Microalbuminuria after pregnancy complicated by pre-eclampsia

The management of hypertension in pregnancy

Hypertensive pregnancy disorders complicate 6% to 8% of pregnancies and cause significant maternal and fetal morbidity and mortality. The goal of treatment is to prevent significant cerebrovascular and cardiovascular events in the mother without compromising fetal well-being. Current guidelines differentiate between the treatment of women with acute hypertensive syndromes of pregnancy and women with preexisting chronic hypertension in pregnancy. This review will address the management of hypertension in pregnancy, review the various pharmacologic therapies, and discuss the future directions in this field.

Association between hypertensive disorders during pregnancy and end-stage renal disease: a population-based study

BACKGROUND

Studies into the association between hypertensive disorders during pregnancy and end-stage renal disease are limited. We investigated the risk of end-stage renal disease after delivery among women with hypertensive disorders during pregnancy.

METHODS

We used insurance claims data from 1998 to 2009 to identify 26,651 women aged 19-40 years old who experienced hypertensive disorders during pregnancy; these women had no history of hypertension, diabetes, kidney disease or lupus. We also randomly selected 213,397 women without hypertensive disorders during pregnancy as a comparison cohort; the frequency was matched by age and index year of pregnancy. We compared the incidence of end-stage renal disease in the 2 cohorts. We calculated hazard ratios (HRs) and 95% confidence intervals (CIs) after controlling for demographic and clinical factors.

RESULTS

Women with hypertensive disorders during pregnancy had a greater risk of chronic kidney disease and end-stage renal disease, with adjusted HRs of 9.38 (95% CI 7.09-12.4) and 12.4 (95% CI 8.54-18.0), respectively, after controlling for urban status, coronary artery disease, congestive heart failure, hyperlipidemia and abruption. The HR for end-stage renal disease was 2.72 (95% CI 1.76-4.22) after we also controlled for hypertension and diabetes. Women with preeclampsia or eclampsia had a higher risk of end-stage renal disease (adjusted HR 14.0, 95% CI 9.43-20.7) than women who had gestational hypertension only (adjusted HR 9.03, 95% CI 5.20-15.7).

INTERPRETATION

Women with hypertensive disorders during pregnancy were at a high risk of end-stage renal disease. The risk was much greater for women who had preeclampsia or eclampsia than those who had gestational hypertension only.

Renal evaluation in women with preeclampsia

BACKGROUND/AIMS

Preeclampsia (PE) is a cause of glomerulopathy worldwide. Urinary retinol-binding protein (RBP) is a marker of proximal tubular dysfunction, albuminuria is an endothelial injury marker, urine protein:creatinine ratio (PCR) may have a predictive value for renal disease later in life, and, recently, podocyturia has been proposed as a sensitive tool in pregnancy, but it needs to be tested. The aim of this study was to evaluate renal involvement in PE and healthy pregnancy.

METHODS

Case-control study with 39 pregnant women assessed after 20 weeks of gestation (25 in the control group, CG, and 14 in the PE group) by performing urinary tests.

RESULTS

Mean (±SD) age and gestational age of the CG were 26.9 ± 6.4 years and 37.1 ± 5.0 weeks, and of the PE group 26.4 ± 6.9 years and 30.6 ± 5.6 weeks, respectively (p = 0.001). Mean (±SD) urinary RBP (p = 0.017), albuminuria (p = 0.002), and urinary albumin concentration (UAC) ratio (p = 0.006) of the CG were 0.4 ± 0.7 mg/l, 7.3 ± 6.9 mg/l, and 8.2 ± 6.7 mg/g and of the PE group 2.0 ± 4.4 mg/l, 2,267.4 ± 2,130.8 mg/l (p = 0.002), and 3,778.9 ± 4,296.6 mg/g (p = 0.006), respectively. Mean (±SD) urine PCR in the PE group was 6.7 ± 6.1 g/g (p < 0.001). No statistical differences were found between podocyturia in the CG and PE group (p = 0.258).

CONCLUSIONS

Urinary RBP, PCR, albuminuria, and UAC ratio were elevated in the PE group in comparison to the CG. Podocyturia did not predict PE.

Long-term outcomes of kidney donors

As the demand for kidney transplantation, particularly from living donors, continues to rise, there is increasing and much needed interest in accurately quantifying the long-term risks of kidney donation. We review the outcomes of kidney donors in the domains of survival, perioperative mortality, risk of end-stage renal disease, quality of life, course of diabetes mellitus in donors, pregnancy after donation, obesity, and prevalence of other health conditions.

Renin angiotensin signaling in normal pregnancy and preeclampsia

Many reports indicate that there is an increase in almost all of the components of the renin-angiotensin system (RAS) during an uncomplicated pregnancy, but renin activity, angiotensin II, and aldosterone decrease in preeclampsia (PE) for reasons that are unclear. PE is a life-threatening disorder of late pregnancy characterized by hypertension, proteinuria, increased soluble fms-like tyrosine kinase-1, as well as renal and placental morphologic abnormalities. Although a leading cause of maternal and perinatal morbidity and mortality, the pathogenic mechanisms of PE remain largely undefined. Immunologic mechanisms and aberrations of the RAS have been long considered contributors to the disorder. Bridging these two concepts, numerous studies report the presence of the angiotensin II type I receptor agonistic autoantibody (AT(1)-AA) found circulating in preeclamptic women. This autoantibody induces many key features of the disorder through AT(1) receptor signaling, and has been implicated in the pathogenesis of PE. Here we review the functions of the RAS during normal pregnancy and PE, and highlight the role of AT(1)-AA in both animal models and in the human disorder.

Pregnancy outcome in women with chronic kidney disease: a prospective cohort study

OBJECTIVE

To evaluate pregnancy outcome in women with chronic kidney disease (CKD) or proteinuria in early pregnancy with concomitant risk for preeclampsia (PE).

METHODS

Thirty-six women with CKD (Cr > 100 μmol/L at booking or Cr > 125 μmol/L prepregnancy or proteinuria ≥ 500 mg/24 hours at booking) and 30 women with proteinuria (≥2+) and known clinical risk for PE were enrolled at 14(+0) to 21(+6) weeks. Pregnancy outcomes were assessed.

RESULTS

Women with mild CKD (prepregnancy Cr < 125 µmol/Cr > 100 µmol at booking; n = 22) had high rates of preeclampsia (40%), preterm delivery (<37 weeks' gestation; 54%), SGA infants (<10th adjusted centile; 64%)and perinatal death (5%). Women with moderate/severe CKD (prepregnancy creatinine > 125 µmol; n = 14) had poor perinatal outcomes: preterm delivery (86%) and perinatal death (14%). Women with proteinuria (≥2+) and concomitant risk of PE also had high rates of pre-eclampsia (60%), preterm delivery (40%), and SGA infants (27%).

CONCLUSIONS

Pregnancy complications for women with CKD remain high. Women with risk factors for PE with proteinuria (≥2+) at booking are also high-risk.

Molecular and vascular targets in the pathogenesis and management of the hypertension associated with preeclampsia

Normal pregnancy is associated with significant hemodynamic changes and vasodilation of the uterine and systemic circulation in order to meet the metabolic demands of the mother and developing fetus. Preeclampsia (PE) is one of the foremost complications of pregnancy and a major cause of maternal and fetal mortality. The pathophysiological mechanisms of PE have been elusive, but some parts of the puzzle have begun to unravel. Genetic factors such as leptin gene polymorphism, environmental and dietary factors such as Ca(2+) and vitamin D deficiency, and co-morbidities such as obesity and diabetes may increase the susceptibility of pregnant women to develop PE. An altered maternal immune response may also play a role in the development of PE. Although the pathophysiology of PE is unclear, most studies have implicated inadequate invasion of cytotrophoblasts into the uterine artery, leading to reduced uteroplacental perfusion pressure (RUPP) and placental ischemia/hypoxia. Placental ischemia induces the release of biologically active factors such as growth factor inhibitors, anti-angiogenic factors, inflammatory cytokines, reactive oxygen species, hypoxia-inducible factors, and antibodies to vascular angiotensin II (AngII) receptor. These bioactive factors could cause vascular endotheliosis and consequent increase in vascular resistance and blood pressure, as well as glomerular endotheliosis with consequent proteinuria. The PE-associated vascular endotheliosis could be manifested as decreased vasodilator mediators such as nitric oxide, prostacyclin and hyperpolarizing factor and increased vasoconstrictor mediators such as endothelin-1, AngII and thromboxane A₂. PE could also involve enhanced mechanisms of vascular smooth muscle contraction including intracellular Ca(2+), and Ca(2+) sensitization pathways such as protein kinase C and Rho-kinase. PE-associated changes in the extracellular matrix composition and matrix metalloproteinases activity also promote vascular remodeling and further vasoconstriction in the uterine and systemic circulation. Some of these biologically active factors and vascular mediators have been proposed as biomarkers for early prediction or diagnosis of PE, and as potential targets for prevention or treatment of the disease.

Hypertension in pregnancy: a comprehensive update

Hypertensive disorders of pregnancies remain a central public health concern throughout the world, and are a major cause of maternal mortality in the developing world. Although treatment options have not significantly changed in recent years, insight on the pathogenesis of preeclampsia/eclampsia has been remarkable. With improved animal models of preeclampsia and large-scale human trials, we have embarked upon a new era where angiogenic biomarkers based on mechanism of disease can be designed to assist in early diagnosis and treatment. There is also a growing recognition of how elusive the diagnosis of eclampsia can be, especially in the postpartum period. Proper treatment of these patients depends heavily on the correct diagnosis, especially by the emergency physician. Finally, large epidemiologic studies have revealed that preeclampsia, once thought to be a self-limited entity, now appears to portend real damage to the cardiovascular and other organ systems in the long term. This review will present the latest update on our understanding of the various hypertensive disorders of pregnancies and their treatment options.

[Late prognosis after preeclampsia]

Preeclampsia, eclampsia and HELLP syndrome are severe complications of pregnancy associated with a high morbidity and mortality for both mother and foetus. The issue of prognosis with regards to risk of relapse is therefore of upmost importance for both the patients and doctors managing their subsequent pregnancies. The overall risk of relapse is estimated to be less than 10%. The risk is especially increased in case of early onset, before the 28(th) week of amenorrhea. In such patients, an underlying renal disease, essential hypertension or secondary hypertension might be identified. A renal consultation must ensure the complete resolution of the hypertension and proteinuria, otherwise investigations need to be carried out looking for an underlying renal or vascular disease affecting the renal parenchyma or outflow. Screening for a hereditary thrombophilia is performed in the immediate post-partum period following and early onset PE, especially if associated with an IUGR, fetal death, or in an early and severe relapse. A renal biopsy is only rarely considered: it is either performed within the first post-partum days whenever a systemic disease flare-up is suspected (i.e. SLE), or late if the proteinuria failed to settle beyond 6 months post-part. Severe PE is a marker of a vascular disease of short duration, but must be considered a risk factor for later atherosclerosis with cardiovascular complications, justifying long term cardiovascular, renal and metabolic follow-up.

PROTEINURIA IN PREECLAMPSIA: FROM BENCH TO BEDSIDE

Pre-eclampsia (PE) remains the leading cause of maternal and fetal mortality in the developed world and parts of the developing world. Morbidity and mortality from PE is increased in the developing world compared to the developed world, as availability and access to antenatal care and pathology services are limited.

Pregnancy outcomes after kidney donation

The outcome of pregnancy in kidney donors has generally been viewed to be favorable. We determined fetal and maternal outcomes in a large cohort of kidney donors. A total of 2102 women have donated a kidney at our institution; 1589 donors responded to our pregnancy surveys; 1085 reported 3213 pregnancies and 504 reported none. Fetal and maternal outcomes in postdonation pregnancies were comparable to published rates in the general population. Postdonation (vs. predonation) pregnancies were associated with a lower likelihood of full-term deliveries (73.7% vs. 84.6%, p = 0.0004) and a higher likelihood of fetal loss (19.2% vs. 11.3%, p < 0.0001). Postdonation pregnancies were also associated with a higher risk of gestational diabetes (2.7% vs. 0.7%, p = 0.0001), gestational hypertension (5.7% vs. 0.6%, p < 0.0001), proteinuria (4.3% vs. 1.1%, p < 0.0001) and preeclampsia (5.5% vs. 0.8%, p < 0.0001). Women who had both pre- and post-donation pregnancies were also more likely to have these adverse maternal outcomes in their postdonation pregnancies. In this large survey of previous living donors in a single center, fetal and maternal outcomes and pregnancy outcomes after kidney donation were similar to those reported in the general population, but inferior to predonation pregnancy outcomes.

A history of preeclampsia identifies women who have underlying cardiovascular risk factors

OBJECTIVE

The objective of this study was to prospectively assess physical and biochemical cardiovascular risk markers in women who had developed preeclampsia (PE) at 1 year postpartum.

STUDY DESIGN

Following an overnight fast, previously PE (n = 70) and normotensive women (n = 70) had weight and blood pressure recorded and levels of morning blood for insulin, glucose, C-reactive protein, lipids, cholesterol, and urine for microalbumin and creatinine measured. Body mass index, homeostatic model assessment index, and incidence of metabolic syndrome were determined.

RESULTS

At 1 year postpartum, markers of cardiovascular disease were different between the groups. There were also differences in the number of women with abnormal values. Mathematical modeling of cardiovascular event risk suggests that PE increases the risk by 2- to 3-fold; the risk was greatest for women with severe PE.

CONCLUSION

The development of PE is 1 of the earliest clinically identifiable markers of a woman's heightened risk of cardiovascular disease.

Preeclampsia and the risk of end-stage renal disease

BACKGROUND

It is unknown whether preeclampsia is a risk marker for subsequent end-stage renal disease (ESRD).

METHODS

We linked data from the Medical Birth Registry of Norway, which contains data on all births in Norway since 1967, with data from the Norwegian Renal Registry, which contains data on all patients receiving a diagnosis of end-stage renal disease (ESRD) since 1980, to assess the association between preeclampsia in one or more pregnancies and the subsequent development of ESRD. The study population consisted of women who had had a first singleton birth between 1967 and 1991; we included data from up to three pregnancies.

RESULTS

ESRD developed in 477 of 570,433 women a mean (+/-SD) of 17+/-9 years after the first pregnancy (overall rate, 3.7 per 100,000 women per year). Among women who had been pregnant one or more times, preeclampsia during the first pregnancy was associated with a relative risk of ESRD of 4.7 (95% confidence interval [CI], 3.6 to 6.1). Among women who had been pregnant two or more times, preeclampsia during the first pregnancy was associated with a relative risk of ESRD of 3.2 (95% CI, 2.2 to 4.9), preeclampsia during the second pregnancy with a relative risk of 6.7 (95% CI, 4.3 to 10.6), and preeclampsia during both pregnancies with a relative risk of 6.4 (95% CI, 3.0 to 13.5). Among women who had been pregnant three or more times, preeclampsia during one pregnancy was associated with a relative risk of ESRD of 6.3 (95% CI, 4.1 to 9.9), and preeclampsia during two or three pregnancies was associated with a relative risk of 15.5 (95% CI, 7.8 to 30.8). Having a low-birth-weight or preterm infant increased the relative risk of ESRD. The results were similar after adjustment for possible confounders and after exclusion of women who had kidney disease, rheumatic disease, essential hypertension, or diabetes mellitus before pregnancy.

CONCLUSIONS

Although the absolute risk of ESRD in women who have had preeclampsia is low, preeclampsia is a marker for an increased risk of subsequent ESRD.

Course of preeclamptic glomerular injury after delivery

We evaluated the early postpartum recovery of glomerular function over 4 wk in 57 women with preeclampsia. We used physiological techniques to measure glomerular filtration rate (GFR), renal plasma flow, and oncotic pressure (πA) and computed a value for the two-kidney ultrafiltration coefficient ( Kf). Compared with healthy, postpartum controls, GFR was depressed by 40% on postpartum day 1, but by only 19% and 8% in the second and fourth postpartum weeks, respectively. Hypofiltration was attributable solely to depression, at corresponding postpartum times, of Kf by 55%, 30%, and 18%, respectively. Improvement in glomerular filtration capacity was accompanied by recovery of hypertension to near-normal levels and significant improvement in albuminuria. We conclude that the functional manifestations of the glomerular endothelial injury of preeclampsia largely resolve within the first postpartum month.

Renal and vascular function in women with previous preeclampsia: A comparison of low- and high-degree proteinuria

The degree of proteinuria during preeclampsia has been considered to be a marker of severity of the disease and of endothelial dysfunction. The aim of the study was to assess whether the degree of proteinuria in preeclamptic pregnancy is related to impairment of vascular dilatation and/or kidney function years after the index pregnancy. Thirty women with a history of severe preeclampsia divided into low (n=8, dU-prot <5 g/day) and high (n=22, dU-prot >/=5 g/day) proteinuric groups and 21 women with previous normotensive pregnancy were studied 5-6 years after index pregnancy. Renal function and blood pressure were assessed together with venous occlusion plethysmography, where changes in brachial artery blood flow, induced by intra-arterial infusions of an endothelium-independent (sodium nitroprusside) and an endothelium-dependent (acetylcholine) vasodilator, were measured. The results showed similar renal function in all groups. There was no difference in vasodilation between preeclamptic groups and controls or correlation between degree of proteinuria during index pregnancy and present vasodilation. We conclude that the degree of proteinuria during preeclampsia does not predict vascular dilatation or renal function 5-6 years after preeclamptic pregnancy.

3-5 year longitudinal follow-up of pediatric patients after acute renal failure

Few data exist regarding the long-term sequelae of acute renal failure (ARF), and these studies are limited to a few renal conditions. We aim to assess the 3-5-year survival and incidence of renal injury in children who previously developed ARF of varying causes. We queried parents, physicians, and hospital/state vital statistics records to find patient survival in 174 children who previously had ARF and survived to hospital discharge. We assessed the following in 29 children for residual renal injury: (a) microalbuminuria, (b) glomerular filtration rate (GFR) by Schwartz formula, (c) hypertension, and (d) hematuria. The 3-5-year survival of children with ARF who survived to hospital discharge was 139/174 (79.9%). Most deaths (24/35 (68.5%)) occurred within 12 months after initial hospitalization. Combining those who died during initial hospitalization and in subsequent 3-5 years, the overall survival rate was 139/245 (56.8%). In all, 16 children progressed to end-stage renal disease; thus, renal survival was 127/173 (91%). Those with primary renal/urologic conditions had lower renal survival than others (24/35 (68.6%) vs 134/139 (96.4%); P<0.0001). Among the 29 patients assessed for long-term sequelae at 3-5 years, 17/29 (59%) subjects had at least one sign of renal injury; microalbuminuria (n=9), hyperfiltration (n=9), decreased GFR (n=4), and hypertension (n=6). A pediatric nephrologist was involved in care of only 6/17 (35%) with chronic renal injury. Patients have high risks of ongoing residual renal injury and death after ARF; therefore, periodic evaluation after the initial insult is necessary.

Subclinical signs of vascular damage relate to enhanced platelet responsiveness among nonpregnant formerly preeclamptic women

OBJECTIVE

In nonpregnant formerly preeclamptic women, the prevalence of occult cardiovascular abnormalities is increased. These high-risk women mildly benefit from low-dose aspirin in the prevention of recurrent disease. How this effect is mediated, either by affecting platelet or vascular function, is still unsettled. In this study, we tested the hypothesis that in these nonpregnant women, enhanced platelet responsiveness is common and related to microvascular damage.

STUDY DESIGN

At least 6 months' postpartum we evaluated in 66 formerly preeclamptic women platelet count, volume, and in vitro response to low-dose ADP (0.5 microg/mL). Peripheral levels of fibronectin (microg/mL), von Willebrand factor antigen (%), C-reactive protein (high-sensitive CRP, mg/L), urinary albumin, and protein (24-hour collection, g/mol creatinine) served as markers of vascular damage. Hemodynamic function was determined by plasma volume (iodine I 125 HSA indicator dilution method, mL/kg lean body mass), cardiac index (Doppler, mL/min/m2), blood pressure and heart rate (Dinamap [Critikon, Tampa, FL], mm Hg and beats/min, respectively). Thereafter, we subdivided these 66 women into 2 subgroups either with (n = 10, 15%) or without increased platelet responsiveness (n = 56, 85%). Both groups were compared nonparametrically.

RESULTS

Groups were comparable with respect to age, blood pressure, body mass index, parity, plasma volume, and cardiac index. Women with enhanced platelet responsiveness had higher levels of circulation fibronectin and CRP, and displayed more often albuminuria and proteinuria. In addition, even though platelet count was comparable between groups, the mean platelet volume was higher among women with enhanced platelet responsiveness.

CONCLUSION

Fifteen percent of formerly preeclamptic women had enhanced platelet responsiveness, which was associated with elevated levels of various markers for (micro) vascular damage. We speculate that in these women platelets are presensitized on a relatively dysfunctional endothelium. Although this association does not prove causality, these results may indicate a subgroup of women who benefit from low-dose aspirin in the prevention of recurrent disease in a next pregnancy.

Adverse perinatal outcome and later kidney biopsy in the mother

Strong associations of adverse perinatal outcomes have been identified with later cardiovascular disease in the mother. Few studies have addressed associations with kidney disease. This study investigated whether perinatal outcomes are associated with later clinical kidney disease as diagnosed by kidney biopsy. The Medical Birth Registry of Norway contains data on all childbirths in Norway since 1967. The Norwegian Kidney Biopsy Registry contains data on all kidney biopsies in Norway since 1988. All women with a first singleton delivery from 1967 to 1998 were included. Pregnancy-related predictors of later kidney biopsy were analyzed by Cox regression analyses. A total of 756,420 women were included, and after a mean period of 15.9+/-9.4 yr, 588 had a kidney biopsy. Compared with women without preeclampsia and with offspring with birth weight of >or=2.5 kg, women with no preeclampsia and with offspring with birth weight of 1.5 to 2.5 kg had a relative risk (RR) for a later kidney biopsy of 1.7, women with no preeclampsia and with offspring with birth weight of <1.5 kg had an RR of 2.9, women with preeclampsia and with offspring with a birth weight of >or=2.5 kg had an RR of 2.5, women with preeclampsia and with offspring with a birth weight of 1.5 to 2.5 kg had an RR of 4.5, and women with preeclampsia and with offspring with a birth weight of <1.5 kg had an RR of 17. Similar results were found in adjusted analyses and after exclusion of women with diabetes, kidney disease, or rheumatic disease before pregnancy. The same risk patterns applied to any of the specific categories of kidney disease as well as specific kidney diseases investigated. Women who have preeclampsia and give birth to offspring with low birth weight and short gestation have a substantially increased risk for having a later kidney biopsy.