Pregnancy-related acute kidney injury: An analysis of 165 cases

Acute Kidney Injury in Pregnancy: A Prospective Study

INTRODUCTION

When acute kidney damage occurs during pregnancy, it poses a difficult clinical problem. One of the main causes of maternal and fetal morbidity and death is pregnancy-related acute kidney injury (AKI), a significant obstetric complication characterized by a fast deterioration in renal function and several subsequent clinical problems. The objective of the study is to analyze the etiological factors, clinical manifestations, and maternal and fetal outcomes of AKI during pregnancy.

MATERIALS AND METHODS

This prospective observational research involved patients hospitalized in the General Medicine and Obstetrics and Gynecology departments at Indira Gandhi Institute of Medical Sciences, Patna, for a year (October 2021 to September 2022) due to obstetric difficulties resulting in acute renal damage.

RESULTS

The study included 62 patients with a mean age of 25.08±4.25 years. The majority of patients in our study were aged 18-25 years (38, 61.3%), followed by 26-30 years (19, 30.6%) and >30 years (5, 8.1%). The majority of patients in our study were non-booked (52, 83.9%) and presented as emergency cases, whereas 10 (16.1%) patients had booked. In addition, 34 (54.8%) patients were primigravida, while 28 (45.1%) were multigravida. There were 25 patients in their third trimester (40.3%), 19 who were postpartum (30.6%), 10 who were post-abortion (16.1%), and eight in their second trimester (12.9%). Upon admission, the majority of the patients showed signs of oliguria, accounting for 45 cases (72.6%). This was followed by nine cases of abnormal kidney function (14.5%) and eight cases of anuria (12.9%). Among the other symptoms, fever was observed in 25 cases (40.32%), whereas breathlessness increased to 15 cases (24.19%), edema was present in 14 cases (22.58%), vomiting and altered sensorium were observed in four cases (6.45%), abdominal pain was observed in three cases (4.83%), and burning micturition was observed in two cases (3.22%). The most common causes of AKI in pregnancy in the present study were puerperal sepsis (18 cases, 29.0%), followed by preeclampsia/eclampsia (14 cases, 22.6%), hemorrhagic shock (10 cases, 16.1%), septic abortion (six cases, 9.7%), hyperemesis gravidarum (four cases, 6.5%), acute fatty liver of pregnancy (three cases, 4.8%), disseminated intravascular coagulation (three cases, 4.8%), drug-induced sepsis (two cases, 3.2%), and urosepsis (two cases, 3.2%). Modes of delivery in this study were normal vaginal delivery (32 cases, 51.6%), lower segment cesarean section (21 cases, 33.9%), dilation and evacuation (seven cases, 11.3%), and total hysterectomy (two cases, 3.2%). Hemodialysis was performed in 39 patients (62.9%), and 51 (82.3%) received blood transfusions. The mean systolic and diastolic BP (mmHg) were 111.37±22.60 and 71.40±18.88, respectively. Maternal outcome data revealed that 48 (77.4%) women had fully recovered, eight (12.9%) had not recovered, 43 (69.4%) were lost to follow-up, and two (3.2%) had died. Neonatal outcomes in the present study were as follows: live birth, 43 (69.4%); abortion, eight (12.9%); intrauterine death of the fetus, five (8.1%); and neonatal mortality, six (9.7%).

CONCLUSION

The diagnosis and treatment of AKI during pregnancy is a significant challenge for the treating physician because of the pathophysiological changes that occur during pregnancy, the variability of symptoms, and the fact that clinical and laboratory features may occasionally overlap.

Role of antenatal care in reducing the risk of postpartum acute kidney injury

Objective

Antenatal visits play a very important role to diagnose and manage pregnancy related health issues. This study was an attempt to identify the reasons that increase the risk of postpartum acute kidney Injury with special focus on antenatal care.

Methods

We analyzed 110 patients in Nephrology and Gynaecology wards in Lahore General Hospital. Out of these 40 had Postpartum Acute Kidney Injury and 70 patients did not have it. Questionnaire regarding aspects of antenatal care (demographics, timing and number of antenatal visits) was filled by the patient or immediate family members.

Results

Mean age of the 110 patients was 26.45 years. Mean Duration of pregnancy in the control group was 36.12 weeks and in cases it was 31.62 weeks. Out of 110 patients, 36(32.72%) patients did not have any antenatal visit while 62(56.3%) patients had more than five visits. Out of the 40 Postpartum Acute Kidney Injury patients, 23(57.5%) patients did not get any antenatal care. Out of 70 patients without Postpartum Acute Kidney Injury, 13 did not have any antenatal care. There were 19 patients who did not have booked visits because of financial Issues, followed by lack of awareness in 12 patients, distance issues for three patients and lack of family support for two patients.

Conclusion

Patients who did not have antenatal care were at an increased risk of developing PPAKI. Financial issues and lack of awareness were the most common risk factors for compromised antenatal care.

Causes and outcome of pregnancy related acute kidney injury

Objective

To determine frequencies of causes and renal outcomes of pregnancy related acute kidney injury.

Method

This descriptive case series study was conducted in Nephrology unit of a tertiary care hospital of Peshawar, from 1st August 2021 to 31st July 2022.A total of 100 patients with acute kidney injury secondary to obstetric conditions were enrolled via non-probability consecutive sampling technique. While patients with pre-existing renal disease, those with renal stones, or having bilateral small kidneys on ultrasound were excluded from the study. Patients were followed till 12 weeks postpartum period. Underlying obstetrical causes and outcome at 12 weeks postnatal period were determined.

Results

The mean age of sample of 100 cases was 29.29 ± 6.45. Mean serum creatinine at presentation was 6.5± 3.13. Majority of patient, 89% were multigravidas. Seventy eight percent patients required hemodialysis. Primary postpartum hemorrhage remained the commonest underlying cause of pregnancy related acute kidney injury in this study. The frequency of persistent renal failure in Pr-AKI (pregnancy related acute kidney injury) in this study was 14%. In about 66% of cases complete recovery occurred. All the underlying obstetrical causes, when adjusted for age, gravidity, place and mode of delivery, had no association with persistent renal failure.

Conclusion

Primary postpartum hemorrhage is the predominant cause of pregnancy related acute kidney injury. By the end of 12 weeks postpartum, two third patients recover completely from pregnancy related acute renal injury.

Risk factors and fetomaternal outcome in pregnancy-related acute kidney injury

Introduction

Pregnancy-related acute kidney injury (PRAKI) is acute kidney injury (AKI) occurring during pregnancy, labor, and postpartum period. AKI is defined as suddenly impaired kidney function with the retention of nitrogenous and other waste products. In high population country like India, not all deliveries are done tertiary care. Even not all are registered one if delivery is conducted at a hospital setup. The majority of patients are being managed by available obstetrician at local places. Early diagnosis and timely management of complications related to pregnancy are very important to avoid PRAKI. We aim to study maternal risk factors and fetomaternal outcome in PRAKI.

Materials and Methods

A prospective study is conducted between 2021 and 2022 in the Department of Obstetrics and Gynaecology, VMMC, and Safdarjung Hospital, New Delhi. For antenatal and delivered women up to 6 weeks, 50 patients were recruited according to KDIGO (Kidney Disease International Global Outcomes) criteria. Patients were followed with CBC, serum electrolytes, serial KFT, urine input/output monitoring, and USG-KUB. Dialysis was done if indicated. Complete renal recovery was considered if S.Cr ≤1.0 mg/dl within 6 weeks of diagnosis of AKI. For statistical significance, a P value of less than 0.05 was considered.

Results

The majority of patients were unbooked, 21-25 years of age, and belonged to lower socioeconomic status (54%). Risk factors were: preeclampsia (28%), puerperal sepsis (24%), PPH (20%), abruption (14%), pyelonephritis (4%), acute gastroenteritis (4%), gestational hypertension with superimposed preeclampsia (2%), antepartum eclampsia (2%), and thrombotic microangiopathy (2%). Hemodialysis is required in 23 (46%). Complete renal recovery was seen in 40 (80%) and partial renal recovery in 3 (6%). Maternal mortality was 14% and causes were: puerperal sepsis (57%), preeclampsia with severe features with MODS (29%), and antepartum eclampsia with hepatorenal failure (14%). Fetal outcome: 76% live birth, 24% intrauterine death, and 16% early neonatal death.

Conclusion

Most common risk factors for PRAKI are preeclampsia followed by puerperal sepsis and PPH where all are preventable causes.

Clinical characteristics and prognosis of pregnancy-related acute kidney injury: a case series study

OBJECTIVE

Acute kidney injury (AKI) seriously affects the health of both pregnant women and fetuses. This study aimed to investigate the clinical characteristics and prognosis of pregnancy-related AKI (PR-AKI).

METHODS

This case series study enrolled pregnant women with PR-AKI admitted to the surgical intensive care unit of Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine between January 2010 and December 2020.

RESULTS

Thirty-one PR-AKI patients were enrolled with a mean age of 29.16 ± 4.97 years. Seventeen pregnant women (54.84%) had complete recovery of renal function, 5 (16.13%) had partial recovery of renal function, 2 (6.45%) patients had no renal function improvement, and 7 (22.58%) died. Among the 31 patients with 35 fetuses, 25 (80.6%) pregnant women had poor fetal outcomes, including 5 cases of stillbirths, 5 neonatal asphyxia, 18 premature births, 10 low birth weight, and 8 deficient birth weight infants. Compared to cases with good fetal outcomes, cases with poor fetal outcomes had significantly shorter gestational weeks (39.26 ± 1.53 vs. 31.62 ± 5.50, P = 0.002), lower platelet count (217.13 ± 122.87 vs. 90.24 ± 84.88, P = 0.005), lower hemoglobin (94.19 ± 13.21 vs. 74.48 ± 20.78, P = 0.036), higher blood urea nitrogen (11.87 ± 4.28 vs. 19.47 ± 10.98, P = 0.013), and higher uric acid (262.41 ± 167.00 vs. 586.87 ± 144.52, P < 0.001).

CONCLUSIONS

The maternal renal function of women with PR-AKI might improve after treatment, but occurrence rates of adverse fetal outcomes were still high.

Preeclampsia pathophysiology and adverse outcomes during pregnancy and postpartum

Background

Preeclampsia is a disease with far-reaching consequences that extend beyond the immediate postpartum period and have a significant impact later in life. Preeclampsia exerts an effect on most organ systems in the body. These sequelae are mediated in part by the incompletely elucidated pathophysiology of preeclampsia and the associated vascular changes.

Content

Current research focuses on unraveling the pathophysiology of preeclampsia with the goal of implementing accurate screening and treatment modalities based on disease development and progression. Preeclampsia causes significant short- and long-term maternal morbidity and mortality, not only in the cardiovascular system but also in other organ systems throughout the body. This impact persists beyond pregnancy and the immediate postpartum period.

Summary

The goal of this review is to discuss the current understanding of the pathophysiology of preeclampsia as it relates to the adverse health consequences in patients impacted by this disease, along with a brief discussion of ways to improve overall outcomes.

Etiology of Pregnancy-related Acute Kidney Injury among Obstetric Patients in India: A Systematic Review

Background

Pregnancy-related acute kidney injury (PRAKI) is an important cause of fetomaternal mortality and morbidity in developing countries. We undertook a systematic review to identify the causes of PRAKI among obstetric patients in India.

Materials and methods

We systematically searched PubMed, MEDLINE, Embase, and Google Scholar using appropriate search terminology between 1 January 2010 to 31 December 2021. Studies reporting the etiology of PRAKI among obstetric patients (pregnant and within 42 days postpartum) in India were included for evaluation. Studies done in any other geographical location besides India were excluded. We also excluded studies done in any one trimester or any specific subgroup of patients [e.g., postpartum acute kidney injury (AKI), postabortal AKI]. A five-point questionnaire was used to assess the risk of bias in included studies. The results were synthesized as per preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines.

Results

A total number of 7 studies with 477 participants were included for analysis. All were single-center descriptive observational studies either done in tertiary care public or private hospitals. Sepsis (mean, 41.9%; median, 49.4%; and range, 6-56.1%) was the most common cause of PRAKI followed by hemorrhage (mean, 22.1%; median, 23.5%; and range, 8.3-38.5%) and pregnancy-induced hypertension (mean, 20.9%; median, 20.7; and range, 11.5-39%). Among these seven studies, five were of moderate quality, one was of high quality, and another one was of low quality. Our study is limited due to the lack of consensus definition of PRAKI in literature and heterogeneity in reporting methods. Our study highlights the need for a structured reporting format for PRAKI to understand the true disease burden and take control measures.

Conclusion

There is a moderate quality of evidence to suggest that sepsis followed by hemorrhage and pregnancy-induced hypertension are the commonest causes of PRAKI in India.

How to cite this article

Gautam M, Saxena S, Saran S, Ahmed A, Pandey A, Mishra P, et al. Etiology of Pregnancy-related Acute Kidney Injury among Obstetric Patients in India: A Systematic Review. Indian J Crit Care Med 2022;26(10):1141-1151.

Incidence of acute kidney injury during pregnancy and its prognostic value for adverse clinical outcomes: A systematic review and meta-analysis

BACKGROUND

Acute kidney injury (AKI) that develops during pregnancy results from pregnancy-induced hypertension, hemorrhage, and sepsis, associated with morbidity and mortality in the fetus and mother. This meta-analysis was conducted to evaluate the incidence of pregnancy-related AKI (PR-AKI) and adverse clinical outcomes.

METHODS

PubMed and Scopus were systematically searched for studies published between 1980 and 2021. We included cross-sectional, retrospective, and prospective cohort studies that reported the incidence of PR-AKI as well as adverse fetal and maternal clinical outcomes. A random-effects model meta-analysis was performed to generate summary estimates.

RESULTS

The meta-analysis included 31 studies (57,529,841 participants). The pooled incidence of PR-AKI was 2.0% (95% confidence interval [CI] 1.0-3.7). Only 49.3% of patients received antenatal care. The most common cause of PR-AKI was preeclampsia (36.6%, 95% CI 29.1-44.7). The proportion of patients requiring hemodialysis was 37.2% (95% CI 26.0-49.9). More than 70% of patients had complete recovery of renal function, while 8.5% (95% CI 4.7-14.8) remained dependent on dialysis. The pooled mortality rate of PR-AKI was 12.7% (95% CI 9.0-17.7). In addition, fetal outcomes were favorable, with an alive birth rate of 70.0% (95% CI 61.2-77.4). However, the rate of abortion and/or stillbirth was approximately 25.4% (95% CI 18.1-34.4), and the rate of intrauterine death was 18.6% (95% CI 12.8-26.2).

CONCLUSIONS

Although the incidence of PR-AKI is not high, this condition has a high impact on morbidity and mortality in both fetal and maternal outcomes. Early prevention and treatment from health care professionals are needed in PR-AKI, especially in the form of antenatal care and preeclampsia medication.

Kidney-Placenta Crosstalk in health and disease

Organ crosstalk allows the interaction between systems to adapt to a constant changing environment, maintaining homeostasis. The process of placentation and the new hormonal environment during pregnancy trigger physiological changes that modulate kidney function to control extracellular volume, acid-base balance, and filtration of metabolic waste products. The bidirectional communication means that acute or chronic dysfunction of one organ can compromise the other. Abnormal placentation in pregnancy-related hypertensive disorders such as pre-eclampsia and HELLP (haemolysis, elevated liver enzymes and low platelet count) syndrome leads to the release of antiangiogenic factors that may cause kidney injury (thrombotic microangiopathy, glomeruloendotheliosis, mesangiolysis and vasoconstriction of peritubular vessels). These hypertensive disorders are a key cause of kidney injury in gestation, which increases maternal morbi-mortality and adverse foetal outcomes. Conversely, prior kidney injury or causes of kidney injury (diabetes, lupus, glomerulonephritis or other form of chronic kidney disease) increase the risk of developing hypertensive pregnancy disorders, providing a baseline higher risk. Inherited kidney diseases are a special concern, given the potential for genetic predisposition to kidney disease in the foetus. Understanding the bidirectional potential for compromise from placenta to kidney and vice versa provides a better framework to limit damage to both organs and improve maternal and foetal outcomes.

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.

Feto-maternal outcome of pregnancy related acute kidney injury in a North Indian population

BACKGROUND

Acute kidney injury (AKI) is a serious complication in pregnancy, resulting in significant maternal and fetal morbidity/mortality. The aim of this study was to evaluate the magnitude of pregnancy-related AKI (PRAKI) in a North Indian population, and its contributing factors.

MATERIALS AND METHODS

This prospective study was carried out at the department of obstetrics and gynecology in collaboration with the nephrology unit and internal medicine department at King George Medical University from June 2019 to October 2020. After informed consent and ethical clearance, a total of 150 PRAKI women were enrolled, and 98 women were subjected to renal replacement therapy as per Kidney Disease Improving Global Outcomes 2012 guideline and were followed for 3 months for renal and fetomaternal outcome.

RESULTS

There was a high incidence (1.02%) of AKI during pregnancy and puerperium. Majority (57.3%) of the women were aged 26-30 years, and 93.3% had institutional deliveries. About 49% of the women suffering from PRAKI were multipara, and most were identified in the postpartum period (82%). Hypertensive disorder of pregnancy (48%), puerperal sepsis (45%), and hemorrhage (34%) were the associated causes for PRAKI. Stillbirth/intrauterine death (IUD) was higher in Stage II (53.8%) and Stage III AKI (37.7%) (none in Stage I AKI). The majority of the neonates were born with a birth weight of ≤2500 g irrespective of the stages of AKI. Preterm deliveries were significantly higher in Stage II AKI (53.8%) than in Stage I (33.3%) and Stage III (20.0%). Thirty-seven cases of PRAKI were managed conservatively, while 98 required dialysis. Complete recovery occurred in 27.3% and partial renal recovery in 31.3%. However, 3.3% progressed to chronic kidney disease, 34% expired, and 4% were lost to follow-up. High maternal mortality of 30.1% was observed in those dialyzed.

CONCLUSION

AKI is associated with fetal growth restriction and preterm deliveries. Stillbirth/IUD is higher in Stage II and Stage III AKI.

Maternal-Perinatal Variables in Patients with Severe Preeclampsia Who Develop Acute Kidney Injury

Introduction: At present, we are witnessing an increase in preeclampsia, especially the most severe forms, which are associated with an increased risk of maternal-perinatal morbidity and mortality. As a severity criterion, acute kidney injury (AKI) has been associated with a worse prognosis, and for this reason, the maternal and perinatal variables associated with AKI in patients with severe preeclampsia (SP) were analysed in this study. Methods: An observational, retrospective, single-centre study of patients with SP treated at a tertiary hospital between January 2007 and December 2018 was conducted. The case criteria based on the criteria established by the ACOG Practice Guidelines for Gestational Hypertension and Preeclampsia. AKI is considered when serum creatinine exceeds 1.1 mg/dL in a pregnant woman with previously normal renal function. In patients with existing chronic kidney disease (CKD), it is referred to as AKI if the baseline serum creatinine increases by 1.5 fold. Pregestational, gestational and postpartum variables were analysed up to 12 weeks postpartum using univariate and multivariate logistic regression analysis. Results: During the study period, 76,828 births were attended, and 303 pregnant women were diagnosed with SP. The annual incidence of SP increased gradually throughout the study period, reaching 1.79/100 births/year in 2018. Acute kidney injury (AKI) occurred in 24.8% of the patients. The multivariate analysis revealed an increased association with a history of previous CKD, the use of assisted reproductive techniques and caesarean section. Uric acid and thrombotic microangiopathy (TMA) had a high correlation with AKI. Indications for caesarean section are associated with AKI in SP. Regarding perinatal outcomes in cases of AKI, there was a higher percentage of neonates who required foetal lung maturation with steroids and an increased need for NICU admission. No case of maternal death was recorded; however, an increase in neonatal mortality was found among patients who did not develop AKI. After 12 weeks postpartum, 72 patients were referred to the nephrology consultation for persistent hypertension, proteinuria or renal failure. Conclusions: In preeclampsia, AKI is a common complication, especially among patients with a history of CKD, those who became pregnant using assisted reproduction techniques and those who delivered via caesarean section. The perinatal impact of AKI is mainly centred on a higher rate of NICU admission and a lower mortality rate. Among biochemical and haematological markers, the uric acid level prior to renal failure has a direct and significant correlation with the risk of AKI, as does the development of TMA in patients with preeclampsia. Therefore, the monitoring of renal function in cases of preeclampsia should be strict, and referral for a nephrology consultation may be necessary in some cases.

Acute kidney injury during pregnancy and puerperium: an Egyptian hospital-based study

INTRODUCTION

While acute kidney injury (AKI) in pregnancy is currently a rare entity in developed countries, it is still a common occurrence in developing countries, representing a major cause of maternal and fetal morbidity and mortality. Scarce data are published regarding pregnancy-related acute kidney injury (PRAKI) in Middle Eastern and African countries. The aim of this work is to report on the frequency, the underlying causes, and the outcomes of patients with PRAKI in an Egyptian tertiary care hospital.

METHODS

This is a prospective observational study that included 40 patients representing all women who presented to the Mansoura Nephrology and Dialysis Unit with PRAKI over two years. All patients were followed up for three months after hospital discharge to assess renal outcome, and till the end of pregnancy to assess the maternal and fetal outcomes.

RESULTS

PRAKI was reported  in about 1% of women who presented to the obstetrics service, and accounted for 14% of all AKI patients who presented to the renal service in our hospital. Preeclampsia (PE) and obstetric hemorrhage were the commonest causes of PRAKI. Maternal mortality occurred in 22.5% of PRAKI patients. The majority of survivors (62.5%) fully recovered, while the remaining (37.5%) individuals became dialysis dependent. Unfavorable fetal events occurred in 24 pregnancies (60%).

CONCLUSION

In our hospital in Mansoura, Egypt, PRAKI represents a relevant burden with potential ominous outcomes obstetric hemorrhage and preeclampsia were the major causes. Further research is needed to understand the causes and improve the outcomes of pregnancy-related AKI.

Bioenergetics adaptations and redox homeostasis in pregnancy and related disorders

Pregnancy is a challenging physiological process that involves maternal adaptations to the increasing energetics demands imposed by the growing conceptus. Failure to adapt to these requirements may result in serious health complications for the mother and the baby. The mitochondria are biosynthetic and energy-producing organelles supporting the augmented energetic demands of pregnancy. Evidence suggests that placental mitochondria display a dynamic phenotype through gestation. At early stages of pregnancy placental mitochondria are mainly responsible for the generation of metabolic intermediates and reactive oxygen species (ROS), while at later stages of gestation, the placental mitochondria exhibit high rates of oxygen consumption. This review describes the metabolic fingerprint of the placental mitochondria at different stages of pregnancy and summarises key signs of mitochondrial dysfunction in pathological pregnancy conditions, including preeclampsia, gestational diabetes and intrauterine growth restriction (IUGR). So far, the effects of placental-driven metabolic changes governing the metabolic adaptations occurring in different maternal tissues in both, healthy and pathological pregnancies, remain to be uncovered. Understanding the function and molecular aspects of the adaptations occurring in placental and maternal tissue's mitochondria will unveil potential targets for further therapeutic exploration that could address pregnancy-related disorders. Targeting mitochondrial metabolism is an emerging approach for regulating mitochondrial bioenergetics. This review will also describe the potential therapeutic use of compounds with a recognised effect on mitochondria, for the management of preeclampsia.

Pregnancy-related acute kidney injury at high altitude: a retrospective observational study in a single center

Background

Pregnancy-related acute kidney injury (Pr-AKI) is associated with maternal and fetal morbidity and mortality. There are few studies focusing on Pr-AKI at high altitude in the literature.

Objectives

to investigate the incidence, etiology, clinical features and maternal-fetal outcomes of Pr-AKI in women living at high altitude.

Methods

6,512 pregnant women attending the Department of Obstetrics & Gynecology at local hospital from January 2015 to December 2018 were screened for Pr-AKI. Patients with serum creatinine above normal range(> 70umol/L) then underwent assessment to confirm the diagnosis of Pr-AKI. AKI was diagnosed and staged based on Kidney Disease Improving Global Outcomes(KDIGO) guideline. Individuals meeting the Pr-AKI criteria were recruited. Their clinical data were recorded and retrospectively analyzed.

Results

Pr-AKI was identified in 136/6512(2.09 %) patients. Hypertensive disorders of pregnancy(HDP) was the leading cause of Pr-AKI(35.3 %). 4(2.9 %) women died and the majority(86.1 %) had recovered renal function before discharge. Fetal outcomes were confirmed in 109 deliveries with gestational age ≥ 20 weeks. Pre-term delivery occurred in 30(27.3 %) cases and perinatal deaths in 17(15.5 %). The rate of low birth weight infant(LBWI) and intrauterine growth restriction(IUGR) was 22.0 and 10.9 % respectively. 16(14.5 %) infants were admitted to NICU after birth. Patients with HDP had a higher cesarean rate(56.3 %). More IUGR(25.0 %) and LBWI(37.8 %) were observed in their infants with a higher risk of admission to NICU(22.0 %). High altitude might have an adverse impact on HDP-related Pr-AKI patients with earlier terminated pregnancy and more stillbirth/neonatal death. Logistic regression models indicated that uncontrolled blood pressure, high altitude and advanced AKI were associated with adverse fetal outcomes in HDP-related Pr-AKI patients.

Conclusions

Pr-AKI was not rare in high-altitude regions and caused severe fetal morbidities and mortalities. Uncontrolled blood pressure, high altitude and advanced AKI were all risk factors for adverse fetal outcomes in Pr-AKI patients, especially for those with hypertensive disorders of pregnancy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02418-7.

Pregnancy-related acute kidney injury and urological comorbidities in morbidly adherent placenta: A potential challenge to AKI-0by25

Pregnancy-related acute kidney injury (PRAKI) and urological complications can significantly increase the maternal morbidity and mortality, and morbidly adherent placenta (MAP) has been found to increase the risk of both. This is a four-year prospective study, conducted on patients with MAP. Baseline parameters (demographic/antenatal/perinatal), operative details (obstetric/urological/hemostatic), peri-operative complications (AKI/urological), and maternal/fetal outcomes were studied till six weeks after delivery. Statistical analysis was done using IBM SPSS Statistics version 21.0, and P <0.05 was considered statistically significant. Out of the 5475 deliveries conducted in the study period, 64 had adherent placentation. AKI occurred in 39.1% of patients, with severe AKI (AKIN-2, 3) in 10.9%, and significantly higher incidence in placenta percreta (P = 0.021, relative risk [RR] - 2.34), urological injuries (P = 0.001, RR - 2.86), and high blood loss (P = 0.001) on univariate analysis, but placenta percreta was the most statistically significant factor P = 0.049) on multivariate analysis. Urological involvement/injuries requiring intervention were encountered in 22 patients, with statistically significantly high incidence in placenta previa (P = 0.023, RR - 1.62), placenta percreta (P = 0.000, RR - 17.18), and patients undergoing hysterectomy (P = 0.000, RR - 2.01) on univariate analysis, but placenta percreta was most statistically significantly implicated on multivariate analysis (P = 0.017). AKI and urological injuries significantly increased the need for intensive care and days of hospitalization. On six-week follow-up, all AKI patients recovered completely; no urinary leak or vesico-vaginal fistula was seen in urologically intervened patients and no maternal mortality occurred. There is an alarmingly high incidence of PRAKI and urological complications in MAP, posing a great threat to their worldwide improving statistics. Awareness of this condition among renal fraternity can significantly improve the maternal renal and overall prognosis.

Acute kidney injury in pregnancy

PURPOSE OF REVIEW

Pregnancy-related acute kidney injury (Pr-AKI) is associated with increased maternal and fetal morbidity and mortality and remains a large public health problem.

RECENT FINDINGS

Pr-AKI incidence has globally decreased over time for the most part. However, the cause presents a disparity between developing and developed countries, reflecting differences in socioeconomic factors and healthcare infrastructure - with the noteworthy outlier of increased incidence in the United States and Canada. Although Pr-AKI can be secondary to conditions affecting the general population, in most cases it is pregnancy specific. Septic abortion, hyperemesis gravidarum, and hemorrhage have become less prevalent with access to healthcare but are being displaced by thrombotic microangiopathies, such as preeclampsia, hemolysis, elevated liver enzymes, low platelets syndrome, thrombotic thrombocytopenic purpura, and pregnancy-associated hemolytic-uremic syndromes, as well as acute fatty liver of pregnancy. Understanding these conditions plays a pivotal role in the timely diagnosis and enhancement of therapeutic approaches.

SUMMARY

In this review, we focus on the renal physiology of the pregnancy, epidemiology, and specific conditions known to cause Pr-AKI, summarizing diagnostic definition, insights in pathophysiology, clinical considerations, and novel treatment approaches, thus providing the reader a framework of clinically relevant information for interdisciplinary management.

Pregnancy-related acute kidney injury: mortality and survival of patients treated at a maternal intensive care unit

INTRODUCTION

Pregnancy-related acute kidney injury (AKI) can be defined as the abrupt decline in renal function during pregnancy or the postpartum period. It remains a relevant cause of fatal complications in obstetric patients. This study aimed to determine the incidence of pregnancy-related AKI in a maternal intensive care unit (ICU) as well as the associated risk factors for dialysis therapy and maternal mortality according to the KDIGO classification system.

METHODS

Retrospective analysis of observational data prospectively collected from January/2014 to April/2016 in a maternal ICU in a public tertiary maternal hospital in Brasília, Federal District, Brazil. All consecutive patients diagnosed with pregnancy-related AKI were included. Cases of renal failure before pregnancy or kidney transplantation were excluded.

RESULTS

Of the 619 admitted patients, pregnancy-related AKI was present in 172 cases (27.8%). One hundred and ten patients were classified as KDIGO 1 (64.0%), 43 as KDIGO 2 (20.9%) and 22 as KDIGO 3 (15.1%). KDIGO stages 2 and 3 were less frequent than KDIGO stage 1 in patients with gestational hypertension (p = 0.0010). Thirteen patients required hemodialysis (7.6%). Higher APACHE II (p = 0.0399) and SOFA (p = 0.0297) scores, hypovolemic shock (p = 0.0189) and septic shock (p = 0.0204) were independently associated with dialysis therapy (hemodialysis in all cases), 15 patients died (8.7%). Time to death was shorter in patients with a higher KDIGO stage (p = 0.002). Norepinephrine (p = 0.0384) and hemodialysis therapy (p = 0.0128) were independently associated with maternal mortality.

CONCLUSIONS

The incidence of pregnancy-related AKI remains high in the maternal ICU setting. Septic shock, hypovolemic shock, and higher APACHE II and SOFA scores were independently associated dialysis therapy (hemodialysis in all cases). KDIGO stages 2 and 3 were less frequent than KDIGO stage 1 in patients with gestational hypertension. Norepinephrine and hemodialysis therapy were independently associated with maternal mortality in patients with pregnancy-related AKI. KDIGO stage 3 was associated with higher maternal mortality.

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.

Non-obstetric complications in preeclampsia

Preeclampsia is a multisystem disorder of pregnancy that remains a leading cause of maternal and foetal morbidity and mortality. It is still an underestimated risk factor for future cardiovascular, cerebrovascular, and kidney disease, developing often in the perimenopausal period of a woman's life. It remains unclear whether preeclampsia is an individual risk factor for future cardiovascular, cerebrovascular, and renal events or an early marker of women with high-risk profiles for these diseases. Risk factors for cardiovascular disorders and preeclampsia are very similar and include the following: obesity, dyslipidaemia, insulin resistance, pro-inflammatory and hypercoagulable state, and endothelial dysfunction. Thus, the pregnancy can only be a trigger for cardiovascular alterations that manifest in development of preeclampsia. On the other hand, there is strong evidence that changes in cardiovascular, endothelial, and metabolic systems occurring in the course of preeclampsia may not fully recover after delivery and can be a cause of future disease, especially in the presence of other metabolic risk factors regarding, for example, perimenopause. In this review the authors present current knowledge about short- and long-term maternal consequences of preeclampsia, such as: cardiovascular disease, cerebrovascular incidents (posterior reversible encephalopathy and stroke), kidney injury (including the risk of end-stage renal disease), liver failure, and coagulopathy (thrombocytopenia and disseminated intravascular coagulation).

Pregnancy protects the kidney from acute ischemic injury

A complex analysis of acute kidney injury (AKI) in pregnant women shows that it is caused by the interaction of gestation-associated pathologies and beneficial signaling pathways activated by pregnancy. Studies report an increase in the regeneration of some organs during pregnancy. However, the kidney response to the injury during pregnancy has not been addressed. We investigated the mechanisms of the pregnancy influence on AKI. During pregnancy, the kidneys were shown to be more tolerant to AKI. Pregnant animals showed remarkable preservation of kidney functions after ischemia/reperfusion (I/R) indicated by the decrease of serum creatinine levels. The pregnant rats also demonstrated a significant decrease in kidney injury markers and an increase in protective markers. Two months after the I/R, group of pregnant animals had a decreased level of fibrosis in the kidney tissue. These effects are likely linked to increased cell proliferation after injury: using real-time cell proliferation monitoring we demonstrated that after ischemic injury, cells isolated from pregnant animal kidneys had higher proliferation potential vs. control animals; it was also supported by an increase of proliferation marker PCNA levels in kidneys of pregnant animals. We suggest that these effects are associated with hormonal changes in the maternal organism, since hormonal pseudopregnancy simulated effects of pregnancy.

Acute Kidney Injury in Pregnancy: The Changing Landscape for the 21st Century

Pregnancy-related acute kidney injury (Pr-AKI) remains a large public health problem, with decreasing incidences in developing countries but seemingly increasing incidences in the United States and Canada. These epidemiologic changes are reflective of the advances in medical and obstetric care, as well as changes in underlying maternal risk factors. The risk factors associated with advanced maternal age, such as hypertension, diabetes, chronic kidney disease, and those associated with reproductive technologies such as multiple gestations, are increasing. Traditional causes of Pr-AKI, such as septic abortions and puerperal sepsis, have been replaced by hypertensive diseases, such as preeclampsia and thrombotic microangiopathies comprising thrombotic thrombocytopenic purpura (TTP) and atypical hemolytic uremic syndrome (aHUS). In this review, we discuss the global impact of Pr-AKI on maternal and fetal outcomes, the predominant etiologies, and key clinical features to distinguish diagnoses, such as preeclampsia/hemolysis elevated liver function test and low platelet (HELLP) syndrome, acute fatty liver disease of pregnancy (AFLP), and other thrombotic microangiopathies. New insights into the pathogenesis of preeclampsia, TTP/aHUS, and AFLP that have unearthed possible therapeutic targets are summarized. We also delve into special consideration needed to give to pyelonephritis and postobstructive causes of Pr-AKI. With each diagnosis, we offer the latest treatment recommendations, such as the positive reports from the use of eculizumab to treat aHUS. In the end, we hope to arm the clinician with the best tools to understand and address this morbid problem that does not seem to be disappearing.

Comparison of acute kidney injury of different etiology reveals in-common mechanisms of tissue damage

Acute kidney injury (AKI) is a syndrome of reduced glomerular filtration rate and urine production caused by a number of different diseases. It is associated with renal tissue damage. This tissue damage can cause tubular atrophy and interstitial fibrosis that leads to nephron loss and progression of chronic kidney disease (CKD). This review describes the in-common mechanisms behind tissue damage in AKI caused by different underlying diseases. Comparing six high-quality microarray studies of renal gene expression after AKI in disease models (gram-negative sepsis, gram-positive sepsis, ischemia-reperfusion, malignant hypertension, rhabdomyolysis, and cisplatin toxicity) identified 5,254 differentially expressed genes in at least one of the AKI models; 66% of genes were found only in one model, showing that there are unique features to AKI depending on the underlying disease. There were in-common features in the form of four genes that were differentially expressed in all six models, 49 in at least five, and 215 were found in common between at least four models. Gene ontology enrichment analysis could be broadly categorized into the injurious processes hypoxia, oxidative stress, and inflammation, as well as the cellular outcomes of cell death and tissue remodeling in the form of epithelial-to-mesenchymal transition. Pathway analysis showed that MYC is a central connection in the network of activated genes in-common to AKI, which suggests that it may be a central regulator of renal gene expression in tissue injury during AKI. The outlining of this molecular network may be useful for understanding progression from AKI to CKD.