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

Exposure to UV-B filter octylmethoxycinnamate and human health effects: Focus on endocrine disruptor actions

Human skin is the first line of photoprotection against UV radiation. However, despite having its defence mechanisms, the photoprotection that the skin exerts is not enough. To protect human skin, the inclusion of UV filters in the cosmetic industry has grown significantly as a photoprotection strategy. Octylmethoxycinnamate, also designated by octinoxate, or 2-ethylhexyl-4-methoxycinnamate (CAS number: 5466-77-3) is one of the most widely used UV-B filter in the cosmetic industry. The toxic effects of OMC have alarmed the public, but there is still no consensus in the scientific community about its use. This article aims to provide an overview of the UV filters' photoprotection, emphasizing the OMC and the possible negative effects it may have on the public health. Moreover, the current legislation will be addressed. In summary, the recommendations should be rethought to assess their risk-benefit, since the existing literature warns us to endocrine-disrupting effects of OMC. Further studies should be focus on the toxicity of OMC alone, in mixture and should consider its degradation products, to improve the knowledge of its risk assessment as EDC.

Oral nifedipine versus intravenous labetalol for hypertensive emergencies during pregnancy: a systematic review and meta-analysis

Aim: The optimal drug management strategy for severe hypertension during pregnancy remains inconclusive. Some randomized controlled trials found that oral nifedipine was more effective than intravenous labetalol in hypertensive emergencies during pregnancy, while others found otherwise. As a result, we conducted a meta-analysis to assess the effectiveness of oral nifedipine versus intravenous labetalol for hypertensive emergencies during pregnancy.Methods: We searched PubMed, Embase, and the Cochrane Library for randomized controlled trials that compared oral nifedipine versus IV labetalol in hypertensive emergencies during pregnancy.Results: 12 RCTs enrolling 1151 participants (573 in the labetalol group and 578 in the nifedipine group) were included in the meta-analysis. Patients who received oral nifedipine reached their target blood pressure more rapidly than those who received intravenous labetalol (MD 7.64, 95%CI 4.08-11.20, p < .0001). The nifedipine group required fewer doses to achieve the target blood pressure (MD 0.62, 95%CI 0.36 to 0.88, p < .00001). There were no meaningful differences on the maternal complications between the two groups, mainly including eclampsia (OR 1.51; 95% CI, 0.75-3.05; p = .25), headache (OR 0.86; 95% CI, 0.52-1.44; p = .57), nausea/vomiting (OR 1.50; 95% CI, 0.76-2.93; p = .24), hypotension (OR 0.49; 95% CI, 0.12-1.99; p = .32), dizziness (OR 2.01; 95% CI, 0.77-5.25; p = .16), HELLP (OR 0.27; 95% CI, 0.05-1.64; p = .16), palpitations (OR 0.63; 95% CI, 0.32-1.27; p = .20), flushing (OR 0.77; 95%CI, 0.18-3.22; p = .72). There were no significant difference in the neonatal complications, including NICU admission (OR 1.24; 95% CI, 0.87-1.77; p = .23), 5 min Apgar score < 7 (OR 1.07; 95% CI, 0.82-1.39; p = .63), neonatal deaths (OR 1.08; 95%CI, 0.66-1.76; p = .77), FHR abnormality (OR 0.94; 95%CI, 0.47-1.88; p = .86).Conclusion: In conclusion, oral nifedipine could achieve target blood pressure more rapidly and required fewer doses than intravenous labetalol in the management of hypertensive emergencies during pregnancy.

Selective serotonin reuptake inhibitors and preeclampsia: A quality assessment and meta-analysis

Serotonin modulates vascular, immune, and neurophysiology and is dysregulated in preeclampsia. Despite biological plausibility that selective serotonin reuptake inhibitors (SSRIs) prevent preeclampsia pathophysiology, observational studies have indicated increased risk and providers may be hesitant. The objective of this meta-analysis and quality assessment was to evaluate the evidence linking SSRI use in pregnancy to preeclampsia/gestational hypertension. PubMed was searched through June 5, 2020 manually and using combinations of terms: "preeclampsia", "serotonin", and "SSRI". This review followed MOOSE guidelines. Inclusion criteria were: 1) Observational cohort or population study, 2) exposure defined as SSRI use during pregnancy, 3) cases defined as preeclampsia or gestational hypertension, and 4) human participants. Studies were selected that addressed the hypothesis that gestational SSRI use modulates preeclampsia and/or gestational hypertension risk. Review Manager Web was used to synthesize study findings. Articles were read and scored (Newcastle-Ottawa Quality Assessment Scale) for quality by two independent reviewers. Publication bias was assessed using a funnel plot and the Egger test. Of 179 screened studies, nine were included. The pooled risk ratio (random effects model) was 1.43 (95 % CI: 1.15-1.78, P < 0.001; range 0.96-4.86). Two studies were rated as moderate quality (both with total score of 6); others were high quality. Heterogeneity was high (I2 = 88 %) and funnel asymmetry was significant (p < 0.00001). Despite evidence for increased preeclampsia risk with SSRIs, shared risk factors and other variables are poorly controlled. Depression treatment should not be withheld due to perceived gestational hypertension risk. Mechanistic evidence for serotonin modulation in preeclampsia demonstrates a need for future research.

The Role of the Kynurenine Pathway in the (Patho) physiology of Maternal Pregnancy and Fetal Outcomes: A Systematic Review

INTRODUCTION

Tryptophan is the precursor of kynurenine pathway (KP) metabolites which regulate immune tolerance, energy metabolism, and vascular tone. Since these processes are important during pregnancy, changes in KP metabolite concentrations may play a role in the pathophysiology of pregnancy complications. We hypothesize that KP metabolites can serve as novel biomarkers and preventive therapeutic targets. This review aimed to provide more insight into associations between KP metabolite concentrations in maternal and fetal blood, and in the placenta, and adverse maternal pregnancy and fetal outcomes.

METHODS

A systematic search was performed on 18 February 2022 comprising all KP metabolites, and keywords related to maternal pregnancy and fetal outcomes. English-written human studies measuring KP metabolite(s) in maternal or fetal blood or in the placenta in relation to pregnancy complications, were included. Methodological quality was assessed using the ErasmusAGE quality score (QS) (range: 0-10). A meta-analysis of the mean maternal tryptophan and kynurenine concentrations in uncomplicated pregnancies was conducted.

RESULTS

Of the 6262 unique records, 37 were included (median QS = 5). Tryptophan was investigated in most studies, followed by kynurenine, predominantly in maternal blood (n = 28/37), and in the second and third trimester of pregnancy (n = 29/37). Compared to uncomplicated pregnancies, decreased tryptophan in maternal blood was associated with an increased prevalence of depression, gestational diabetes mellitus, fetal growth restriction, spontaneous abortion, and preterm birth. Elevated tryptophan was only observed in women with pregnancy-induced hypertension compared to normotensive pregnant women. In women with preeclampsia, only kynurenic acid was altered; elevated in the first trimester of pregnancy, and positively associated with proteinuria in the third trimester of pregnancy.

CONCLUSIONS

KP metabolite concentrations were altered in a variety of maternal pregnancy and fetal complications. This review implies that physiological pregnancy requires a tight balance of KP metabolites, and that disturbances in either direction are associated with adverse maternal pregnancy and fetal outcomes.

Serotonin-estrogen interactions: What can we learn from pregnancy?

We have reviewed the scientific literature related to four diseases in which to serotonin (5-HT) is involved in the etiology, herein named 5-HT-linked diseases, and whose prevalence is influenced by estrogenic status: depression, migraine, irritable bowel syndrome and eating disorders. These diseases all have in common a sex-dimorphic prevalence, with women more frequently affected than men. The co-occurrence between these 5-HT-linked diseases suggests that they have common physiopathological mechanisms. In most 5-HT-linked diseases (except for anorexia nervosa and irritable bowel syndrome), a decrease in the serotonergic tone is observed and estrogens are thought to contribute to the improvement of symptoms by stimulating the serotonergic system. Human pregnancy is characterized by a unique 5-HT and estrogen synthesis by the placenta. Pregnancy-specific disorders, such as hyperemesis gravidarum, gestational diabetes mellitus and pre-eclampsia, are associated with a hyperserotonergic state and decreased estrogen levels. Fetal programming of 5-HT-linked diseases is a complex phenomenon that involves notably fetal-sex differences, which suggest the implication of sex steroids. From a mechanistic point of view, we hypothesize that estrogens regulate the serotonergic system, resulting in a protective effect against 5-HT-linked diseases, but that, in turn, 5-HT affects estrogen synthesis in an attempt to retrieve homeostasis. These two processes (5-HT and estrogen biosynthesis) are crucial for successful pregnancy outcomes, and thus, a disruption of this 5-HT-estrogen relationship may explain pregnancy-specific pathologies or pregnancy complications associated with 5-HT-linked diseases.

Altered methylation and expression patterns of genes regulating placental nitric oxide pathway in patients with severe preeclampsia

Pre-eclampsia is a common pregnancy disorder syndrome whose molecular mechanism is not clear. Nitric oxide (NO) is a key regulator of placentation. Reduction of NO has previously been associated with endothelial dysfunction in pre-eclamptic women. Therefore, we measured expression and methylation of some placental genes that were involved in NO pathway like named ARG II, PRMT1 and DDAH2 in pre-eclampsia and normal pregnancies in order to determine whether impairment of expression of these genes in the pre-eclamptic placenta could contribute to development of disease. ARG II, PRMT1 expressions as well as DDAH2 expression and methylation, in placentas collected from 59 patients with preeclampsia and 40 normotensive pregnancies were measured using real-time PCR and methylation specific PCR, respectively. The relationship among ARG II, PRMT1 and DDAH2 expressions was analyzed statistically. ARG II expression was increased, PRMT1 expression was not significantly changed. DDAH2 expression was decreased and qualitative methylation patterns were 32/59 and 21/40 in placentas from patients with pre-eclampsia compared with control group, respectively. The alterations in ARG II and DDAH2 expressions in pre-eclampsia patients maybe correlated with decreased eNOS expression. These findings indicate that ARG II and DDAH2 may be involved in pre-eclampsia pathogenesis and could be potential therapeutic targets for this disease.

Oral nifedipine versus intravenous labetalol for severe hypertension during pregnancy: a systematic review and meta-analysis

BACKGROUND

Oral nifedipine is recommended along with labetalol and hydralazine for treatment of severe hypertension during pregnancy by most authorities. Although nifedipine is cheap and easily administered, the usage pattern among health care providers suggests a strong preference for labetalol despite lack of evidence for the same.

OBJECTIVES

To determine the efficacy and safety of oral nifedipine for treatment of severe hypertension of pregnancy compared with intravenous labetalol.

SEARCH STRATEGY

We systematically searched for articles comparing oral nifedipine with intravenous labetalol for the treatment of severe hypertension during pregnancy in any language, over Medline, Cochrane Central Register of Clinical Trials and Google Scholar from inception till February 2014.

SELECTION CRITERIA

We included all RCTs that compared intravenous labetalol with oral nifedipine for treatment of severe hypertension during pregnancy, addressing relevant efficacy and safety outcomes.

DATA COLLECTION AND ANALYSIS

Eligible studies were reviewed, and data were extracted onto a standard form. We used Cochrane review manager software for quantitative analysis. Data were analysed using a fixed effect model.

MAIN RESULTS

The pooled analysis of seven trials (four from developing countries) consisting of 363 woman-infant pairs showed that oral nifedipine was associated with less risk of persistent hypertension (RR 0.42, 95% CI 0.18-0.96) and reported maternal side effects (RR 0.57, 95% CI 0.35-0.94). However, on sensitivity analysis the outcome 'persistent hypertension' was no longer significant. Other outcomes did not reach statistical significance.

CONCLUSION

Oral nifedipine is as efficacious and safe as intravenous labetalol and may have an edge in low resource settings.

TWEETABLE ABSTRACT

Although studies to date are few in number and small, nifedipine shows promise for severe hypertension in pregnancy.

Oral nifedipine or intravenous labetalol for hypertensive emergency in pregnancy: a randomized controlled trial

OBJECTIVE

To compare the effectiveness of orally administered nifedipine and intravenously administered labetalol for acute blood pressure control in hypertensive emergency of pregnancy.

METHODS

In this double-blind, randomized, controlled trial, pregnant women with sustained increase in systolic blood pressure of 160 mm Hg or higher or diastolic blood pressure of 110 mm Hg or higher were randomized to receive nifedipine (10 mg tablet orally up to five doses) and intravenous placebo saline injection or intravenous labetalol injection in escalating doses of 20, 40, 80, 80, and 80 mg and a placebo tablet every 20 minutes until the target blood pressure of 150 mm Hg systolic and 100 mm Hg diastolic, or lower, was achieved. Crossover treatment was administered if the initial treatment failed. The primary endpoint of the study was time necessary to achieve target blood pressure. Secondary endpoints were number of dosages required, adverse maternal and neonatal effects, side effect profile, and perinatal outcome.

RESULTS

From October 2012 to April 2013, we enrolled 60 patients. The median time taken to achieve target blood pressure was 40 minutes (interquartile range, 20-60 minutes) compared with 60 minutes (interquartile range 40-85 minutes) for nifedipine and labetalol, respectively (P=.008). The median dose required was two (interquartile range 1-3) compared with three (interquartile range 2-4.25) for nifedipine and labetalol, respectively (P=.008). No serious adverse maternal or perinatal side effects were witnessed in either group.

CONCLUSION

As administered in this trial, oral nifedipine lowered blood pressure more quickly than did intravenous labetalol during hypertensive emergency in pregnancy.

CLINICAL TRIAL REGISTRATION

Clinical Trials Registry-India, www.ctri.nic.in, CTRI/2013/02/003350.

LEVEL OF EVIDENCE

I.

A comprehensive review of hypertension in pregnancy

Hypertension is the most common medical disorder encountered during pregnancy. Hypertensive disorders are one of the major causes of pregnancy-related maternal deaths in the United States. We will present a comprehensive update of the literature pertinent to hypertension in pregnancy. The paper begins by defining and classifying hypertensive disorders in pregnancy. The normal vascular and renal physiological changes which occur during pregnancy are detailed. We will summarize the intriguing aspects of pathophysiology of preeclampsia, emphasizing on recent advances in this field. The existing diagnostic tools and the tests which have been proposed for screening preeclampsia are comprehensively described. We also highlight the short- and long-term implications of preeclampsia. Finally, we review the current management guidelines, goals of treatment and describe the potential risks and benefits associated with various antihypertensive drug classes. Preeclampsia still remains an enigma, and the present management focuses on monitoring and treatment of its manifestations. We are hopeful that this in depth critique will stimulate the blossoming research in the field and assist practitioners to identify women at risk and more effectively treat affected individuals.

The effect of maternal ketanserin use on the circulation of the neonate: a prospective, observational study

OBJECTIVE

High ketanserin levels are found in the umbilical cord after maternal treatment. However, the effect on the circulation of the neonate has never been investigated.

STUDY DESIGN

A prospective, observational study was performed at the neonate ward at the Medical Centre Leeuwarden, The Netherlands. All neonates exposed in utero to ketanserin administered to the mother, from May 2007 to December 2009 (n=58), were included. We studied the effect of ketanserin exposure on the circulation of the neonate, by monitoring heart rate and blood pressure during the first 24h of life. Non-parametric as well as parametric tests were used to analyze the effect of gestational age, birth weight, gender, various ketanserin factors (cumulative dosage, duration of therapy and last dosage rate), other maternal drug use and maternal diagnosis on the blood pressure of the neonate.

RESULTS

Eight neonates became hypotensive during the first 8h of life (13.8%). The last dosage rate as well as the mean dosage rate (cumulative dosage divided by duration of therapy in hours) were significantly higher in the group with hypotension (P=.005 and P=.002, respectively). All hypotensive neonates were exposed to a last dosage rate of at least 8 mg/h. Maternal HELLP syndrome was diagnosed more often in hypotensive compared to normotensive neonates (P=.048).

CONCLUSION

In utero exposure to ketanserin lowers the blood pressure of the neonate. The risk of hypotension is associated with the last dosage rate of maternal ketanserin treatment and the co-existence of maternal HELLP syndrome.

Antihypertensive drugs in pregnancy

Blood pressure targets and medications that are safe differ in pregnant women compared with nonpregnant individuals. The principles of treatment for mild, moderate, and severe hypertension in pregnancy, chronic versus gestational versus preeclampsia, and women hypertensive at term versus remote from term are reviewed. The choice of antihypertensive drugs also is discussed; methyldopa, labetalol, and nifedipine, among others, appear safe for use in pregnancy, whereas angiotensin converting enzyme inhibitors and angiotensin receptor blockers should be avoided. The management of increased blood pressure in the postpartum period, and agents to use in lactation, are also discussed.

The effect of maternal ketanserin treatment on foetal 5-HT receptor function in umbilical cord artery of pre-eclamptic patients

BACKGROUND

Maternal treatment with the 5-HT(2A) receptor antagonist ketanserin (KT) in pre-eclamptic patients is associated with a high placental transmission of KT, resulting in pharmacologically active levels of KT in the umbilical cord artery (UCA) and the neonate. Prolonged exposure to a 5-HT receptor antagonist may influence the functionality of foetal 5-HT receptors and compromise foetal development.

OBJECTIVE

To study whether exposure to KT influences the characteristics of foetal 5-HT receptors, functional studies were performed on 5-HT(2A) and 5-HT(1B/1D) receptors in UCA from pre-eclamptic patients treated with KT.

METHODS

UCAs were obtained, immediately after delivery, from pre-eclamptic patients (n = 7), treated antenatally with intravenous KT. Pre-eclamptic patients (n = 13), not treated with KT (non-KT), were included as a control group. Segments of UCA were prepared and mounted in tissue baths and isometric force changes were determined. Cumulative concentration response curves to 5-HT and to the 5-HT(1B/1D )receptor agonist sumatriptan were constructed in the absence or presence of the 5-HT(2A) receptor antagonist KT or the 5-HT(1B/1D) receptor antagonist GR125743, respectively.

RESULTS

All UCA segments showed contractile responses to both 5-HT and sumatriptan, and the concentration response curves showed a rightward shift with increasing concentrations of KT and GR125743, respectively, indicating the presence of functional 5-HT(2A) and 5-HT(1B/1D) receptors in the foetal tissue. No significant differences were found in maximum response (E(max))(expressed in percent of response on 100 mM KCl) or potency (pEC(50)) of 5-HT in both groups (E(max) = 141 +/- 7.7%, pEC(50) = 7.67 +/- 0.26 in KT-treated group and E(max) = 162 +/- 12.6%, pEC(50) = 7.69 +/- 0.14 in non-KT treated group, respectively). No significant differences were found in the potency of the antagonist KT in both study groups (pK(b) = 7.65 +/- 0.31 in KT group and 7.46 +/- 0.17 in non-KT group, respectively). Similarly, with sumatriptan, no significant differences were found between KT-treated patients and non-KT treated patients (E(max) = 142 +/- 16.2 and 140 +/- 14.7%, respectively, pEC(50) = 6.17 +/- 0.37 and 6.41 +/- 0.28 respectively, pK(b) of GR125743 = 7.83 +/- 0.48 and 8.43 +/- 0.29, respectively).

CONCLUSION

Foetal exposure to KT in pre-eclamptic patients does not seem to influence the functional characteristics of 5-HT(2A) and 5-HT(1B/1D) receptors in the UCA.

Insufficient efficacy of intravenous ketanserin in severe early-onset pre-eclampsia

OBJECTIVE

To analyze the efficacy of intravenous ketanserin in controlling blood pressure of severe early-onset pre-eclamptic patients.

STUDY DESIGN

Pre-eclamptic patients (n=47) with a gestational age (GA) between 21 and 32 weeks were treated with intravenous ketanserin in a maximum dosage of 14 mg/h, to obtain a diastolic blood pressure of 90 mmHg or below. The number of patients reaching and maintaining target blood pressure was retrospectively assessed. Patient characteristics associated with an adequate or inadequate response to ketanserin treatment were identified.

RESULTS

With a maximum intravenous dosage of ketanserin, target blood pressure was not achieved in 15 (32%) patients. A high systolic blood pressure at the start of treatment was significantly (p=0.02) associated with failure of ketanserin treatment. The median period of ketanserin treatment in the responding group was 3 days (range 1-10 days). In 26 (55%) of initially successfully treated patients, additional antihypertensive drugs had to be added to maintain adequate blood pressure control.

CONCLUSION

Intravenous ketanserin lacks antihypertensive efficacy in a substantial proportion of severe pre-eclamptic patients, despite high dosages. In patients who initially respond well to ketanserin treatment, additional antihypertensive treatment is often necessary to maintain adequate blood pressure control.

Population pharmacokinetics of ketanserin in pre-eclamptic patients and its association with antihypertensive response

Ketanserin is an antihypertensive drug that is increasingly being used parenterally in the treatment of pre-eclampsia. Because of lack of efficacy in a substantial part of our pre-eclamptic patients, we determined the plasma concentrations of ketanserin in 51 pre-eclamptic patients. Population pharmacokinetic parameters were assessed using the iterative two-stage Bayesian population procedure. The influence of individual pharmacokinetic parameters on antihypertensive response, expressed as the attainment of a diastolic blood pressure <or=90 mmHg using ketanserin treatment, was analysed. Almost all plasma concentrations of ketanserin were in or above the therapeutic range. The individual pharmacokinetics of ketanserin in pre-eclamptic patients showed an accurate fit using a three-compartment model. The pharmacokinetic parameters in our pre-eclamptic population were a metabolic clearance (Cl(m)) of 37.9+/-10.86 L/h and volume of distribution (V1) of 0.544+/- 0.188 L/kg, which is comparable with data from healthy volunteers. Despite a considerable inter-individual variation, no correlation was found between differences in pharmacokinetic parameters and antihypertensive response. We conclude that therapeutic plasma levels can be obtained in pre-eclamptic patients with a fixed dosage schedule of ketanserin and differences in antihypertensive responses within a pre-eclamptic population cannot be attributed to pharmacokinetic differences.

Can SSRIs reduce the risk of preeclampsia in pregnant, depressed patients?

Preeclampsia causes substantial morbidity and mortality. A significant part of the etiology of preeclampsia involves endothelial damage and platelet activation and in this way can be conceived as an illness with a pathophysiology similar to coronary artery disease. Depression is an independent risk factor for the progression of cardiovascular disease [Am Heart J 140 (2000) S57] and there is evidence to suggest that it may be a risk factor for preeclampsia as well. SSRIs have been shown to reduce the progression of coronary artery disease, independent of improvement in mood. SSRIs may also reduce risk factors for preeclampsia in addition to treating depression in pregnancy. This is an important area for further research.

Spectrum of hypertensive emergencies in pregnancy

Hypertension in pregnancy represents a spectrum of clinical entities, including pregnancy-induced hypertension (PIH), preeclampsia, eclampsia, and hemolysis, elevated liver enzyme levels, low platelet count syndrome. Although hypertension is a common denominator in this group of disorders, the pathogenesis, clinical features, and clinical course of these disorders is variable and somewhat distinct. Therapy must be tailored to the clinical entity and the patient. The incidence and prevalence of preeclampsia and eclampsia is decreasing worldwide. This decrease partly may be caused by the improved treatment of PIH and improved obstetrical services.

Ketanserin in pre-eclamptic patients: transplacental transmission and disposition in neonates

The aim of this prospective, observational study was to assess transplacental transmission of ketanserin, an antihypertensive drug used in pre-eclampsia, and to determine disposition and effects in the neonate after maternal ketanserin use. In 22 pregnant women with severe pre-eclampsia, admitted to the antenatal ward in the period 1999-2001, the ratio of drug levels in the umbilical cord to drug levels in maternal blood just before delivery was used as an indicator of placental transmission. Disposition of ketanserin was assessed using neonatal plasma concentrations of ketanserin in eight neonates after birth. A median placental transmission was found in the pre-eclamptic women of 0.95 (0.612-1.24) for ketanserin and for its metabolite, ketanserinol, of 0.60 (0.5-0.77). Pharmacologically relevant concentrations of ketanserin were found in the neonate after delivery. The elimination half-life of ketanserin in the neonate varied between 12.7 and 43.7 hours (median 19.3 hours) and of ketanserinol between 13.8 and 34.4 hours (median 18.7 hours). Despite the high placental transmission and disposition in the neonate, no apparent adverse effects in the neonates could be detected. In conclusion, a high placental transmission of ketanserin and its metabolite ketanserinol occurred after maternal treatment of pre-eclampsia with ketanserin and pharmacologically active concentrations of ketanserin are found in the neonate for a prolonged period after delivery.

Plasma volume and blood pressure regulation in hypertensive pregnancy

BACKGROUND

Pre-eclampsia is a multisystem disorder, peculiar to and frequent in human pregnancy. It remains a leading cause of maternal and neonatal morbidity and mortality. Hemodynamic disturbances are the most prominent features of the syndrome.

PURPOSE

To provide an overview of plasma volume regulation and blood pressure control mechanisms outside pregnancy, and of the changes in normal pregnancies and in pregnancies complicated by hypertensive disorders. Furthermore, to discuss the rationale of several hemodynamic interventions.

RESULTS

In normal pregnancy, large cardiovascular changes take place. A generalized fall in vascular tone by systemic vasorelaxation causes increased blood volume, heart rate and cardiac output. In the preclinical phase, differences have been observed between normal and hypertensive pregnancies in the function of the autonomic nervous system, cardiac output and plasma volume, the volume remaining at the non-pregnant level. In the clinical phase of pre-eclampsia the typical case picture is one of a vasoconstrictive state with low plasma volume and cardiac output, high blood pressure and systemic vascular resistance in combination with signs of organ damage [proteinuria, hemolysis elevated liver enzymes low platelets (HELLP) syndrome]. Hemodynamic management is necessary in severe disease to prevent maternal complications. Management primarily focuses on pharmacological treatment of blood pressure. Clinicians make educated choices from a limited array of available drugs: beta-receptor antagonists, nifedipine, dihydralazine, methyldopa or ketanserine. Other drugs have restricted use in pregnancy. Management of low circulating volume with plasma expanders remains a subject of controversy.

The endocrinology of pre-eclampsia

Pre-eclampsia is a pregnancy specific syndrome that is a principal cause of maternal morbidity and mortality, accounting for almost 15% of pregnancy associated deaths, and is one of the major causes of iatrogenic prematurity among new born babies. The mild form of pre-eclampsia most commonly presents with the features of maternal hypertension and proteinuria, but can swiftly and unpredictably become severe with numerous multisystem complications involving the maternal liver, kidneys, lungs, blood and platelet coagulation and nervous systems. The diverse symptoms of pre-eclampsia have made it a difficult disease not only to define, but also to identify a causative agent for the symptoms. This review examines the complex endocrinological mechanisms believed to be responsible for the extensive complications of pre-eclampsia from the role of placental and endothelial dysfunction, to the causes of the oxidative stress and the ensuing general inflammation. It also highlights current endocrine findings that exhibit the potential for clinical application, as either potential markers or novel therapeutic targets, with the aim of either preventing or altering the course of this life-threatening disease of pregnancy.

Hypertensive diseases and eclampsia

Worldwide, pre-eclampsia and eclampsia contribute to the death of a pregnant woman every 3 min. In the UK in recent decades, hypertensive disorders of pregnancy have remained one of the leading causes of both maternal and perinatal morbidity and mortality. The management of pregnancies complicated by hypertension has not significantly altered for many years, possibly as a result of little progress being made in our understanding of the condition. New insights, however, have recently been gained into the pathophysiology of pre-eclampsia. These have yet to be translated into new interventions or to make any impact on clinical management of these pregnancies. This review will therefore focus on recent advances relating to research into the aetiology and pathogenesis of pre-eclampsia, but will conclude with a brief update on current therapeutic strategies.

Antihypertensive therapy in pregnancy

Human pregnancy, normally characterized by systemic vasodilation and modest hypotension, can be complicated by underlying maternal hypertension and several unique hypertensive disorders, including pre-eclampsia. Although well-designed and adequately powered clinical trials are critically needed, there have been several recent meta-analyses of this large literature, along with consensus statements and treatment guidelines from three distinct multidisciplinary groups of clinicians and investigators. In this paper we review recent analyses and guidelines, advising on our current approach to antihypertensive therapy in pregnant women.

Management and monitoring of severe preeclampsia

Preeclampsia is associated with increased maternal and perinatal morbidity and mortality. Preeclampsia is more than pregnancy-induced hypertension. The hypertension is only one manifestation of an underlying multifactorial, multisystem disorder, initiated early in pregnancy. In established severe disease there is volume contraction, reduced cardiac output, enhanced vascular reactivity, increased vascular permeability and platelet consumption. Medical treatment of severe hypertension in pregnancy is required. The more controversial issues are the role of pharmacological treatment in conservative management of severe preeclampsia aiming at prolongation of pregnancy, the ability of such therapy to modify the course of the underlying systemic disorder and the effects on fetal and maternal outcome. This paper presents an overview concerning the current developments in management and monitoring of severe preeclampsia. Controversial topics such as the role of plasma volume expansion in preeclampsia, expectant versus aggressive management of severe preeclampsia remote from term, and pharmacological interventions in the management of eclampsia and the HELLP syndrome are addressed.