Pregnancy Related Acute Kidney Injury Among Women With Preeclampsia at Kenyatta National Hospital: Risk Factors, Progression and Pregnancy Outcomes

Abstract

Background: Pregnancy related acute kidney injury (PrAKI) is a global problem affecting mothers in varying incidences. PrAKI contributes 7-52% of AKI cases. Majority of PrAKI cases are in resource poor countries where access to antenatal care is limited especially in rural areas and where unsafe delivery practices occur. These pregnancies suffer a significantly higher risk of maternal and neonatal mortality and morbidity than in a normal pregnancy. There is an added risk of developing CKD in the long term. Information on the burden of disease of PrAKI in our local setting is scarce. Less is known of the risk factors that contribute to the occurrence of PrAKI, which is one of the hallmarks of the AKI management pathways proposed in the 0by25 initiative: risk assessment. This study aims to identify a set of risk factors that would guide patient stratification, early identification, and eventual early treatment of women with PrAKI with the hope of improving their health and pregnancy outcomes. Study Objective: To determine the risk factors for pregnancy related acute kidney injury amongst women with preeclampsia and describe their pregnancy outcomes at Kenyatta National Hospital Methodology: This was a prospective cohort study conducted at the Kenyatta National Hospital Obstetric Units involving 196 patients admitted with preeclampsia. Patients were identified and selected through consecutive sampling method and enrolled upon consent. Patients with preeclampsia and AKI, n=47 were compared to patients with preeclampsia only, n=149. Information was collected through a data extraction form and urine samples of patients obtained at enrolment. Data was analysed and with STATA and R software. Chi-square analysis and Odds

Ratio were calculated to determine the differences in demographic, clinical data, urine microscopy, pre-defined risk factors for PrAKI and the pregnancy outcomes between the two groups. A p value < 0.05 was considered significant in determining associations. Results: The mean age of patients was 29.6 years amongst PrAKI group versus 30.2 amongst the non PrAKI group. Significant risk factors for PrAKI were a lower gestation age of < 28weeks (OR 4.2, 95% CI: 1.2-14.5), fewer antenatal visits (OR 2.6, 95% CI: 1.2-5.5), thrombocytopenia of <50×109/l) (OR 10.1, 95% CI: 4.3-24.1) and HELLP syndrome (OR 8.5, 95% CI: 4.0-17.9). Patients with PrAKI were more likely to undergo vaginal delivery and have persistent elevated blood pressure (>140/90) at discharge (SBP>140mmHg OR 2.1, 95% CI: 1.0-4.4 and DBP>90mmHg OR 2.0, 95% CI: 1.0-3.9). Perinatal outcomes were significantly adverse across all variables examined (perinatal mortality, birth weight, Apgar score at 5 minutes and new-born unit admission). Patients with persistently elevated serum creatinine at the end of the study had stage 2 and 3 AKI. The renal recovery rate was 44%. On multivariate analysis, early onset preeclampsia and severe thrombocytopenia were strongly associated with PrAKI and had the greatest effect on neonatal birth weight. Conclusion and recommendation: PrAKI was significantly associated with poor antenatal attendance, lower gestational age, severe thrombocytopenia and HELLP syndrome and had worser perinatal outcomes compared with non-PrAKI patients. Partial renal recovery was seen in patients with advanced AKI stages. Further investigation on the long-term outcomes of PrAKI is needed.