Acute Kidney Injury in pregnancy associated with adverse cardiovascular and renal outcomes, finds study
Acute kidney injury (AKI) occurs in approximately 2% of pregnancies and is associated with significant maternal morbidity. It is becoming more prevalent due to increasing age and maternal comorbidities. AKI in pregnancy is considered a sudden deterioration in renal function during pregnancy. Outside pregnancy, AKI is defined by either a fall in urine output and/or a rise in serum creatinine. Due to the physiological reduction in serum creatinine in pregnancy and the dynamic nature of creatinine in pregnancy, there is currently no agreed and robust definition for AKI in pregnancy and no existing AKI criteria are validated for use in pregnancy.
The association between AKI in pregnancy and adverse maternal and foetal outcomes has been previously described in the literature. These include maternal death, intensive care unit admission, haemorrhage, stillbirth, preterm birth and low birth weight. AKI has also been associated with some adverse cardiovascular and renal outcomes. For example, cardiovascular events, dialysis, chronic kidney disease and endstage renal failure. However, adverse cardiovascular and renal outcomes following AKI in pregnancy have not been systematically evaluated. Authors aimed to quantify the risk of adverse cardiovascular and renal outcomes following AKI in pregnancy and to determine the variation in AKI definition.
To quantify and perform a meta-analysis of the risk of adverse cardiovascular and renal outcomes following AKI in pregnancy, a systematic search of MEDLINE, Cochrane Library and EMBASE from inception until 23 January 2024 was conducted.
A total of 17 studies were included with 50 285 836 pregnant women, of which 36,806 women were affected by AKI. The evidence synthesis showed that AKI in pregnancy is associated with a 52-fold increase in the risk of composite adverse renal outcomes (OR 52.37; 95% CI 4.67–587.63), a 23-fold increase in the risk of heart failure (OR 22.55; 95% CI 4.39–115.71) and stroke (OR 22.92; 95% CI 2.32–226.65), as well as a 9.3-fold and 3.9-fold increased risk of maternal mortality (OR 9.26; 95% CI 2.53–33.96) and intensive care unit admission (OR 3.86; 95% CI 1.93–7.71), respectively.
This systematic review and meta-analysis of 17 studies included over 50 million women, with over 36000 women affected by AKI. The evidence synthesis showed that AKI in pregnancy is associated with a 52-fold increase in risk of composite adverse renal outcomes, a 10-fold risk of maternal mortality and a 4-fold increased risk of intensive care unit admission. However, AKI in pregnancy is not associated with an increase in risk of hypertension. Subgroup analysis showed there was a higher risk of composite adverse renal outcomes when AKI was defined using the KDIGO classification compared with using an arbitrary serum creatinine level.
This study highlights the importance of AKI in pregnancy as a risk factor for significant future adverse cardiovascular and renal outcomes. As a common renal problem in pregnancy, it is crucial to ensure women who sustain AKI in pregnancy are followed up and monitored appropriately. In the future, researchers need to consider ways to standardise the definition and measurement of AKI in pregnant women, as a robust definition for AKI in pregnancy is still not available. There is an urgent need for high-quality primary studies as there are limited studies focusing on cardiovascular and renal outcomes with a validated measurement for AKI in pregnancy. Furthermore, studies to elucidate the potential underlying mechanisms of these associations will benefit management of women with AKI in pregnancy. In conclusion, this study has shown that AKI is associated with long-term adverse cardiovascular and renal outcomes which increase the risk burden for this population. The study, with its limitations, highlights the potential implications for patient care via surveillance, early detection of risk factors and early management to optimise risk factors of adverse cardiovascular and renal outcomes.
Source: Deepthika Jeyaraman, Dimuth P. Peiris, Mark Lambie;
BJOG: An International Journal of Obstetrics & Gynaecology, 2025; 0:1–8
https://doi.org/10.1111/1471-0528.18352
