Acute kidney injury in pregnancy with special reference to pregnancy-specific disorders: a hospital based study (2014-2016).

Introduction: There are numerous reports in the literature describing acute kidney injury in pregnancy (P-AKI) due to various obstetric complications. However, there is a dearth of studies on AKI related to pregnancy-specific disorders from India. We aimed to analyze clinical features and outcome of P-AKI related to pregnancy-specific disorders compared to total pregnancy, in India.

Method: All pregnant women attending the department of Obstetrics and Gynecology from November 2014 to July 2016 were screened for AKI based on: (1) sudden elevation of serum creatinine ≥ 1 mg/dl; (2) oligoanuria for > 12 h; and (3) need for dialysis. The detailed clinical profile of AKI in patients with preeclampsia/eclampsia (PE/E), hemolysis/elevated liver enzymes/low platelet count (HELLP) syndrome, acute fatty liver of pregnancy (AFLP), and pregnancy-associated thrombotic microangiopathy (P-TMA) was analyzed. Laboratory investigations included: complete blood count, renal function tests, urinalysis, coagulation profile (platelet count, INR, prothrombin time and activated partial thromboplastin time), and immunological assay (C3, C4, ANA, anti-dsDNA antibody, antiphospholipid antibody). Contrast-enhanced CT scan of kidney ureter and bladder (KUB) and renal biopsy were performed in selected cases. Maternal and fetal outcome were analyzed individually. The patients were followed for 3 months or longer to determine the recovery of renal function or progression to chronic kidney disease (CKD).

Results: Overall, 4741 pregnant women (mean age 26.8 ± 4.8 years) were evaluated for AKI. P-AKI was found in 132/4741 (2.78%) patients. In the majority (91.6%), AKI developed in the late 3rd trimester and post-partum period. P-AKI was related to obstetric complications (in 61.4%), pregnancy-specific disorders (in 57.5%) and miscellaneous factors (7.5%). Puerperal sepsis, ante-partum and post-partum hemorrhage were contributing factors for P-AKI in 34 (25.8%), 11 (8.3%) and 28 (21.2%) patients, respectively. P-AKI due to pregnancy-specific disorders developed in 76/4741 patients, i.e. in 1:62 pregnancies. PE/E was the cause of P-AKI in 62 patients (46.9%) followed by HELLP syndrome in 9 (6.8%) and AFLP in 05 (3.8%). P-TMA causing AKI was not observed. Complete recovery of renal function occurred in 89.4% of patients while 6 (4.6%) progressed to CKD (ESRD: 3 and CKD stage IV: 3). Maternal mortality was 6%. Puerperal sepsis was the sole cause of patchy cortical necrosis in 5 (3.7%) cases. Premature delivery occurred in 40.9% patients and full-term delivery in 35.6%. Perinatal mortality was 23.5%, mainly due to intrauterine death (17.5%) and prematurity (6%).

Conclusion: PE/E was the commonest cause of P-AKI in our study, similar to the situation in developed countries. Post-partum hemorrhage was the second-most common (21.5%) cause. Puerperal sepsis contributed to AKI in one-fourth of pregnant women. P-TMA was not recorded in this study and AFLP was an uncommon cause of P-AKI in our country. Renal function returned to normal in all patients with P-AKI due to pregnancy-specific disorders. However, perinatal mortality was high despite the good prognosis of P-AKI.