Acute Kidney Injury in Pregnancy: The Need for Higher Awareness. A Pragmatic Review Focused on What Could Be Improved in the Prevention and Care of Pregnancy-Related AKI, in the Year Dedicated to Women and Kidney Diseases

Characteristics and outcome of pregnancy-related acute kidney injury in a teaching hospital in a low-resource setting: a five-year retrospective review

BACKGROUND

Pregnancy-related kidney injury contributes to a high burden of acute kidney injury in low-resource settings and causes maternal and perinatal morbidity and mortality. Few studies have examined the impact of acute kidney injury in resource-limited countries, with very limited research on pregnancy-specific disorders in Ethiopia. This study aimed to determine the characteristics of pregnancy-related acute kidney injury, outcomes and associated factors.

METHODS

A retrospective study was conducted to evaluate the clinical profile and maternal-fetal outcome of pregnancy-related acute kidney injury at Ayder Comprehensive Specialized Hospital in Tigray, Ethiopia, from January 1, 2017, to December 31, 2021. Maternal and fetal outcomes were analyzed using descriptive statistics. Multivariate logistic regression was used to determine the association between the dependent and independent variables.

RESULTS

Of 27,350 mothers who delivered at Ayder Comprehensive Specialized Hospital between January 1, 2017, and December 31, 2021, a total of 187 women developed pregnancy-related acute kidney injury, a prevalence rate of 68 per 100,000 births. Preeclampsia, sepsis and pre-renal causes due to dehydration and hemorrhage were the most common causes of pregnancy-related acute kidney injury in this study. Hemodialysis was needed in 8.6% (n = 16) of patients. Of the 187 pregnancy-related acute kidney injuries, 143 (76.5%) recovered completely and 30 (16%) partially. The mortality rate was 7.5%. Preexisting chronic kidney disease (AOR = 30.13; 95% CI: 2.92, 310.84), use of vasoactive agents (AOR = 5.77; 95% CI: 1.47, 22.67), increase in creatinine per unit (AOR = 1.65; 95% CI: 1.11, 2.45) and complications related to acute kidney injury (AOR = 5.26; 95% CI: 1.73, 16.00) were determinants of the composite endpoints (partial renal recovery and death).

CONCLUSIONS

This study emphasizes acute kidney injury in resource-limited settings is a significant cause of maternal and fetal morbidity and mortality. The vast majority of patients with pregnancy-related acute kidney injury recovered completely from kidney injury. The main causes of pregnancy-related acute kidney injury were preeclampsia, sepsis and pre-renal associated with hemorrhage and dehydration. Preexisting renal disease, use of vasopressors, increase in creatinine per unit and complications associated with acute kidney injury were determining factors for concomitant fetomaternal mortality. Appropriate preventive strategies during prenatal care and prompt treatment are needed for pregnancy-related acute kidney injury.

Miscarriage-Related Acute Kidney Injury: A Case Report

Background

Pregnancy-related acute kidney injury (Pr-AKI) is associated with significant maternal and fetal morbidity and mortality, with a three- to four-fold increase in perinatal mortality. Pr-AKI can arise from various obstetric complications, such as hyperemesis gravidarum, septic abortion, hypertensive disorders of pregnancy, pyelonephritis, and antiphospholipid antibody syndrome. Therefore, early diagnosis and appropriate intervention, including the identification of the underlying etiology, are important to effectively manage Pr-AKI. Therefore, we report a case of Pr-AKI after early miscarriage in a patient without hyperemesis gravidarum or septic abortion whose renal function gradually improved postoperatively for miscarriage.

Case Presentation

A 34-year-old primigravid woman was referred to us for perinatal management at 6 weeks of gestation. Unfortunately, she was diagnosed with miscarriage 1 week later. The patient had no history of hyperemesis gravidarum or septic abortion; however, she developed oliguria, and her serum creatinine and blood urea nitrogen levels were abnormally increased. Consequently, she underwent a renal biopsy to evaluate renal dysfunction, which indicated tubulointerstitial damage. The patient also underwent manual vacuum aspiration for a miscarriage. Postoperatively, her urine output increased, and her renal function improved. She was determined to have experienced Pr-AKI due to her miscarriage.

Conclusion

Our patient had Pr-AKI after a miscarriage in the absence of other causes. This case report highlights the presence of unknown causes of Pr-AKI, warranting further research for the development of preventive interventions.

Characteristics and Outcomes of Patients With Pregnancy-Related End-Stage Kidney Disease

Importance

The incidence of pregnancy-related acute kidney injury is increasing and is associated with significant maternal morbidity including progression to end-stage kidney disease (ESKD). Little is known about characteristics and long-term outcomes of patients who develop pregnancy-related ESKD.

Objectives

To examine the characteristics and clinical outcomes of patients with pregnancy-related ESKD and to investigate associations between pre-ESKD nephrology care and outcomes.

Design, Setting, and Participants

This was a cohort study of 183 640 reproductive-aged women with incident ESKD between January 1, 2000, and November 20, 2020, from the US Renal Data System and maternal data from births captured in the US Centers for Disease Control and Prevention publicly available natality data. Data were analyzed from December 2022 to June 2023.

Exposure

Pregnancy-related primary cause of ESKD, per International Classification of Diseases, Ninth Revision (ICD-9) and ICD-10 codes reported at ESKD onset by the primary nephrologist on Centers for Medicare and Medicaid Services form 2728.

Main Outcomes Measures

Multivariable Cox proportional hazards and competing risk models were constructed to examine time to (1) mortality, (2) access to kidney transplant (joining the waiting list or receiving a live donor transplant), and (3) receipt of transplant after joining the waitlist.

Results

A total of 341 patients with a pregnancy-related primary cause of ESKD were identified (mean [SD] age 30.2 [7.3]). Compared with the general US birthing population, Black patients were overrepresented among those with pregnancy-related ESKD (109 patients [31.9%] vs 585 268 patients [16.2%]). In adjusted analyses, patients with pregnancy-related ESKD had similar or lower hazards of mortality compared with those with glomerulonephritis or cystic kidney disease (adjusted hazard ratio [aHR], 0.96; 95% CI, 0.76-1.19), diabetes or hypertension (aHR, 0.49; 95% CI, 0.39-0.61), or other or unknown primary causes of ESKD (aHR, 0.60; 95% CI, 0.48-0.75). Despite this, patients with pregnancy-related ESKD had significantly lower access to kidney transplant compared with those with other causes of ESKD, including (1) glomerulonephritis or cystic kidney disease (adjusted subhazard ratio [aSHR], 0.51; 95% CI, 0.43-0.66), (2) diabetes or hypertension (aSHR, 0.81; 95% CI, 0.67-0.98), and (3) other or unkown cause (aSHR, 0.82; 95% CI, 0.67-0.99). Those with pregnancy-related ESKD were less likely to have nephrology care or have a graft or arteriovenous fistula placed before ESKD onset (nephrology care: adjusted relative risk [aRR], 0.47; 95% CI, 0.40-0.56; graft or arteriovenous fistula placed: aRR, 0.31; 95% CI, 0.17-0.57).

Conclusion and Relevance

In this study, those with pregnancy-related ESKD had reduced access to transplant and nephrology care, which could exacerbate existing disparities in a disproportionately Black population. Increased access to care could improve quality of life and health outcomes among these young adults with high potential for long-term survival.

Gestational hypertension as a factor associated with chronic kidney disease: the importance of obstetric history of women undergoing hemodialysis

INTRODUCTION

Pregnancy-related complications may impact women's reproductive cycle and health through their lives. The objective of this study was to evaluate the sociodemographic, clinical, and obstetric history of women undergoing hemodialysis.

METHODS

We performed a cross-sectional study in a specialized health facility with four hemodialysis units. Sociodemographic characteristics, clinical and personal history, obstetric and perinatal results of women with pregnancies before hemodialysis were evaluated. Prevalence, bivariate, and logistic regression analyses were performed.

RESULTS

We included 208 (87.76%) women. Hypertension was the main cause of chronic kidney disease (CKD) (128 women). Rates of adverse perinatal outcomes, including prematurity, low birth weight, miscarriage, fetal death, and neonatal death, were 19.3%, 14.5%, 25.5%, 12.1%, and 5.3%, respectively. Hypertensive syndromes during pregnancy occurred in 37.0% of women, with 12.5% reporting preeclampsia and 1.4% reporting eclampsia. Up to 1 year after birth, 45.2% of women reported hypertension. Hemodialysis due to hypertension was associated with a history of hypertension during pregnancy (OR 2.33, CI 1.27 - 4.24), gestational hypertension (2.41, CI 3.30 - 4.45), and hypertension up to one year after birth (OR 1.98, CI 1.11 - 3.51). Logistic regression showed that gestational hypertension was independently associated with CKD due to hypertension (aOR 2.76, CI 1.45 - 5.24).

CONCLUSION

Women undergoing hemodialysis due to hypertension were more likely to have gestational hypertension or hypertension up to one year after birth. To delay end-stage renal disease, it is necessary to identify women at risk of kidney failure according to their reproductive history.

Pregnancy in Chronic Kidney Disease: Acute Kidney Injury in Pregnant Women and Management of Chronic Kidney Disease in the Pregnant Patient

Women pursue pregnancy with comorbidities such as hypertension and kidney disease, necessitating primary care physicians to remain up to date with current clinical practice. Hypertensive disorders of pregnancy pose risks to the pregnancy and to the woman in the short and long term. These risks and their management are detailed in this review. Normally, pregnancy is associated with hemodynamic and kidney-specific changes. Here the authors discuss these changes and review the impact and management of pregnancy-related acute kidney injury, chronic kidney disease, and dialysis in pregnant patients. Kidney transplant recipients may experience return of fertility and require counseling to improve outcomes.

Pregnancy and postpartum experiences of women undergoing hemodialysis: a qualitative study

INTRODUCTION

There are particularities of chronic kidney disease (CKD) in women and their treatment. The biology of women exposes them to greater risk factors for CKD and both pregnancy and the postpartum period place an additional burden on renal health. Pregnancy complications may cause or worsen CKD.

OBJECTIVE

To explore the experiences of women with CKD undergoing hemodialysis in relation to their reproductive history.

METHODS

This study consisted of clinical-qualitative design with semi-structured individual interviews and open-ended questions. The sample selection was intentional and according to the theoretical saturation criterion. The data analysis was carried out based on the seven steps of the clinical-qualitative content analysis and validated by Nvivo11. This study was conducted in a public hemodialysis clinic of the Brazilian National Health System.

RESULTS

Twelve women undergoing hemodialysis were interviewed. The results from the analysis revealed three categories: 1) Association of pregnancy with CKD; 2) Nebulosity in relation to diagnosis and reproductive history 3) Being a woman undergoing hemodialysis.

CONCLUSION

Our study showed the importance of considering the specificities of CKD in women, suggesting that these issues are important for diagnosis and treatment adherence. Consideration of reproductive life history allows the health of women undergoing hemodialysis to be promoted holistically, including aspects of mental health.

Ethnic disparities in pregnancy-related acute kidney injury in a United Kingdom population

BACKGROUND

The incidence of acute kidney injury in pregnancy (P-AKI) is rising and is associated with detrimental maternal and foetal outcomes. Ethnic disparities in pregnancy outcomes are well recognized, with females who identify as Black or Asian being more likely to die during pregnancy compared to females who identify as White ethnicity.

METHODS

This study reports rates of P-AKI and associated risk factors in pregnant females of different ethnicities. All pregnancies were recorded between 2016 and 2020. AKI episodes were identified using electronic alerts. Ethnicity, AKI stage (1-3), obstetric outcomes and risk factors for P-AKI (chronic hypertension, pregnancy-induced hypertension and pre-eclampsia, and haemorrhage) were assessed.

RESULTS

There were 649 P-AKI episodes from 16,943 deliveries (3.8%). Black females were more likely to have P-AKI (5.72%) compared to those who were White (3.12%), Asian (3.74%), mixed ethnicity (2.89%) and Other/Not Stated (3.10%). Black females, compared to White females, were at greater risk of developing P-AKI if they had haemorrhage requiring blood transfusion (OR 2.44, 95% CI 1.31,4.54; p < 0.001) or pregnancy-induced hypertension (OR 1.79, 95% CI 1.12, 2.86; p < 0.001). After adjusting for risk factors, Black females had increased risk of developing P-AKI (OR 1.52, 95% CI 1.22, 1.80; p < 0.001) compared to White females. Black females were at increased risk of developing P-AKI compared to White females. Mode of delivery, pregnancy-induced hypertension and haemorrhage are likely to have contributed. The increased risk persists despite accounting for these variables, suggesting that other factors such as socioeconomic disparities need to be considered.

CONCLUSIONS

The incidence of P-AKI is likely higher than previously stated in the literature. However, caution must be exercised, particularly with AKI stage 1, as the KDIGO system is not validated in pregnancy and gestational changes in renal physiology need to be considered. Pregnancy-specific AKI definitions are needed.

Kidney Biopsy in Pregnant Women with Glomerular Diseases: Focus on Lupus Nephritis

Despite significant improvements of renal and obstetrical management, pregnancies in women with glomerular diseases and with lupus nephritis continue to be associated with increased complications both for the mother and the fetus as compared to those of pregnancies in healthy women. To reduce the risk of these complications, planning pregnancy in a phase of stable remission of the underlining disease is necessary. A kidney biopsy is an important event in any phase of pregnancy. A kidney biopsy can be of help during counselling before pregnancy in cases of incomplete remission of the renal manifestations. In these situations, histological data may differentiate active lesions that require the reinforcement of therapy from chronic irreversible lesions that may increase the risk of complications. In pregnant women, a kidney biopsy can identify new-onset systemic lupus erythematous (SLE) and necrotizing or primitive glomerular diseases and distinguish them from other, more common complications. Increasing proteinuria, hypertension, and the deterioration of kidney function during pregnancy may be either due to a reactivation of the underlying disease or to pre-eclampsia. The results of the kidney biopsy suggest the need to initiate an appropriate treatment, allowing the progression of the pregnancy and the fetal viability or the anticipation of delivery. Data from the literature suggest avoiding a kidney biopsy beyond 28 weeks of gestation to minimize the risks associated with the procedure vs. the risk of preterm delivery. In case of the persistence of renal manifestations after delivery in women with a diagnosis of pre-eclampsia, a renal kidney assessment allows the final diagnosis and guides the therapy.

Hipertensão gestacional como fator associado à doença renal crônica: a importância do histórico obstétrico de mulheres submetidas à hemodiálise

RESUMO Introdução: Complicações relacionadas à gestação podem afetar o ciclo reprodutivo e a saúde das mulheres ao longo de suas vidas. Este estudo visou avaliar histórico sociodemográfico, clínico e obstétrico de mulheres em hemodiálise. Métodos: Realizamos estudo transversal em unidade de saúde especializada com quatro unidades de hemodiálise. Avaliou-se características sociodemográficas, histórico clínico e pessoal, resultados obstétricos e perinatais de mulheres com gestações anteriores à hemodiálise. Foram realizadas análises de prevalência, bivariadas e regressão logística. Resultados: Incluímos 208 (87,76%) mulheres. Hipertensão foi a principal causa de doença renal crônica (DRC) (128 mulheres). Taxas de desfechos perinatais adversos, incluindo prematuridade, baixo peso ao nascer, aborto espontâneo, óbito fetal e neonatal, foram de 19,3%, 14,5%, 25,5%, 12,1% e 5,3%, respectivamente. Síndromes hipertensivas durante a gestação ocorreram em 37,0% das mulheres, com 12,5% relatando pré-eclâmpsia e 1,4% relatando eclampsia. Até 1 ano após o parto, 45,2% das mulheres relataram hipertensão. Hemodiálise devido à hipertensão foi associada ao histórico de hipertensão na gestação (OR 2,33; IC 1,27 - 4,24), hipertensão gestacional (2,41; IC 3,30 - 4,45), e hipertensão até um ano após o parto (OR 1,98; IC 1,11 - 3,51). A regressão logística mostrou que hipertensão gestacional foi independentemente associada à DRC devido à hipertensão (ORa 2,76; IC 1,45 - 5,24). Conclusão: Mulheres submetidas à hemodiálise por hipertensão foram mais propensas a apresentar hipertensão gestacional ou hipertensão até um ano após o parto. Para retardar a doença renal em estágio terminal, deve-se identificar mulheres em risco de insuficiência renal de acordo com sua história reprodutiva.

Pregnancy-related acute kidney injury in the African continent: where do we stand? A systematic review

BACKGROUND

Pregnancy-Related Acute kidney injury (PR-AKI) is a global health problem with substantial maternal and fetal morbidity and mortality. However, little is known about the current situation in the developing world including African countries. Africa is the poorest continent per capita, and women from Sub-Saharan Africa alone account for 66% of the estimated global maternal deaths from preventable obstetric causes.

METHODS

OBJECTIVE: To review the literature on the clinical profile, maternal and renal outcomes of women with PR-AKI in the African continent.

SEARCH STRATEGY

Medline, ISI Web of Science, Scopus, and Cochrane library were searched in February 2022, using the MeSH terms and text key words: "pregnancy", "pregnant", "acute kidney injury", "acute renal insufficiency", "acute renal injury", "acute renal failure", and "Africa".

SELECTION CRITERIA AND DATA COLLECTION

Studies from African countries which reported maternal and renal outcomes in women with PR-AKI during pregnancy or postpartum were included. Editorials, short communications, and case reports were excluded. The study quality was assessed using the NHLBI tool. Data extraction was done using predefined data fields.

RESULTS

A total of 167 studies were evaluated, of which 14 studies from seven African countries met the inclusion criteria. Preeclampsia, obstetric hemorrhage, and sepsis represented the main causes of PR-AKI. Maternal mortality ranged between 0 and 34.4%. Although the majority of women needed ICU admission and hemodialysis, renal recovery occurred in 53.1-90% of patients. Perinatal mortality has been reported to be 1.5-60.5% in the included studies.

AUTHORS' CONCLUSIONS

PR-AKI in Africa represents the second leading cause of AKI. Limited access to obstetric care, late referral, and late diagnosis of women with risks for PR-AKI hinder the curtailment of the problem. Provision of health care facilities with adequately trained personnel and implementation of preventive strategies will be of great value in decreasing the magnitude of the problem.

Experiências de gravidez e puerpério de mulheres em hemodiálise: um estudo qualitativo

Resumo Introdução: Existem particularidades da doença renal crônica (DRC) em mulheres e seu tratamento. A biologia das mulheres as expõe a fatores de risco mais elevados para DRC e tanto a gravidez quanto o puerpério implicam um ônus adicional à saúde renal. Complicações na gestação podem causar ou piorar a DRC. Objetivo: Explorar as experiências de mulheres com DRC submetidas à hemodiálise em relação ao seu histórico reprodutivo. Métodos: Este estudo consistiu em desenho clínico-qualitativo com entrevistas individuais semiestruturadas e questões abertas. A seleção da amostra foi intencional e de acordo com o critério de saturação teórica. A análise de dados foi realizada com base nos sete passos da análise clínico-qualitativa de conteúdo e validada pelo Nvivo11. Este estudo foi realizado em uma clínica pública de hemodiálise do Sistema Único de Saúde brasileiro. Resultados: Foram entrevistadas 12 mulheres em hemodiálise. Os resultados da análise revelaram três categorias: 1) Associação da gravidez com DRC; 2) Nebulosidade em relação ao diagnóstico e à história reprodutiva; 3) Ser mulher e fazer hemodiálise. Conclusões: Nosso estudo mostrou a importância de considerar as especificidades da DRC em mulheres, sugerindo que estas questões são importantes para o diagnóstico e a adesão ao tratamento. A consideração do histórico de vida reprodutiva permite promover de forma holística a saúde das mulheres submetidas à hemodiálise, incluindo aspectos de saúde mental.

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.

The Hypertensive Disorders of Pregnancy: A Focus on Definitions for Clinical Nephrologists

About 5-10% of pregnancies are complicated by one of the hypertensive disorders of pregnancy. The women who experience these disorders have a greater risk of having or developing kidney diseases than women with normotensive pregnancies. While international guidelines do not provide clear indications for a nephrology work-up after pregnancy, this is increasingly being advised by nephrology societies. The definitions of the hypertensive disorders of pregnancy have changed greatly in recent years. The objective of this short review is to gather and comment upon the main definitions of the hypertensive disorders of pregnancy as a support for nephrologists, who are increasingly involved in the short- and long-term management of women with these disorders.

Renal Outcomes of Pregnancy-Related Acute Kidney Injury: a Single Centre Experience in India

Objective:This study aimed to investigate the incidence, clinical characteristics, and outcomes of acute kidney injury (AKI) during pregnancy in Indian population. Materials and methods:A prospective observational study was conducted in pregnant patients admitted to Pt. B.D. Sharma PGIMS, Rohtak, Haryana, India. Acute kidney injury was assessed using Risk, Injury, Failure, Loss of function, and End-stage renal disease (RIFLE) criteria. Patients were analyzed on the basis of demographic data, detailed history, clinical examination, and laboratory investigations. The primary outcome was maternal renal outcome, including return to normal renal function and progression to chronic kidney disease (CKD). The secondary outcomes included the mode of delivery, complications of pregnancy, intensive care unit (ICU) admission, and maternal death. Results:A total of 51 patients with an average age of 29.5 years were included in the present study. About 49.9% of subjects had severe anemia and 41.2% were primigravida. The main cause of AKI was pre-eclampsia and postpartum hemorrhage. There was a marked improvement in renal outcome with 33 patients having complete renal recovery and six patients developed CKD was observed during three months follow-up period. The peaked median value of blood urea was 62.0 mg% in patients with normal renal function, 178.5 mg% in those with CKD and 120.0 mg% in expired patients (P=0.001). A statistically significant change in serum potassium (P=0.010) and creatinine levels (P<0.001) was observed during the follow-up period. Liver enzymes, including serum glutamic oxaloacetic transaminase and serum glutamic pyruvic transaminase, were high in all patients at the time of admission, but decreased to normal on follow-up. Conclusion:Our study indicates that pregnancy-related AKI patients present with multiorgan complications and many of them require mechanical ventilation and renal replacement therapy. Most of these patients have poor outcome. Hence, the management of pregnancy-related AKI presents a challenge that requires proper evaluation of causative factors to facilitate appropriate treatment.

Acute kidney injury e-alerts in pregnancy: rates, recognition and recovery

BACKGROUND

Acute kidney injury (AKI) in pregnancy (Pr-AKI) is associated with substantial maternal morbidity and mortality. E-alerts are routinely used for detection of AKI in non-pregnant patients but their role in maternity care has not been explored.

METHODS

All pregnant or postpartum women with AKI e-alerts for AKI Stages 1-3 (Kidney Disease Improving Global Outcomes (KDIGO) criteria) were identified at a tertiary centre >2 years. Two women matched by delivery date for each case were selected as controls. AKI stage, recognition of AKI, pregnancy outcomes, renal recovery, AKI aetiology and risk factors were extracted from electronic patient records.

RESULTS

288 of 11 922 (2.4%) women had AKI e-alerts, of which only 118 (41%) were recognized by the obstetric team. Common Pr-AKI causes included infection (48%), pre-eclampsia (26%) and haemorrhage (25%), but no cause was identified in 15% of women. Renal function recovered in 213 (74%) women, but in 47 (17%) repeat testing was not undertaken and 28 (10%) did not recover function. Hypertensive disorders of pregnancy and Caesarean section were associated with increased incidence of Pr-AKI compared with controls.

CONCLUSIONS

Pr-AKI e-alerts were identified in ∼1 in 40 pregnancies. However, a cause for Pr-AKI was not identified in many cases and e-alerts may have been triggered by gestational change in serum creatinine. Pregnancy-specific e-alert algorithms may be required. However, 1 in 10 women with Pr-AKI had not recovered kidney function on repeat testing. Better understanding of long-term impacts of Pr-AKI on pregnancy and renal outcomes is needed to inform relevant Pr-AKI e-alert thresholds.

Acute kidney injury during pregnancy leads to increased sFlt-1 and sEng and decreased renal T regulatory cells in pregnant rats with HELLP syndrome

BACKGROUND

The incidence of acute kidney injury (AKI) during pregnancy precedes a high maternal mortality rate of 20-40%. AKI during pregnancy has multiple etiologies; however, the more common are maternal hypertensive disorders, which include preeclampsia and HELLP (hemolysis, elevated liver enzyme, low platelet) syndrome. Therefore, we sought to assess the impact of AKI on blood pressure, kidney injury, and anti-angiogenic factors during pregnancies with and without HELLP syndrome.

METHODS

On gestational day (GD) 12, mini-osmotic pumps were inserted into a subset of normal pregnant (NP) rats infusing 4.7 μg/kg soluble fms-like tyrosine kinase-1 (sFlt-1) and 7 μg/kg soluble endoglin (sEng) to induce HELLP syndrome. On GD18, the renal pedicles were occluded for 45 min to induce AKI via bilateral ischemia reperfusion in a subset of NP (n = 18) or HELLP (n = 20) rats. Control NP (n = 20) and HELLP (n = 20) rats underwent a SHAM surgery on GD18. Plasma, urine, and maternal organs were saved for further analysis. Renal injury was assessed via renal histopathology, glomerular filtration rate (GFR), T cell infiltration, and assessment of kidney injury molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL). Data was measured via two-way analysis of variance with Tukey's test for post hoc analysis.

RESULTS

Blood pressures were increased in HELLP+AKI rats (p = 0.0001); both NP+AKI and HELLP+AKI rats had increased lactate dehydrogenase (p < 0.0001) and aspartate aminotransferase levels (p < 0.0001), and decreased platelet levels (p < 0.001) vs. NP rats. HELLP+AKI (p = 0.002) and HELLP rats (p = 0.0002) had evidence of renal fibrosis vs. NP rats. GFR was decreased in HELLP+AKI (p = 0.01) rats vs. NP rats. Urinary KIM-1 was increased in NP+AKI rats vs. NP (p = 0.003) and HELLP rats (p = 0.01). HELLP+AKI rats had increased urinary KIM-1 vs. NP (p = 0.0008) and HELLP rats (p = 0.004) and increased NGAL vs. HELLP rats (p = 0.002). HELLP+AKI rats had increased sFlt-1 (p = 0.009) vs. NP rats. NP+AKI (p = 0.02) and HELLP+AKI (p = 0.007) rats had increased sEng vs. NP rats. CD3+CD4+ T cells were significantly increased in HELLP+AKI rats vs. NP (p = 0.0002) and NP+AKI (p = 0.05) rats. T regulatory cells were significantly decreased in HELLP+AKI (p = 0.03) and NP+AKI (p = 0.02) rats vs. NP rats; there were no changes between groups in T helper 17 cells (p = 0.34).

CONCLUSION

The findings in this study suggest that AKI during pregnancy contributes to increased blood pressure and biochemical markers for HELLP syndrome, creates an anti-angiogenic imbalance, and exacerbates kidney injury as shown on histopathology, GFR, and kidney injury markers.

Racial and Ethnic Disparities in Pregnancy-Related Acute Kidney Injury

BACKGROUND

Pregnancy-related AKI (PR-AKI) is increasing in the United States. PR-AKI is associated with adverse maternal outcomes. Disparities in racial/ethnic differences in PR-AKI by race have not been studied.

METHODS

This was a retrospective cohort study using the National Inpatient Sample (NIS) from 2005 to 2015. We identified patients who were admitted for a pregnancy-related diagnosis using the Neomat variable provided by the NIS database that indicates the presence of a maternal or neonatal diagnosis code or procedure code. PR-AKI was identified using ICD codes. Survey logistic regression was used for multivariable analysis adjusting for age, medical comorbidities, socioeconomic factors, and hospital/admission factors.

RESULTS

From 48,316,430 maternal hospitalizations, 34,001 (0.07%) were complicated by PR-AKI. Hospitalizations for PR-AKI increased from 3.5/10,000 hospitalizations in 2005 to 11.8/10,000 hospitalizations in 2015 with the largest increase seen in patients aged ≥35 and black patients. PR-AKI was associated with higher odds of miscarriage (adjusted odds ratio [aOR], 1.64; 95% CI, 1.34 to 2.07) and mortality (aOR, 1.53; 95% CI, 1.25 to 1.88). After adjustment for age, medical comorbidities, and socioeconomic factors, blacks were more likely than whites to develop PR-AKI (aOR, 1.17; 95% CI, 1.04 to 1.33). On subgroup analyses in hospitalizations of patients with PR-AKI, blacks and Hispanics were more likely to have preeclampsia/eclampsia compared with whites (aOR, 1.29; 95% CI, 1.01 to 1.65; and aOR, 1.69; 95% CI, 1.23 to 2.31, respectively). Increased odds of mortality in PR-AKI compared with whites were only seen in black patients (aOR, 1.61; 95% CI, 1.02 to 2.55).

CONCLUSIONS

The incidence of PR-AKI has increased and the largest increase was seen in older patients and black patients. PR-AKI is associated with miscarriages, adverse discharge from hospital, and mortality. Black and Hispanic patients with PR-AKI were more likely to have adverse outcomes than white patients. Further research is needed to identify factors contributing to these discrepancies.

Acute Kidney Injury in Pregnancies Complicated With Preeclampsia or HELLP Syndrome

Acute kidney injury that occurs during pregnancy or in the post-partum period (PR-AKI) is a serious obstetric complication with risk of significant associated maternal and fetal morbidity and mortality. Recent data indicates that the incidence of PR-AKI is increasing, although accurate calculation is limited by the lack of a uniform diagnostic criteria that is validated in pregnancy. Hypertensive and thrombotic microangiopathic disorders of pregnancy have been identified as major contributors to the burden of PR-AKI. As is now accepted regarding preeclampsia, HELLP syndrome and atypical hemolytic uremic syndrome, it is believed that PR-AKI may have long-term renal, cardiovascular and neurocognitive consequences that persist beyond the post-partum period. Further research regarding PR-AKI could be advanced by the development of a pregnancy-specific validated definition and classification system; and the establishment of refined animal models that would allow researchers to further elucidate the mechanisms and sequelae of the disorder.

Acute kidney injury associated with preeclampsia or hemolysis, elevated liver enzymes, and low platelets syndrome

OBJECTIVE

To determine the prevalence of acute kidney injury (AKI), placental abruption and postpartum hemorrhage in patients with preeclampsia or HELLP syndrome.

STUDY DESIGN

A retrospective study of patients with preeclampsia or HELLP syndrome treated at the University of Mississippi Medical Center from January 2000 through December 2010.

MAIN OUTCOME MEASURES

Relationships among the obstetric complications of placental abruption, postpartum hemorrhage, and AKI (serum creatinine >107 µmol/L) of women with preeclampsia or HELLP syndrome. Additional analysis was undertaken to explore if there was a correlation between postpartum hemorrhage/placental abruption and the severity of HELLP syndrome according to the Mississippi classification system.

RESULTS

Data from 1276 women over 11 years were included in the analysis. 67 of 466 patients (14.4%) with HELLP syndrome and 38 of 810 preeclampsia patients (4.7%) met criteria for AKI. Women with either placental abruption or postpartum hemorrhage had statistically significant increased odds of also having AKI (p < 0.01). Women with HELLP and AKI were also more likely to experience either placental abruption or postpartum hemorrhage. Women with Class 1 HELLP with placental abruption or postpartum hemorrhage were also more likely to have AKI than women with preeclampsia.

CONCLUSION

HELLP syndrome, AKI and placental abruption or postpartum hemorrhage appear to be interrelated. AKI occurs more frequently in women with HELLP syndrome with or without associated postpartum hemorrhage and placental abruption.

The Changing Landscape of Acute Kidney Injury in Pregnancy from an Obstetrics Perspective

Pregnancy-related acute kidney injury (PR-AKI) is a heterogeneous disorder with multiple aetiologies that can occur at any time throughout pregnancy and the post-partum period. PR-AKI is an important obstetric complication that is associated with significant maternal and foetal morbidity and mortality. Although there has been an overall decline in the incidence of PR-AKI worldwide, a recent shift in the occurrence of this disease has been reported. Following improvements in obstetric care, PR-AKI incidence has been reduced in developing countries, whereas an increase in PR-AKI incidence has been reported in developed countries. Awareness of the physiological adaptations of the renal system is essential for the diagnosis and management of kidney impairment in pregnancy. In this review we scrutinize the factors that have contributed to the changing epidemiology of PR-AKI and discuss challenges in the diagnosis and management of acute kidney injury (AKI) in pregnancy from an obstetrics perspective. Thereafter we provide brief discussions on the diagnostic approach of certain PR-AKI aetiologies and summarize key therapeutic measures.

Delayed Initiation of Hemodialysis in Pregnant Women with Chronic Kidney Disease: Logistical Problems Impact Clinical Outcomes. An Experience from an Emerging Country

Background: Chronic kidney disease (CKD) is associated with reduction of fertility and increased complications during pregnancy. The aim of this work is to analyze the clinical outcomes and risk factors in pregnant women who needed to start dialysis with different schedules in a public hospital in Mexico City, with particular attention on the interference of social and cultural elements as well as resource limitations. Material and methods: CKD women who needed dialysis in pregnancy over the period 2002–2014 and had with complete demographic and outcome data were included in this retrospective study. Clinical background, renal function during pregnancy, dialysis schedule, and clinical outcomes were reviewed. Results: Forty pregnancies in women with CKD who needed dialysis in pregnancy (39 singleton and one twin pregnancy) were studied: All patients were treated with hemodialysis. Thirty-nine patients had CKD stages 4 or 5 at referral; only one patient was of stage 3b. Dialysis was considered as indicated in the presence of fluid overload, unresponsive hypertension in the setting of advanced CKD, or when blood urea nitrogen values were increased to around 50 mg/dL. However, the initiation of dialysis was often delayed by days or weeks. The main reason for delaying the initiation of dialysis was patient (and family) refusal to start treatment. All patients were treated with thrice weekly dialysis, in 3–5 h sessions, with a target urea of <100 mg/dL. The number of hours on dialysis did not impact pregnancy outcomes. Ten pregnancies ended in miscarriages (8 spontaneous), 29 in pre-term delivery, and 1 in term delivery. Fifteen women were diagnosed with preeclampsia, one with eclampsia, and one with HELLP (hemolysis, elevated liver enzymes, low platelets,) syndrome. Twenty-four of the neonates survived (77.4% of live births); six singletons and one twin died as a consequence of prematurity. Two neonates displayed malformations: cleft palate with ear anomalies and duodenal atresia. Conclusions: CKD requiring hemodialysis in pregnancy is associated with a high frequency of complications; in the setting of delayed start and of thrice-weekly hemodialysis, dialysis schedules do not appear to influence outcomes.