“Hypertensive disorders of pregnancy—specifically gestational hypertension and preeclampsia—are important causes of morbidity in pregnant women,” explains Joshua Shapiro, MD. “In addition to organ dysfunction occurring during a hypertensive disorder of pregnancy, women are at increased risk for long-term end-organ effects following the episode. A robust body of literature exists demonstrating a relationship between hypertensive disorders of pregnancy and the subsequent development of chronic kidney disease (CKD), but there is less research on the risk for future acute kidney injury (AKI), a condition that can potentially be mitigated with early identification and management. Therefore, knowledge of factors that predispose to AKI can help identify at-risk patients who may benefit from closer monitoring of kidney function, especially during times of illness or other stressors that may affect the kidneys.”

For a paper published in the American Journal of Kidney Diseases, Dr. Shapiro and colleagues aimed to examine the risk for AKI after the resolution of hypertensive disorders of pregnancy. The researchers conducted a retrospective population-based cohort consisting of patients (n = 1,142,656) aged 14-50 who delivered at 20 weeks or more of gestation one or more times between April 1, 2002, and March 31, 2015, accounting for a total of 1,826,235 deliveries. The study team examined the rates of AKI after pregnancy in patients with hypertensive disorders of pregnancy compared with women with pregnancies not affected by gestational hypertension or preeclampsia.

History of Preeclampsia Linked With Risk of Future AKI

“We found that a history of preeclampsia is a marker of increased risk for the subsequent development of AKI,” Dr. Shapiro says. “This has relevance to OB/GYNs who are likely to see these patients during, immediately after, and in pregnancies subsequent to an episode of preeclampsia. This is also of relevance to nephrologists, who may see these patients if AKI occurs. Our research also reinforces the well-established association between hypertensive disorders of pregnancy and later development of end-stage kidney disease (ESKD). Ideally, nephrologists will become involved before kidney disease has progressed to this stage.”

Preeclampsia, but not gestational hypertension, correlated with an increased risk for AKI, Dr. Shapiro notes. Neither preeclampsia nor gestational hypertension were associated with AKI requiring dialysis, although this outcome was particularly infrequent. Both hypertensive disorders of pregnancy were associated with the subsequent development of ESKD. “The main takeaway is that AKI in this population is rare, but that a history of preeclampsia is linked with an increased future risk of AKI (Table),” he says.

Monitoring of Kidney Function After Preeclampsia Recommended

“For OB/GYNs, our study suggests that patients with preeclampsia may benefit from monitoring of kidney function, including after resolution of the episode,” Dr. Shapiro says. For nephrologists, our findings support the inclusion of preeclampsia on the list of factors associated with vulnerability to AKI and highlight the importance of pregnancy history when assessing a patient’s risk profile for AKI.”

 Dr. Shapiro and colleagues concur that the pathophysiology of preeclampsia and its effects on the kidneys remains an incomplete but evolving picture that future studies will hopefully continue to elucidate. “With a better understanding of the pathophysiology, therapeutic targets can be identified to better treat or prevent preeclampsia and minimize damage to the kidneys,” he says. “Future studies may also examine strategies to address the increased risk for AKI associated with a past episode of preeclampsia.