Hemodynamic and hemorheological profiles in women with proteinuric hypertension of pregnancy and in pregnant controls

Reference ranges for third-trimester maternal cardiovascular function parameters measured in normotensive pregnant women using a non-invasive cardiac output monitor: A study based on data from the prospective PEACH cohort study

OBJECTIVE

We defined reference ranges for maternal cardiac output, systemic vascular resistance, and stroke volume measured in the third trimester of pregnancy using the Ultrasound Cardiac Output Monitor 1A.

DESIGN

Based on data from the prospective PEACH (PreEclampsia, Angiogenesis, Cardiac dysfunction and Hypertension) cohort study.

SETTING

Rigshospitalet and Hvidovre Hospital, Denmark.

SAMPLE

Normotensive pregnant women aged 18-45 years with singleton pregnancies, enrolled in the PEACH study in 2016-2018.

METHODS

We modelled cardiac output, systemic vascular resistance and stroke volume as a function of gestational age using multilevel linear models with fractional polynomials.

MAIN OUTCOME MEASURES

Unconditional and conditional reference ranges for cardiovascular parameters measured in gestational weeks 28-40.

RESULTS

Our study cohort included 405 healthy pregnant women who contributed 1210 cardiovascular function measurements for analysis. Maximum cardiac output and stroke volume values were measured in gestational weeks 30-32 and decreased over the third trimester, whereas systemic vascular resistance increased during the same period. We created reference ranges for eight combinations of maternal height, age and parity. We also created a simple calculator to allow for implementation of the reference ranges in clinical practice.

CONCLUSIONS

Our reference ranges allow the use of a bedside ultrasound device to non-invasively assess cardiac function in pregnancy and identify women at risk of complications. The unconditional ranges allow clinicians to evaluate isolated measurements and identify women needing follow-up. The conditional ranges incorporate information from previous measurements and improve monitoring over time.

Investigating the blood rheology in the first trimester pregnancies with high risk for preeclampsia

BACKGROUND

Pregnancy is a dynamic process associated with changes in vascular and rheological resistance. Maternal maladaptation to these changes is the leading cause of pregnancy complications such as preeclampsia.

OBJECTIVE

This study aimed to assess the hemorheological alterations in pregnancies with a high risk for preeclampsia in the first trimester.

METHODS

Ninety-two pregnant women were allocated into the high preeclampsia risk group (37 cases) and control groups (55 cases). Plasma and whole blood viscosity and red blood cell morphodynamic properties, including deformability and aggregation were assessed by Brookfield viscometer and laser-assisted optical rotational cell analyzer (LORRCA) at 11-14 gestational weeks.

RESULTS

Whole blood viscosity was significantly higher in the high-risk group at all shear rates. Plasma viscosity and hematologic factors showed no differences between the groups. Hematocrit levels positively correlated with high blood viscosity only in the high-risk group. There were no significant changes in the other deformability and aggregation parameters.

CONCLUSIONS

Changes in the whole blood viscosity of pregnant women with high preeclampsia risk refer to impaired microcirculation beginning from the early weeks of gestation. We suggest that the whole blood viscosity is consistent with the preeclampsia risk assessment in the first trimester, and its measurement might be promising for identifying high-preeclampsia-risk pregnancies.

The Importance of Doppler Analysis of Uterine Circulation in Pregnancy for a Better Understanding of Preeclampsia

BACKGROUND

The etiology of preeclampsia has still not been completely explained. Early identification of women with the risk of developing preeclampsia is a key goal of antenatal care.

OBJECTIVE

To investigate risk factors for preeclampsia from the history, laboratory and ultrasound findings (Doppler).

METHODS

Pregnant women with normal Doppler sonography in the second trimester of pregnancy were classified as a control group, while pregnant women with impaired Doppler in the second trimester were considered as the investigated group with presumably increased risk for preeclampsia. A total number of 80 patients was included in the study (40 patients in each group).

RESULTS

The difference of urea, uric acid and lactate dehydrogenase (LDH) in the serum of the control and investigated group was statistically significant, while the differences were not statistically significant for creatinine, aspartate aminotransferase (AST) and alanine aminotransferase (ALT). The presence of a notch sign during assessment of blood flow in uterine arteries in subjects in the investigated group with the diagnosis of preeclampsia had the specificity of 47.62%, and sensitivity of 88.89%. The positive predictive value of a notch sign during assessment of blood flow in uterine arteries as a marker for diagnosis of preeclampsia in the second trimester of pregnancy was 90.91%, and its negative. Systolic and diastolic blood pressure are dependent variables which are predicting preeclampsia, whilst a notch sign in uterine arteries was designated as an independent variable predicting preeclampsia.

CONCLUSION

From the laboratory tests the following parameters were considered as the risk factors for preeclampsia: increasing levels of urea, uric acid, and LDH. Notch sign was considered to be a very strong predictor of preeclampsia, especially if present bilaterally. Doppler sonography in the second trimester of pregnancy is a good predictor for early diagnosis of preeclampsia.

Uric Acid Values Along with Doppler Sonography Findings as a Tool for Preeclampsia Screening

Introduction

Preeclampsia is defined as hypertension (systolic pressure ≥140 mmHg or diastolic pressure ≥90 mmHg) after week 20 of gestation with one or more of the following symptoms: proteinuria, organ dysfunction (including renal, hepatologic, hematologic or neurological complications) and in case of stagnation of fetal development. So far, there are no valid clinical tools or tests that can tell with sufficient sensitivity and specificity in early pregnancy which pregnant woman will develop preeclampsia or have unwanted outcomes.

Aim

To present the properties of biochemical parameter, uric acid, in patients with signs of preclampsia, which was confirmed by Doppler sonography.

Methods

The study included 60 female subjects in the second trimester of pregnancy who were examined or were hospitalized at the Clinic of Gynecology and Obstetrics, Clinical Center University of Sarajevo. Pregnant women who had normal Doppler sonography scan of the uterine arteries in the second trimester of pregnancy were included in the control group, while pregnant women with pathologic Doppler sonographic findings in the second trimester of pregnancy were included in the group of pregnant women at risk of preeclampsia, i.e. the study group.

Results

There is statistically significant difference between the average value of uric acid in the control and in the study group (213.36 ± 28.96 μmol / L vs 249.73 ± 47.06 μmol / L) (F = 12.991; p = 0.001). Applying the Wilcoxon non-parametric paired test to the average uric acid values during all measurements within the control group, no statistically significant difference was found. There was a statistically significant increase in the study group between all measurements, from 18.04 μmol / L between the first and second measurement (Z = -1.955; p = 0.043), 29.10 μmol / L between the second and third measurement (Z = -2.973; p = 0.003), 37.27 μmol / L between the third and fourth measurement (Z = -4.325; p = 0.001) and 109.87 μmol / L at the end of the study in comparison to values from the start of the study (Z = -4.309; p = 0.001).

Conclusion

Uric acid values should become part of a broad biochemical range in screening and optimizing the treatment of patients diagnosed with early preeclampsia.

Maternal venous Doppler characteristics are abnormal in pre-eclampsia but not in gestational hypertension

OBJECTIVE

To compare functional characteristics of maternal thoraco-abdominal arteries and veins in proteinuric and non-proteinuric hypertension in pregnancy.

METHODS

This retrospective study included women with singleton pregnancies during the third trimester, which were either uncomplicated or complicated with different clinical types of hypertension: non-proteinuric gestational hypertension (GH), early-onset pre-eclampsia (PE) diagnosed < 34 weeks or late-onset PE diagnosed ≥ 34 weeks. Demographic maternal and neonatal data were recorded, together with maternal serum and urine analytes. All women underwent standardized automated blood-pressure measurement, together with non-invasive impedance cardiography (ICG), for measurement of cardiac output (CO), aortic flow velocity index (VI) and aortic flow acceleration index (ACI). A standardized combined Doppler-electrocardiography assessment of maternal venous hemodynamics was performed to measure renal interlobar vein impedance index (RIVI), hepatic vein impedance index (HVI) and venous pulse transit time (VPTT) in liver and kidneys. Finally, resistance index (RI), pulsatility index (PI) and arterial pulse transit time (APTT) were measured in the uterine arcuate arteries. Mann-Whitney U-tests and Fisher's exact tests were used for intergroup comparisons, and linear dependence between variables was assessed using Pearson's correlation coefficient (r).

RESULTS

A total of 150 pregnancies were evaluated: 22 with uncomplicated pregnancy, 41 GH, 31 early PE and 56 late PE. Aortic VI and ACI were lower in GH, early PE and late PE than in uncomplicated pregnancy. Both early PE and late PE differed from GH by having shorter APTT in the uterine arcuate arteries and higher RIVI. Hemodynamic abnormalities were most pronounced in early PE, during which uterine arcuate artery RI was higher and VPTT in kidneys was shorter than in late PE. There was a significant correlation between degree of proteinuria and RIVI for the left (r = 0.381) and right (r = 0.347) kidney in late PE, but this was not true for early PE.

CONCLUSIONS

There is a gradient of worsening arterial and venous hemodynamic abnormalities from GH to late PE and then to early PE. Venous hemodynamic abnormalities are present only in PE, with a linear correlation between proteinuria and RIVI in late PE. The role of the maternal venous compartment in the pathophysiology and etiology of PE-related symptoms may be much more important than considered at present.

Comparison of gestational diabetes mellitus and pre-eclampsia in women with high hemoglobin in the first trimester of pregnancy: A longitudinal study

OBJECTIVE

To determine the association between high hemoglobin with gestational diabetes mellitus (GDM) and preeclampsia in pregnant women in the first trimester.

METHODS

This cohort study was conducted among 973 pregnant women who started their antenatal booking in the first trimester (first 14 weeks of gestation). Women with first-visit high Hb levels (> 12.5 g/L) on first visit of the pregnancy period were selected as the study group and were compared with those who had normal Hb value (< 12.5 g/L) as controls. Adverse pregnancy outcomes including preeclampsia and GDM were compared between the two groups.

RESULTS

Complete obstetric records of 448 women with high Hb levels and 486 women with normal Hb levels were studied. The follow up showed that the women with high Hb levels had significantly higher rates of preeclampsia and GDM than those with normal Hb levels; the risks were 5.4 (95% cl; 2.8 to 10.5) and 3.7 (95%cl; 2.2 to 6.4), respectively.

CONCLUSION

This study found that high Hb in the first trimester is associated with higher risk of subsequent preeclampsia and gestational diabetes mellitus (GDM).

PP13 and PAPP-A in the First and Second Trimesters: Predictive Factors for Preeclampsia?

Background. Preeclampsia affects 5-6% of all pregnancies. Predictive factors of preeclampsia can be helpful in early diagnosis of this disease. In this study the predictive values of biochemical markers placenta protein 13 (PP13) and pregnancy-associated plasma protein A (PAPP-A) have been assessed in early diagnosis of preeclampsia. Methods. This case-control study was conducted on 1500 women who presented to a healthcare center of Sari, Iran, between 2010 and 2011. Blood samples were drawn in weeks 11–13 and 24–28 of pregnancy. Of them who developed preeclampsia were considered as case group. A control group consisted of similar women regarding mean age, body mass index (BMI), and pregnancy age. PAPP-A and PP13 serum levels were measured. Data were analyzed using proper statistical tests. Results. PAPP-A and PP13 serum levels were significantly lower in both the first and second trimesters in women who developed preeclampsia (P < 0.001). The cumulative value of all four variables with cut-off point of 238.5 has sensitivity, specificity of 91.0%, and undercurve surface of 0.968 which is the most diagnostic value for preeclampsia. Conclusion. It is possible to advantage measuring of PAPP-A and PP13 in the first and second trimesters especially their cumulative values in both trimesters for prediction of the incidence of preeclampsia.

First trimester maternal blood rheology and pregnancy induced hypertension

This study evaluates the relationship between the first trimester assessment of maternal rheology and the subsequent development of pregnancy induced hypertension. This is a prospective observational study based in the Glasgow Royal Maternity Hospital, Scotland. From an original population of 744 consecutive antenatal attendees a total of 579 women were booked at less than 14 weeks' gestation. The main study group is a further subset comprising 251 primigravid women booking with a singleton pregnancy without essential hypertension. Previously published data from a group of non-pregnant women of similar age drawn from the same local community was used for external comparison. Blood samples were collected at the booking visit, from which fibrinogen, red cell aggregation, haematocrit and plasma, whole blood, relative and corrected viscosities were recorded. Information was obtained from the case notes in retrospect starting approximately 1 year after the first patients had first been recruited into the trial. The overall outcome of the pregnancies was noted with particular reference to pregnancy induced hypertension (PIH), birth weight, antepartum haemorrhage, pre-term labour, perinatal death, condition at delivery and neonatal complication. Our results show PIH is associated with a significantly raised mean blood viscosity and fibrinogen at time of booking. All significance disappears after adjustment for smoking, diastolic blood pressure and age. Viscosity is, however, only marginally non-significant (p = 0.07). In conclusion, blood rheology, in particular blood viscosity and fibrinogen, may play a predictive role in the development of pregnancy-induced hypertension. When combined with measurement of smoking and diastolic blood pressure at booking, these measurements could be used to calculate a risk score for the development of PIH, allowing targeting of antenatal care. Further data is required.

The oxygen consumption/oxygen delivery curve in severe preeclampsia: evidence for a fixed oxygen extraction state

OBJECTIVE

Increased total body oxygen consumption requirements are usually met by increased oxygen delivery and increased oxygen extraction. In certain conditions (e.g., adult respiratory distress syndrome) the ability to increase oxygen extraction is lost, and any increase in oxygen consumption depends on increased oxygen delivery. The objective of this study was to investigate the oxygen delivery/oxygen consumption relationship in severe preeclampsia.

STUDY DESIGN

Thirty-two patients with severe preeclampsia (blood pressure > 160/110 mm Hg; 3 to 4+ proteinuria) were monitored with a pulmonary artery catheter. Baseline oxygen consumption and delivery in a group without volume expansion or pharmacologic vasodilatation were compared with those in a group who had received a magnesium sulfate infusion.

RESULTS

Oxygen consumption, oxygen delivery, arterial-venous-oxygen difference, and the oxygen extraction ratio were low when compared to that for normal 32 to 38 week pregnancy. The oxygen extraction ratio, defined as the ratio of oxygen consumption to oxygen delivery, was abnormally low for pregnancy, especially considering the low oxygen delivery levels in these patients. Oxygen consumption was dependent on oxygen delivery over the entire range of values seen.

CONCLUSIONS

Severe preeclampsia is associated with an abnormality of tissue oxygen extraction, as evidenced by a low and unresponsive oxygen extraction ratio. Oxygen consumption increases proportionately with increases in oxygen delivery without reaching an oxygen delivery-independent state. Even at high oxygen delivery levels the oxygen consumption in preeclamptic patients is still abnormally low for pregnancy.