Postpartum kidney disease associated with placental abruption: a population-based retrospective cohort study.

BACKGROUND

Placental abruption can lead to renal decompensation, including disseminated intravascular coagulation, and the release of cytokines and vasoactive substances, causing kidney damage. Despite the strong biological plausibility, whether this renal damage persists in the postpartum period is unknown. The aims of the study were to examine the association between abruption and kidney disease hospitalisation, and whether these risks are modified by hypertensive disorders of pregnancy (HDP).

METHODS

We designed a population-based retrospective cohort study of hospital deliveries and readmissions in the US, 2010-2020. All persons who had a hospital delivery with and without an abruption diagnosis were followed up for readmission for kidney disease in the same calendar year. We fit Cox proportional hazards models to estimate the associations based on two outcomes: fatal or non-fatal kidney disease and in-hospital mortality. We evaluated whether HDP modified these risks.

FINDINGS

Of 17,826,038 delivery hospitalisations, 194,740 (1.1%) were complicated by abruption. The median follow-up after delivery was 6.4 months (interquartile range, 3.7, 9.2) among abruption and non-abruption deliveries. The rates of hospitalisations with an acute kidney injury (AKI) diagnosis among abruption and non-abruption groups were 236 and 106 per 100,000 hospitalisations, respectively (adjusted hazard ratio [HR] 1.7, 95% confidence interval [CI], 1.5-1.9). The corresponding rates for hospitalisations with chronic kidney disease (CKD) diagnosis among abruption and non-abruption groups were 82 and 25 per 100,000 hospitalisations, respectively (HR 2.1, 95% CI, 1.6-2.7). The HR for AKI mortality associated with abruption was 4.1 (95% CI, 2.8-6.1). Kidney disease risks related to abruption were high among those without an HDP diagnosis; these risks were substantially higher among persons with HDP.

INTERPRETATION

This population-based study shows that placental abruption, even in the absence of HDP, is associated with increased short-term postpartum risks of AKI and CKD hospitalisations. These risks are higher in the presence of HDP. This study underscores the importance of close postpartum monitoring of patients diagnosed with placental abruption in their pregnancies for the risk of kidney disease. It is also essential to elucidate whether these risks persist beyond the postpartum period and extend to the maternal life course.

FUNDING

None.