The hypertensive disorders of pregnancy

The differential placental expression of ERp44 and pre-eclampsia; association with placental zinc, the ERAP1 and the renin-angiotensin-system

INTRODUCTION

Endoplasmic reticulum resident protein 44 (ERp44) is a zinc-metalloprotein, regulating Endoplasmic reticulum aminopeptidase 1 (ERAP1) and Angiotensin II (Ang II). We explored placental ERp44 expression and components of the renin-angiotensin-system (RAS) in pre-eclampsia (PE), correlating these to ERAP1 expression and placental zinc concentrations.

METHODS

Placental tissue, taken at time of delivery in normotensive women or women with PE (n = 12/group), were analysed for ERp44, AT1R, AT2R and AT4R by qPCR. Protein ERp44 expression was measured by immunohistochemistry and compared to previously measured ERAP1 expression. Placental zinc was measured by inductively-coupled-mass-spectrometry.

RESULTS

ERp44 gene/protein expression were increased in PE (P < 0.05). AT1R expression was increased (P = 0.02) but AT4R decreased (P = 0.01) in PE, compared to normotensive controls. A positive association between ERp44 and AT2R expression was observed in all groups. ERp44 was negatively correlated with ERAP1 protein expression in all samples. Placental zinc concentrations were lower in women with PE (P = 0.001) and negatively associated with ERp44 gene expression.

DISCUSSION

Increased placental ERp44 could further reduce ERAP1 release in PE, potentially preventing release of Ang IV and thus lowering levels of Ang IV which consequently diminishes the possibility of counterbalancing the activity of vasoconstrictive, Ang II. The lower placental zinc may contribute to dysfunction of the ERp44/ERAP1 complex, exacerbating the hypertension in PE.

Evaluation of sleep problems in preeclamptic, healthy pregnant and non-pregnant women

OBJECTIVE

Sleep problems are common complaints among pregnant women. This study was designed to compare subjective sleep problems in non-pregnancy condition, healthy and preeclamptic pregnancy as a major complication of pregnancy. We hypothesized that some sleep problems are more prevalent in females with preeclampsia.

METHODS

In this cross-sectional study, 102 women with preeclampsia, 106 healthy pregnant women in the third trimester and 103 healthy non-pregnant women were selected through random sampling. Age and parity were matched in the three groups. We used Global sleep assessment questionnaire (GSAQ) to check the subjective sleep problems, and then we performed statistical analysis using Analysis of variance (ANOVA) and Pearson Chi-square tests.

RESULTS

Our findings revealed significant differences in initial insomnia (p = 0.034), fragmented sleep (p = 0.022), snoring (p<0.001), non-idiopathic insomnia (p = 0.045) and sadness and anxiety (p = 0.001) between the three groups. Some sleep problems were more common in preeclampctic compared to healthy pregnant women including initial insomnia, fragmented sleep, snoring, sleep apnea and non-idiopathic insomnia. Moreover, the subjects with preeclampsia revealed more fragmented sleep, snoring, sadness and anxiety and lack of getting enough sleep due to other activities compared to non-pregnant women.

CONCLUSION

Different kinds of sleep problems can occur in subjects with preeclampsia in comparison with the non-pregnant and healthy pregnant subjects. Sleep problems should be evaluated during pregnancy, particularly in pregnant women with preeclampsia, and suitable treatment should be provided for any specific sleep problem.

Relationship between high consumption of marine fatty acids in early pregnancy and hypertensive disorders in pregnancy

OBJECTIVE

To investigate whether there is a relationship between maternal intake of cod-liver oil in early and late pregnancy and hypertensive disorders in pregnancy.

DESIGN

An observational prospective study.

SETTING

Free-living conditions in a community with traditional fish and cod-liver oil consumption.

POPULATION

Four hundred and eighty-eight low-risk pregnant Icelandic women.

METHODS

Maternal use of cod-liver oil, foods and other supplements was estimated with a semiquantitative food frequency questionnaire covering food intake together with lifestyle factors for the previous 3 months. Questionnaires were filled out twice, between 11 and 15 weeks of gestation and between 34 and 37 weeks of gestation. Supplements related to hypertensive disorders in pregnancy, i.e. gestational hypertension and pre-eclampsia, were presented, with logistic regression controlling for potential confounding.

MAIN OUTCOME MEASURES

Gestational hypertension, pre-eclampsia, cod-liver oil and multivitamins.

RESULTS

The odds ratio for developing hypertensive disorders in pregnancy for women consuming liquid cod-liver oil was 4.7 (95% CI 1.8-12.6, P= 0.002), after adjusting for confounding factors. By dividing the amount of n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA) into centiles, the odds ratio for hypertensive disorders across groups for n-3 LCPUFA suggested a u-shaped curve (P = 0.008). Similar results were found for gestational hypertension alone. Further, the use of multivitamin supplements without vitamins A and D in late pregnancy doubled the odds of hypertensive disorders (OR 2.4, 95% CI 1.0-5.4, P= 0.044).

CONCLUSIONS

Consumption of high doses of n-3 LCPUFA in early pregnancy, or other nutrients found in liquid cod-liver oil, may increase the risk of developing hypertensive disorders in pregnancy.

Critically ill parturient women and admission to intensive care: a 5-year review

Thirty-nine parturient women were admitted to a general intensive care unit (ICU) from April 1989 to March 1994 and of these four were readmitted (total 43 admissions). Twelve women were admitted to the obstetric unit from peripheral hospitals in different regions, but no requirement for intensive care was perceived on referral. Six women were transfered directly into the intensive care unit from different hospitals in the region. The incidence of obstetric patients requiring ICU admission, excluding direct transfers, was 0.64%. The majority (85%) were postpartum, and 64% were primiparous. Morbidity was caused primarily by hypertensive disorders (33%) and haemorrhage (33%). The remainder included medical disorders (21%)[ sepsis (13%) and surgical problems (5%). Associated major complications were acute renal failure, coagulopathies and adult respiratory distress syndrome. A multidisciplinary approach to management is practised and specialist interventions included haemofiltration and haemodialysis (18%) and radiological arterial embolisation (10%). Ventilatory and inotropic support were given in 38% and 41% of patients respectively. Only one patient died on the intensive care unit, this was from multiorgan failure secondary to sepsis.

Obesity and pregnancy

BACKGROUND

As obesity is an increasing problem among fertile women, it is crucial that specialists involved in the treatment of these women be aware of the risks of complications and know how to deal with them. Complications associated with obesity in pregnancy are gestational diabetes mellitus, hypertensive disorders, and thromboembolic complications. Complications associated with obesity in labor are augmentation, early amniotomy, cephalopelvic disproportion, cesarean section, and perioperative morbidity. Complications associated with obesity in children are macrosomia, shoulder dystocia, small for gestational age, late fetal death, and congenital malformations, especially neural tube defects.

OBJECTIVE

The aim was to review the potential complications associated with obesity and pregnancy.

RESULTS

Obesity is associated with a higher risk of all reviewed complications except small for gestational age.

Effect of changes in body posture on vasoactive hormones in pre-eclamptic women

The aim of this study was to determine the normality or otherwise of neurohormone indices, particularly the sympathetic nervous system, in pre-eclamptic patients and document whether changes in body posture magnify any differences between pre-eclamptic and normal women. We studied 11 women with pre-eclampsia and compared them with 17 matched normotensive pregnant women and eight nonpregnant women. Measurements of arterial pressure, heart rate and neurohormones were carried out with subjects in the left lateral position, then supine, left lateral, with upright posture and finally with assumption of the left lateral position again. Main outcome measures were arterial pressure, heart rate and hormones (plasma norepinephrine, renin activity, natriuretic peptides and endothelin-1). We observed that plasma norepinephrine levels were higher in pre-eclamptic than normotensive pregnant women and this was most obvious in the upright position. Plasma renin activity was likewise higher in pre-eclamptic than normotensive pregnant women, again most obvious with upright posture. Plasma natriuretic peptides and endothelin-1 levels were similar in pre-eclamptics and normotensive pregnant women. These data strengthen the premise that pre-eclampsia is associated with sympathetic overactivity as reflected by plasma norepinephrine levels, most obviously observed in the upright position.

Neuroimaging of delayed eclampsia. Report of 3 cases and review of the literature

Computed tomography and magnetic resonance imaging findings consistent with eclampsia were recently encountered in 3 patients who developed severe headache days to weeks after uncomplicated delivery. The neurologic presentation was nonspecific, and pre-eclamptic symptoms were not present, including significant hypertension. Variable expression of pre-eclampsia occurred during the course of their observation. Conventional angiography obtained in 2 patients because of a concern for aneurysm demonstrated central and peripheral vasospasm. Magnetic resonance angiography demonstrated central vasospasm in the third patient.

Nausea and vomiting during pregnancy

The differential diagnosis of nausea and vomiting is extensive and the underlying cause can be difficult to diagnose. Treatment of nausea and vomiting also can be unsatisfactory because the available pharmacotherapy does not correct the fundamental underlying pathophysiologic abnormalities. In contrast, the diagnosis of nausea and vomiting of pregnancy generally is straightforward. Almost 80% of women have some degree of nausea in the first trimester of pregnancy, and the diagnosis of pregnancy is established easily by the patient or physician. The spectrum varies from mild nausea to hyperemesis gravidarum. Various treatment approaches are addressed.

Evolutionary adaptations to pre-eclampsia/eclampsia in humans: low fecundability rate, loss of oestrus, prohibitions of incest and systematic polyandry

Gestational-hypertension/pre-eclampsia occurs in approximately 10% of human pregnancies. This persistent complication of pregnancy has been reported to occur more frequently in couples conceiving very shortly after the beginning of their sexual relationship and/or after a change in paternity. Primipaternity may be the leading cause of pre-eclampsia in women under 30 years of age when genetic susceptibility to cardio-vascular disease has not yet been expressed, especially in women before their twenties, who for the last 40,000 years have perhaps comprised the age group when the majority of parturients classified as Homo sapiens sapiens initiated their reproductive life. In terms of evolution, the prevalence of pre-eclampsia represents a distinct reproductive disadvantage in humans as compared with other mammals. Indeed, pre-eclampsia is a consequence of the defect of the normal human-specific deep endovascular invasion of the trophoblast. The large size of the human fetal brain imposing this deep trophoblastic invasion induced the need for major immunogenetic compromises in terms of paternal-maternal tissue tolerance. The price that mankind has had to pay to adapt to the pre-eclampsia risk is a low fecundability rate and therefore loss of oestrus, possibly a step in the deviation between apes and hominids. Further, pre-eclampsia risk may be a contributing factor leading to the rejection of systematic polyandry in human societies and have influenced prohibition of incest.

Sympathetic neural mechanisms in normal and hypertensive pregnancy in humans

BACKGROUND

Direct recordings from peripheral sympathetic nerves have shown an increased sympathetic drive in pregnancy-induced hypertension (PIH) and preeclampsia (PE). It is unknown whether sympathetic drive is altered in normal pregnancy, when arterial blood pressure can be normal or relatively low. The aim of this study was to measure and compare peripheral sympathetic discharge, its vasoconstrictor effect and its baroreceptor control, during pregnancy and postpartum in women with normal pregnancy (NP) and PIH and in normotensive nonpregnant (NN) women.

METHODS AND RESULTS

Twenty-one women with NP, 18 women with PIH, and 21 NN women had muscle sympathetic nerve activity assessed from multiunit discharges (MSNA) and from single units with defined vasoconstrictor properties (s-MSNA). The s-MSNA in NP (38+/-6.6 impulses/100 beats) was greater (P<0.05) than in NN women (19+/-1.8 impulses/100 beats) despite similar age and body weight but less than in PIH women (P<0.001) (146+/-23.5 impulses/100 beats). MSNA followed a similar trend. Cardiac baroreceptor reflex sensitivity (BRS) was impaired in NP and PIH women relative to NN. After delivery, sympathetic activity decreased to values similar to those obtained in NN, and there was an increase in BRS. In women with NP, the decrease in sympathetic output occurred despite an insignificant change in blood pressure.

CONCLUSIONS

Central sympathetic output was increased in women with normal pregnancy and was even greater in the hypertensive pregnant group. The findings suggest that the moderate sympathetic hyperactivity during the latter months of normal pregnancy may help to return the arterial pressure to nonpregnant levels, although when the increase in activity is excessive, hypertension may ensue.

Inspiratory flow limitation during sleep in pre-eclampsia: comparison with normal pregnant and nonpregnant women

Self-reported snoring is common in pregnancy, particularly in females with pre-eclampsia. The prevalence of inspiratory flow limitation during sleep in preeclamptic females was objectively assessed and compared with normal pregnant and nonpregnant females. Fifteen females with pre-eclampsia were compared to 15 females from each of the three trimesters of pregnancy, as well as to 15 matched nonpregnant control females (total study population, 75 subjects). All subjects had overnight monitoring of respiration, oxygen saturation, and blood pressure (BP). No group had evidence of a clinically significant sleep apnoea syndrome, but patients with pre-eclampsia spent substantially more time (31+/-8.4% of sleep period time, mean+/-SD) with evidence of inspiratory flow limitation compared to 15.5+/-2.3% in third trimester subjects and <5% in the other three groups (p=0.001). In the majority of preeclamptics, the pattern of flow limitation was of prolonged episodes lasting several minutes without associated oxygen desaturation. As expected, systolic and diastolic BPs were significantly higher in the pre-eclamptic group (p<0.001), but all groups showed a significant fall (p< or =0.05) in BP during sleep. Inspiratory flow limitation is common during sleep in patients with pre-eclampsia, which may have implications for the pathophysiology and treatment of this disorder.

Pharmacological treatment of severe hypertension in pregnancy and the role of serotonin(2)-receptor blockers

Hypertensive disorders of pregnancy are the leading cause of maternal and perinatal mortality and morbidity in developing and developed countries. The etiology of preeclampsia is still unknown. Delivering the baby is the only definite treatment. The benefits of acute pharmacological control of severe hypertension prior to and/or post-delivery are generally accepted. Most drugs commonly used in the management of severe hypertension in pregnancy have significant maternal and/or neonatal adverse side effects. Furthermore, some are not effective to acutely lower the blood pressure in patients with a hypertensive crisis. Until recently not one of the commonly used antihypertensive drugs has been tailored to the pathophysiology of severe preeclampsia, being a clinical syndrome characterized by endothelial cell dysfunction, vasospasm and platelet aggregation. Ketanserin, a serotonin(2)-receptor blocker, is a drug that appears to be tailored for treating this pregnancy-associated enthothelial cell dysfunction. The results of several prospective trials show that there is a definite place for serotonin(2)-receptor blockers in the treatment of pregnancy-induced hypertensive disorders. This review provides a summary on the more established drugs as well as on some of the newer antihypertensive drugs used in pregnancy with emphasis on the existing experience with ketanserin.

Relationship of systemic hemodynamics, left ventricular structure and function, and plasma natriuretic peptide concentrations during pregnancy complicated by preeclampsia

OBJECTIVE

This study was done to evaluate left ventricular structure and function among pregnant patients with preeclampsia and compare them with those of normotensive pregnant and nonpregnant subjects. It also tested the hypothesis that abnormalities in left ventricular structure and function are associated with elevated plasma levels of natriuretic peptides.

STUDY DESIGN

The study compared 75 pregnant women (n = 40 with preeclampsia; n = 35 normotensive pregnant women) and 10 nonpregnant normotensive control subjects undergoing an echocardiographic and biohumoral (renin activity and aldosterone, atrial natriuretic peptide, and brain natriuretic peptide concentrations) evaluation. The statistical analysis was carried out by analysis of variance, and significance was set at P <.05.

RESULTS

Comparison of pregnant patients with preeclampsia versus both normotensive pregnant women and nonpregnant women showed significant increases in left ventricular mass and left ventricular endsystolic and end-diastolic volumes and significant reductions in left ventricular ejection fraction and percentage of fractional shortening. These changes coincided with increases in plasma levels of atrial natriuretic peptide and brain natriuretic peptide that were linearly related to the left ventricular structural and functional changes observed in patients with preeclampsia.

CONCLUSION

Pregnant patients with preeclampsia showed adaptation to the increase in systemic blood pressure, with significant modification of left ventricular structure and function related to the plasma levels of both atrial natriuretic peptide and brain natriuretic peptide. A simple evaluation of plasma natriuretic peptide concentrations could help to discriminate patients with preeclampsia who have a condition of mild left ventricular overload.

Effects of two antihypertensive agents, labetalol and metoprolol, on the production of reactive oxygen species by normal polymorphonuclear leukocytes in vitro

OBJECTIVE

Increased lipid peroxidation is a putative causal factor for preeclampsia. Because oxygen free radicals are involved in inducing the lipid oxidation chain reaction, we evaluated two beta adrenoreceptor blockers, labetalol and metoprolol, currently used for treating hypertension with regard to their ability to inhibit the formation of reactive oxygen species during respiratory burst of human normal polymorphonuclear leukocytes in vitro.

METHODS

We determined whether labetalol or metoprolol have antioxidative activity in a model of polymorphonuclear leukocytes stimulated in vitro with phorbol-12-myristate-13-acetate (PMA) and N-formyl-methionin-leucin-phenylalanin (fMLP). We also studied the scavenging properties of these two drugs using acellular systems.

RESULTS

Labetalol inhibits O2-. production by neutrophils activated by fMLP (IC50 = 17.5 mg/L) and weakly by PMA (43.6% inhibition at 100 mg/L). It also possesses a significant activity on OH. production (IC50 = 65 mg/L) that may depend in part on its ability to interfere with iron in the Fenton reaction. The same assays performed with metoprolol did not show any inhibitory effect on O2.- generation. It decreased weak OH. production by neutrophils, as a result of cellular and scavenging effects.

CONCLUSION

Labetalol shows important antioxidative properties in vitro with regard to normal leukocyte oxidative metabolism.

Blood pressure and vasoactive hormones in mild preeclampsia and normal pregnancy

OBJECTIVE

Changes in vasoactive hormones are reported to play an important role in the pathogenesis of preeclampsia linking placental hypoperfusion with hypertension, systemic disease, and proteinuria. We, therefore, studied diurnal patterns of vasoactive hormones in mild preeclampsia.

METHODS

Venous blood samples were drawn every 2 h over 25 h for measurements of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), norepinephrine, renin activity, and aldosterone and two urine collections (12 h each) for stable prostaglandin metabolite measurements. The patients were nine women with mild preeclampsia and, for comparison, nine control women matched for gestation and parity.

RESULTS

Women with mild preeclampsia had higher norepinephrine levels throughout 25 h, and lower systemic prostacyclin production as measured by the urinary 2,3-dinor-6-keto PGF1 alpha excretion during the daytime. Plasma endothelin and ANP and BNP concentrations tended to be higher throughout 25 h in preeclampsia, but differences between the two groups did not reach levels of statistical significance. Plasma renin activity and aldosterone did not differ between the groups. Whereas control women exhibited a diurnal variation in plasma norepinephrine, ANP, BNP, and aldosterone, and in both urinary prostacyclin and thromboxane A2 metabolites, this was less distinct or absent in patients with mild preeclampsia.

CONCLUSIONS

We conclude that mild preeclampsia is associated with elevated plasma norepinephrine levels, lower systemic daytime production of prostacyclin, and blunting of the normal diurnal variation for a number of indices including plasma levels of BNP, ANP, norepinephrine, and aldosterone, and urinary prostacyclin metabolites.

Factor V Leiden and thermolabile methylenetetrahydrofolate reductase gene variants in an East Anglian preeclampsia cohort

Preeclampsia is a heritable condition that develops as a result of widespread vascular endothelial dysfunction. The thrombotic tendency in this condition has suggested a number of candidate genes, and there have been recent reports of positive association with the Leiden variant of factor V and the thermolabile variant of methylenetetrahydrofolate reductase. We attempted to reproduce these results in a large cohort of well-characterized women with preeclampsia, recruited prospectively within the East Anglian region of the United Kingdom. Women in the preeclampsia cohort (n=283) were genotyped for both the Leiden variant (G1691A) of factor V and the thermolabile variant (C677T) of methylenetetrahydrofolate reductase. Genotype and allele frequencies were compared with those of 2 control groups, one consisting of women recruited prospectively (n=100) from the same maternity hospital as the subjects and another consisting of normotensive women (n=100) from East Anglia. No significant differences were detected. Specifically, the carrier rate for the Leiden variant was 5.3% in the preeclampsia group and 5. 5% in the combined control group. T677 homozygotes for methylenetetrahydrofolate reductase were 11% and 11.5% in the 2 groups, respectively. We conclude that there is no evidence of association of preeclampsia with either of these 2 polymorphisms in our study population.

Anesthetic management of preeclampsia/eclampsia

Preeclampsia/eclampsia affects only a small proportion of all pregnancies, yet accounts for much of the obstetric morbidity and mortality seen in the USA and UK. A full understanding of preeclampsia/eclampsia, its variable presentation and complex pathophysiology allows the consulting anesthesiologist to optimize a plan for anesthetic management of the afflicted patient.

Sympathetic nerve discharge in normal pregnancy and pregnancy-induced hypertension

BACKGROUND

Microneurographic assessment of processed bursts that represent multi-unit nerve discharge has suggested that sympathetic hyperactivity occurs in pregnancy induced hypertension and pre-eclampsia in comparison with normal pregnancy.

OBJECTIVE

To examine the differences between peripheral sympathetic outputs in pregnancy-induced hypertension and normal pregnancy by directly measuring single impulses of neural discharge.

DESIGN

We compared the sympathetic neural discharge at rest and its reflex responses in subjects with pregnancy-induced hypertension and normal pregnancy and re-examined their progress at least 6 weeks post partum. The patients with pregnancy-induced hypertension were hospital in-patients for whom the diagnosis could be strictly defined and the normally pregnant women were recruited to match the former.

METHODS

Standard microneurography was performed to quantify single impulses of action potentials, together with the processed multi-unit bursts from fibres innervating the leg muscles. We measured neural discharge with vascular vasoconstrictive properties, heart rate and finger arterial blood pressure at rest and their responses to standard isometric hand-grip exercise and cold pressor tests.

RESULTS

As expected, patients with pregnancy-induced hypertension (n = 13) had higher levels of finger arterial blood pressure than did women with normal pregnancies (n = 11). The number of single impulses of action potentials (per min and per 100 cardiac beats) in resting patients with pregnancy-induced hypertension was more than three times greater than that in resting women with normal pregnancies, and the number of multi-unit bursts was twofold greater. After delivery of their child, sympathetic activity and heart rate in nine patients decreased, but finger arterial blood pressure decreased in patients with pregnancy-induced hypertension only.

CONCLUSIONS

From results of cross-sectional and longitudinal studies, pregnancy-induced hypertension is associated with a greater resting sympathetic output than that of women with normal pregnancies. Follow-up data after parturition suggest that this hyperactivity is not the only cause of hypertension.

Maternal intrauterine infection, cytokines, and brain damage in the preterm newborn

To evaluate the hypothesis that the proinflammatory cytokines IL-1, IL-6, and tumor necrosis factor-alpha might be the link between prenatal intrauterine infection (IUI) and neonatal brain damage, the authors review the relevant epidemiologic and cytokine literature. Maternal IUI appears to increase the risk of preterm delivery, which in turn is associated with an increased risk of intraventricular hemorrhage, neonatal white matter damage, and subsequent cerebral palsy. IL-1, IL-6, and TNF-alpha have been found associated with IUI, preterm birth, neonatal infections. and neonatal brain damage. Unifying models not only postulate the presence of cytokines in the three relevant maternal/fetal compartments (uterus, fetal circulation, and fetal brain) and the ability of the cytokines to cross boundaries (placenta and blood-brain barrier) between these compartments, but also postulate how proinflammatory cytokines might lead to IVH and neonatal white matter damage during prenatal maternal infection. Interrupting the proinflammatory cytokine cascade might prevent later disability in those born near the end of the second trimester.