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.


Introduction
One major cause of maternal and fetal morbidity and death during pregnancy is acute kidney injury (AKI), which is a public health concern [1].There is an increase in the risk of hospitalization and long-term mortality from AKI [2].In addition, AKI worsens kidney function, which leads to chronic kidney disease and end-stage kidney disease, which in turn increases the risk of unfavorable cardiovascular events, healthcare use, and hospital stays [3,4].Hence, it is crucial to identify and treat AKI in pregnancy as soon as possible; doing so might save lives.Legalizing abortion and improving prenatal and obstetric care have led to a dramatic decline in the incidence of pregnancy-related acute kidney damage during the last half century, from 20-40% in 1960 to less than 10% in the present series.
There is a significant risk of maternal death and fetal loss ranging from 30% to 60% linked to AKI during pregnancy (PR-AKI), which is a potentially fatal condition [5].According to the Kidney Disease Improving Global Outcomes definition, AKI is characterized as follows: a serum creatinine level greater than 0.3 mg/dL from baseline or more than 1.5 times the reference value or a decrease in urine output below 0.5 mL/kg/hour lasting 6-12 hours.The purpose of the study is to identify the current trend in PR-AKI.This study was a prospective observational study.Its objective is to analyze the etiological factors, clinical manifestations, and maternal and fetal outcomes of PR-AKI.

Patient selection
Patients hospitalized in the General Medicine and Obstetrics and Gynecology departments at Indira Gandhi Institute of Medical Sciences, Patna, for a year, from October 2021 to September 2022, with obstetric difficulties resulting in acute renal damage, were the participants of this prospective observational study.The study received ethical clearance from the Institutional Ethics Committee of Indira Gandhi Institute of Medical Sciences, Patna (approval number: 1791/IEC/IGIMS/2020, dated September 30, 2020).This study included pregnant women who were previously healthy and had developed AKI, who had an increase in serum creatinine ≥0.3 mg/dl within 48 hours, who had an increase in serum creatinine ≥1.5 times from baseline, who had an oliguria urine output <0.5 ml/kg/h for six hours, and who had given consent for the study.The study excluded patients with evidence of renal disease before pregnancy, a history of renal stone diseases, and elevated serum creatinine before gestation.

Outcome of interest
We analyzed patients by examining their demographics, medical history, clinical symptoms, and results from several laboratory tests (e.g., complete blood count, prothrombin time/international normalized ratio (PT/INR), liver function test, kidney function test, and ultrasound of the whole abdomen).A comprehensive obstetric evaluation was performed on every patient.We asked detailed questions about the birth method, blood transfusion, and surgical procedure and whether dialysis was necessary.Reversible renal failure, partial recovery, and full recovery were the metrics used to measure maternal outcomes.Standard indications were followed when hemolysis was conducted.When the patient was able to stop using dialysis and maintain normal renal function and urine production, it was deemed a positive result, representing a full recovery.Partial recovery was defined as patients who were dialysis-independent upon discharge and whose renal function had improved, but not to a normal level.An undesirable result was the onset of chronic renal disease or death.Chronic renal disease was diagnosed in patients when dialysis was still necessary three months after discharge.

Statistical analysis
We encrypted and stored all the data in MS Excel.We analyzed the obtained data using IBM SPSS Statistics for Windows, Version 23.0 (Released 2015; IBM Corp., Armonk, New York, United States) for this investigation.For continuous variables, the descriptive statistics were given as medians, interquartile ranges, and standard deviations; for categorical variables, the frequencies, percentages, and ages were given.To compare two groups utilizing continuously dispersed data, the t-test for independent samples was used.Data that did not conform to a normal distribution were subjected to the Wilcoxon test or other suitable nonparametric tests.We developed the chi-squared test to compare sets of category data thoroughly.Since the predicted frequency was less than five, Fisher's exact test was used for over 25% of the cells in the contingency tables.When the p-value was less than 0.05 or 0.001, the findings were deemed significant.

Discussion
Obstetric AKI has a significant influence on both fetal and maternal complications [6].The literature has reported the incidence of AKI during pregnancy as 1-2.8% for developed countries, whereas in developing countries, it is almost 9-25.3%[7,8].The incidence is lower in developed countries because of appropriate antenatal care, timely diagnosis, and treatment of complications [9].The age range in our study was 18-40 years, with a mean age of 25.08±4.25.A study conducted by Arrayhani et al. [6] reported an age range of 18-40 years.In a study by Verma and Sharma [10], the mean age was 29.33±5.31years, and it was 25.23±3.8years in a study by Paudyal et al. [11].The mean age was almost the same in all related studies.This might be because all the studies focused on AKI related to pregnancy and the mean age of marriage and pregnancy is almost identical among most young women.
The majority of patients in our study were non-booked patients (52, 83.9%) and presented as emergency cases.Only 10 (16.1%) patients in our study received regular antenatal care.A study conducted by Mehta et al. [12] also reported that 66% of the patients in their study were not booked and did not receive adequate antenatal care.The most common etiological factor for the development of AKI in our study was 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%), DIC (three cases, 4.8%), AFLP (three cases, 4.8%), urosepsis (two cases, 3.2%), and drug-induced AKI (two cases, 3.2%).The drugs responsible for AKI in this study were amikacin and diclofenac sodium.
Sepsis was the main cause of AKI in a study conducted by Mahesh et al. [13], in contrast to a study conducted by Taj et al., which identified postpartum hemorrhage (eight cases, 18.2%) as the main cause [14], causing hypotension for the development of AKI in pregnancy.Preeclampsia/eclampsia (14 cases, 26.6%) is another common cause of AKI in our study, which is consistent with the study by Prakash et al., which reported preeclampsia and eclampsia to be the most common causes of pregnancy-related acute renal injury, contributing to 35.29% of cases [15].
Huang and Chen also identified preeclampsia/eclampsia as the common etiological factor for the occurrence of AKI in pregnancy [16].Patients with AKI may have clear symptoms at presentation.The most common presentation at the time of diagnosis of AKI in our study was oliguria (42 cases, 72.6%).Oliguria was also the most common presentation in the studies conducted by other authors, such as Gayathiri et al., who reported that 57% of patients had oliguria [17].In this study, 23 (69.2%) patients diagnosed with AKI were managed conservatively without hemodialysis, whereas 39 (37.1%) patients needed hemodialysis.In a study by Paudyal et al., the need for hemodialysis was as high as 80% [11], and in a study conducted by Gayathiri et al., two (33%) patients required hemodialysis, and 11% required plasmapheresis [18].The lack of proper emergency services in the periphery hospitals and late diagnosis of disease and referral may be directly related to the need for hemodialysis.This is a common problem in developing countries due to inadequate infrastructure.Complete recovery was seen in 48 (77.4%) patients in our study.In a study conducted in Morocco by Arrayhani et al., complete recovery was seen in 75.67% of the patients [6], and according to the study conducted by Trakarnvanich et al. [19], 70.6% of patients with PR-AKI achieved complete recovery, 14.7% achieved partial recovery, and 8.5% remained dependent on dialysis.The limitation of the present study is that there was a short duration of follow-up, as further long-term follow-up is required to assess the outcome of patients with chronic kidney disease.

Conclusions
Acute kidney damage poses a difficult clinical problem when it occurs during pregnancy.AKI during pregnancy continues to be a major public health problem in underdeveloped nations.In the present study, the leading cause of AKI was sepsis, which became worse throughout pregnancy.In addition to sepsis, which is both curable and preventive, postpartum hemorrhage and antepartum hemorrhage were the leading causes of AKI.Deaths and illnesses caused by AKI could be reduced with improved prenatal care, easier access to emergency care, and prompt diagnosis and referral.

FIGURE 1 :
FIGURE 1: Clinical feature of the patients Data is shown as a bar graph representing clinical features on the x-axis and the number of patients on the y-axis

FIGURE 3 :
FIGURE 3: Distribution of blood transfusion

TABLE 3 : Distribution of participants in terms of "etiology of AKI"
Data are shown as frequency, percentage, and 95% CI CI: confidence interval; AFLP: acute fatty liver of pregnancy; AKI: acute kidney injury