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.