6 GW. Our observations, in accordance with the previous experiment published by Roberts et al.1, strongly challenge the classic trophoblastic plug theory.

High-fat, high-carbohydrate diet-induced prediabetes preconception in Sprague-Dawley rats as a risk factor for the development of preeclampsia: assessing changes in placental metabolic insults

Introduction

Hyperglycemia preconception deranges the establishment of a functional placenta; however, the risk of developing preeclampsia (PE) in prediabetic patients remains obscure. The aim was to assess abnormal placental changes as a risk factor for the development of PE in high-fat, high-carbohydrate (HFHC) diet-induced prediabetic (PD) rats.

Methods

HFHC diet-induced female prediabetic Sprague-Dawley rats were mated, and blood glucose concentrations, mean arterial pressure (MAP), and body weights were monitored on gestational days (GNDs) 0, 9, and 18. On GND 18, animals were euthanized. Blood and placentas were collected for biochemical analysis.

Results

Prediabetic rats showed significantly increased blood glucose concentration, proinflammatory cytokines, MAP, placental weight, and fetoplacental ratio compared with non-prediabetic (NPD) rats. Prediabetic rats showed significantly decreased placental vascular endothelial growth factor receptor 1 (VEGFR1) and placental growth factor (PLGF) and plasma nitric oxide (NO) compared with NPD.

Discussion

Prediabetes may have promoted endothelial dysfunction in the placenta and hypoxia, thus reducing PLGF and VEGFR1, which may have promoted proinflammation, endothelial dysfunction associated with NO decline, and hypertension, which is also observed in preeclamptic patients. Prediabetes may have promoted lipogenesis in placentas and fetuses that may have induced macrosomia and IUGR, also observed in preeclamptic patients. The findings from this study highlight the need for screening and monitoring of prediabetes during pregnancy to reduce the risk of developing preeclampsia.

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.

The cardiac-fetal-placental unit: fetal umbilical vein flow rate is linked to the maternal cardiac profile in fetal growth restriction

BACKGROUND

The functional maternal-fetal hemodynamic unit includes fetal umbilical vein flow and maternal peripheral vascular resistance.

OBJECTIVE

This study investigated the relationships between maternal and fetal hemodynamics in a population with suspected fetal growth restriction.

STUDY DESIGN

This was a prospective study of normotensive pregnancies referred to our outpatient clinic for a suspected fetal growth restriction. Maternal hemodynamics measurement was performed, using a noninvasive device (USCOM-1A) and a fetal ultrasound evaluation to assess fetal biometry and velocimetry Doppler parameters. Comparisons among groups were performed with 1-way analysis of variance with Student-Newman-Keuls correction for multiple comparisons and with Kruskal-Wallis test where appropriate. The Spearman rank coefficient was used to assess the correlation between maternal and fetal hemodynamics. Pregnancies were observed until delivery.

RESULTS

A total of 182 normotensive pregnancies were included. After the evaluation, 54 fetuses were classified as growth restricted, 42 as small for gestational age, and 86 as adequate for gestational age. The fetus with fetal growth restriction had significantly lower umbilical vein diameter (P<.0001), umbilical vein velocity (P=.02), umbilical vein flow (P<.0001), and umbilical vein flow corrected for fetal weight (P<.01) than adequate-for-gestational-age and small-for-gestational-age fetuses. The maternal hemodynamic profile in fetal growth restriction was characterized by elevated systemic vascular resistance and reduced cardiac output. The umbilical vein diameter was positively correlated to maternal cardiac output (r_s=0.261), whereas there was a negative correlation between maternal systemic vascular resistance (r_s=-0.338) and maternal potential energy-to-kinetic energy ratio (r_s=-0267). The fetal umbilical vein time averaged max velocity was positively correlated to maternal cardiac output (r_s=0.189) and maternal inotropy index (r_s=0.162), whereas there was a negative correlation with maternal systemic vascular resistance (r_s=-0.264) and maternal potential energy-to-kinetic energy ratio (r_s=-0.171). The fetal umbilical vein flow and the flow corrected for estimated fetal weight were positively correlated with maternal cardiac output (r_s=0.339 and r_s=0.297) and maternal inotropy index (r_s=0.217 and r=0.336), whereas there was a negative correlation between maternal systemic vascular resistance (r_s=-0.461 and r_s=-0.409) and maternal potential energy-to-kinetic energy ratio (r_s=-0.336 and r_s=-0.408).

CONCLUSION

Maternal and fetal hemodynamic parameters were different in the 3 groups of fetuses: fetal growth restriction, small for gestational age, and adequate for gestational age. Maternal hemodynamic parameters were closely and continuously correlated with fetal hemodynamic features. In particular, a maternal hemodynamic profile with high systemic vascular resistance, low cardiac output, reduced inotropism, and hypodynamic circulation was correlated with a reduced umbilical vein flow and increased umbilical artery pulsatility index. The mother, placenta, and fetus should be considered as a single cardiac-fetal-placental unit. The correlations of systemic vascular resistance, cardiac output, and inotropy index with umbilical artery impedance indicate the key role of these 3 parameters in placental vascular tree development. The umbilical vein flow rate and, therefore, the placental perfusion seems to be influenced not only by these three parameters but also by the maternal cardiovascular kinetic energy.

Umbilical vein blood flow: State-of-the-art

Placental blood supply to the fetus can be measured by evaluating the umbilical vein blood flow. Despite its potential application in healthcare, the umbilical vein blood flow volume is still used only in research setting. One of the reasons is a concern regarding its reproducibility, partly due to technology issues. Nowadays, technology improvements make this evaluation accurate and reproducible. The aim of this review is to refresh basic elements of the physiology of umbilical vein blood flow and its analysis. Its evaluation in normal and abnormal fetal growth is also discussed.

Assessing maternal cardiac function by obstetricians: technique and reference ranges

BACKGROUND

A strong body of evidence has now coalesced indicating that some obstetrical syndromes may result from maladaptive responses of the maternal cardiovascular system. Longitudinal studies have shown that these changes are complex and present before the clinical recognition of preeclampsia and fetal growth restriction, suggesting that hemodynamic maladaptation may play an etiologic role in obstetrical complications. Chronic hypertension is one of the most frequent complications of pregnancy, and recent evidence suggests that control of mild hypertension in early pregnancy improves outcome. The management of chronic hypertension can be improved by understanding specific cardiovascular hemodynamic abnormalities such as increased cardiac output or increased systemic vascular resistance, which can respond to either beta or calcium channel blockers, depending on the hemodynamic findings. Evaluation of maternal cardiac function has not been previously available to obstetrical healthcare providers using diagnostic ultrasound equipment used for fetal evaluation.

OBJECTIVE

Obstetrical ultrasound machines may be configured for various probes (endovaginal, abdominal, 3D/4D, and cardiac). This study used a cardiac probe placed in the suprasternal notch to image and measure the descending aorta diameter and the velocity time integral using pulsed and continuous wave Doppler ultrasound in normal pregnant women between 11 and 39 weeks of gestation. These measurements were followed by computation of maternal left ventricular preload, afterload, contractility, and blood flow.

STUDY DESIGN

This was a prospective cross-sectional study. A total of 400 pregnant women were recruited between 11 and 39 weeks of gestation. Imaging of the maternal aortic arch was performed by placing a cardiac probe in the suprasternal notch to identify the aortic arch using 2D and color Doppler ultrasound. The end-systolic diameter of the aorta was measured at the junction of the left subclavian artery with the descending aorta, which was followed by insonation of the descending aorta to obtain the Doppler waveform. Following insonation of the descending aorta, measurements of the aortic diameter, velocity time integral, ejection time, mean pressure gradient, heart rate, maternal weight and height, and systolic and diastolic blood pressures were entered into an Excel spreadsheet to compute the following: (1) preload measurements of stroke volume, stroke volume index, and stroke work index; (2) afterload measurements of systemic vascular resistance and the potential-to-kinetic energy ratio; (3) contractility measurements of inotropy and the Smith-Madigan inotropy index; and (4) blood flow measurements of cardiac output and the cardiac output index. Fractional polynomial regression analysis was performed for each of the above measurements using gestational age as the independent variable.

RESULTS

The diastolic and mean arterial blood pressure decreased from 11 to 18 weeks of gestation and then increased until term. The afterload measurements demonstrated similar characteristics, as all values decreased from 11 weeks until the mid and late second trimester, after which all values increased until term. Changes in contractility demonstrated an increase from 11 weeks to 25 to 28 weeks, followed by a decline until term. Changes in blood flow demonstrated an increase from 11 to 27 weeks and then declined until term. The continuous wave Doppler values were greater than the pulsed Doppler values except for the contractility measurements. Examples of abnormal cardiac measurements were identified in pregnant patients with hypertension and fetal growth restriction. An Excel calculator was created to provide quick computation of z-score measurements and their corresponding centiles described in this study.

CONCLUSION

The technique for evaluation of maternal cardiac function described in this study would allow screening of maternal left ventricular preload, afterload, contractility, and blood flow in the obstetrical clinical milieu once a cardiac probe is acquired for obstetrical ultrasound machines used for fetal evaluation. The above measurements would allow the clinician to select appropriate hypertensive medication on the basis of the results of the evaluation of the maternal left ventricle.

Is Maternal Cardiovascular Performance Impaired in Altitude-Associated Fetal Growth Restriction?

Mundo, William, Lilian Toledo-Jaldin, Alexandrea Heath-Freudenthal, Jaime Huayacho, Litzi Lazo-Vega, Alison Larrea-Alvarado, Valquiria Miranda-Garrido, Rodrigo Mizutani, Lorna G. Moore, Any Moreno-Aramayo, Richard Gomez, Patricio Gutierrez, and Colleen G. Julian. Is maternal cardiovascular performance impaired in altitude-associated fetal growth restriction? High Alt Med Biol. 23:352-360, 2022. Introduction: The incidence of fetal growth restriction (FGR) is elevated in high-altitude resident populations. This study aims to determine whether maternal central hemodynamics during the last trimester of pregnancy are altered in high-altitude FGR. Methods: In this cross-sectional study of maternal-infant pairs (FGR, n = 27; controls, n = 26) residing in La Paz, Bolivia, maternal heart rate, cardiac output (CO), stroke volume, and systemic vascular resistance (SVR) were assessed using continuous-wave Doppler ultrasound. Transabdominal Doppler ultrasound was used for uterine artery (UtA) resistance indices and fetal measures. Maternal venous soluble fms-like tyrosine kinase-1 (sFlt1) levels were measured. Results: FGR pregnancies had reduced CO, elevated SVR and UtA resistance, fetal brain sparing, and increased maternal sFlt1 versus controls. Maternal SVR was positively associated with UtA resistance and inversely associated with middle cerebral artery resistance and birth weight. Maternal sFlt1 was greater in FGR than controls and positively associated with UtA pulsatility index. Women with elevated sFlt1 levels also tended to have lower CO and higher SVR. Conclusion: Noninvasive assessment of maternal cardiovascular function may be an additional method for detecting high-risk pregnancies at high altitudes, thereby informing the need for increased surveillance and appropriate allocation of resources to minimize adverse outcomes.

Preeclampsia and Fetal Growth Restriction as Risk Factors of Future Maternal Cardiovascular Disease-A Review

Cardiovascular diseases (CVDs) remain the leading cause of death in women worldwide. Although traditional risk factors increase later-life CVD, pregnancy-associated complications additionally influence future CVD risk in women. Adverse pregnancy outcomes, including preeclampsia and fetal growth restriction (FGR), are interrelated disorders caused by placental dysfunction, maternal cardiovascular maladaptation to pregnancy, and maternal abnormalities such as endothelial dysfunction, inflammation, hypercoagulability, and vasospasm. The pathophysiologic pathways of some pregnancy complications and CVDs might be linked. This review aimed to highlight the associations between specific adverse pregnancy outcomes and future CVD and emphasize the importance of considering pregnancy history in assessing a woman's CVD risk. Moreover, we wanted to underline the role of maternal cardiovascular maladaptation in the development of specific pregnancy complications such as FGR.

Placental MRI Predicts Fetal Oxygenation and Growth Rates in Sheep and Human Pregnancy

Magnetic resonance imaging (MRI) assessment of fetal blood oxygen saturation (SO2 ) can transform the clinical management of high-risk pregnancies affected by fetal growth restriction (FGR). Here, a novel MRI method assesses the feasibility of identifying normally grown and FGR fetuses in sheep and is then applied to humans. MRI scans are performed in pregnant ewes at 110 and 140 days (term = 150d) gestation and in pregnant women at 28+3  ± 2+5 weeks to measure feto-placental SO2 . Birth weight is collected and, in sheep, fetal blood SO2 is measured with a blood gas analyzer (BGA). Fetal arterial SO2 measured by BGA predicts fetal birth weight in sheep and distinguishes between fetuses that are normally grown, small for gestational age, and FGR. MRI feto-placental SO2 in late gestation is related to fetal blood SO2 measured by BGA and body weight. In sheep, MRI feto-placental SO2 in mid-gestation is related to fetal SO2 later in gestation. MRI feto-placental SO2 distinguishes between normally grown and FGR fetuses, as well as distinguishing FGR fetuses with and without normal Doppler in humans. Thus, a multi-compartment placental MRI model detects low placental SO2 and distinguishes between small hypoxemic fetuses and normally grown fetuses.

Maternal hemodynamics and computerized cardiotocography during labor with epidural analgesia

PURPOSE

To analyze the mechanisms involved in the fetal heart rate (FHR) abnormalities after the epidural analgesia in labor.

METHODS

A prospective unblinded single-center observational study on 55 term singleton pregnant women with spontaneous labor. All women recruited underwent serial bedside measurements of the main hemodynamic parameters using a non-invasive ultrasound system (USCOM-1A). Total vascular resistances (TVR), heart rate (HR), stroke volume (SV), cardiac output (CO) and arterial blood pressure were measured before epidural administration (T0), after 5 min 5 (T1) from epidural bolus and at the end of the first stage of labor (T2). FHR was continuously recorded through computerized cardiotocography before and after the procedure.

RESULTS

The starting CO was significantly higher in a subgroup of women with low TVR than in women with high-TVR group. After the bolus of epidural analgesia in the low-TVR group there was a significant reduction in CO and then increased again at the end of the first stage, in the high-TVR group the CO increased insignificantly after the anesthesia bolus, while it increased significantly in the remaining part of the first stage of labor. On the other hand, CO was inversely correlated with the number of decelerations detected on cCTG in the 1 hour after the epidural bolus while the short-term variation was significantly lower in the group with high-TVR.

CONCLUSION

Maternal hemodynamic status at the onset of labor can make a difference in fetal response to the administration of epidural analgesia.

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.

Evaluating the predictive value of fetal Doppler indices and neonatal outcome in late-onset preeclampsia with severe features: a cross-sectional study in a resource-limited setting

Background

Preeclampsia constitutes a major health problem with substantial maternal and perinatal morbidity and mortality. The aim of this study was to detect the diagnostic efficacy of fetal Doppler in predicting adverse outcomes in severe late onset preeclampsia (LOP).

Methods

A prospective study was conducted among childbearing women who presented with severe LOP and matched controls. Umbilical artery (UA) and middle cerebral artery (MCA) Doppler indices including pulsatility index (PI), resistance index (RI), systolic/diastolic ratio (S/D) and cerebroplacental ratio (CPR) were measured.

Results

All UA indices were significantly higher in the case group compared to the controls (p < 0.001). UA PI and RI were significantly correlated with all neonatal adverse outcomes except cord pH status (p < 0.05). Abnormal CPR was the most sensitive index that positively correlated with intrauterine growth retardation (IUGR), low 5- minute Apgar score and neonatal intensive care unit admission (79, 72.8 and 73.3%, respectively). In the same context, Abnormal UA PI and RI represented the most specific tool for predicting IUGR, low 1- and 5- minutes Apgar score with positive predictive values were 52, 87 and 57%, respectively.

Conclusion

In severe LOP, UA Doppler remains the preferential indicator for adverse birth outcomes with CPR is the best index that could be solely used for predicting such outcome.

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.

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.

Association of second trimester uterine artery Doppler parameters with maternal hypertension 2–7 years after delivery

Background

Reduced uterine artery compliance is associated with adverse pregnancy outcomes (APOs) and may indicate underlying maternal cardiovascular pathology. We investigated associations between second trimester uterine artery Doppler (UAD) parameters and incident maternal hypertension 2–7 years after delivery.

Methods

A cohort of 10,038 nulliparous US participants was recruited early in pregnancy. A subgroup of 3739, without baseline hypertension and with complete follow-up visits 2–7 years after delivery, were included in this analysis. We investigated UAD indicators of compliance including: 1) early diastolic notch; 2) resistance index (RI); and 3) pulsatility index (PI). We defined hypertension as systolic blood pressure ≥130 mmHg, diastolic ≥80 mmHg, or antihypertensive medication use. We calculated odds ratios (OR) and 95 % confidence intervals (95%CI) for associations between UAD parameters and hypertension, adjusting for age, obesity, race/ethnicity, insurance, smoking, and APOs.

Results

A total of 187 (5 %) participants developed hypertension after the index pregnancy. Presence of early diastolic notch on UAD was not associated with incident hypertension. Increased RI and PI correlated with higher odds of hypertension (RI: adjusted OR 1.15 [95 % CI 1.03–1.30]; PI: adjusted OR 1.03 [95%CI 1.01–1.05] for each 0.1 unit increase). Maximum RI above 0.84 or maximum PI above 2.3 more than doubled the odds of incident hypertension (RI: adjusted OR 2.49, 95%CI 1.45–4.26; PI: adjusted OR 2.36, 95%CI 1.45–3.86).

Conclusion

Higher resistance and pulsatility indices measured on second trimester UAD were associated with increased odds of incident hypertension 2–7 years later, and may be biomarkers of higher maternal cardiovascular risk.

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.

Neurodevelopment of infant with late fetal growth restriction

Late fetal growth restriction has increasingly gain interest. Differently from early fetal growth restriction, the severity of this condition and the impact on perinatal mortality and morbidity is less severe. Nevertheless, there is some evidence to suggest that fetuses exposed to growth restriction late in pregnancy are at increased risk of neurological dysfunction and behavioral impairment. The aim of our review was to discuss the available evidence on the neurodevelopmental outcome in fetuses exposed to growth restriction late in pregnancy. Cerebral blood flow redistribution, a Doppler hallmark of late fetal growth restriction, has been associated with this increased risk, although there are still some controversies. Currently, most of the available studies are heterogeneous and do not distinguish between early and late fetal growth restriction when evaluating the long-term outcome, thus, making the correlation between late fetal growth restriction and neurological dysfunction difficult to interpret. The available evidence suggests that fetuses exposed to late growth restriction are at increased risk of neurological dysfunction and behavioral impairment. The presence of the cerebral blood flow redistribution seems to be associated with adverse neurodevelopmental outcome, however, from the present literature the causality cannot be ascertained.

Doppler assessment of the fetus in pregnant women recovered from COVID-19

OBJECTIVE

The aim of this study was to evaluate the maternal-fetal Doppler patterns in pregnant women recovered from COVID-19.

METHODS

This prospective case-control study was conducted in Ankara City Hospital between July 1, 2020 and August 30, 2020. Thirty pregnant women who were diagnosed with COVID-19 and completed the quarantine process were compared with 40 healthy pregnant women in terms of the fetal Doppler parameters. All pregnant women diagnosed with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection were followed up in our clinic and their diagnoses have been confirmed in nasopharyngeal and oropharyngeal samples by quantitative real time reverse transcriptase polymerase chain reaction (RT-PCR) method. Doppler ultrasonographic assessment of the uterine arteries (UtA) and middle cerebral artery (MCA) were used in addition to umbilical artery (UA) Doppler between 23 and 40 weeks of gestation. Also, cerebroplacental ratio (CPR) was calculated according to gestational age.

RESULTS

The pulsatility and resistance indices of umbilical and UtA showed a significant increase in pregnant women in the study group compared to the control group (p < 0.05). Multivariable logistic regression analysis revealed that pulsatility and resistance indices of the mean UtA were independently associated with disease (OR > 1000, 95%CI 9.77 to >1000, p = 0.009; OR 0,000 95%CI 0,000-0,944, p = 0,049), respectively. Medical treatment was given to 16/30 (53%) of pregnant women diagnosed with COVID-19.

CONCLUSION

In conclusion, uterine artery Doppler indices in the third trimester may have clinical value in pregnant women recovered from COVID-19.

Maternal hemodynamic assessment by USCOM® device in the first trimester of pregnancy

BACKGROUND

Preeclampsia is a main obstetric disease and could be caused by the inability of the woman hemodynamic system to face the cardiovascular effort required by gestation.

OBJECTIVE

The aim of the present study is to evaluate the correlation between maternal hemodynamic parameters detected by UltraSonic Cardiac Output Monitor (USCOM^®) and ultrasound or biochemical parameters in women during the first-trimester screening of chromosomal abnormalities.

METHODS

This was a prospective observational study with 162 women enrolled during the first-trimester ultrasound, recording demographic, biochemical and ultrasound data, including the pulsatility index of uterine arteries (UTPI). Hemodynamic indices were obtained using the USCOM^® system. We also analyzed the outcomes of pregnancy of those women who delivered in our clinic.

RESULTS

As for the correlation between biochemical and ultrasound parameters, pregnancy-associated plasma protein A (PAPP-A) relates inversely with the mean UTPI (r _s -0.298, p < .001). We also reported a statistically significant correlation between the mean UTPI and the maternal haemodynamic parameters detected by USCOM^® (higher values of mean UTPI are associated with lower values of indexed cardiac output, CO, and higher indexed peripheral resistances, TVR). When comparing women with higher UTPI and TVR or lower CO to patients who had regular values of these parameters, we noticed that between these groups there were significant differences in all the remaining hemodynamic parameters, including inotropy index and stroke volume, as well as in the biochemical values of PAPP-A. Analyzing postpartum data, if we combine the onset of hypertensive disorders and fetal growth restriction, the most predictive parameter is indexed TVR.

CONCLUSION

Our study confirmed the correlation between PAPP-A and placental function, expressed through the determination of the pulsatility index of the uterine arteries. Moreover, we found a clear correlation between biochemical markers, placental function and maternal hemodynamics, since the first trimester of pregnancy. The inclusion of maternal hemodynamic evaluation could be useful in the screening protocols of preeclampsia. If we combine the onset of hypertensive disorders and of fetal growth restriction, the most predictive parameter is indexed total vascular resistances.

Longitudinal changes in maternal left atrial volume index and uterine artery pulsatility indices in uncomplicated pregnancy

BACKGROUND

Data on the relationship between longitudinal changes in maternal volume-dependent echocardiographic parameters and placentation in uncomplicated pregnancy are limited.

OBJECTIVE

This study aimed to evaluate changes in volume-dependent echocardiographic parameters in uncomplicated pregnancy to test the hypothesis of the existence of an association between volume-dependent echocardiographic parameters and Doppler ultrasound parameters of fetal circulation and the uterine artery in uncomplicated pregnancy and to establish which of the volume-dependent echocardiographic parameters best depicts volume changes and correlates best with Doppler ultrasound of fetal circulation and the uterine artery in healthy pregnancy.

STUDY DESIGN

Data from 60 healthy pregnant women were analyzed. A complete echocardiographic study was performed at 11 to 13, 20 to 22, and 30 to 32 weeks' gestation: left ventricular end-diastolic volume, early diastolic peak flow velocity, late diastolic peak flow velocity, left atrial area, and left atrial volume index were assessed. Obstetrical assessment was performed including fetal growth and uterine artery pulsatility index. Fetal well-being was assessed by umbilical and middle cerebral artery blood flow. Serum pregnancy-associated plasma protein A and free β-human chorionic gonadotropin were assessed during the routine first-trimester scan (11-13 weeks' gestation).

RESULTS

Left ventricular end-diastolic volume and left atrial area increased significantly between 11 to 13 and 20 to 22 weeks' gestation but not between 20 to 22 and 30 to 32 weeks' gestation. Left atrial volume index measured at 30 to 32 weeks' gestation correlated with uterine artery pulsatility indices in 3 trimesters. Changes in the left atrial volume index between the third and first trimesters correlated significantly with the uterine artery pulsatility index measured at 20 to 22 weeks' gestation (r=-0.345; P=.020) and at 30 to 32 weeks' gestation (r=-0.452; P=.002). Changes in the left atrial volume index between the second and first trimesters significantly correlated with the uterine artery pulsatility index measured in the first trimester (r=-0.316; P=.025).

CONCLUSION

Our study showed that in an uncomplicated pregnancy, among volume-dependent echocardiographic parameters, left atrial volume index increased between both the first and second trimesters and the second and third trimesters and correlated with parameters of Doppler ultrasound of the fetal circulation and the uterine artery. Our results expand on the previous observation on the relationship between maternal cardiovascular adaptation and placentation in women with heart diseases to the population of healthy women with uncomplicated pregnancy.

Fetal weight change close to term is proportional to the birthweight percentile

OBJECTIVE

To investigate the relationship between the difference in estimated fetal weight and birthweight at or close to term, and in relation to Doppler parameters.

STUDY DESIGN

A cohort study of all term singleton pregnancies who underwent an ultrasound within two weeks of delivery after 36 weeks at one institution in one calendar year. When available, Doppler measurements of umbilical and middle cerebral artery pulsatility index were recorded. Data were analysed by Pearson rank correlation.

RESULTS

Of 8517 eligible deliveries, 885 women had an ultrasound scan within 2 weeks of delivery. Mean daily differences between estimated fetal weight and birth weight were: those born <10th percentile lost 26 g per day (95 % CI -36 to -16), 10-50th percentile gained 7 g per day (95 % CI -2 to 15), 50th-90th percentile gained 27 g per day (95 % CI 19-35) and >90th percentile gained 48 g per day (95 % CI 32-64). There was a negative correlation between umbilical: middle cerebral artery pulsatility index and the change in weight per day (n = 348, p = 0.001, r = 0.17).

CONCLUSIONS

Difference in the estimated fetal weight and birthweight, expressed as grams growth per day, is proportional to the birthweight percentile. Fetuses with a birthweight >10th percentile gain weight, while those with a birthweight <10th percentile apparently decline in weight between their final ultrasound estimated fetal weight and delivery. In babies with the smallest or apparent negative weight gain there was an association with Doppler parameters that signified hypoxia indicating fetal growth at term may be restricted by impaired placental function. Estimated fetal weight may be a poor predictor of birthweight for reasons other than ultrasound or algorithmic error.

PlGF Immunological Impact during Pregnancy

During pregnancy, the mother’s immune system has to tolerate the persistence of paternal alloantigens without affecting the anti-infectious immune response. Consequently, several mechanisms aimed at preventing allograft rejection, occur during a pregnancy. In fact, the early stages of pregnancy are characterized by the correct balance between inflammation and immune tolerance, in which proinflammatory cytokines contribute to both the remodeling of tissues and to neo-angiogenesis, thus, favoring the correct embryo implantation. In addition to the creation of a microenvironment able to support both immunological privilege and angiogenesis, the trophoblast invades normal tissues by sharing the same behavior of invasive tumors. Next, the activation of an immunosuppressive phase, characterized by an increase in the number of regulatory T (Treg) cells prevents excessive inflammation and avoids fetal immuno-mediated rejection. When these changes do not occur or occur incompletely, early pregnancy failure follows. All these events are characterized by an increase in different growth factors and cytokines, among which one of the most important is the angiogenic growth factor, namely placental growth factor (PlGF). PlGF is initially isolated from the human placenta. It is upregulated during both pregnancy and inflammation. In this review, we summarize current knowledge on the immunomodulatory effects of PlGF during pregnancy, warranting that both innate and adaptive immune cells properly support the early events of implantation and placental development. Furthermore, we highlight how an alteration of the immune response, associated with PlGF imbalance, can induce a hypertensive state and lead to the pre-eclampsia (PE).

Luteolin-induced vasorelaxation in uterine arteries from normal pregnant rats

BACKGROUND

The flavonoid, luteolin, promotes vasorelaxation in various arteries through endothelial-dependent and independent mechanisms. Although there is growing interest in the vasoactive effects of flavonoids on maternal vascular function during pregnancy, it is unknown whether luteolin elicits vasorelaxation in the uterine circulation. We tested the hypothesis that luteolin induces vasorelaxation via endothelial-dependent mechanisms in uterine arteries from normal pregnant rats during late gestation.

METHODS

Uterine arteries and aortas were isolated from Sprague-Dawley rats at gestational day 19 and prepared for wire myography.

RESULTS

The potency of luteolin-induced vasorelaxation was examined between uterine arteries and the aortas. By 50 µM of luteolin, there was complete relaxation (100.5 ± 5.2%) in uterine arteries as compared to aortas (27.5 ± 10.0%). Even the highest concentration of 100 µM luteolin produced less than half relaxation (43.6 ± 8.6%) in aortas compared to uterine arteries. We then explored if luteolin-induced vasorelaxation in uterine arteries from pregnant rats was mediated by endothelial-dependent vasorelaxation pathways, including nitric oxide synthase (NOS), cyclooxygenase (COX), or potassium (K⁺) channels. Blocking these pathways with N(G)-Nitro-l-arginine methyl ester hydrochloride (L-NAME), indomethacin, or tetraethylammonium (TEA)/high potassium chloride (KCl), respectively, did not alter luteolin responses in uterine arteries from pregnant rats. These findings suggested that endothelial factors may not mediate luteolin-induced vasorelaxation in uterine arteries during pregnancy. Indeed, experiments where the endothelium was removed did not alter luteolin-induced vasorelaxation in uterine arteries during pregnancy.

CONCLUSIONS

Luteolin directly promotes vasorelaxation in the medial smooth muscle layer of uterine arteries during normal pregnancy.

Maternal Cardiovascular Dysfunction is Associated with Hypoxic Cerebral and Umbilical Doppler Changes

We investigate the relationship between maternal cardiovascular (CV) function and fetal Doppler changes in healthy pregnancies and those with pre-eclampsia (PE), small for gestational age (SGA) or fetal growth restriction (FGR). This was a three-centre prospective study, where CV assessment was performed using inert gas rebreathing, continuous Doppler or impedance cardiography. Maternal cardiac output (CO) and peripheral vascular resistance (PVR) were analysed in relation to the uterine artery, umbilical artery (UA) and middle cerebral artery (MCA) pulsatility indices (PI, expressed as z-scores by gestational week) using polynomial regression analyses, and in relation to the presence of absent/reversed end diastolic (ARED) flow in the UA. We included 81 healthy controls, 47 women with PE, 65 with SGA/FGR and 40 with PE + SGA/FGR. Maternal CO was inversely related to fetal UA PI and positively related to MCA PI; the opposite was observed for PVR, which was also positively associated with increased uterine artery impedance. CO was lower (z-score 97, p = 0.02) and PVR higher (z-score 2.88, p = 0.02) with UA ARED flow. We report that maternal CV dysfunction is associated with fetal vascular changes, namely raised impedance in the fetal-placental circulation and low impedance in the fetal cerebral vessels. These findings are most evident with critical UA Doppler changes and represent a potential mechanism for therapeutic intervention.

Hypertension Programmed in Adult Hens by Isolated Effects of Developmental Hypoxia In Ovo

In mammals, pregnancy complicated by chronic hypoxia can program hypertension in the adult offspring. However, mechanisms remain uncertain because the partial contributions of the challenge on the placenta, mother, and fetus are difficult to disentangle. Here, we used chronic hypoxia in the chicken embryo-an established model system that permits isolation of the direct effects of developmental hypoxia on the cardiovascular system of the offspring, independent of additional effects on the mother or the placenta. Fertilized chicken eggs were exposed to normoxia (N; 21% O₂) or hypoxia (H; 13.5%-14% O₂) from the start of incubation (day 0) until day 19 (hatching, ≈day 21). Following hatching, all birds were maintained under normoxic conditions until ≈6 months of adulthood. Hypoxic incubation increased hematocrit (+27%) in the chicken embryo and induced asymmetrical growth restriction (body weight, -8.6%; biparietal diameter/body weight ratio, +7.5%) in the hatchlings (all P<0.05). At adulthood (181±4 days), chickens from hypoxic incubations remained smaller (body weight, -7.5%) and showed reduced basal and stimulated in vivo NO bioavailability (pressor response to NG-nitro-L-arginine methyl ester, -43%; phenylephrine pressor response during NO blockade, -61%) with significant hypertension (mean arterial blood pressure, +18%), increased cardiac work (ejection fraction, +12%; fractional shortening, +25%; enhanced baroreflex gain, +456%), and left ventricular wall thickening (left ventricular wall volume, +36%; all P<0.05). Therefore, we show that chronic hypoxia can act directly on a developing embryo to program hypertension, cardiovascular dysfunction, and cardiac wall remodeling in adulthood in the absence of any maternal or placental effects.

Placental function and fetal weight are associated with maternal hemodynamic indices in uncomplicated pregnancies at 35-37 weeks of gestation

BACKGROUND

Over the years, there has been an increasing interest in the assessment of maternal hemodynamic responses during pregnancy. With the use of both noninvasive devices and/or maternal echocardiography, it has been shown that mothers who have pregnancy complications have altered hemodynamics compared with those who have uncomplicated pregnancies. It also has been suggested that preexisting maternal cardiac changes might drive the development of complications in pregnancy that are associated with impaired placentation. To understand, however, this potential link in complicated pregnancies, it is important to clarify whether placental function is associated with maternal cardiac functional indices in normal pregnancies.

OBJECTIVE

To determine whether placental function, perfusion, and fetal weight are associated with maternal cardiac hemodynamic responses at 35-36 weeks of gestation in normal pregnancies.

STUDY DESIGN

Prospective screening of women attending Kings' College Hospital for routine hospital visit at 35-37 weeks' gestation. We recorded maternal characteristics and measured mean arterial pressure, uterine artery pulsatility index, sonographic estimated fetal weight, and serum placental growth factor and soluble fms-like tyrosine kinase 1. We also performed maternal echocardiogram to assess cardiac output and peripheral vascular resistance as well as indices of diastolic and systolic function, including global longitudinal systolic function and left ventricular mass indexed to body surface area.

RESULTS

We studied 1386 women. Maternal characteristics were associated with both maternal hemodynamics and functional and structural indices. Uterine artery pulsatility index was associated with left ventricular mass (P=.03) and global longitudinal systolic function (P=.017). There were significant nonlinear associations between placental growth factor and cardiac output and peripheral vascular resistance (P<.001 for both) and between soluble fms-like tyrosine kinase 1 and peripheral vascular resistance (P=.018). Estimated fetal weight was associated with maternal cardiac output (mean increase=0.186, 95% confidence interval, 0.133-0.238, P<.001) and peripheral vascular resistance (mean decrease=-0.164, 95% confidence interval, -0.217 to -0.111, P<.001). No association was noted between placental and fetal parameters and maternal cardiac functional and structural indices. In multivariable analysis, placental growth factor remained strongly associated with maternal cardiac output and peripheral vascular resistance (P=.002 for both) over and above maternal characteristics and estimated fetal weight. Estimated fetal weight was associated with left ventricular mass (0.102, 95% confidence interval, 0.044-0.162, P=.001).

CONCLUSION

The results of this study suggest a strong link between maternal hemodynamic responses and fetoplacental needs across the whole spectrum in normal pregnancies. These findings would also indicate that to diagnose maternal cardiac dysfunction in pregnancies complicated by impaired placentation a more extensive echocardiographic assessment might be needed rather than relying on hemodynamics which are strongly associated with fetoplacental indices.

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.

Maternal cardiac parameters can help in differentiating the clinical profile of preeclampsia and in predicting progression from mild to severe forms

BACKGROUND

A primary role of maternal heart dysfunction in the pathophysiology of preeclampsia had been previously advocated although if contradictory results have been reported.

OBJECTIVES

The objectives of the study were to describe maternal hemodynamic parameters according to 2 main preeclampsia phenotypes and to investigate whether cardiac findings may be helpful in characterizing the severity and the progression of the disease.

STUDY DESIGN

This was a prospective cohort study. We used an ultrasonic cardiac output monitor system to compare the hemodynamic parameters of women with preeclampsia with a group of healthy normotensive women enrolled as controls with a ratio of 1:2. Cardiac output, systemic vascular resistance, and stroke volume were compared among controls and preeclamptic women who were grouped in accordance to the following characteristics: early preeclampsia (<34 weeks' gestation) vs late preeclampsia onset (≥34 weeks' gestation); preeclampsia associated with appropriate for gestational age or small-for-gestational-age newborns. Hemodynamic characteristics were also compared between preeclamptic women with a mild form vs those who progressed toward a severe form.

RESULTS

A total of 38 preeclamptic women and 61 normotensive women were included in the study. Both cases of preeclampsia associated with small-for-gestational-age neonates as those with normal-sized ones showed higher systemic vascular resistance compared with the control group (respectively, 1580.6 ± 483.2 vs 1479.1 ± 433.3 vs 1105.3 ± 293.1; P < .0001), while a lower cardiac output was reported only for preeclamptic women with small-for-gestational-age neonates compared with controls (5.7 ± 1.5 vs 6.5 ± 1.3; P = .02). Maternal cardiac parameters were comparable between these 2 groups of preeclamptic women (small-for-gestational-age vs appropriate-for-gestational-age preeclampsia) with the exception of a lower stroke volume in the former one (64.8 ± 24.4 vs 75.2 ± 17.8; P = .04). Similarly, women with both early and late preeclampsia showed higher systemic vascular resistance compared with controls (1559.5 ± 528.3 vs 1488.5 ± 292.9 vs 1105.3 ± 293.1, respectively; P < .001), while a lower cardiac output was noted only in the early-onset group compared with controls (5.5 ± 1.2 P = .02). Maternal cardiac findings were similar between women with early vs late-onset preeclampsia. Hemodynamic parameters are significantly different between those women with mild preeclampsia who remained stable compared with those who progressed toward a severe disease. Cardiac output Z-score, systemic vascular resistance Z-score, and uterine arteries' pulsatility index Z-score showed similar sensitivity (80% vs 75% vs 80%, respectively) and specificity (73% vs. 73% vs 74%, respectively), while the association of systemic vascular resistance Z-score and uterine arteries pulsatility index Z-score showed a sensitivity of 95% and a specificity of 80% (area under the curve, 0.90) in predicting evolution toward severe forms.

CONCLUSION

Evaluation of maternal cardiovascular system could help clinician in defining a subset of preeclamptic patients with more profound placental impairment and might predict the likelihood of progression toward a severe condition in cases with a mild preeclampsia at clinical onset.