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

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

Nitric oxide donor increases umbilical vein blood flow and fetal oxygenation in fetal growth restriction. A pilot study

INTRODUCTION

To evaluate the maternal and fetal hemodynamic effects of treatment with a nitric oxide donor and oral fluid in pregnancies complicated by fetal growth restriction.

METHODS

30 normotensive participants with early fetal growth restriction were enrolled. 15 participants were treated until delivery with transdermal glyceryl trinitrate and oral fluid intake (Treated group), and 15 comprised the untreated group. All women underwent non-invasive assessment of fetal and maternal hemodynamics and repeat evaluation 2 weeks later.

RESULTS

In the treated group, maternal hemodynamics improved significantly after two weeks of therapy compared to untreated participants. Fetal hemodynamics in the treated group showed an increase in umbilical vein diameter by 18.87 % (p < 0.01), in umbilical vein blood flow by 48.16 % (p < 0.01) and in umbilical vein blood flow corrected for estimated fetal weight by 30.03 % (p < 0.01). In the untreated group, the characteristics of the umbilical vein were unchanged compared to baseline. At the same time, the cerebro-placental ratio increased in the treated group, while it was reduced in the untreated group, compared to baseline values. The treated group showed a higher birthweight centile (p = 0.03) and a lower preeclampsia rate (p = 0.04) compared to the untreated group.

DISCUSSION

The combined therapeutic approach with nitric oxide donor and oral fluid intake in fetal growth restriction improves maternal hemodynamics, which becomes more hyperdynamic (volume-dominant). At the same time, in the fetal circuit, umbilical vein flow increased and fetal brain sparing improved. Although a modest sample size, there was less preeclampsia and a higher birthweight suggesting beneficial maternal and fetal characteristics of treatment.

Maternal cardiovascular profile is altered in the preclinical phase of normotensive early and late intrauterine growth restriction

BACKGROUND

The maternal cardiovascular profile of patients who develop late fetal growth restriction has yet to be well characterized, however, a subclinical impairment in maternal hemodynamics and cardiac function may be present before pregnancy and may become evident because of the hemodynamic alterations associated with pregnancy.

OBJECTIVE

This study aimed to investigate if maternal hemodynamics and the cardiovascular profile might be different in the preclinical stages (22-24 weeks' gestation) in cases of early and late fetal growth restriction in normotensive patients.

STUDY DESIGN

This was a prospective echocardiographic study of 1152 normotensive nulliparous pregnant women at 22 to 24 weeks' gestation. The echocardiographic evaluation included morphologic parameters (left ventricular mass index and relative wall thickness, left atrial volume index) and systolic and diastolic maternal left ventricular function (ejection fraction, left ventricular global longitudinal strain, E/A ratio, and E/e' ratio). Patients were followed until the end of pregnancy to note the development of normotensive early or late fetal growth restriction.

RESULTS

Of the study cohort, 1049 patients had no complications, 73 were classified as having late fetal growth restriction, and 30 were classified as having early fetal growth restriction. In terms of left ventricular morphology, the left ventricular end-diastolic diameter was greater in uneventful pregnancies (4.84±0.28 cm) than in late (4.67±0.26 cm) and in early (4.55±0.26 cm) (P<.001) fetal growth restriction cases, whereas left ventricular end-systolic diameter was smaller in uneventful pregnancies (2.66±0.39 cm) than in late (2.83±0.40 cm) and in early (2.82±0.38 cm) (P<.001) fetal growth restriction cases. The relative wall thickness was slightly higher in early (0.34±0.05) and late (0.35±0.04) fetal growth restriction cases than in uneventful pregnancies (0.32±0.05) (P<.05). In terms of systolic left ventricular function, at 22 to 24 weeks' gestation, cardiac output was higher in uneventful pregnancies (6.58±1.07 L/min) than in late (5.40±0.97 L/min) and in early (4.76±1.05 L/min) (P<.001) fetal growth restriction cases with the lowest values in the early-onset group. Left ventricular global longitudinal strain was lower in appropriate for gestational age neonates (-21.6%±2.0%) and progressively higher in late (-20.1%±2.2%) and early (-18.5%±2.3%) (P<.001) fetal growth restriction cases. In terms of diastolic left ventricular function, the E/e' ratio showed intermediate values in the late fetal growth restriction group (7.90±2.73) when compared with the appropriate for gestational age group (7.24±2.43) and with the early fetal growth restriction group (10.76±3.25) (P<.001). The total peripheral vascular resistance was also intermediate in the late fetal growth restriction group (1300±199 dyne·s·cm-5) when compared with the appropriate for gestational age group (993±175 dyne·s·cm-5) and the early fetal growth restriction group (1488±255 dyne.s.cm-5) (P<.001).

CONCLUSION

Early and late fetal growth restriction share similar maternal hemodynamic and cardiovascular profiles with a different degree of expression. These features are already present at 22 to 24 weeks' gestation and are characterized by a hypodynamic state. The degree of these cardiovascular changes may influence the timing of the manifestation of the disease; a hypovolemic, high resistance, low cardiac output state might be associated with early-onset fetal growth restriction, whereas a milder hypovolemic state seems to favor the development of the disease in the final stages of pregnancy.

Intrauterine Growth Restriction: Need to Improve Diagnostic Accuracy and Evidence for a Key Role of Oxidative Stress in Neonatal and Long-Term Sequelae

Intrauterine growth restriction (IUGR) and being small for gestational age (SGA) are two distinct conditions with different implications for short- and long-term child development. SGA is present if the estimated fetal or birth weight is below the tenth percentile. IUGR can be identified by additional abnormalities (pathological Doppler sonography, oligohydramnion, lack of growth in the interval, estimated weight below the third percentile) and can also be present in fetuses and neonates with weights above the tenth percentile. There is a need to differentiate between IUGR and SGA whenever possible, as IUGR in particular is associated with greater perinatal morbidity, prematurity and mortality, as well as an increased risk for diseases in later life. Recognizing fetuses and newborns being "at risk" in order to monitor them accordingly and deliver them in good time, as well as to provide adequate follow up care to ameliorate adverse sequelae is still challenging. This review article discusses approaches to differentiate IUGR from SGA and further increase diagnostic accuracy. Since adverse prenatal influences increase but individually optimized further child development decreases the risk of later diseases, we also discuss the need for interdisciplinary follow-up strategies during childhood. Moreover, we present current concepts of pathophysiology, with a focus on oxidative stress and consecutive inflammatory and metabolic changes as key molecular mechanisms of adverse sequelae, and look at future scientific opportunities and challenges. Most importantly, awareness needs to be raised that pre- and postnatal care of IUGR neonates should be regarded as a continuum.

Longitudinal maternal hemodynamic evaluation in uncomplicated twin pregnancies according to chorionicity: physiological cardiovascular dysfunction in monochorionic twin pregnancy

OBJECTIVE

Maternal cardiac function plays a crucial role in placental function and development. The maternal hemodynamic changes in twin pregnancy are more pronounced than those in singleton pregnancy, presumably due to a greater plasma volume expansion. In view of the correlation between maternal cardiac and placental function, it is plausible that chorionicity could influence maternal cardiac function. The aim of this study was to compare the longitudinal maternal hemodynamic changes between uncomplicated dichorionic (DC) and monochorionic (MC) twin pregnancies and in comparison to singleton pregnancies.

METHODS

Included in the study were 40 MC diamniotic and 35 DC diamniotic uncomplicated twin pregnancies. These were compared with a group of 294 healthy singleton pregnancies from a previous cross-sectional study. All participants underwent a hemodynamic evaluation using an Ultrasound Cardiac Output Monitor (USCOM®), at three different stages in pregnancy (11-15 weeks, 20-24 weeks and 29-33 weeks). The following parameters were recorded: mean arterial pressure (MAP), stroke volume (SV), stroke volume index (SVI), heart rate, cardiac output (CO), cardiac index (CI), systemic vascular resistance (SVR), systemic vascular resistance index (SVRI), stroke volume variation, Smith-Madigan inotropy index (INO) and potential-to-kinetic-energy ratio (PKR).

RESULTS

In the first trimester, DC and MC twin pregnancies showed lower MAP, SVR and PKR and higher CO and SV in comparison to singleton pregnancy. In the second trimester, maternal CO (8.33 vs 7.30 L/min, P = 0.03) and CI (4.52 vs 4.00 L/min/m2 , P = 0.02) were significantly higher in MC compared with DC twin pregnancy. In the third trimester, compared with in singleton pregnancy, women with MC twin pregnancy showed significantly higher PKR (24.06 vs 20.13, P = 0.03) and SVRI (1837.20 vs 1698.48 dynes × s/cm5 /m2 , P = 0.03), and significantly lower SV (78.80 vs 88.80 mL, P = 0.01), SVI (42.79 vs 50.31 mL/m2 , P < 0.01) and INO (1.70 vs 1.87 W/m2 , P = 0.03); these differences were not observed between DC twin and singleton pregnancies.

CONCLUSIONS

Maternal cardiovascular function undergoes significant change during uncomplicated twin pregnancy and chorionicity influences maternal hemodynamics. In both MC and DC twin pregnancy, hemodynamic changes are detectable as early as the first trimester, showing higher maternal CO and lower SVR compared with singleton pregnancy. In DC twin pregnancy, the maternal hemodynamics remain stable during the rest of pregnancy. In contrast, in MC twin pregnancy, the rise in maternal CO continues in the second trimester in order to sustain the greater placental growth. There is a subsequent crossover, with a reduction in cardiovascular performance during the third trimester. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Associations between Maternal Nutritional Status, Hemodynamic Parameters, and Delivery Outcomes in Low-Risk Pregnancies: A Prospective Observational Study

Maternal nutritional status represents a pivotal predictor of pregnancy outcome. This prospective observational study investigates the associations between maternal characteristics and nutritional habits at term, hemodynamic parameters, and pregnancy outcomes. Healthy women with singleton uncomplicated pregnancies were enrolled at 36-41 gestational weeks. At enrollment, a nutritional score (0-10) was calculated in order to quantify maternal adherence to a healthy diet and lifestyle. Maternal hemodynamic parameters were assessed by using the Ultrasonic Cardiac Output Monitor (USCOM), including cardiac output (CO), systemic vascular resistance (SVR) and Smith-Madigan inotropy index (SMII). Pregnancy outcomes were recorded at delivery. Associations between maternal characteristics and nutritional score, hemodynamic parameters, and pregnancy outcomes were investigated by using multi-adjusted generalized linear models. In total, 143 pregnancies were enrolled. Pregestational body mass index (BMI) was positively associated with SVR, and negatively associated with CO and SMII. Additionally, a positive association was detected between the nutritional score and SMII. Finally, CO was positively associated with birth and placental weight, while RVS showed a negative association with birth and placental weight. This study shows that maternal derangements in nutritional status and habits are associated with a compromised hemodynamic profile at term, with additional impacts on intrauterine growth.

NO donors on top of anti-hypertensive therapy reduces complications in chronic hypertensive pregnancies with hypodynamic circulation

OBJECTIVES

Chronic hypertension is associated with significant adverse maternal and fetal outcomes that appear to be often associated to a hypodynamic circulation. Treatment of hypertensive disorders of pregnancy tailored on maternal hemodynamics might reduce or mitigate these complications. Our purpose was to assess the hemodynamic modifications induced by the addition of NO donors and increased oral fluid intake on top of standard antihypertensive therapy in hypodynamic chronic hypertensive patients. We further evaluated if the possible hemodynamic modification induced by NO donors and increased oral fluid intake might be associated to a reduction of the severity and rate of complications vs. patients on antihypertensive standard treatment.

STUDY DESIGN

This was a case-control study of 321 chronic hypertensive patients with a hypodynamic circulation at the echocardiographic evaluation at 24 weeks' gestation. We included 160 controls (standard antihypertensive therapy) and 161 cases (standard therapy + NO donor patches + increased oral fluid intake). Student T test for paired and unpaired data, univariate logistic regression analysis, ROC curve analysis, and Cox Hazards Regression analysis were used as appropriate.

RESULTS

At enrollment the hemodynamic parameters were similar between the two groups. After 3-4 weeks stroke volume (77 ± 19 mL vs. 69 ± 19 mL; p < 0.001), and cardiac output (6.2 ± 1.7 L vs. 5.0 ± 1.6 L; p < 0.001) were higher and total peripheral vascular resistance (1465 ± 469 dyne·s·cm-5 vs. 1814 ± 524 dyne·s·cm-5; p < 0.001) was lower in the cases vs controls. Superimposed preeclampsia, preterm delivery before 34 weeks, abruptio placentae, HELLP Syndrome, fetal growth restriction, and perinatal death were more represented in the standard treatment group vs NO treated patients (81% vs 53%; p < 0.001). In particular, the standard treatment group showed 48% fetal growth restriction vs 34% in the NO treated group (p < 0.011). The Cox proportional-hazards regression showed a lower proportion of event-free pregnancies in controls on standard treatment (HR 2.6; 95% CI 2.0-3.5; p < 0.0001), and a prolongation of pregnancies in CH cases complicated by fetal growth restriction taking NO donors (HR 0.29; 95% CI 0.19-0.43; p = 0.0001).

CONCLUSIONS

The tailored treatment with NO donors and oral fluids of hypodynamic CH might have positive effects on the reduction or mitigations of adverse outcomes.

Fetal Growth Restriction Is Associated with Pregnancy Associated Plasma Protein A and Uterine Artery Doppler in First Trimester

Fetal growth restriction (FGR) is a major cause of stillbirth and poor neurodevelopmental outcomes. The early prediction may be important to establish treatment options and improve neonatal outcomes. The aim of this study was to assess the association of parameters used in first-trimester screening, uterine artery Doppler pulsatility index and the development of FGR. In this retrospective cohort study, 1930 singleton pregnancies prenatally diagnosed with an estimated fetal weight under the third percentile were included. All women underwent first-trimester screening assessing maternal serum pregnancy-associated plasma protein A (PAPP-A), free beta-human chorionic gonadotrophin levels, fetal nuchal translucency and uterine artery Doppler pulsatility index (PI). We constructed a Receiver Operating Characteristics curve to calculate the sensitivity and specificity of early diagnosis of FGR. In pregnancies with FGR, PAPP-A was significantly lower, and uterine artery Doppler pulsatility index was significantly higher compared with the normal birth weight group (0.79 ± 0.38 vs. 1.15 ± 0.59, p < 0.001 and 1.82 ± 0.7 vs. 1.55 ± 0.47, p = 0.01). Multivariate logistic regression analyses demonstrated that PAPP-A levels and uterine artery Doppler pulsatility index were significantly associated with FGR (p = 0.009 and p = 0.01, respectively). To conclude, these two parameters can predict FGR < 3rd percentile.

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.

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.

Maternal hemodynamics for the identification of early fetal growth restriction in normotensive pregnancies

We aimed at testing systemic vascular resistance (SVR) for the correct identification of early fetal growth restriction (FGR). 61 normotensive patients, gestational age 29 + 0-32 + 0, with suspected diagnosis of early FGR, were submitted to USCOM and to an ultrasound evaluation. 24 patients met the criteria of FGR, and 9 patients developed umbilical artery Doppler alterations. SVR>1006 dyn s·cm^-5 correctly identified patients with a subsequent diagnosis of FGR, whereas SVR>1222 dyn s·cm^-5 was related to FGR with subsequent umbilical artery Doppler alterations. These data might be important to introduce USCOM in the clinical practice to identify and treat FGR.

Hemodynamic assessment in patients with preterm premature rupture of the membranes (pPROM)

OBJECTIVE

The aim of this study was to assess the hemodynamic differences in women with pPROM versus physiological pregnancies.

STUDY DESIGN

This was a prospective case control study of 15 patients with pPROM and 45 controls. Patients and controls were submitted at enrollment to a non-invasive hemodynamic evaluation with UltraSonic Cardiac Output Monitor (USCOM), and to blood tests to check white blood cells count and C-reactive protein (CRP) levels. We followed pPROM patients until delivery noting fetal/neonatal and maternal unfavorable outcomes (maternal fever, APGAR 1' and 5'< 7, stillbirth).

RESULTS

Patients with pPROM showed higher values of cardiac output (9.1 ± 2.3 vs 7.1 ± 0.85, p < 0.01), lower systemic vascular resistances (792.1 ± 162 vs 1006.2 ± 110.7, p < 0.01), higher minute distance (32.3 ± 7.8 vs 25 ± 2.8, p < 0.01), lower Potential to Kinetic Energy Ratio (16.5 ± 5.3 vs 22.4 ± 6.8, p < 0.01), higher heart rate (97.5 ± 15.4 vs 82.4 ± 12, p < 0.01) and higher oxygen delivery (1313.2 ± 325.8 vs 1080.7 ± 151.8, p < 0.01) vs. controls. Six out of 15 pPROM patients had an unfavorable outcome. There were no significant differences in CRP levels and WBC count at admission in the two pPROM subgroups, whereas maternal hemodynamics was characterized by lower SVR (718 ± 72 vs 863 ± 123, p = 0.02) in subsequently complicated patients.

CONCLUSIONS

Maternal hemodynamics is altered in pPROM patients, with a lower Systemic Vascular Resistance and higher Cardiac Output vs. controls. This hyperdynamic circulation appears to anticipates the changes of serum markers of inflammation (CRP, WBC count) and seems to be more pronounced at admission in pPROM patients developing unfavorable outcomes.

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.

Maternal peripheral vascular resistance at mid gestation in chronic hypertension as a predictor of fetal growth restriction

We aimed at analyzing the relationship between maternal hemodynamics as expressed by Peripheral Vascular Resistance (PVR) at mid gestation and fetal growth at delivery in chronic hypertension. 152 chronic hypertensive patients were submitted to echocardiography noting PVR at 22-24 weeks' gestation and were followed until delivery noting birthweight centile and the diagnosis of fetal growth restriction (FGR). The logarithmic correlation analysis showed that PVR at mid gestation was strongly related to birthweight at delivery (r = -0.72; p < .001). Moreover, PVR was predictive of both a birthweight <10th centile (PVR >1466 Sensitivity 75.0%, Specificity 93.4%, AUC 0.83, p < .001) and FGR (PVR > 1355 Sensitivity 84.2%, Specificity 93.2%, AUC 0.88, p < .001). This study highlights the importance of maternal hemodynamics as expressed by PVR at mid gestation for the identification of chronic hypertensive patients at risk for developing fetal growth restriction. This observation might open new areas of intervention to treat patients with altered hemodynamics (PVR > 1355 dyne s cm^-5).