OBJECTIVES: To determine if the normal gestational changes in mechanical properties of the arterial system are altered in pre-eclampsia. DESIGN: Prospective controlled observational study. SETTING: University urban tertiary medical centre. POPULATION: Eleven pre-eclamptics and 10 chronic hypertensives with superimposed pre-eclampsia were compared with 14 normotensive gravidas experiencing preterm labour, all receiving MgSO(4). Two additional control groups were studied as well: (A) nine normal pregnant women receiving neither magnesium nor epidural, for baseline comparisons; and (B) eight normotensive gravidas receiving epidural anaesthesia. METHODS: Two-dimensional targeted M-mode echocardiograms and continuous wave Doppler velocity were used to obtain instantaneous pressure and flow data. Total vascular resistance (TVR) quantified the steady component of systemic arterial load; pulsatile arterial load was characterised by global arterial compliance (AC), aortic input impedance spectrum (Z(1)) and characteristic impedance (Z(0)). MAIN OUTCOME MEASURES: TVR, AC, Z(1), Z(0). RESULTS: Controls, pre-eclamptics and chronic hypertensives with superimposed pre-eclampsia, respectively: TVR index 1328 [299], 1973 [609]*, 2428 [562]*(,#) dyn second cm(-5) m(2); AC area index 1.69 [0.46], 1.19 [0.46]*, 0.93 [0.38]* mL mmHg(-1) m(-2); Z(0) index 253.2 [61.3], 327.0 [135.1], 307.5 [130.9] dyn second cm(-5) m(2); and Z(1) index 184.2 [56.5], 283.6 [81.6]*, 357.1 [119.5]* dyn second cm(-5) m(2) (*P < 0.05 vs control;(#)P < 0.05 vs pre-eclampsia). Normal gravidas (in secondary controls group A) had decreased mean systolic and diastolic blood pressures, and increased AC and cardiac indices, compared with women receiving magnesium tocolysis, verifying the need for these primary controls. No differences were noted between normotensive gravidas receiving epidural anaesthesia (secondary controls group B) and the non-anesthetised controls (group A), eliminating epidural as a confounder. CONCLUSIONS: The normal gestational changes in systemic arterial mechanical properties are significantly altered in pre-eclampsia and these alterations are more marked with superimposed hypertensive disease.

Adult↗

PubMed2004

The renal response to preeclampsia.

Proteinuria and decreased renal function are classic hallmarks of preeclampsia. The kidney, with its reliance on glomerular blood flow and glomerular barrier integrity, provides a unique window to view the preeclamptic disease process. This review briefly details the characteristic renal structural changes seen in preeclampsia and then focuses on the disordered renal hemodynamics and other determinants of ultrafiltration. Both renal blood flow and glomerular filtration rate (GFR) decrease in preeclampsia, although absolute values may remain above the nonpregnant range. A decrease in the ultrafiltration coefficient (K f ), in the order of 50%, either alone or in combination with reduced renal blood flow, is presented as the most likely mechanism for the decrease in GFR. Proteinuria develops, at least in part, secondary to impaired glomerular barrier integrity with a loss of size selectivity revealed by fractional dextran clearance studies and it is proposed, although yet to be proven, that this is accompanied by a loss of glomerular barrier charge selectivity.

Female↗

PubMed2004

Glomerular endotheliosis in normal pregnancy and pre-eclampsia.

Explore the source record for details and available documents.

Biopsy↗

PubMed2003

Summary of the NHLBI Working Group on Research on Hypertension During Pregnancy.

A Working Group on Research in Hypertension in Pregnancy was recently convened by the National Heart Lung and Blood Institute to determine the state of knowledge in this area and suggest appropriate directions for research. Hypertensive disorders in pregnancy, especially preeclampsia, are a leading cause of maternal mortality worldwide and even in developed countries increase perinatal mortality five-fold. Much has been learned about preeclampsia but gaps in the knowledge necessary to direct therapeutic strategies remain. Oxidative stress is a biologically plausible contributor to the disorder that may be amenable to intervention. Hypertension that antedates pregnancy (chronic hypertension) bears many similarities to hypertension in nonpregnant women but the special setting of pregnancy demands information to guide evidence based therapy. The recommendations of the Working Group are to attempt a clinical trial of antioxidant therapy to prevent preeclampsia that is be complemented by mechanistic research to increase understanding of the genetics and pathogenesis of the disorder. For chronic hypertension clinical trials are recommended to direct choice of drugs, evaluate degree of control and assess implications to the mother and fetus. Recommendations to increase participation in this research are also presented.

Adult↗

PubMed2003

Glomerular ultrafiltration in normal and preeclamptic pregnancy.

GFR and renal plasma flow (RPF) decrease in preeclampsia, a serious hypertensive complication of pregnancy. Serial data derived in late pregnancy (LP) and >5 mo postpartum (PP) in 13 healthy controls and 10 preeclamptic women (13 and 5, respectively) returning PP for theoretical analysis of neutral dextran sieving curves (theta(D)), are presented and are used to calculate the key determinants of glomerular ultrafiltration. Normal LP hyperfiltration was associated with increases in RPF and the ultrafiltration coefficient (K(f)), as well as in the nondiscriminatory shunt pathway (omega(0)) and the SD of pore size (S). Preeclamptic LP showed the largest omega(0) and S values, indicating a loss of size-selectivity, accompanying reduced K(f) and RPF, both of which are implicated in the relative hypofiltration. Despite a 100-fold increase in urinary albumin excretion (UAE), LP preeclamptic theta(D) values were reduced for the equivalent neutral dextran (36A), providing indirect evidence for a loss of glomerular barrier charge-selectivity. All the determinants of GFR and all modeled parameters were comparable across both groups PP, strong evidence that preeclamptic glomerular dysfunction resolves.

Albuminuria↗

PubMed2002

Adverse perinatal outcomes are significantly higher in severe gestational hypertension than in mild preeclampsia.

OBJECTIVE: The current literature emphasizes increased risk of adverse outcomes in the presence of proteinuria and hypertension. The objective of this study was to compare the frequency of adverse fetal outcomes in women who developed hypertensive disorders with or without proteinuria. STUDY DESIGN: The study design was a secondary analysis of data from women who had preeclampsia in a previous pregnancy (n = 598) who were enrolled in a multicenter trial of aspirin for the prevention of preeclampsia. The women had no history of chronic hypertension or renal disease and were normotensive at study inclusion. The maternal and perinatal outcome variables assessed were preterm delivery at <37 and <35 weeks of gestation, rate of small-for-gestational-age infants, and abruptio placenta. Data were analyzed by using the chi-square test, and women who remained normotensive or who had mild gestational hypertension were considered as a single group because they had similar outcomes. RESULTS: As compared to mild preeclampsia, women who developed severe gestational hypertension (without proteinuria) had higher rates of both preterm delivery at <37 weeks of gestation and small-for-gestational-age infants. In addition, when compared to women with mild preeclampsia, for women with severe gestational hypertension, gestational age and birth weight were significantly lower at delivery (P <.003 for both age and birth weight). Moreover, women who developed severe gestational hypertension had higher rates of preterm delivery at <37 weeks of gestation (54.2% vs 17.8%, P =.001) and at <35 weeks of gestation (25.0% vs 8.4%, P =.0161), and delivery of small-for-gestational-age infants (20.8% vs 6.5%, P =.024) when compared to women who remained normotensive or those who developed mild gestational hypertension. There were no statistically significant differences in perinatal outcomes between the normotensive/mild gestational hypertension and the mild preeclampsia groups. Overall, women who had severe gestational hypertension had increased rates of preterm delivery and delivery of small-for-gestational-age infants than women with mild gestational hypertension or mild preeclampsia. In the presence of severe hypertension, proteinuria did not increase the rates of preterm delivery or delivery of small-for-gestational-age infants. CONCLUSIONS: In women who have gestational hypertension or preeclampsia, increased rates of preterm delivery and delivery of small-for-gestational-age infants are present only in those with severe hypertension. In these women, the presence of proteinuria does not influence perinatal outcome.

Adult↗

PubMed2002

Perinatal outcome in women with recurrent preeclampsia compared with women who develop preeclampsia as nulliparas.

OBJECTIVE: To compare the rates and perinatal outcome in women who experienced preeclampsia in a previous pregnancy to those in women who developed preeclampsia as nulliparas. STUDY DESIGN: This is a secondary analysis of data from 2 separate multi-center trials of aspirin for prevention of preeclampsia. Women who had preeclampsia in a previous pregnancy (n = 598) were compared with nulliparous women (n = 2934). Outcome variables were rates of preeclampsia, preterm delivery at <37 and <35 weeks of gestation, small-for-gestational-age infant, abruptio placentae, and perinatal death. Data were compared by using chi-square analysis and Wilcoxon rank sum test. RESULTS: The rates of preeclampsia and of severe preeclampsia were significantly higher in the previous preeclamptic group as compared to the nulliparous group (17.9% vs 5.3%, P <.0001, and 7.5% vs. 2.4%, P <.0001, respectively). Women who had recurrent preeclampsia experienced more preterm deliveries before 37 and 35 weeks of gestation than nulliparous women who developed preeclampsia. In addition, among women who developed severe preeclampsia, those with recurrent preeclampsia had higher rates of preterm delivery both before 37 weeks (67% vs 33%, P =.0004) and before 35 weeks of gestation (36% vs 19%, P =.041), and higher rates of abruptio placentae (6.7% vs 1.5%) and fetal death (6.7% vs 1.4%) than did nulliparous women. CONCLUSION: Compared to nulliparous women, women with preeclampsia in a previous pregnancy had significantly higher rates of preeclampsia and adverse perinatal outcomes associated with preterm delivery as a result of preeclampsia.

Abruptio Placentae↗