Increased cerebral blood flow in preeclampsia with magnetic resonance imaging

Temporal patterns of pre- and post-natal target organ damage associated with hypertensive pregnancy: a systematic review

AIMS

Hypertensive pregnancy is associated with increased risks of developing a range of vascular disorders in later life. Understanding when hypertensive target organ damage first emerges could guide optimal timing of preventive interventions. This review identifies evidence of hypertensive target organ damage across cardiac, vascular, cerebral, and renal systems at different time points from pregnancy to postpartum.

METHODS AND RESULTS

Systematic review of Ovid/MEDLINE, EMBASE, and ClinicalTrials.gov up to and including February 2023 including review of reference lists. Identified articles underwent evaluation via a synthesis without meta-analysis using a vote-counting approach based on direction of effect, regardless of statistical significance. Risk of bias was assessed for each outcome domain, and only higher quality studies were used for final analysis. From 7644 articles, 76 studies, including data from 1 742 698 pregnancies, were identified of high quality that reported either blood pressure trajectories or target organ damage during or after a hypertensive pregnancy. Left ventricular hypertrophy, white matter lesions, proteinuria, and retinal microvasculature changes were first evident in women during a hypertensive pregnancy. Cardiac, cerebral, and retinal changes were also reported in studies performed during the early and late post-partum period despite reduction in blood pressure early postpartum. Cognitive dysfunction was first reported late postpartum.

CONCLUSION

The majority of target organ damage reported during a hypertensive pregnancy remains evident throughout the early and late post-partum period despite variation in blood pressure. Early peri-partum strategies may be required to prevent or reverse target organ damage in women who have had a hypertensive pregnancy.

Is there a role of proinflammatory cytokines on degenerin-mediated cerebrovascular function in preeclampsia?

Preeclampsia (PE) is associated with adverse cerebrovascular effects during and following parturition including stroke, small vessel disease, and vascular dementia. A potential contributing factor to the cerebrovascular dysfunction is the loss of cerebral blood flow (CBF) autoregulation. Autoregulation is the maintenance of CBF to meet local demands with changes in perfusion pressure. When perfusion pressure rises, vasoconstriction of cerebral arteries and arterioles maintains flow and prevents the transfer of higher systemic pressure to downstream microvasculature. In the face of concurrent hypertension, loss of autoregulatory control exposes small delicate microvessels to injury from elevated systemic blood pressure. While placental ischemia is considered the initiating event in the preeclamptic cascade, the factor(s) mediating cerebrovascular dysfunction are poorly understood. Elevated plasma proinflammatory cytokines, such as tumor necrosis factor α (TNF-α) and interleukin-17 (IL-17), are potential mediators of autoregulatory loss. Impaired CBF responses to increases in systemic pressure are attributed to the impaired pressure-induced (myogenic) constriction of small cerebral arteries and arterioles in PE. Myogenic vasoconstriction is initiated by pressure-induced vascular smooth muscle cell (VSMC) stretch. Recent studies from our laboratory group indicate that proinflammatory cytokines impair the myogenic mechanism of CBF autoregulation via inhibition of vascular degenerin proteins, putative mediators of myogenic constriction in VSMCs. This brief review links studies showing the effect of proinflammatory cytokines on degenerin expression and CBF autoregulation to the pathological cerebral consequences of preeclampsia.

The Nine Month Stress Test: Pregnancy and Exercise - Similarities and Interactions

Of all physiological systems, the cardiovascular system takes on the most profound adaptation in pregnancy to support fetal growth and development. The adaptations that arise are systemic and involve structural and functional changes that can be observed at the cerebral, central, peripheral, and microvascular beds. This includes, although is not limited to increased heart rate, stroke volume and cardiac output with negligible change to blood pressure, reductions in vascular resistance and cerebral blood flow velocity, systemic artery enlargement, enhanced endothelial function. All of this takes place to accommodate blood volume expansion and ensure adequate fetal and maternal oxygen delivery. In some instances, the demand placed on the vasculature can manifest as cardiovascular maladaptation and thus, cardiovascular complications can arise. Exercise is recommended in pregnancy because of its powerful ability to reduce the incidence and severity of cardiovascular complications in pregnancy. However, the mechanism by which it acts is poorly understood. The first aim of this review is to describe the systemic adaptations that take place in pregnancy. Secondly, this review aims to describe the influence of exercise on these systemic adaptations. It is anticipated that this review can comprehensively capture the extent of knowledge in this area while identifying areas that warrant further investigation.

What Is the Role of the Maternal Ophthalmic and Cervical Internal Carotid Arteries in Predicting Maternal Adverse Outcomes in Preeclampsia?

OBJECTIVES

We aimed to investigate the efficacy of maternal ophthalmic artery (OA) and cervical internal carotid artery (CICA) in predicting adverse maternal outcomes and gestational age at birth in preeclampsia (PE).

METHODS

The study was performed at the Zeynep Kamil Women and Children's Diseases Training and Research Hospital. Measurements were made in 2 groups consisting of 50 pregnant women with PE and 50 healthy pregnant women. The peak systolic velocity (PSV), end-diastolic velocity, PI, RI, first diastolic peak velocity, systolic/diastolic (S/D) ratio, and peak ratio of the maternal OA were measured by a transorbital Doppler ultrasound (US) scan. The PSV, end-diastolic velocity, PI, RI, and S/D ratio of the CICA were measured. The differences of Doppler indices between groups with P < .05 were considered statistically significant. Cutoff values were calculated, which could be used to predict adverse maternal outcomes and gestational age at birth.

RESULTS

The RI and PI values of the OA were lower, and the first diastolic peak velocity, PSV, and peak ratio values were higher among the PE group. The RI and S/D values of the CICA were significantly lower in the PE group compared to the healthy group. The OA RI was determined to be the strongest US variable in predicting adverse maternal outcomes and gestational age at birth, with a cutoff value of 0.72, 76% sensitivity, and 76% specificity.

CONCLUSIONS

Maternal OA Doppler indices can be used as US markers to predict adverse maternal outcomes.

The role of the erythrocyte in the outcome of pregnancy with preeclampsia

The objective of this study was to analyze the relationships of osmotic and mechanical stability of erythrocytes with anthropometric, biochemical, hematologic and hemodynamic variables in pregnant women with preeclampsia (PE). The studied population consisted of 20 normotensive patients and 16 patients with PE. Patients with PE presented worse gestational outcome, greater hematologic impairment, erythrocytes osmotically more stable in vitro, but in conditions of isotonicity with the in vivo medium, in addition to hyperflow in orbital territory, when compared to normotensive patients. The correlation analysis between anthropometric, hematologic and hemodynamic variables in patients with PE indicated that erythrocytes with lower volumes and lower levels of hemoglobin favor the occurrence of a better gestational outcome, because they are more stable and because they are associated with a decrease in the hemodynamic changes present in the disease. This should mean that the tendency to microcytosis, probably due to a mechanism of compensatory mechanical selection, is a desirable characteristic in the disease.

Assessment of cerebral perfusion and edema in preeclampsia with intravoxel incoherent motion MRI

INTRODUCTION

Cerebral complications are the main reasons for morbidity and mortality in preeclampsia and eclampsia. As yet, we do not know whether the pathophysiology entails hypo- or hyperperfusion of the brain, or how and when edema emerges, due to the difficulty of examining the cerebral circulation.

MATERIAL AND METHODS

We have used a non-invasive diffusion weighted-magnetic resonance imaging technique, intravoxel incoherent motion, to study cerebral perfusion on the capillary level and cerebral edema in women with preeclampsia (n = 30), normal pregnancy (n = 32), and non-pregnant women (n = 16). Estimates of cerebral blood volume, blood flow, and edema were measured in 5 different regions. These points were chosen to represent blood supply areas of both the carotid and vertebrobasilar arteries, and to include both white and gray matter.

RESULTS

Except for the caudate nucleus, we did not detect any differences in cerebral perfusion measures on a group level. In the caudate nucleus, we found lower cerebral blood volume and lower blood flow in preeclampsia than in either normal pregnancy (P = .01 and P = .03, respectively) or non-pregnant women (both P = .02). No differences in edema were detected between study groups.

CONCLUSION

The cerebral perfusion measures were comparable between the study groups, except for a portion of the basal ganglia where hypoperfusion was detected in preeclampsia but not in normal pregnancy or non-pregnant women.

Are There Differences in the Anthropometric, Hemodynamic, Hematologic, and Biochemical Profiles between Late- and Early-Onset Preeclampsia?

Preeclampsia (PE) is classified as early-onset PE (EOPE) and late-onset PE (LOPE) when present before or after 34 weeks of gestation, respectively. This transversal study aimed to investigate the differences and possible associations existing in the anthropometric, hemodynamic, hematologic, and biochemical profiles of late- and early-onset preeclampsia. The study included 65 volunteers admitted to a tertiary hospital in Brazil: 29 normotensive and 36 with preeclampsia (13 with EOPE and 23 with LOPE). Pregnant women with LOPE presented greater weight gain and borderline increase in body mass index at the end of gestation in relation to the other groups, which is compatible with the metabolic origin, associated with obesity, attributed to this form of the disease. Pregnant women with EOPE presented a borderline reduction in the number of erythrocytes and a significant decrease in the number of platelets, in addition to a significant increase in reticulocytes, serum iron, and ferritin when compared to normotensive pregnant women and pregnant women with LOPE. A significant increase in osmotic stability of erythrocytes was observed in the EOPE group in relation to other groups. Hemodynamic analysis by Doppler ultrasonography of the ophthalmic artery showed that both groups of pregnant women with PE presented alterations compatible with the occurrence of hyperflow in the orbital territory. These hemodynamic changes were associated with changes in hematimetric indices.

Preeclampsia and the brain: neural control of cardiovascular changes during pregnancy and neurological outcomes of preeclampsia

Preeclampsia (PE) is a form of gestational hypertension that complicates ∼5% of pregnancies worldwide. Over 70% of the fatal cases of PE are attributed to cerebral oedema, intracranial haemorrhage and eclampsia. The aetiology of PE originates from abnormal remodelling of the maternal spiral arteries, creating an ischaemic placenta that releases factors that drive the pathophysiology. An initial neurological outcome of PE is the absence of the autonomically regulated cardiovascular adaptations to pregnancy. PE patients exhibit sympathetic overactivation, in comparison with both normotensive pregnant and hypertensive non-pregnant females. Moreover, PE diminishes baroreceptor reflex sensitivity (BRS) beyond that observed in healthy pregnancy. The absence of the cardiovascular adaptations to pregnancy, combined with sympathovagal imbalance and a blunted BRS leads to life-threatening neurological outcomes. Behaviourally, the increased incidences of maternal depression, anxiety and post-traumatic stress disorder (PTSD) in PE are correlated to low fetal birth weight, intrauterine growth restriction (IUGR) and premature birth. This review addresses these neurological consequences of PE that present in the gravid female both during and after the index pregnancy.

Contemporary clinical management of the cerebral complications of preeclampsia

The neurological complications of preeclampsia and eclampsia are responsible for a major proportion of the morbidity and mortality arising from these conditions, for women and their infants alike. This paper outlines the evidence base for contemporary management principles pertaining to the neurological sequelae of preeclampsia, primarily from the maternal perspective, but with consideration of fetal and neonatal aspects as well. It concludes with a discussion regarding future directions in the management of this potentially lethal condition.

Seizures and intracranial hemorrhage

Seizures and intracranial hemorrhage are possible medical diseases that any obstetrician may encounter. This article reviews the cause, treatment, and medical management in pregnancy for seizures and intracranial hemorrhage, and how the two can overlap into preeclampsia or eclampsia. This article also highlights some challenging management issues from the obstetrician's perspective.

Hypertension in pregnancy

Hypertension complicates 5% to 7% of all pregnancies. A subset of preeclampsia, characterized by new-onset hypertension, proteinuria, and multisystem involvement, is responsible for substantial maternal and fetal morbidity and is a marker for future cardiac and metabolic disease. This American Society of Hypertension (ASH) position paper summarizes the clinical spectrum of hypertension in pregnancy, focusing on preeclampsia. Recent research breakthroughs relating to etiology are briefly reviewed. Topics include classification of the different forms of hypertension during pregnancy, and status of the tests available to predict preeclampsia, and strategies to prevent preeclampsia and to manage this serious disease. The use of antihypertensive drugs in pregnancy, and the prevention and treatment of the convulsive phase of preeclampsia, eclampsia, with intravenous MgSO(4) is also highlighted. Of special note, this guideline article, specifically requested, reviewed, and accepted by ASH, includes solicited review advice from the American College of Obstetricians and Gynecologists.

Low maternal middle cerebral artery Doppler resistance indices can predict future development of pre-eclampsia

OBJECTIVE

To determine if decreased resistance (vasodilatation) in the maternal middle cerebral artery (MCA) in the second trimester can predict third-trimester development of pre-eclampsia.

METHODS

Four-hundred and five low-risk gravidas had MCA transcranial Doppler (TCD) once in the second trimester. Maternal/neonatal outcomes were evaluated after delivery. Mean blood pressure, MCA velocities, resistance index (RI), pulsatility index (PI) and cerebral perfusion pressure (CPP) were compared between normotensive and pre-eclamptic cohorts.

RESULTS

Seven subjects (1.7%) developed pre-eclampsia. An RI of < 0.54 and a PI of < 0.81 were clinically useful in predicting subsequent pre-eclampsia. Areas under the receiver-operating characteristics curves for RI and PI were 0.93 and 0.93, respectively, with optimal sensitivity and specificity of 86% and 93% for both variables. Positive and negative likelihood ratios were 11.8/0.15 (RI) and 12.3/0.15 (PI).

CONCLUSION

TCD indices of low maternal MCA resistance in the second trimester are predictive of the subsequent development of pre-eclampsia in a low-risk, ethnically homogeneous population.

Seizures in Women with Preeclampsia: Mechanisms and Management

Eclampsia is defined in the obstetrical literature as the occurrence of unexplained seizure during pregnancy in a woman with preeclampsia. In the Western world, the incidence of eclampsia is ~1 per 2000 to 1 per 3000 pregnancies, but the incidence is 10-fold higher in tertiary referral centers and undeveloped countries where there is poor prenatal care, and in multi-fetal gestations. Nearly 1 in 50 women with eclampsia die as do 1 in 14 of their offspring, and mortality rates are considerably higher in undeveloped countries. Eclampsia is also associated with significant life-threatening complications, including neurological events. Seizure acutely can cause stroke, haemorrhage, oedema and brain herniation and thus lead to epilepsy and cognitive impairment later in life.

[Sixty-nine consecutive cases of eclampsia: prodromes and circumstances]

OBJECTIVE

To specify clinical and biological characteristics of patients developing eclampsia, and identify atypical eclampsia without prior signs and symptoms of severe preeclampsia.

PATIENTS AND METHODS

This was a retrospective observational study conducted from January 1996 to December 2008 in a maternity type IIB in French Guiana. Data of patients who experienced eclampsia were collected from obstetric records.

RESULTS

Sixty-nine patients were selected among 21,525 patients who delivered during this period, corresponding to a prevalence of 3.2 ‰. The average patient age was 21 years (range from 12 to 45 years). Sixty-six percent of patients were nulliparous. The gestational age was greater than 37 weeks of gestation for 62% of patients, between 26 and 37 weeks of gestation for 36% and less than 26 weeks of gestation for 2% of patients. Two thirds of the patients had been examined less than a month before the eclamptic seizure, blood pressure was normal in 62% of cases. Seventy-four percent of patients had at least one Doppler study of the uterine and umbilical arteries velocimetry, the Dopplers studies were normal in 78% of cases. The eclampsia occurred in ante-, peri- and post-partum in 59, 6 and 35% of the cases, respectively 10% of patients were hospitalized for preeclampsia at the time of eclamptic seizure. Less than 10% of patients developed HELLP syndrome. One patient had died of aspiration pneumonia. Newborns had a mean birth weight over 2500 g in 88% of cases. During the follow-up period, 41% of the patients had subsequent pregnancies with 62% without hypertension, 24% complicated by recurrent gestational hypertension, 24% by preeclampsia and 4% by eclampsia.

DISCUSSION AND CONCLUSION

In a majority of the patients in our study, eclampsia was the main manifestation, and only 10% were preceded by severe preeclampsia. These results are comparable to recent studies, which found in their series that 40 to 60% of eclampsia manifested without preeclamptic prodromi. Eclampsia can occur after an unremarkable pregnancy, in women without risk factors, and then it is hardly predictable. Prenatal follow-up must be very cautious paying attention to any markers such as intermittent hypertension, functional symptoms or appearance of proteinuria.

Maternal cerebral blood flow during normal pregnancy: a cross-sectional study

OBJECTIVE

Pregnancy is associated with substantial changes in the maternal circulatory physiology. Our aim was to investigate maternal cerebral blood flow (CBF) during normal pregnancies.

STUDY DESIGN

We prospectively measured maternal CBF in 210 low-risk pregnant women at different gestational ages, and in 15 nonpregnant women. CBF was assessed by measuring blood flow volume in the internal carotid artery (ICA) by dual-beam angle-independent digital Doppler ultrasound.

RESULTS

ICA blood flow volume increased during pregnancy from 318 mL/min ± 40.6 mL/min in the first trimester to 382.1 mL/min ± 50.0 mL/min during the third trimester, corresponding to CBF values of 44.4 and 51.8 mL/min(-1)/100 g(-1), respectively (P < .0001). CBF changes were associated with progressive decrease in cerebral vascular resistance and moderate increase in ICA diameter.

CONCLUSION

Maternal CBF is gradually increasing during normal pregnancy. Vasorelaxing impact of estrogens and other factors on cerebral vessels may explain the changes in CBF during pregnancy.

Maternal cerebral blood flow and glucose metabolism in pregnancies complicated by severe preeclampsia

OBJECTIVE

To investigate maternal cerebral blood flow and glucose metabolism in pregnancies complicated by severe preeclampsia compared to normal pregnancies.

METHODS

A prospective study was conducted including six women with severe preeclampsia and nine normotensive women. Transcranial Doppler (TCD) was performed pre- and postoperatively. The anterior, middle, and posterior cerebral arteries (ACA, MCA, PCA) were selected for study; the cerebral perfusion pressure (CPP) and cerebral flow index (CFI) were calculated for each vessel. To evaluate the cerebral glucose metabolism, F-18 fluorodeoxyglucose positron emission tomography was performed postoperatively.

RESULTS

The preoperative CFI in each artery was similar in the comparisons between the two groups. However, the CPP in the MCA and the PCA was higher in the patients with severe preeclampsia. Compared to the preoperative values, the postoperative CPP and CFI in the ACA and the MCA were significantly increased in the severe preeclampsia group, while they were significantly decreased in the control group. Overall, the regional cerebral glucose uptake was not significantly different in comparisons between the two groups. In addition, there was no correlation between the cerebral Doppler indices and their corresponding regional cerebral glucose uptake.

CONCLUSIONS

Severe preeclampsia was associated with an increase in the cerebral blood flow and perfusion pressure, particularly during the postpartum period, but it was not associated with a significant change in the cerebral glucose metabolism.

Hypertension in pregnancy

Hypertension complicates 5% to 7% of all pregnancies. A subset of preeclampsia, characterized by new-onset hypertension, proteinuria, and multisystem involvement, is responsible for substantial maternal and fetal morbidity and is a marker for future cardiac and metabolic disease. This American Society of Hypertension (ASH) position paper summarizes the clinical spectrum of hypertension in pregnancy, focusing on preeclampsia. Recent research breakthroughs relating to etiology are briefly reviewed. Topics include classification of the different forms of hypertension during pregnancy, and status of the tests available to predict preeclampsia, and strategies to prevent preeclampsia and to manage this serious disease. The use of antihypertensive drugs in pregnancy, and the prevention and treatment of the convulsive phase of preeclampsia, eclampsia, with intravenous MgSO(4) is also highlighted. Of special note, this guideline article, specifically requested, reviewed, and accepted by ASH, includes solicited review advice from the American College of Obstetricians and Gynecologists.

Ophthalmic Artery-Resistive Index and Evidence of Overperfusion-Related Encephalopathy in Severe Preeclampsia

Neurological findings in preeclampsia fulfill diagnostic criteria of posterior reversible encephalopathy syndrome (PRES), which is related to cerebral autoregulation impairment associated with high blood pressure. In preeclampsia, PRES may occur without a significant increase in blood pressure. Our aim was to investigate the association between ophthalmic artery resistive index (OARI) and clinical evidence of PRES, defined as the presence of headache and blurred vision, in patients with severe preeclampsia. OARI and main clinical and laboratory parameters were obtained in 112 patients with severe preeclampsia. Differences in these parameters were analyzed in the function of clinical evidence of PRES with a 2-sample t test. The area under receiver operating characteristic curve for each of these parameters in the function of clinical evidence of PRES was obtained. Logistic regression models were established with parameters categorized by cutoff points obtained in receiver operating characteristic curves. Among 112 patients with severe preeclampsia, 46 (41%) presented clinical evidence of PRES. These patients presented lower OARI ( P <0.0001), higher mean blood pressure at admission ( P <0.0001), higher mean blood pressure elevation after the first trimester ( P <0.0001), and higher lactate dehydrogenase ( P <0.0001) than those without clinical evidence of PRES. OARI presented an area under receiver operating characteristic curve of 0.810±0.039 (95% CI: 0.742 to 0.895; P <0.0001). OARI <0.56 was associated with clinical evidence of PRES, with an odds ratio of 12.67 (95% CI: 4.08 to 39.39; P <0.0001). Data suggest that OARI is a relevant biomarker of PRES in severe preeclampsia.

ASH position paper: hypertension in pregnancy

The American Society of Hypertension is publishing a series of Position Papers in their official journals throughout the 2008-2009 years. The following Position Paper originally appeared: JASH. 2008;2(6):484-494. Hypertension complicates 5% to 7% of all pregnancies. A subset of preeclampsia, characterized by new-onset hypertension, proteinuria, and multisystem involvement, is responsible for substantial maternal and fetal morbidity and is a marker for future cardiac and metabolic disease. This American Society of Hypertension, Inc (ASH) position paper summarizes the clinical spectrum of hypertension in pregnancy, focusing on preeclampsia. Recent research breakthroughs relating to etiology are briefly reviewed. Topics include classification of the different forms of hypertension during pregnancy, status of the tests available to predict preeclampsia, and strategies to prevent preeclampsia and to manage this serious disease. The use of antihypertensive drugs in pregnancy, and the prevention and treatment of the convulsive phase of preeclampsia, eclampsia, with intravenous magnesium sulfate is also highlighted. Of special note, this guideline article, specifically requested, reviewed, and accepted by ASH, includes solicited review advice from the American College of Obstetricians and Gynecologists.

Neurologic complications of pre-eclampsia

Pre-eclampsia is mainly responsible for the world's large maternal mortality rates, mostly due to acute cerebral complications. This review provides insight into the pathogenesis of the neurologic complications of hypertensive disease in pregnancy. In addition, practical relevance for clinical care is highlighted. Pertaining to pregnancy, the blood pressure level at which cerebral autoregulation operates and possible deregulation occurs is unknown, but is likely to be variable. From clinical observation, eclampsia may occur despite a mild clinical picture and before the development of hypertension or proteinuria. Furthermore, failure of cerebrovascular autoregulatory mechanisms in response to either an acute and/or relatively large blood pressure increase may be more important than the absolute blood pressure value. It may be the acuity of the blood pressure rise in the setting of endothelial dysfunction that interrupts the delicate balance between capillary and cellular perfusion pressures that leads to the neurological complications of pre-eclampsia.

ASH position paper: hypertension in pregnancy

The American Society of Hypertension is publishing a series of Position Papers in their official journals throughout the 2008-2009 years. The following Position Paper originally appeared: JASH. 2008;2(6):484-494. Hypertension complicates 5% to 7% of all pregnancies. A subset of preeclampsia, characterized by new-onset hypertension, proteinuria, and multisystem involvement, is responsible for substantial maternal and fetal morbidity and is a marker for future cardiac and metabolic disease. This American Society of Hypertension, Inc (ASH) position paper summarizes the clinical spectrum of hypertension in pregnancy, focusing on preeclampsia. Recent research breakthroughs relating to etiology are briefly reviewed. Topics include classification of the different forms of hypertension during pregnancy, status of the tests available to predict preeclampsia, and strategies to prevent preeclampsia and to manage this serious disease. The use of antihypertensive drugs in pregnancy, and the prevention and treatment of the convulsive phase of preeclampsia, eclampsia, with intravenous magnesium sulfate is also highlighted. Of special note, this guideline article, specifically requested, reviewed, and accepted by ASH, includes solicited review advice from the American College of Obstetricians and Gynecologists.

Magnesium sulfate decreases cerebral perfusion pressure in preeclampsia

OBJECTIVE

To determine the cerebral hemodynamic effect of magnesium sulfate (MgSO4) in preeclampsia.

DESIGN

Prospective observational study.

SETTING

Tertiary Care Medical Center.

POPULATION

Preeclamptic patients (systolic < 160, diastolic < 110 mmHg).

METHODS

Transcranial Doppler (TCD) of the middle cerebral arteries (MCA) of 15 preeclamptics, before and after IV MgSO4. No vasoactive drugs other than MgSO4 were given. 11 patients with mild range BP (140/90-160/110 mmHg) had measurements at baseline, 30 and 120 minutes after MgSO4, and 7 patients with elevated CPP had baseline and 30 minute measurements. Hemodynamic parameters were compared with normative curves.

MAIN OUTCOME MEASURES

Mean arterial pressure (MAP), heart rate (HR), cerebral perfusion pressure (CPP), resistance index (RI), resistance area product (RAP), and cerebral flow index (CFI).

RESULTS

Eight women had normal baseline CPP, and 11 had normal CFI. 11 had mild preeclampsia range blood pressure and MgSO4 had no significant effect on CPP, CFI, HR, MCA velocities, or RAP but did decrease the MAP in the first 30 minutes (107 +/- 8 to 100 +/- 9 mmHg; p = 0.035), mainly due to a drop in diastolic pressure (87 +/- 10 to 82 +/- 9 mmHg; p = 0.004). 7 patients with elevated baseline CPP had a significant reduction in CPP, but no change in CFI, after MgSO4.

CONCLUSIONS

MgSO4 does not significantly effect CPP or CFI in preeclamptics with baseline blood pressure in the mild range, but does significantly reduce CPP in those with high baseline CPP. This may be important in the prevention of hypertensive encephalopathy.

Advances in the understanding of eclampsia

Preeclampsia, a serious hypertensive complication of pregnancy characterized by new-onset hypertension and proteinuria after midpregnancy, is a multisystem disorder that often involves the central nervous system. Neurologic signs and symptoms include hyperreflexia, headaches, visual disturbance, seizures, and cerebral hemorrhage. Eclampsia-new-onset seizures in the setting of preeclampsia-usually occurs before or within 48 hours of delivery, but can present as late as 1 month postpartum (late postpartum eclampsia). Magnesium sulfate is the drug of choice to prevent and treat eclampsia, a recommendation validated through large, randomized, and placebo-controlled trials. This review describes the pathogenesis, clinical features, and treatment of eclampsia, focusing on recent observations regarding roles of circulating antiangiogenic factors in the pathogenesis of the neurologic complications of eclampsia.

Post-treatment hemodynamics of a basilar aneurysm and bifurcation

To investigate whether or not a successful aneurysm treatment procedure can subject a parent artery to harmful hemodynamic stresses, computational fluid dynamics simulations are performed on a patient-specific basilar aneurysm and bifurcation before and after a virtual endovascular treatment. Prior to treatment, the aneurysm at systole is filled with a periodic train of vortex tubes, which form at the aneurysm neck and advect upwards into the dome. Following the treatment procedure however, the motion of the vortex train is inhibited by the aneurysm filling material, which confines the vortex tubes to the region beneath the aneurysm neck. Analysis of the post-treatment flow field indicates that the impingement of the basilar artery flow upon the treated aneurysm neck and the close proximity of a vortex tube to the parent artery wall increase the maximum wall shear stresses to values approximately equal to 50 Pa at systole. Calculation of the time-averaged wall shear stresses indicates that there is a 1.4 x 10(-7) m(2) area on the parent artery exposed to wall shear stresses greater than 37.9 Pa, a value shown by Fry [Circ. Res. 22(2):165-197, 1968] to cause severe damage to the endothelial cells that line the artery wall. The results of this study demonstrate that it is possible for a treatment procedure, which successfully isolates the aneurysm from the circulation and leaves no aneurysm neck remnant, to elevate the hemodynamic stresses to levels that are injurious to the artery wall.

Psychosocial impact of early-onset hypertensive disorders and related complications in pregnancy

OBJECTIVE

The objective of the study was to examine the psychosocial impact of severe hypertensive disorders during pregnancy.

STUDY DESIGN

All women (n = 216) in a prospective study cohort with severe hypertensive disorders of pregnancy were invited at term age, 3 months, and 1 year postterm to complete the 90-item Symptom Check List (SCL-90) questionnaire for assessment of their psychosocial condition. The association of hypothesized determinants was tested by binary logistic analysis.

RESULTS

Psychosocial impact decreased over time in all women (P < .01). Women with an adverse infant outcome had a worse score at term age (P = .04). The only parameter relating significantly to SCL-90 score in multivariate analysis was gestational age at inclusion. One year postterm, 72% resumed work and 9% were still on sick leave.

CONCLUSION

Severe hypertensive disorders of pregnancy have a high psychological impact, especially when gestational age at onset of disease is below 30 weeks or if adverse infant outcome occurs.

Maternal Serum Interleukin-10, Interleukin-2 and Interleukin-6 in Pre-Eclampsia and Eclampsia

PROBLEM

The aim of the study was to investigate and compare the concentrations of interleukin (IL)-2, IL-6, and IL-10 in serum of women with mild pre-eclampsia, severe pre-eclampsia, eclampsia, and normotensive pregnancy.

METHOD OF STUDY

A total of 69 consecutive cases, 38 mild pre-eclampsia, 20 severe pre-eclampsia, 11 eclampsia, and 20 normotensive controls were included in this study. Serum IL-2, IL-6, and IL-10 levels were determined using enzyme-linked immunosorbent assay method.

RESULTS

Gestational age (P = 0.210) and body mass index (P = 0.214) between the groups were similar. The mean concentration of serum IL-2 and IL-6 were not different between the groups (P = 0.261, P = 0.141 respectively). The median concentrations of serum IL-10 in patients with mild and severe pre-eclampsia were similar (P < 0.282) and was significantly lower than those of controls (P < 0.001) and patients with eclampsia (P < 0.001). In patients with eclampsia, the median concentration of IL-10 was significantly higher than that of all other groups (P < 0.001 for each comparison).

CONCLUSION

Pre-eclampsia is associated with a deficiency serum IL-10. High serum IL-10 is correlated with the presence of eclampsia.

Pathophysiology and medical management of systemic hypertension in preeclampsia

Hypertension that complicates preeclampsia in pregnancy is a disorder that requires special consideration in both prevention and pharmacologic treatment. In recent years, few advances have been made regarding the pathophysiology and prevention of preeclampsia; however, there have been some promising results from studies on possible modes of screening women for preeclampsia before clinical signs and symptoms are apparent. The recommendations for first-line drug therapy for the hypertensive complications of preeclampsia have changed little, primarily because first-line medications have had the advantage of extensive research experience. Recent clinical trials have demonstrated the efficacy and safety of various second-line drugs for the hypertensive complications of preeclampsia; whether these therapies can eventually replace the standard recommended first-line medications will require more extensive long-term investigation.

Cerebral blood flow autoregulation and edema formation during pregnancy in anesthetized rats

Eclampsia is considered a form of hypertensive encephalopathy in which an acute elevation in blood pressure causes autoregulatory breakthrough, blood-brain barrier disruption, and edema formation. We hypothesized that pregnancy predisposes the brain to eclampsia by lowering the pressure of autoregulatory breakthrough and enhancing cerebral edema formation. Because NO production is increased in pregnancy, we also investigated the role of NO in modulating autoregulation. Cerebral blood flow autoregulation was determined by phenylephrine infusion and laser Doppler flowmetry. Four groups were studied: untreated nonpregnant (n=7) and late-pregnant (days 19 to 21; n=8) Sprague-Dawley rats and nonpregnant (n=8) and late-pregnant (n=8) animals treated with an NO synthase inhibitor (N(G)-nitro-l-arginine methyl ester; 0.5 to 0.7 g/L). Brain water content and blood-brain barrier permeability to sodium fluorescein were determined after breakthrough. Pregnancy caused no change in autoregulation or the pressure of breakthrough. However, treatment with the NO synthase inhibitor significantly increased the pressure of autoregulatory breakthrough (nonpregnant: 183.6+/-3.0 mm Hg versus 212.0+/-2.8 mm Hg, P<0.05; late-pregnant: 180.8+/-3.2 mm Hg versus 209.3+/-4.7 mm Hg, P<0.05). After autoregulatory breakthrough, only late-pregnant animals showed a significant increase in cerebral edema formation, which was attenuated by NO synthase inhibition. There was no difference in blood-brain barrier permeability between nonpregnant and late-pregnant animals in response to acute hypertension, suggesting that pregnancy may predispose the brain to eclampsia by increasing cerebral edema through increased hydraulic conductivity.

Cerebral Hemodynamics in Preeclampsia: Cerebral Perfusion and the Rationale for an Alternative to Magnesium Sulfate

Preeclampsia and eclampsia continue to be major causes of maternal death. Currently, approximately 18% of U.S. maternal deaths are attributed to hypertensive disorders and eclampsia, and several hundred women die from eclampsia and its complications every year. In the United States, preeclamptic women have received magnesium sulfate as a seizure prophylaxis agent for 3 decades, and this practice is becoming more widely accepted internationally. In addition to a recognized failure rate, there are financial, logistic, and safety concerns associated with the universal administration of magnesium sulfate. Many institutions in the developing world lack the necessary equipment and expertise to administer the medication, and many preeclamptic patients thus do not receive magnesium sulfate before their first seizure. As effective as it has been in reducing mortality from eclampsia, magnesium sulfate is also associated with appreciable morbidity and mortality from administration errors and magnesium toxicity. The availability of an easily administered, cheap, safe, and orally administered alternative to magnesium sulfate would be welcomed in the developing world and would provide an extremely useful alternative therapy to the current standard of care. Recent advances in the understanding of the pathophysiology of preeclampsia and eclampsia, primarily related to cerebral perfusion and blood flow, could allow us to reduce the seizure rate in treated preeclamptic women even further than what is currently reported. This article deals with the rationale behind the use of labetalol as an alternative to magnesium sulfate for the prevention of eclampsia.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader should be able to recall that hypertensive diseases of pregnancy contribute a significant portion of today's maternal mortality, explain that methods of preventing eclampsia are not applicable worldwide, and state that understanding of the pathophysiology of preeclampsia/eclampsia may assist in developing safe and effective medications that can be used universally.

Stroke and severe preeclampsia and eclampsia: a paradigm shift focusing on systolic blood pressure

OBJECTIVE

To identify important clinical correlates of stroke in patients with preeclampsia and eclampsia.

METHODS

The case histories of 28 patients who sustained a stroke in association with severe preeclampsia and eclampsia were scrutinized with particular attention to blood pressures.

RESULTS

Stroke occurred antepartum in 12 patients, postpartum in 16. Stroke was classified as hemorrhagic-arterial in 25 of 27 patients (92.6%) and thrombotic-arterial in 2 others. Multiple sites were involved in 37% without distinct pattern. In the 24 patients being treated immediately before stroke, systolic pressure was 160 mm Hg or greater in 23 (95.8%) and more than 155 mm Hg in 100%. In contrast, only 3 of 24 patients (12.5%) exhibited prestroke diastolic pressures of 110 mm Hg or greater, only 5 of 28 reached 105 mm Hg, and only 6 (25%) exceeded a mean arterial pressure of 130 mm Hg before stroke. Only 3 patients received prestroke antihypertensives. Twelve patients sustained a stroke while receiving magnesium sulfate infusion; 8 had eclampsia. Although all blood pressure means after stroke were significantly higher than prestroke, only 5 patients exhibited more than 110 mm Hg diastolic pressures. In 18 of 28 patients, hemolysis, elevated liver enzymes, low platelets syndrome did not significantly alter blood pressures compared with non-hemolysis, elevated liver enzymes, low platelets. Mean systolic and diastolic changes from pregnancy baseline to prestroke values were 64.4 and 30.6 mm Hg, respectively. Maternal mortality was 53.6%; only 3 patients escaped permanent significant morbidity.

CONCLUSION

In contrast to severe systolic hypertension, severe diastolic hypertension does not develop before stroke in most patients with severe preeclampsia and eclampsia. A paradigm shift is needed toward considering antihypertensive therapy for severely preeclamptic and eclamptic patients when systolic blood pressure reaches or exceeds 155-160 mm Hg.

LEVEL OF EVIDENCE

III.