Prevention and treatment of pregnancy-associated hypertension: what have we learned in the last 10 years?

Associations between Maternal Risk Factors and Intrinsic Placental and Fetal Brain Functional Properties in Congenital Heart Disease

The relationship between maternal risk factors (MRFs) (particularly pre-gravid obesity, diabetes, and hypertension) and congenital heart disease (CHD) to placental and fetal brain outcomes is poorly understood. Here, we tested the hypothesis that MRF and CHD would be associated with reduced intrinsic placental and fetal brain function using a novel non-invasive technique. Pregnant participants with and without MRF and fetal CHD were prospectively recruited and underwent feto-placental MRI. Using intrinsic properties of blood oxygen level dependent imaging (BOLD) we quantified spatiotemporal variance of placenta and fetal brain. MRFs and CHD were correlated with functional characteristics of the placenta and fetal brain. Co-morbid MRF (hypertension, diabetes, and obesity) reduced spatiotemporal functional variance of placenta and fetal brain (p < 0.05). CHD predicted reduced fetal brain temporal variance compared to non-CHD (p < 0.05). The presence of both MRF and CHD was associated with reduced intrinsic pBOLD temporal variance (p = 0.047). There were no significant interactions of MRFs and CHD status on either temporal or spatial variance of intrinsic brain BOLD. MRF and CHD reduced functional characteristic of placenta and brain in fetuses. MRF modification and management during pregnancy may have the potential to not only provide additional risk stratification but may also improve neurodevelopmental outcomes.

What a paediatric nephrologist should know about preeclampsia and why it matters

Preeclampsia is a protean syndrome causing a kidney disease characterised by hypertension and proteinuria, usually considered transitory and reversible after delivery. Its prevalence ranges from 3-5 to 10% if all the related disorders are considered. This narrative review, on behalf of the Kidney and Pregnancy Study Group of the Italian Society of Nephrology, focuses on three reasons why preeclampsia should concern paediatric nephrologists and how they can play an important role in its prevention, as well as in the prevention of future kidney and cardiovascular diseases. Firstly, all diseases of the kidney and urinary tract diagnosed in paediatric age are associated with a higher risk of adverse pregnancy-related outcomes, including preeclampsia. Secondly, babies with low birth weights (small for gestational age, born preterm, or both) have an increased risk of developing the full panoply of metabolic diseases (obesity, hypertension, early-onset cardiopathy and chronic kidney disease) and girls are at higher risk of developing preeclampsia when pregnant. The risk may be particularly high in cases of maternal preeclampsia, highlighting a familial aggregation of this condition. Thirdly, pregnant teenagers have a higher risk of developing preeclampsia and the hypertensive disorders of pregnancy, and should be followed up as high risk pregnancies. In summary, preeclampsia has come to be seen as a window on the future health of both mother and baby. Identification of subjects at risk, early counselling and careful follow-up can contribute to reducing the high morbidity linked with this disorder.

A systematic review and meta-analysis indicates long-term risk of chronic and end-stage kidney disease after preeclampsia

Preeclampsia is a pregnancy-related syndrome of variable severity, classically characterized by acute kidney involvement, with hypertension and/or proteinuria and reduced kidney function. Once considered a self-limited disease healed by delivery, it is now acknowledged that preeclampsia can affect cardiovascular and kidney health in the long term. The entity of risk has not been established and consequently follow-up policies have not been defined. Here we undertook a systematic review to gain better insights into the need for post-preeclampsia follow-up. Articles published between January 2000 and March 2018 were selected, dealing with at least 20 preeclampsia patients, with follow-up of 4 years or more (MEDLINE, Embase, and Cochrane Library). No quality selection or language restriction was performed. Of the 10,510 titles and abstracts originally considered, 21 papers were selected, providing information on 110,803 cases with and 2,680,929 controls without preeclampsia, with partial overlap between studies on the same databases. Heterogeneity was high, and a random meta-analytic model selected. The increase in risk of end stage renal disease after preeclampsia was significant (meta-analytic risk ratios (95% confidence interval) 6.35 (2.73-14.79)); the risk of albuminuria and chronic kidney disease increased but statistical significance was not reached (4.31 (0.95-19.58) and 2.03 (0.58-7.32), respectively). Translating meta-analytic risk into the number of patients who need follow-up to detect one adverse event, 310 patients with preeclampsia are needed to identify one woman with end stage renal disease or four to identify one woman with albuminuria. Heterogeneity in definitions, insufficient follow-up and incomplete recruitment may account for discrepancies. Thus, preeclampsia significantly increases the risk of end stage renal disease. However, there is lack of sufficient data to show a relationship between preeclampsia, albuminuria and chronic kidney disease, underlining the need for further prospective studies.

A best practice position statement on the role of the nephrologist in the prevention and follow-up of preeclampsia: the Italian study group on kidney and pregnancy

Preeclampsia (PE) is a protean syndrome causing a transitory kidney disease, characterised by hypertension and proteinuria, ultimately reversible after delivery. Its prevalence is variously estimated, from 3 to 5% to 10% if all the related disorders, including also pregnancy-induced hypertension (PIH) and HELLP syndrome (haemolysis, increase in liver enzyme, low platelets) are included. Both nephrologists and obstetricians are involved in the management of the disease, according to different protocols, and the clinical management, as well as the role for each specialty, differs worldwide. The increased awareness of the role of chronic kidney disease in pregnancy, complicating up to 3% of pregnancies, and the knowledge that PE is associated with an increased risk for development of CKD later in life have recently increased the interest and redesigned the role of the nephrologists in this context. However, while the heterogeneous definitions of PE, its recent reclassification, an emerging role for biochemical biomarkers, the growing body of epidemiological data and the new potential therapeutic interventions lead to counsel long-term follow-up, the lack of resources for chronic patients and the increasing costs of care limit the potential for preventive actions, and suggest tailoring specific interventional strategies. The aim of the present position statement of the Kidney and Pregnancy Study Group of the Italian Society of Nephrology is to review the literature and to try to identify theoretical and pragmatic bases for an agreed management of PE in the nephrological setting, with particular attention to the prevention of the syndrome (recurrent PE, presence of baseline CKD) and to the organization of the postpartum follow-up.

Investigation of the effects of the chronic administration of some antihypertensive drugs on enzymatic and non-enzymatic oxidant/antioxidant parameters in rat ovarian tissue

OBJECTIVE

In this study, effects of chronic antihypertensive drug (clonidine, methyldopa, amlodipine, ramipril, and rilmenidine) treatment on antioxidant-oxidant parameters were investigated in rat ovarian tissue.

STUDY DESIGN

Chronic drug administration for 30 days and at the end, biochemical examinations (total glutathione (tGSH), glutathione peroxidase (GPO), glutathione reductase (GR), glutathione s-transferase (GST), superoxide dismutase (SOD), nitric oxide (NO), catalase (CAT), malondialdehyde (MDA), and myeloperoxidase (MPO) analyses) were performed.

RESULTS

The levels of glutathione (GSH) and NO, and the activities of GPO, GR, GST, SOD, and CAT were measured the lowest in ramiprile group. Also in ramiprile group, the level of MDA and the activity of MPO was the highest.

CONCLUSION

We divided the drugs into four groups according to their biochemical side effect potentials in ovarian tissue: (I) Drugs which have no clear negative effect on ovarian tissue: clonidine, rilmenidine; (II) Drugs which have mild negative effect on ovarian tissue: methyldopa; (III) Drugs which have moderate negative effect on ovarian tissue: amlodipine; (IV) Drugs which have severe negative effect on ovarian tissue: ramipril. These data might be useful in the selection of the least toxic antihypertensive drug in pregnant and/or normal females.

Management of severe preeclampsia

Features of severe preeclampsia include severe proteinuric hypertension and symptoms of central nervous system dysfunction, hepatocellular injury, thrombocytopenia, oliguria, pulmonary oedema, cerebrovascular accident and severe intrauterine growth restriction. Women with severe preeclampsia must be hospitalized to confirm the diagnosis, to assess the severity of the disease, to monitor the progression of the disease and to try to stabilize the disease. Severe preeclampsia may be managed expectantly, in selected cases. The objective of expectant management in these patients is to improve neonatal outcome. Expectant management is based on antihypertensive treatment and prevention of end organ dysfunction. Antihypertensive treatment improves maternal outcome but has the potential to be deleterious for the foetus. Plasma volume expansion has been suggested for severe preeclampsia but trials failed to show any benefit. Magnesium sulfate is the anticonvulsivant of choice to treat or prevent eclampsia when indicated. Antenatal corticosteroids are recommended in severely preeclamptic women with 26-34 weeks gestation. Timing of delivery is based upon gestational age, severity of preeclampsia, maternal and foetal risks.

Serum leptin and ghrelin concentrations of maternal serum, arterial and venous cord blood in healthy and preeclamptic pregnant women

Preeclampsia, a common complication of pregnancy, is associated with alteration in the concentration of leptin in maternal blood. The action of leptin is antagonistic to that of ghrelin. Here, we compared the levels of leptin and ghrelin in maternal serum and in arterial and venous cord blood between healthy pregnant women and those suffering from mild and severe preeclampsia. The levels of leptin in maternal and newborn's blood were elevated in both mild and severe preeclamptic patients (p < 0.05). Moreover, serum ghrelin levels were negatively correlated with blood pressure and leptin/ghrelin ratio was decreased in preeclampsia (p < 0.05). We concluded that increased production of ghrelin may represent a compensatory hypotensive mechanism in preeclamptic women.

Outcomes of pregnancies achieved by donor egg in vitro fertilization--a comparison with standard in vitro fertilization pregnancies

OBJECTIVE

Prior studies on donor egg in vitro fertilization (DE-IVF) outcomes have been limited by the lack of an appropriate control group. Here, we review the obstetric and perinatal outcomes of pregnancies achieved by DE-IVF and compare these pregnancies with those of women who also needed similar assisted reproductive techniques, of similar socioeconomic status, and cared for by a small group of 8 physicians applying consistent diagnostic and treatment approaches.

STUDY DESIGN

A retrospective review of 50 consecutive pregnancies achieved by DE- IVF and 50 consecutive pregnancies achieved by standard IVF (STD-IVF) was performed. Comparisons were made for demographic and medical confounding factors and for outcome measures.

RESULTS

The 2 groups were nearly identical for gravidity, parity, and multiple gestations but did vary in maternal age. Average age of patients receiving DE-IVF was 41.9(+/-5.1), whereas the STD-IVF averaged 37.7(+/-3.6) years ( P < .001). Key obstetric outcomes did not differ between the 2 groups with the exception of pregnancy-induced hypertension. In patients with DE-IVF, 26% had pregnancy-induced hypertension (PIH) develop, whereas this occurred in only 8% of the STD-IVF group ( P = .02). Examining nulliparous patients only, 37.1% of DE-IVF had PIH develop, whereas only 8% of STD-IVF group achieved that diagnosis ( P < .003). An analysis with a multiple logistic regression in nulliparous patients found odds ratios of 7.1 (95% CI, 1.4-36.7) in DE versus STD-IVF, odds ratio 4.9 (95% CI, 1.3-18.3) for multiple gestation versus singleton, and odds ratio 1.0 (95% CI, 0.9-1.1) for maternal age.

CONCLUSION

Nulliparous pregnancies achieved by DE-IVF are associated with an increased risk of PIH; however, excellent outcomes can still be expected.

Recent progress in the therapeutic management of pre-eclampsia

Pre-eclampsia is a pregnancy-specific syndrome of unknown aetiology, observed in 3 - 5% of all pregnancies, associated with pathological vascular lesions in multiple organs, activation of the coagulation system, and maternal multisystemic and fetal complications. Clinically, pre-eclampsia is characterised by the onset of hypertension, proteinuria and oedema, usually beginning in the third trimester. Conventionally, antihypertensive agents are the main pharmacological treatment. Recently, some studies have shown that the treatment of pre-eclampsia with antithrombin concentrate corrects the hypercoagulability and improves the fetal status and the perinatal outcome. No clear evidence supports the use of heparin. A conservative treatment of moderate- to- severe pre-eclampsia, based on the administration of antithrombin concentrate, may allow a significant prolongation of pregnancy and a better neonatal outcome, as well as fewer maternal complications.

Obstetric and prenatal outcome in menopausal women: a 12-year clinical study

The obstetric and prenatal outcome in post-menopausal women of advanced age in an oocyte donation programme is described in this paper, the oldest being aged 63 years. A total of 2729 candidates were visited up to November 2000. Only 1150 (42%) were accepted, with 1579 being rejected during a rigorous selection procedure. Several excluding clinical conditions were noted, including hypertension of varying severity, cardiovascular disease, smoking, dysfunctions of the hepatic, thyroid and renal systems and diabetes. Overall, 489 (38%) clinical pregnancies were established in 1288 recipient cycles, with 390 healthy babies delivered out of 363 pregnancies (28%), while 126 (25.7%) were lost. In all, 327 (90%) of the pregnancies reached full term, with 36 involving premature deliveries, 24 involving multiple gestation, 21 sets of twins, three sets of triplets (0.9%) and no quadruplets. Antenatal complications arising in 86 patients (23.6% of deliveries) included 33 preterm deliveries, 43 cases of gestational hypertension, four cases of pre-eclampsia, three cases of gestational diabetes and three of abruptio placentae. A total of 272 (75%) of all deliveries were by Caesarean section. Neonatal complications included two cases of growth retardation. There were no neonatal or maternal deaths. The 63-year-old woman reached full term pregnancy in July 1994, with delivery by Caesarean section of a boy in good health. Proper screening for risks has enabled this treatment to be given to a preselected group of patients.

Nifedipine or hydralazine as a first-line agent to control hypertension in severe preeclampsia

BACKGROUND

Pre-eclampsia is one of the most serious and common complications of pregnancy. Nifedipine, a calcium channel blocker, and the vasodilator hydralazine have both been used as antihypertensive agents in this condition. The aim of this study was to determine which of these two agents is the most appropriate antihypertensive in the management of severe pre-eclampsia.

METHODS

One hundred and twenty-six pre-eclamptic patients with a gestational age of more than 20 weeks were randomized to receive either 8 mg nifedipine sublingually or 5-10 mg intravenous hydralazine. Women with a history of heart failure and women receiving antihypertensive treatment during the course of the current pregnancy were excluded. For each patient the following data were recorded; the number of drug administrations, the time needed to control blood pressure, mean urinary output, the time interval between effective control and a new hypertensive crisis after each drug administration and relevant adverse effects in mother or fetus.

RESULTS

Effective control of blood pressure was achieved in both treatment arms. Data analysis indicated significantly fewer drug administrations in the nifedipine arm of the study. The time interval before a new hypertensive crisis following initial effective control of blood pressure was significantly longer in the nifedipine group when compared with hydralazine. Effective control of blood pressure was achieved more rapidly in multiparous patients receiving nifedipine (p=0.026). Mean urinary output before and after delivery was greater in the nifedipine arm of the study. There were no significant differences between the two groups in other variables. In addition, in neither group were there any serious adverse effects in mother or fetus.

CONCLUSION

Nifedipine is safe and more effective than hydralazine in controlling blood pressure in severe pre-eclampsia. It has the added advantage of being cheaper and more widely available than the latter and is easily administered.

Renal vascular walls in patients with preeclampsia superimposed on essential hypertension

This study was performed to clarify the relationship between changes in contractile proteins in renal vascular walls and the prognosis of hypertension during pregnancy. Twenty preeclamptic patients underwent renal biopsies after delivery and were divided into the following three groups: group I, patients with persistent hypertension after delivery (n = 7; mean age, 34.8 +/- 1.4 years [SE]); group II, patients who became normotensive after delivery and hypertensive again during follow-up (n = 5; mean age, 34.8 +/- 1.6 years), and group III, patients who became normotensive after delivery (n = 8; mean age, 28.0 +/- 1.0 years). We also examined age-matched healthy controls (group IV; n = 7; mean age, 34.9 +/- 1.5 years). Renal biopsy specimens were immunohistochemically stained by the avidin-biotinylated peroxidase complex method using antimonoclonal smooth muscle cell myosin heavy chain isoform antibodies (SM-1, SM-2) and antimonoclonal alpha-smooth muscle cell actin antibody (actin). We estimated and semiquantitatively scored the degree of staining in each section. In interlobular arteries, SM-1, SM-2, and actin staining in group I were significantly reduced compared with group IV (SM-1, SM-2, P: < 0.05; actin, P: < 0.01). In afferent arterioles (Afs), SM-1, SM-2, and actin staining were reduced in group I. SM-2 staining in group I was significantly reduced compared with the other three groups (versus group II, P: < 0.05; versus groups III and IV, P: < 0.01). These findings suggest that phenotypic changes in vascular smooth muscle cells (especially the disappearance of SM-2 in Afs) reflect the stage of underlying essential hypertension and can predict from the change in hypertension during pregnancy whether it will persist after delivery.

Increased blood pressure response to the cold pressor test in pregnant women developing pre-eclampsia

OBJECTIVES

Recent data indicate an increased vascular reactivity due to an overactivity of the sympathetic nervous system in women with pre-eclampsia. We therefore evaluated whether this increased vascular reactivity can be detected prior to the clinical manifestation of preeclampsia by the use of a physiological stimulus.

DESIGN

Prospective data collection.

SETTING

Clinic of Obstetrics and Gynecology in a 2000 bed tertiary care hospital.

PARTICIPANTS

One hundred and twenty-three pregnant women between the 16th to 20th week of gestation.

INTERVENTIONS

A cold pressor test was performed by positioning an ice-bag on the forehead of the woman for 3 min. Blood pressure and heart rate were monitored by a continuous, noninvasive blood pressure measurement device during the stimulus and after removal of the icebag. A clinical follow-up was carried out by review of the charts after delivery to identify those women who have developed pre-eclampsia.

RESULTS

Ten (8%) out of 123 pregnant women developed pre-eclampsia. During the cold pressor test systolic as well as diastolic blood pressure increased significantly and was more pronounced in women developing pre-eclampsia compared with healthy pregnant women (systolic blood pressure: 14.2 +/- 5.5 versus 8.5 +/- 7.2 mmHg, P= 0.02; diastolic blood pressure: 7.3 +/- 4.9 versus 3.9 +/- 4.7 mmHg, P=0.03). The change in heart rate was similar between both groups (8 +/- 2.6 versus 10.4 +/- 6.4 beats/min, not significant).

CONCLUSIONS

An increased vasoconstrictive response to a physiological stimulus is present in women with pre-eclampsia as a sign of an increased vascular reactivity prior to clinical manifestation of the disease. The cold pressor test may be a suitable diagnostic tool to identify women, who will develop pre-eclampsia. However, future studies in larger cohorts are required to establish the final value of this test.

The influence of donated gametes on the incidence of hypertensive disorders of pregnancy

Pregnancies achieved from oocyte, sperm or embryo donation are unique, since they have resulted from donor gametes that are immunologically foreign to the mother. Thus, studying the obstetric outcome of such pregnancies may shed some light on the pathophysiology of preeclampsia, particularly in women conceiving with donated embryos, since the entire fetal genome is allogenic in these pregnancies. In this retrospective cohort study, a total of 144 women were studied. Of these, 72 were infertility patients who had conceived as a result of sperm, ovum or embryo donation and the other 72 women were age- and parity-matched control patients who became pregnant with their own gametes, either spontaneously, or following intrauterine insemination with their partner's spermatozoa. Study patients were divided into three groups depending on the origin of the donated gametes. Group 1 consisted of pregnancies achieved by intrauterine insemination with washed donor spermatozoa (n = 33). Group 2 included women who conceived using donated oocytes (n = 27) and group 3 consisted of women who conceived as a result of embryo donation (n = 12). The incidence of pregnancy-induced hypertension in the donated gametes study group was 12.5% (9/72) compared with 2.8% (2/72) in the control group. In addition, pre-eclampsia was diagnosed in 18.1% (13/72) of the donated gametes study group compared to 1.4% (1/72) in the age- and parity-matched controls. The increased incidence of gestational hypertension in pregnancies resulting from donated gametes gives evidence for a maternal genetic component, with an equally strong fetal influence, in the complicated aetiology of gestational hypertension, and pre-eclampsia in particular.

Association of circulating endothelium and noradrenaline with increased calcium-channel binding sites in the placental bed in pre-eclampsia

OBJECTIVE

To evaluate factors contributing to both placental hypoperfusion and maternal vasoconstriction in pre-eclampsia.

DESIGN

Single centre, comparative study of calcium-channel density and affinity in the placental bed of pregnant women with normotension and pre-eclampsia.

SETTING

Teaching hospital.

PARTICIPANTS

Twenty-two primigravidae in the third trimester of pregnancy: 10 with pre-eclampsia and 12 normotensive.

METHODS

Plasma levels of endothelin-1 (by RIA) and noradrenaline (by HPLC-ED) were measured. Both pharmacological characterisation and anatomical localisation of dihydropyridine-sensitive binding sites (using radioligand-binding studies and autorradiographic techniques) were determined with 3H-isradipine in placental bed tissues to determine both the density (Bmax) and the affinity (Kd) of receptor sites.

RESULTS

Higher plasma levels of endothelin-1 and noradrenalin were found in women with pre-eclampsia compared with normotensive women. Placental bed tissues bound 3H-isradipine in a saturable, reversible time and temperature-dependent manner with very low Kd values. Study of the 3H-isradipine specificity binding included the use of several dihydropyridine displacers. In the group with pre-eclampsia the Scatchard analysis of the results showed a significant increase (P < 0.001) both in the affinity [Kd = 0.23 nmol (0.04) vs 0.45 nmol (0.03), pre-eclampsia vs normotensive] and in the density of calcium-channel binding sites [Bmax = 77.70 fmol/mg (1.30) vs 64.30 fmol/mg (1 80) tissue, pre-eclampsia vs normotensive]. Autoradiography confirmed that in the placental bed tissue of those with pre-eclampsia there was a much higher silver grain density in the arteries walls, compared with normotensive women.

CONCLUSIONS

In pre-eclampsia there is an increase in the maternal circulation of two strong vasoconstrictor factors (endothelin-1 and noradrenalin) and a sharp increase both in the density and the affinity of calcium-channel binding sites in placental bed central area. The latter may strongly contribute to the perpetuation of the uteroplacental hypoperfusion either by itself or by amplifying the local actions of circulating factors, such as endothelin-1 and noradrenalin.

Blood pressure variability during gestation in healthy and complicated pregnancies

The evaluation of predictable variability in blood pressure by the use of ambulatory devices, and the proper processing of the time series thus obtained, can be useful for the early assessment of hypertensive complications in pregnancy. We have used this approach to quantify a predictable pattern of blood pressure and heart rate throughout pregnancy in clinically healthy women as well as in pregnant women who developed gestational hypertension or preeclampsia. We analyzed 503 blood pressure series from 71 healthy pregnant women and 256 series from 42 women who developed gestational hypertension or preeclampsia. Blood pressure monitoring (48-hour) was done once every 4 weeks after the first obstetric consultation. The pattern of variation along gestation of the 24-hour mean of blood pressure for groups of normotensive and hypertensive pregnant women was established by polynomial regression analysis. This method revealed predictable patterns of variation of 24-hour means with gestational age: for normotensive pregnant women, results indicate a steady decrease in blood pressure up to the 21st week of pregnancy, followed by an increase in blood pressure up to the day of delivery. This pattern of variation is not found in pregnancies complicated with gestational hypertension or even preeclampsia: the 24-hour mean of blood pressure is stable until the 22nd week of pregnancy and then correlated with gestational age, indicating a significant linear increase of blood pressure in the second half of pregnancy. For both healthy and complicated pregnancies, heart rate slightly increases until the end of the second trimester, and it is stable thereafter. This study confirms and extends to ambulatory everyday life conditions the predictable pregnancy-associated variability in blood pressure. The differences between uncomplicated and complicated pregnancies offer new end points for an early identification of gestational hypertension and preeclampsia.

Conflicting data on intervillous circulation in early pregnancy

According to classic embryological textbooks intervillous circulation is established early in the first trimester. This process starts with trophoblastic invasion of the decidua in which proteolytic enzymes facilitate the penetration and erosion of the adjacent maternal capillaries with formation of the lacunae. After the lacunar or previllous stage trophoblast invades deeper portions of endometrium with belonging spiral arteries. This gradual process finishes with direct opening of the spiral arteries in the intervillous space under the fully developed placenta. This classic concept of establishment of the intervillous circulation was challenged in 1987 and 1988 by the experiments of HUSTIN and SHAAPS. The authors believed that blood flow in the intervillous space is absent in incompletely development before 12 weeks of gestation. After the introduction of the new generation of far more sensitive color Doppler devices in the last few years, our group and several others reported a positive finding of intervillous circulation during the first trimester of pregnancy.

Lysosomal enzymuria in preeclampsia

We hypothesize that the preeclamptic patient has proximal tubule epithelial injury, which leads to the release of lysosomal enzymes, and that the excretion of these enzymes might serve as a diagnostic or predictive marker in preeclamptic women. The study group consisted of 14 women with preeclampsia (10 severe and 4 mild, as defined by The American College of Obstetricians and Gynecologists criteria) and 28 normotensive controls with singleton pregnancies at 27 to 41 weeks. There were no significant differences between the two groups for gestational age, maternal age, or race. Maternal serum and urine specimens were prospectively obtained and analyzed for beta-glucuronidase, beta-hexosaminidase, alpha-galactosidase, beta-galactosidase, and alpha-mannosidase using fluorometric assays. Median serum and urine activities and fractional excretions of each of the five hydrolases were compared between the two study groups using the Mann-Whitney two-sample rank test. The serum enzyme activities of beta-hexosaminidase (P = 0.002), alpha-galactosidase (P = 0.0001), and alpha-mannosidase (P = 0.02) were significantly lower in preeclamptic patients than in controls. The urine enzyme activities of beta-glucuronidase (P = 0.001), alpha-galactosidase (P = 0.002), beta-galactosidase (P 0.0003), and alpha-mannosidase (P = 0.003) were significantly higher in the preeclamptic patients. The fractional enzyme excretions of all five lysosomal hydrolases were higher in preeclamptic patients than in controls with P < or = 0.0003 for each enzyme. Preeclampsia is associated with a significant decrease in serum activities of three of the five hydrolases studied, a significant increase in urine enzyme activities in four of the five hydrolases studied, and a significant increase in the fractional excretion of all five lysosomal hydrolases.

Alterations of intrauterine eicosanoid production in pregnancy-induced hypertension: decreased production of 12-hydroxyeicosatetraenoic acid in the placenta

The important role of eicosanoids in pregnancy-induced hypertension is generally accepted. Because of the lack of innervation of the uteroplacental vessels, humoral vasoactive factors are important for the regulation of vascular tone. Until now, mainly the balance of vasodilatative and vasoconstrictive prostaglandins has been studied. We were able to confirm their intrauterine imbalance in hypertensive pregnancies. In addition, the placental production of less known lipoxygenase metabolites has been analyzed in this study. Intrauterine tissues (30-100mg wet weight) were examined for their release of eicosanoids. Short term tissue cultures were performed in Hanks balanced salts solution (HBSS) at 37 degrees C in an atmosphere of 95% air/5% CO2 with and without incorporation of tritiated arachidonic acid. The arachidonate metabolites in culture media were analyzed by High Performance Liquid Chromatography (HPLC) with radioactivity detection or by enzyme immunoassays or radioimmunoassays, respectively. All intrauterine tissues released more lipoxygenase metabolites than cyclooxygenase metabolites with 12-hydroxy-eicosatetraenic acid (12-HETE) as their main metabolite. The placental release of 12-HETE was significantly decreased in hypertensive pregnancies. In hypertensive pregnancies the ratio TXB2/6-keto-PGF1 alpha synthesis was increased. Lipoxygenase metabolites, especially 12-HETE, seem to have important physiological and pathophysiological functions in the intrauterine compartment. Their biological role in this context needs further investigation.

Hypertension in pregnancy: hemodynamics and diurnal arterial pressure profile

OBJECTIVE

To characterize the 24-h arterial pressure (AP) profile and the left ventricular (LV) structures and functions in women with pregnancy-associated hypertension.

METHODS

Twenty nulliparous pregnant women after 20 weeks' gestation, 10 normotensive and 10 hypertensive women matched for gestational age, were hemodynamically investigated using 24-h AP monitoring and Doppler echocardiography to determine LV structures and functions, both systolic and diastolic.

RESULTS

The hypertensive women had significantly higher AP determinations throughout the 24 h, with no change in diurnal variation, i.e. nocturnal decline and early morning peaks. Their LV mass was greater and it was accompanied by a slight reduction in contractility and a significant reduction in LV relaxation. The increased AP was due to peripheral vasoconstriction, while cardiac output was preserved.

CONCLUSIONS

It appears that pregnancy-associated hypertension is caused mainly by arterial vasoconstriction and not by higher cardiac output. The hypertension increases the LV mass, which is associated with a fall in LV relaxation.

Hypertension in pregnancy

High blood pressure, which complicates approximately 10% of all pregnancies, remains a major cause of morbidity and mortality for both mother and fetus. A relative paucity of investigative data, as well as the frequent difficulty in making an etiological diagnosis by clinical criteria alone, may be among the reasons why there are many conflicts about the management of hypertension during pregnancy. This clinical conference summarizes current concepts regarding the hypertensive disorders of gestation, focusing on the most dangerous cause, preeclampsia-eclampsia. It further highlights a recent report of the Working Group on High Blood Pressure in Pregnancy convened by the National High Blood Pressure Education Program at the National Heart, Lung, and Blood Institute (the Consensus Report). Among the Working Group's most interesting recommendations in controversial areas were a return to the classification schema suggested by the American College of Obstetricians and Gynecologists in 1972, use of the fifth Korotkoff sound to determine diastolic blood pressure levels, and institution of treatment with antihypertensive drugs for sudden elevations of blood pressure near term to diastolic levels greater than or equal to 105 mm Hg or for levels of 100 mm Hg or higher in pregnant women with chronic hypertension. The Consensus Report further recommended parenteral hydralazine and methyldopa as the drugs of choice for the acute hypertensive crisis and management of chronic hypertension, respectively, based on the long histories of safe use of these agents in gravidas. Parenteral magnesium sulfate remained the preferred therapeutic approach for avoiding or treating the convulsive complication, eclampsia, but the Working Group underscored the need for controlled trials of magnesium's efficacy. Finally, they noted that diuretics should be avoided in preeclampsia, but that these drugs can be continued during gestation if taken before conception, and may be prescribed to pregnant women with chronic hypertension who appear overly salt sensitive.

New insights into the etiology of pre-eclampsia

Pre-eclampsia is a pregnancy-specific syndrome of unknown etiology, defined by clinical findings of elevated blood pressure combined with proteinuria and oedema. The decidual portion of the spiral arteries of women who later develop pre-eclampsia does not undergo the normal pregnancy-induced remodelling that converts these vessels to high volume-low resistance conduits. We have postulated that this failure leads to vascular spasm, restricted blood flow, placental ischaemia and the release of toxic substances that enter the maternal circulation, resulting in multi-organ disease. The complex and interwoven pathways of endocrine, paracrine and autocrine factors appear to result in a vicious cycle of endothelial cell dysfunction, which is expressed clinically as pre-eclampsia.

The kidney in hypertensive pregnancies--victim and villain

Many changes in renal function occur in normal pregnancy. Without a proper understanding of these changes, routine clinical investigations may easily be misinterpreted. Women with preeclampsia have further alterations in renal function and, in occasional cases, develop acute renal failure. Understanding of abnormal renal physiology and hormonal changes in these women allows the clinician to interpret biochemical tests appropriately and make proper use of vasodilator therapy with careful attention to volume homeostasis. Women who undertake pregnancy with a primary renal disease, most commonly glomerulonephritis or reflux nephropathy, have a higher risk of adverse fetal and maternal outcomes. Awareness of these risks provides a basis for proper preconceptual counseling, as well as careful monitoring of maternal blood pressure and renal function and fetal growth during such pregnancies. These strategies will optimize the chances of a successful pregnancy outcome for both mother and baby.