Epidemiology of acute kidney injury in hospitalized pregnant women in China

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.

Clinical features and prognosis of pregnancy-related renal damage and pregnancy after chronic kidney disease

OBJECTIVE

To explore the clinical features of renal damage related to pregnancy and pregnancy after chronic kidney disease (CKD), providing clinical evidence for the relationship between renal damage and pregnancy.

METHODS

A retrospective analysis was performed on patients admitted to our hospital between March 2013 and February 2021 who had both pregnancy and kidney damage. The study collected pathology results from renal biopsies, 24-hour urinary protein quantity, albumin (Alb), serum creatinine (Scr), blood lipids, coagulation function, blood routine, and other indicators during and after pregnancy.

RESULTS

This study included 82 cases, with 48 cases in the pregnancy-related renal damage group. Thirty-four cases were in the post-CKD pregnancy group. Of the patients, 30 cases (88.24%) had CKD stage 1-2. Results showed better pregnancy and fetal outcomes in the post-CKD pregnancy group compared to the pregnancy-related renal damage group (Ρ was 0.029 and 0.036, respectively). Renal biopsy pathology revealed that 16 cases (33.33%) in the pregnancy-related renal damage group mainly had focal segmental glomerulosclerosis (FSGS), while the post-CKD pregnancy group was dominated by 14 cases (43.75%) of IgA nephropathy. The first blood test indicators revealed that the pregnancy-related renal damage group had lower estimated glomerular filtration (eGFR) and Alb levels compared to the post-CKD pregnancy group (Ρ was 0.003 and 0.000, respectively). Additionally, 24-hour urinary protein quantity, total cholesterol (Tch), triglyceride (TG), and platelet (PLT) counts were higher in the pregnancy-related renal damage group compared to the post-CKD pregnancy group (Ρ was 0.005, 0.001, 0.008, and 0.031, respectively). The abnormal rate of Scr during pregnancy was 41.67% (20/48) in the pregnancy-related renal damage group and 17.39% (4/23) in the post-CKD pregnancy group, with a statistically significant difference (Ρ was 0.043).

CONCLUSION

The pregnancy-related renal damage group is mainly associated with FSGS, while the post-CKD pregnancy group is characterized by IgA nephropathy. Patients with CKD1-2 can have a successful pregnancy after achieving good control of eGFR, albumin, 24-hour urinary protein quantity and other indicators, resulting in better pregnancy and fetal outcomes. Abnormal Scr levels during pregnancy of pregnancy-related renal damage can be improved within 3 months after delivery.

Correlations between Maternal and Fetal Outcomes in Pregnant Women with Kidney Failure

BACKGROUND

Kidney function impairment in pregnancy is challenging, with incidence and prognosis only partially known. Studies concerning maternal and fetal outcomes in pregnancies occurring in patients with renal injury and the therapeutic strategies for improving the prognosis of these patients are scarce due to the limited number of cases reported.

OBJECTIVES

We aimed to establish correlations between the main maternal and fetal outcomes in patients with severe CKD or AKI in pregnancy to improve the prognosis, referring to a control group of patients with mild kidney impairment.

METHODS

For this purpose, we conducted a retrospective study, at University Emergency Hospital in Bucharest, Romania, from January 2019 until December 2021, selecting 38 patients with AKI and 12 patients diagnosed with advanced CKD, compared to 42 patients displaying borderline values of serum creatinine (0.8-1 mg/dL), reflecting the presence of milder kidney impairment.

RESULTS

The probability of having a child that is premature and small for gestational age, with a lower Apgar score and more frequent neonatal intensive care unit admissions, delivered by cesarean section, is higher in patients with highly reduced kidney function.

CONCLUSION

Severe kidney function impairment is associated with a grim fetal prognosis and obstetrical complications.

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.

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.

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.

Acute Kidney Injury in Asia: Disease Burden

Acute kidney injury (AKI) is a common and critical clinical disorder with non-negligible morbidity and mortality and remains a large public health problem. Asia, as the world's largest and most populous continent, is crucial in eliminating unsatisfactory outcomes of AKI. The diversities in climate, customs, and economic status lead to various clinical features of AKI across Asia. In this review, we focus on the epidemiologic data and clinical features of AKI in different Asian countries and clinical settings, and we show the huge medical and economic burden of AKI in Asian countries. Drugs and sepsis are the most common etiologies for AKI, however, an adequate surveillance system has not been well established. There is significant undertreatment of AKI in many regions, and medical resources for renal replacement therapy are not universally available. Although substantial improvement has been achieved, health care for AKI still needs improvement, especially in developing regions.

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.

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.