Type-specific orthostatic hemodynamic response of hypertensive diseases in pregnancy.

Posture changes may differ between types of hypertensive disease. The aim is to evaluate the orthostatic response of impedance cardiography (ICG) measurements in uncomplicated and hypertensive pregnancies. Measurements were performed in supine and standing position in 202 women: 41 uncomplicated pregnancies (UP), 59 gestational hypertension (GH), 35 early-onset (EPE, < 34 weeks) and 67 late-onset (LPE, ≥ 34 weeks) preeclampsia were assessed. Measurements were recorded of heart rate, blood pressure, aortic flow parameters, cardiac output, pre-ejection period and left ventricular ejection time. Overall, orthostatic shifts were different between all groups (P < 0.001). UP was different from the hypertensive complicated gestations in the orthostatic change of the aortic acceleration. In contrast to patients with preeclampsia, those with GH had an increased blood pressure and Heather index, and stable pre-ejection period after posture change. EPE differed from LPE by change in blood pressure and aortic flow parameters. In addition to static ICG-measurements, orthostatic shifts improved group characterization from 57.4% to 65.8%. The orthostatic response is altered in hypertensive pregnancies. ICG measurements in the upright as well as during an orthostatic test might have the potential to improve the discriminative yield between hypertensive diseases in pregnancy.

Maternal venous hemodynamics assessment for prediction of preeclampsia should be longitudinal.

OBJECTIVE: To address the question whether maternal venous abnormalities exist at the onset of, or develop during the course of pregnancy. METHODS: We present five case reports of patients with early onset preeclampsia (EPE), late onset preeclampsia (LPE), gestational hypertension (GH), essential hypertension (EH) and an uncomplicated pregnancy (UP). Maternal renal and hepatic vein Doppler waves and maternal venous pulse transit times (VPTT) were assessed in early pregnancy and again shortly before delivery. RESULTS: In all cases, maternal VPTT were normal in early pregnancy and changed to abnormal values in EPE and LPE, which was not true for UP and GH or EH. CONCLUSION: These observations support the view that venous hemodynamic dysfunction of preeclampsia (PE) develops during the course of pregnancy. Therefore, assessment of an individual's venous function for prediction of PE should be serial and longitudinal.

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

BACKGROUND: It is well known that hepatic hemodynamics is an important physiologic mechanism in the regulation of cardiac output (CO). It has been reported that maternal cardiac output relates to neonatal weight at birth. AIMS: In this study, we assessed the correlation between maternal hepatic vein Doppler flow parameters, cardiac output and neonatal birth weight. METHODS: Healthy women with uncomplicated second or third trimester pregnancy attending the outpatient antenatal clinic of Ziekenhuis Oost-Limburg in Genk (Belgium), had a standardized combined electrocardiogram-Doppler ultrasound with Impedance Cardiography, for measurement of Hepatic Vein Impedance Index (HVI  =  [maximum velocity - minimum velocity]/maximum velocity), venous pulse transit time (VPTT  =  time interval between corresponding ECG and Doppler wave characteristics) and cardiac output (heart rate x stroke volume). After delivery, a population-specific birth weight chart, established from a cohort of 27000 neonates born in the index hospital, was used to define customized birth weight percentiles (BW%). Correlations between HVI, VPTT, CO and BW% were calculated using Spearman's ρ, linear regression analysis and R2 goodness of fit in SPSS 22.0. RESULTS: A total of 73 women were included. There was a negative correlation between HVI and VPTT (ρ = -0.719, p < 0.001). Both HVI and VPTT correlated with CO (ρ = -0.403, p < 0.001 and ρ = 0.332, p < 0.004 resp.) and with BW% (ρ =  -0.341, p < 0.003 and ρ = 0.296, p < 0.011 resp.). CONCLUSION: Our data illustrate that the known contribution of hepatic hemodynamics in the regulation of cardiac output is also true for women with uncomplicated pregnancies. Our study is the first to illustrate a potential link between maternal hepatic hemodynamics and neonatal birth weight. Whether this link is purely associative or whether hepatic vascular physiology has a direct impact on fetal growth is to be evaluated in more extensive clinical and experimental research.

Is there a correlation between maternal venous hemodynamic dysfunction and proteinuria of preeclampsia?

OBJECTIVES: To evaluate in early and late preeclampsia a correlation of maternal venous Doppler flow characteristics with biochemical parameters in maternal serum and urine, or with gestational outcome. STUDY DESIGN: In this observational cross-sectional study, renal interlobar vein impedance index (RIVI) was measured according to a standardised protocol for combined electrocardiogram-Doppler ultrasonography in 86 women with uncomplicated pregnancy, 78 women with late onset preeclampsia (≥34w) and 67 with early onset preeclampsia (<34w). For each group, maternal age, pre-gestational BMI and parity were recorded together with birth weight and -percentile. For both early onset and late onset preeclampsia, maternal serum was analysed for thrombocyte count and concentrations of creatinine, ASAT, ALAT and uric acid and 24h urine collections were analysed for creatinine clearance and proteinuria (mg/24h). A non-parametric Mann-Whitney U-tests was performed for continuous data and a Fisher's exact tests for categorical data. Significant linear dependence between variables was identified using Pearson's correlation coefficient at nominal level a=0.05. RESULTS: Proteinuria was higher in early onset than in late onset preeclampsia (1756mg [838-6116mg] versus 877mg [416-1696mg], p<0.001), and this was also true for RIVI in both left (0.45 [0.40-0.55] versus 0.41 [0.35-0.45], p=0.001) and right kidney (0.45 [0.39-0.55] versus 0.38 [0.30-0.43], p<0.001). In our data set, there was a significant correlation between proteinuria and RIVI of left (correlation coefficient=0.172, p=0.036) and right kidney (correlation coefficient=0.218, p=0.009) in late onset but not early onset preeclampsia. CONCLUSION: Maternal RIVI may correlate with proteinuria of late onset preeclampsia.

Intra-abdominal pressure measurements in term pregnancy and postpartum: an observational study.

OBJECTIVE: To determine intra-abdominal pressure (IAP) and to evaluate the reproducibility of IAP-measurements using the Foley Manometer Low Volume (FMLV) in term uncomplicated pregnancies before and after caesarean section (CS), relative to two different reference points and to non-pregnant values. DESIGN: Observational cohort study. SETTING: Secondary level referral center for feto-maternal medicine. POPULATION: Term uncomplicated pregnant women as the case-group and non-pregnant patients undergoing a laparoscopic assisted vaginal hysterectomy (LAVH) as control group. METHODS: IAP was measured in 23 term pregnant patients, before and after CS and in 27 women immediately after and 1 day after LAVH. The midaxillary line was used as zero-reference (IAPMAL) in all patients and in 13 CS and 13 LAVH patients, the symphysis pubis (IAPSP) was evaluated as additional zero-reference. Intraobserver correlation (ICC) was calculated for each zero-reference. Paired student's t-tests were performed to compare IAP values and Pearson's correlation was used to assess correlations between IAP and gestational variables. MAIN OUTCOME MEASURES: ICC before and after surgery, IAP before and after CS, IAP after CS and LAVH. RESULTS: The ICC for IAPMAL before CS was lower than after (0.71 versus 0.87). Both mean IAPMAL and IAPSP were significantly higher before CS than after: 14.0±2.6 mmHg versus 9.8±3.0 mmHg (p<0.0001) and 8.2±2.5 mmHg versus 3.5±1.9 mmHg (p = 0.010), respectively. After CS, IAP was not different from values measured in the LAVH-group. CONCLUSION: IAP-measurements using FMLV is reproducible in pregnant women. Before CS, IAP is increased in the range of intra-abdominal hypertension for non-pregnant individuals. IAP significantly decreases to normal values after delivery.

Incarceration of the gravid uterus: diagnosis and preoperative evaluation by magnetic resonance imaging.

Incarceration of the gravid uterus is a rare obstetric disorder that is often not recognized despite the ready availability of ultrasound. However, detailed imaging of the disturbed uterine and pelvic anatomy - from an obstetric point of view- is the key in reducing the potentially severe complications of this condition and planning its treatment. In this paper, we will describe the specific magnetic resonance imaging (MRI) features of an incarceration of the gravid uterus and we will discuss the role of magnetic resonance imaging in defining anatomy and in the medical decision whether to operate or not.

Maternal venous hemodynamics in gestational hypertension and preeclampsia.

BACKGROUND: To evaluate characteristics of venous hemodynamics, together with cardiac and arterial function, in uncomplicated pregnancies (UP), non-proteinuric gestational hypertension (GH) and preeclampsia (PE). METHODS: In this observational cross-sectional study, venous hemodynamics was assessed using a standardised protocol for combined electrocardiogram (ECG)-Doppler ultrasonography, together with a non-invasive standardised cardiovascular assessment using impedance cardiography (ICG) in 13 women with UP, 21 with GH, 34 with late onset PE ≥ 34 w (LPE) and 22 with early onset PE < 34 w (EPE). ECG-Doppler parameters were impedance index at the level of hepatic veins (HVI) and renal interlobar veins (RIVI) together with venous pulse transit times (VPTT), as well as resistive and pulsatility index, and arterial pulse transit time (APTT) at the level of uterine arcuate arteries. ICG parameters were aortic flow velocity index (VI), acceleration index (ACI) and thoracic fluid content. Mann Whitney U-test, Kruskall-Wallis test and linear regression analysis with heteroskedastic variance was used for statistical analysis. RESULTS: RIVI in both kidneys was >15% higher (P ≤ .010) in LPE and EPE, as compared to GH and UP. Next to this, >30% lower values for VI and ACI (P ≤ .029), and > 15% lower values for APTT (P ≤ .012) were found in GH, LPE and EPE, as compared to GH. CONCLUSION: In comparison to UP, similar abnormalities of central arterial function and APTT were found in GH, EPE and LPE. Proteinuria of LPE and EPE was associated with increased RIVI, this was not observed in GH.

Improving the reliability of venous Doppler flow measurements: relevance of combined ECG, training and repeated measures.

The nature of venous Doppler waves is highly variable. An additional electrocardiogram (ECG) improves the interpretation of venous Doppler wave characteristics and allows measurement of venous pulse transit time. The purpose of this study was to assess the reproducibility of ECG-guided repeated measurements of venous Doppler flow characteristics before and after sonographer training and the inter- and intra-observer variability. In four groups of 25 healthy women, venous Doppler flow measurements were performed at the level of the kidneys and liver according to a standardized protocol. Intra-observer Pearson correlation coefficients of the renal interlobar vein Doppler indices were ≥ 0.80 with the addition of the ECG, which are higher than the results of a former study. The inter-observer correlation between an experienced ultrasonographer and an inexperienced ultrasonographer improved from ≥ 0.71 to ≥ 0.91 after training. The correlation range of all parameters between two independent observers improved when values were based on repeated measures. The addition of an ECG to the Doppler image, training and repeated measurements are helpful in improving venous Doppler wave interpretation.

Maternal cardiovascular profiling in the first trimester of pregnancies complicated with gestation-induced hypertension or fetal growth retardation: a pilot study.

OBJECTIVE: In this study, we determine whether maternal cardiovascular (CV) profiling can detect first trimester differences between women with uncomplicated pregnancies (UP) and those who will develop gestational hypertensive disorders (GHD) or normotensive fetal growth retardation (FGR). METHODS: Cardiac, arterial, and venous function were evaluated in 242 pregnant women around 12 weeks of gestation, using impedance cardiography (ICG) and combined electrocardiogram - Doppler ultrasonography. After postnatal determination of gestational outcome, first trimester measurements were compared between groups using Mann-Whitney U test for continuous data or Fisher's Exact test for categorical variables (SPSS 20.0). RESULTS: Compared to UP, first trimester aortic flow velocity index [71 ± 0.96 versus 61 ± 4.91 1/1000/s (p = 0.016)], acceleration index [133 ± 2.25 versus 106 ± 11.26 1/100/s(2) (p = 0.023)] and Heather index [23.1 ± 0.35 versus 19.2 ± 1.70 Ω/s(2) (p = 0.019)] were lower in GHD pregnancies, and first trimester stroke volume [77 ± 1.16 versus 67 ± 3.97 ml (p = 0.033)] and cardiac output [7.3 ± 0.10 versus 6.2 ± 0.31 l/min (p = 0.025)] were lower in FGR pregnancies. CONCLUSIONS: Maternal CV function in the first trimester of pregnancy differs between UP and those destined to develop GHD or FGR. This can be assessed with non-invasive maternal CV profiling, opening perspectives for the application of this technique in early gestational screening for GHD and FGR.

Non-invasive assessment of gestational hemodynamics: benefits and limitations of impedance cardiography versus other techniques.

To obtain data for maternal stroke volume and cardiac output during pregnancy, it is preferable to use a non-invasive, accurate and reproducible method. In this aspect, impedance cardiography is an excellent technique which is also highly accessible and easy to perform. This paper is a comprehensive review on the published literature about impedance cardiography and highlights the strengths and limitations of its applications in obstetrics.

Non-invasive cardiovascular profiling using combined electrocardiogram-Doppler ultrasonography and impedance cardiography: An experimental approach.

In the present study, the feasibility of cardiovascular profiling using both combined electrocardiogram (ECG)-Doppler ultrasonography and impedance cardiography (ICG) was evaluated. Fourteen non-pregnant healthy women received 500 mL saline solution (NaCl 0.9% at 999 mL/h) intravenously by steady state infusion. Before and after this acute volume loading, we measured orthostatic-challenged cardiac and arterial characteristics using ICG and assessed venous characteristics by combined ECG-Doppler before and during the Valsalva manoeuvre. Changes are expressed as the mean ± SEM and were evaluated by the one-sample Wilcoxon signed-rank test. After volume loading, the observed fall in stroke volume after postural change from supine to standing decreased (-14 ± 3 vs -23 ± 2%; P = 0.011). Hepatic A wave velocity increased 63 ± 28% after volume loading (P = 0.007) and decreased during the Valsalva manoeuvre (-205 ± 21%; P = 0.001). Volume loading raised the thoracic fluid content index in both the supine and standing positions (7 ± 2% and 10 ± 1%, respectively; P ≤ 0.014). Combined ECG-Doppler ultrasonography and ICG enables the non-invasive identification of concomitant haemodynamic changes at the level of the heart, the arterial bed and the venous compartment. Our data support the view that non-invasive cardiovascular profiling is feasible, which seems particularly useful for the evaluation of patients who are not critically ill, such as pregnant women.

Characteristics of heart, arteries, and veins in low and high cardiac output preeclampsia.

OBJECTIVE: To assess the feasibility of non-invasive measurements of maternal cardiac output in relation to birth weight percentile and cardiovascular physiology in preeclampsia. STUDY DESIGN: In a cohort of 62 women with preeclampsia, impedance cardiography was used to measure cardiac output and to evaluate heart and arteries. Venous characteristics were assessed by combined electrocardiogram-Doppler ultrasonography. Statistical differences were evaluated by Mann-Whitney U-tests. RESULTS: Cardiac output correlated with birth weight percentile (P=.002), with more small for gestational age newborns in low cardiac output preeclampsia (<7.5L/min) than in high cardiac output preeclampsia (≥8.9L/min) (12/29 vs. 2/16, P=.044). This was associated with lower aortic flow indices and shorter venous pulse transit times in low than in high cardiac output preeclampsia. CONCLUSION: Non-invasive impedance cardiography measurements of maternal cardiac output correlate with birth weight percentile and are associated with different functionality of heart, arteries, and veins in low and high cardiac output preeclampsia.

PP070. Maternal cardiovascular profiling in the first trimester ofpregnancies complicated with gestation induced hypertension or fetal growth restriction.

INTRODUCTION: Maternal cardiovascular (CV) profiling is useful in the assessment of gestational hypertensive disorders (GHD)(1). The onset of GHD occurs during the first weeks of gestation(2). OBJECTIVE: To evaluate whether CV profiling can detect first trimester differences between women with uncomplicated pregnancies (UP) and those who will develop GHD or fetal growth restriction (FGR). METHODS: CV function was evaluated according to standardised protocols in 242 pregnant women around 12 weeks of gestation, using impedance cardiography (ICG) and combined ECG - Doppler ultrasonography. Outcome was evaluated after delivery and categorized as UP (n=218), GHD with or without proteinuria (n=13), and pregnancies complicated with FGR (n=11). Measurements were compared between groups using Mann-Whitney U test for continuous data or Fisher's Exact test for categorical variables. RESULTS: As compared to UP, women destined to develop GHD showed increased systolic blood pressure, diastolic blood pressure and mean arterial pressure; and decreased ICG aortic velocity - and acceleration index. Pregnancies complicated with FGR showed decreased stroke volume and cardiac output when compared to UP. No differences were found concerning the maternal veins. CONCLUSION: First trimester maternal CV function differs between women with uncomplicated pregnancies and those destined to develop GHD or FGR. Non-invasive CV profiling enables the identification of these differences.

PP078. The influence of maternal position on gestational hemodynamics.

INTRODUCTION: Cardiovascular profiling is useful for gestational hemodynamic studies. Conflicting results of cardiac output evolution from third trimester pregnancy to term are frequently reported. OBJECTIVES: To stress the effect of maternal position in the assessment of maternal cardiac and arterial parameters during normal pregnancy. METHODS: Impedance cardiography measurements were executed during 16 normal pregnancies using a standard protocol with known reproducibility. Gestational evolution of stroke volume, cardiac output, cardiac cycle time intervals, aortic flow parameters and total peripheral vascular resistance was measured in supine, standing and sitting positions. SAS procedure MIXED for linear mixed models was used for each parameter separately. RESULTS: Evolution of stroke volume and cardiac output in supine position differed from standing (p<0.01) and sitting positions (p<0.05). Next to this, pre-ejection period, left ventricular ejection time index, systolic time ratio and total peripheral vascular resistance also showed a different evolution between supine and standing positions (p<0.05); no differences were observed between standing and sitting positions (p⩾0.19). CONCLUSION: Next to the frequently reported cardiac output, gestational evolutions of other pre-load dependent parameters are influenced by maternal position. This study shows the importance of a standardized protocol for the measurement of cardiovascular parameters in pregnancy.

Venous pulse transit time in normal pregnancy and preeclampsia.

Uncomplicated pregnancies (n = 16) were evaluated longitudinally and compared to early- (n = 12) and late-onset (n = 14) preeclampsia patients, assessed once at diagnosis. Pulse transit time (PTT), equivalent to pulse wave velocity, was measured as the time interval between corresponding characteristics of electrocardiography and Doppler waves, corrected for heart rate, at the level of renal interlobar veins, hepatic veins, and arcuate branches of uterine arteries. Impedance cardiography was used to measure PTT at the level of the thoracic aorta. In normal pregnancy, all PTT increased gradually (P ≤ .01). Pulse transit time was shorter in late-onset preeclampsia (P < .05) and also in early-onset preeclampsia, with exception for hepatic veins and thoracic aorta (P > .05). Our results indicate that PTT is an easy and highly accessible measure for vascular reactivity at both arterial and venous sites of the circulation. Our observations correlate well with known gestational cardiovascular adaptation mechanisms. This suggests that PTT could be used as a new parameter in the evaluation and prediction of preeclampsia.

Early neonatal complications from pulmonary arteriovenous malformations in hereditary hemorrhagic telangiectasia: case report and review of the literature.

Hereditary hemorrhagic telangiectasia (HHT) is a rare but life-threatening disease characterized by multi system telangiectasias and arteriovenous malformations (AVM). Complications in adults have been reported extensively, but neonatal (NN) complications have only been published in incidental case reports. In this paper, we present a literature review on NN pulmonary AVM related to HHT, following our own experience with a NN death due to this disease. As prenatal diagnosis of pulmonary AVM is feasible, we recommend that a family history of HHT should be an indication for expertise prenatal anomaly scanning, in order to organise optimal NN support at birth.

Diurnal and position-induced variability of impedance cardiography measurements in healthy subjects.

Cardiovascular (CV) parameters and their measurements are subject to variation. In this study, we evaluated the reproducibility of impedance cardiography (ICG) measurements following orthostatic and diurnal challenges for a set of 22 CV parameters in ten randomly selected healthy nonpregnant women. A standard protocol was used to record a consecutive series of measurements for each parameter before and after three position changes. This series of measurements was performed twice (AM and PM sessions). For each parameter, measurement-shift following position change was evaluated at 5% cutoff and compared between sessions. Intra- and intersession intraclass correlation (ICC) was calculated for individual measurements per position using repeated-measures analysis of variance. Intra- and intersession Pearson's correlation coefficient (PCC) was calculated for mean values per position. Intersession correlation for measurement-shift following position change was 0·42 (5/12) for pressure parameters, whereas this was 0·96 (52/54) for other parameters. Inter- and intrasession ICC for individual measurements varied between 0·02 and 1 for all parameters, however inter- and intrasession PCC for mean values was consistently >0·80 for stroke volume (SV), stroke index (SI), cardiac output (CO), acceleration and velocity index (ACI and VI), thoracic fluid content (TFC), TFC index (TFCI) and heart period duration (HPD). We conclude that in healthy subjects under standardised conditions, reproducibility of means of multiple ICG measurements is high for SV, SI, CO, ACI, VI, TFC, TFCI and HPD. From our data, we cannot draw conclusions on trends in diseased subjects.

Recurrent incarceration and/or sacculation of the gravid uterus: a review.

Retroverted uterine incarceration with sacculation of the anterior wall is reported to occur approximately in 1/3000 pregnancies. A literature search identified only one case report of incarceration of an anteflexed gravid uterus and six reported cases of recurrent incarceration and/or sacculation. We present a case of an incarceration of an anteflexed uterus in the first pregnancy, followed by a retroflexed incarceration in the second pregnancy. From this, a review is presented on recurrent uterine incarceration and/or sacculation.

Ultrasound experience substantially impacts on diagnostic performance and confidence when adnexal masses are classified using pattern recognition.

AIM: To determine how accurately and confidently examiners with different levels of ultrasound experience can classify adnexal masses as benign or malignant and suggest a specific histological diagnosis when evaluating ultrasound images using pattern recognition. METHODS: Ultrasound images of selected adnexal masses were evaluated by 3 expert sonologists, 2 senior and 4 junior trainees. They were instructed to classify the masses using pattern recognition as benign or malignant, to state the level of confidence with which this classification was made and to suggest a specific histological diagnosis. Sensitivity, specificity, accuracy and positive and negative likelihood ratios (LR+ and LR-) with regard to malignancy were calculated. The area under the receiver operating characteristic curve (AUC) of pattern recognition was calculated by using six levels of diagnostic confidence. RESULTS: 166 masses were examined, of which 42% were malignant. Sensitivity with regard to malignancy ranged from 80 to 86% for the experts, was 70 and 84% for the 2 senior trainees and ranged from 70 to 86% for the junior trainees. The specificity of the experts ranged from 79 to 91%, was 77 and 89% for the senior trainees and ranged from 59 to 83% for the junior trainees. The experts were uncertain about their diagnosis in 4-13% of the cases, the senior trainees in 15-20% and the junior trainees in 67-100% of the cases. The AUCs ranged from 0.861 to 0.922 for the experts, were 0.842 and 0.855 for the senior trainees, and ranged from 0.726 to 0.795 for the junior trainees. The experts suggested a correct specific histological diagnosis in 69-77% of the cases. All 6 trainees did so significantly less often (22-42% of the cases). CONCLUSION: Expert sonologists can accurately classify adnexal masses as benign or malignant and can successfully predict the specific histological diagnosis in many cases. Whilst less experienced operators perform reasonably well when predicting the benign or malignant nature of the mass, they do so with a very low level of diagnostic confidence and are unable to state the likely histology of a mass in most cases.