Acute kidney injury during pregnancy

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.

Accuracy of Spot Urine Albumin Creatinine Ratio With Respect to 24-Hour Urine Albumin for the Detection of Proteinuria in Antenatal Women With Preeclampsia: A Descriptive Study

Background Among the hypertensive disorders of pregnancy, certain diseases like preeclampsia (PE) and eclampsia have the maximum impact on morbidity and mortality of the mother as well as the newborn. Proteinuria determination is used to assess renal damage in PE. There are several ways to evaluate proteinuria in pregnant women, but the gold standard remains the 24-hour urine albumin (24-h UA) excretion. Spot urine albumin creatinine ratio (UACR) can be used for rapid diagnosis of PE which is fast, reliable, and easy to use. Hence, our tertiary care center conducted the current study to assess the accuracy of spot UACR with 24-h UA for detecting proteinuria in antenatal women to diagnose PE and to evaluate the obstetric outcome in antenatal women with PE. Methodology A descriptive, cross-sectional study was conducted on 98 antenatal women diagnosed with PE. Urine albumin was done by dipstick method and the presence or absence of proteinuria was noted. Both, the 24-h urine sample and a random sample for spot UACR were sent for analysis. Results Spot UACR has more specificity than sensitivity along with a high negative predictive value for the detection of proteinuria. Additionally, significant proteinuria was associated with an increased rate of induced labor, a cesarean section in patients, lower mean gestational age at the time of delivery, lower birth weight, and increased rate of intrauterine fetal death. Conclusion The study concluded that spot UACR has more specificity than sensitivity along with a high negative predictive value for the detection of proteinuria and therefore, can be used for the diagnosis of proteinuria in women with PE. Hence, spot UACR is a reliable, faster, and more accurate method for the detection of proteinuria in PE and can be used for early diagnosis and timely management leading to a decrease in mortality and morbidity of the mother and the fetus.

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.

Diagnosis of proteinuria using a random urine protein-creatinine ratio and its correlation with adverse outcomes in pregnancy with preeclampsia characterized by renal damage

Based on a limited number of studies, a random urine protein‐creatinine ratio (uPCR) value of ≥ 0.3 indicates abnormal proteinuria in preeclampsia with renal damage. However, current guidelines do not recommend a reasonable diagnostic threshold of uPCR for severe preeclampsia with renal damage. Furthermore, the correlation between the uPCR value and clinical adverse outcomes remains poorly understood. The aim of the present study was to evaluate the value of uPCR in the diagnosis of significant proteinuria and to assess its correlation with adverse pregnancy outcomes in preeclampsia characterized by renal damage. In all, 1837 women were enrolled in this retrospective cohort study. Eventually, 961 women were enrolled under the exclusion criteria. First, the authors found that uPCR and 24‐hour proteinuria showed a significant association (r = 0.901). The optimal threshold of uPCR for diagnosing preeclampsia was 0.295, and for diagnosing severe preeclampsia the cut‐off was 0.625. Meanwhile, the adjusted odds ratio per 1 unit increase in ln (uPCR) was 1.679 (95% confidence interval [CI]:1.142–2.469) for severe adverse perinatal outcomes; 1.456 (95% CI: 1.242–1.705) for small for gestational age; 1.380 (95% CI: 1.051–1.811) for severe small for gestational age; 1.672 (95% CI: 1.210–2.310) for very early preterm birth; 1.989 (95% CI 1.726–2.293) for severe hypertension; and 2.279 (95% CI 1.906–2.724) for preterm birth. This study indicated that there was a significant and positive correlation between uPCR and 24‐hour urine protein. For neonatal and maternal adverse outcomes, uPCR is an independent predictor of prognosis.

Acute kidney injury in pregnant women following SARS-CoV-2 infection: A case report from Iran

We reported a 33-year-old female case with novel coronavirus disease 2019 (COVID-19) accompanied by Acute tubular necrosis (ATN). She had a gestational age of 34 weeks. The patient referred to treatment clinic for COVID-19 in Imam Reza hospital of Tabriz (Iran) after having flu-like symptoms. In radiologic assessment, ground glass opacity (GGO) with consolidation was found in upper right lobe. Lopinavir/ritonavir (200mg/50mg) two tablet tow times, Ribavirin 200mg every 6 h, and Oseltamivir 75mg tow times were given for the treatment of COVID-19. The medications used for treatment of pneumonia were Meropenem, Ciprofloxacin, Vancomycin. All doses of medications were administrated by adjusted dose assuming the patient is anephric. Also, a few supplements were also given after ATN development including daily Rocaltrol and Nephrovit (as a multivitamin appropriate for patients with renal failure), Folic acid and Calcium carbonate. The patient is still under ventilator with a Fraction of inspired oxygen (FiO₂) of 60% and Positive end-expiratory pressure (PEEP) of eight. SpO₂ is 94% but the patient's ATN problem has been resolved. We started weaning from mechanical ventilator. The patient is conscious with full awareness to time, person and place. The maternal well-being is achieved and her neonate was discharged.

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.

Preeclampsia: Acute Complications and Management Priorities

Acute complications of preeclampsia contribute substantially to maternal and fetal morbidity and mortality. The considerable variation in onset, clinical presentation, and severity of this hypertensive disease that is unique to pregnancy creates challenges in identifying risk factors for clinical deterioration. Delivery of the fetus remains the only definitive treatment for preeclampsia. Surveillance of signs and symptoms and laboratory parameters consistent with progression in severity requires an appreciation of the dynamic and progressive nature of the disease. This article provides a comprehensive overview of the pathophysiology of preeclampsia, setting the foundation for discussion of management priorities for acute complications that pose the greatest risks to maternal health.

Atypical hemolytic-uremic syndrome as one of the causes of acute kidney injury in pregnant women

AIM

Analysis of clinical manifestations, course and outcomes of obstetric aHUS.

MATERIALS AND METHODS

45 patients with aHUS development during pregnancy or immediately after childbirth were observed between 2011 and 2017, age from 16 to 42 years.

RESULTS

All patients had AKI (serum creatinine 521,5±388,0 µmol/l, oliguria or anuria that required initiation of hemodialysis). 93.3% pts had extrarenal manifestations of TMA with the development of multiple organ failure (MOF). The mean number of damage organs was 3,7±1,2. In all patients, the development of aHUS was preceded by obstetric complications, surgery, infection, etc. In the outcome: 53.4% women showed complete recovery of renal function, 11.1% developed CKD 4-5 stages, 35.5% had dialysis-dependent end-stage renal failure (ESDR). Maternal mortality was 23.9%. Perinatal mortality was 32.6%. The early start of eculizumab treatment (within 1-2 weeks from the onset of aHUS), compared with therapy start after 3 weeks, increased the chances of favorable outcome for mother in 5.33 times, and the chances for normalization of renal function in 48.7 times.

CONCLUSION

Obstetric aHUS is characterized by the development of AKI in 100% of cases. In most patients, the obstetric aHUS occurs with the development of MOF. Timely diagnosis of aHUS and immediate treatment by eculizumab allows not only to save the life of patients, but also completely restore their health.

Relaxin-2 connecting peptide (pro-RLX2) levels in second trimester serum samples to predict preeclampsia

OBJECTIVES

Preeclampsia is a serious complication of pregnancy, threatening fetal and maternal health. The aim of our study is to examine the association between preeclampsia and the connecting peptide of the pregnancy hormone relaxin (pro-RLX2) as a potential new biochemical marker.

STUDY DESIGN

This is a nested case/control study derived from the cohort of pregnancies delivering at Women & Infants Hospital. Cases were identified at a clinic or by hospital codes, and individually confirmed by record review. Stored samples were available from 'integrated' Down syndrome screening. Results were expressed as multiples of the median (MoM).

MAIN OUTCOME MEASURES

Preeclampsia was classified as early/severe, late/severe, or mild based on professional guidelines.

RESULTS

Fifty-one cases were each matched with five control pregnancies. Population distribution parameters were derived for cases and controls. As shown previously, discrimination between cases and controls (applying MoM analysis) was possible for PlGF (0.576, p < .05), inhibin A (1.45, p < .05) and endoglin (1.278, p < .05). No association with preeclampsia was found for pro-RLX2. However, pro-RLX2 correlates with Inhibin A and Endoglin.

CONCLUSIONS

Endoglin, Inhibin A and PlGF are highly predictive of preeclampsia. Quantification of pro-RLX2 is not able to predict preeclampsia. Nevertheless, the potential involvement of relaxin 2/pro-RLX2 in the pathophysiology of preeclampsia requires further study.

Pregnancy outcomes in patients with acute kidney injury during pregnancy: a systematic review and meta-analysis

Background

Presently, the matter of pregnancy outcomes of patients with pregnancy related AKI (PR-AKI) were disputed. Thus, we conducted a meta-analysis to evaluate the impact of PR-AKI on pregnancy outcomes.

Method

We systematically searched MEDLINE, Embase, VIP, CNKI and Wanfang Databases for cohort or case-control studies in women with PR-AKI and those without AKI as a control group to assess the influence of PR-AKI on pregnancy outcomes and kidney outcome. Reduction of odd ratio (OR) was calculated by a random-effects model.

Results

One thousand one hundred fifty two articles were systematically reviewed, of those 11 studies were included, providing data of 845 pregnancies in 834 women with PR-AKI and 5387 pregnancies in 5334 women without AKI. In terms of maternal outcomes, women with PR-AKI had a greater likelihood of cesarean delivery (OR, 1.49; 95% confidence interval [CI], 1.37 to 1.61), hemorrhage (1.26; 1.02 to 1.56), HELLP syndrome (1.86; 1.41 to 2.46), placental abruption (3.13; 1.96 to 5.02), DIC (3.41; 2.00 to 5.84), maternal death (4.50; 2.73 to 7.43), but had a lower risk of eclampsia (0.53; 0.34 to 0.83). Women with PR-AKI also had a longer stay in ICU (weighted mean difference, 2.13 day [95% CI 1.43 to 2.83 day]) compared with those without PR-AKI. As for fetal outcomes, higher incidence of stillbirth/perinatal death (3.39, 2.76 to 4.18), lower mean gestational age at delivery (−0.70 week [95% CI -1.21 to −0.19 week]) and lower birth weight (−740 g [95% CI -1180 to 310 g]) were observed in women with PR-AKI. The occurrence of kidney outcome, defined as ESRD requiring dialysis, in women with PR-AKI was 2.4% (95% CI 1.3% to 4.2%).

Conclusions

PR-AKI remains a grave complication and has been associated with increased maternal and fetal mortality.

Electronic supplementary material

The online version of this article (doi:10.1186/s12884-017-1402-9) contains supplementary material, which is available to authorized users.

Pregnancy outcomes among renal transplant recipients and patients with end-stage renal disease on dialysis

AIM

The purpose of our study is to compare pregnancy outcomes between women with a functioning renal transplant and women with end-stage renal disease (ESRD).

METHODS

We carried out a population-based retrospective cohort study using the Healthcare Cost and Utilization Project Nationwide Inpatient Sample database from 2006 to 2011. Logistic regression analysis was used to estimate the age-adjusted effect of functioning renal transplant vs. ESRD requiring dialysis on pregnancy outcomes.

RESULTS

We identified 264 birth records to women with a functional renal transplant and 267 birth records to women with ESRD on dialysis among 5,245,452 births. As compared to women with ESRD on dialysis, renal transplant recipients were less likely to have placental abruption [odds ratio, OR 0.23 (95% confidence interval, CI 0.08-0.70)], to receive blood transfusions [OR 0.17 (95% CI 0.09-0.30)], and to have growth-restricted and small-for-gestational-age babies [OR 0.45 (95% CI 0.23-0.85)]. Renal transplant recipients were more likely to have an instrumental delivery [OR 15.38 (95% CI 1.92-123.3)]. Among renal transplant women, there was a trend towards delivery by cesarean section as compared to patients with ESRD [OR 1.31 (95% CI 0.93-1.85)]. However, these results were not statistically significant. Fetal deaths were less likely to occur in women with a renal transplant [OR 0.41 (95% CI 0.17-0.96)]. There were four maternal deaths among patients with ESRD on dialysis and no maternal deaths among renal transplant patients.

CONCLUSION

Patients with a functional renal graft had an overall lower rate of morbidity and adverse pregnancy complications when compared to patients with ESRD on dialysis.

Multisystem Effects of Hypertensive Disorders of Pregnancy: A Comprehensive Review

Hypertension predisposes the woman and fetus to adverse outcomes during the pregnancy and postpartum. The risk for maternal complications and neonatal morbidity associated with the necessity of preterm birth extends beyond the postpartum and postnatal period. A comprehensive review of the multisystem effects of hypertensive disorders and underlying pathophysiology is provided to support the role of prompt identification of and management of acute complications of hypertension.