Kidney Disease in Pregnancy Often Overlooked for Care

— These women had less nephrology care prior to end-stage disease onset

by
Kristen Monaco, Senior Staff Writer, MedPage Today
December 8, 2023

Women with pregnancy-related end-stage kidney disease (ESKD) had lower access to care compared with those who had other causes of ESKD, according to results from a cohort study.

Women with a pregnancy-related primary cause of ESKD had significantly reduced access to kidney transplant — defined as joining the deceased donor waiting list or receiving a kidney transplant from a living donor — when compared with those who had other causes of ESKD, including other or unknown cause (adjusted subhazard ratio [aSHR] 0.82, 95% CI 0.67-0.99), diabetes or hypertension (aSHR 0.81, 95% CI 0.67-0.98), or glomerulonephritis or cystic kidney disease (aSHR 0.51, 95% CI 0.43-0.66), according to Lauren Kucirka, MD, PhD, of the University of North Carolina at Chapel Hill in North Carolina, and colleagues.

These women were also 53% less likely to receive nephrology care prior to ESKD onset, and 69% less likely to have had a graft or arteriovenous fistula placed prior to onset, researchers reported in JAMA Network Open.

“Though our study only included those with a pregnancy-related primary cause of ESKD, our findings may serve as a foundation to guide clinical care and future research within the much larger population of patients with pregnancy-related AKI who are at significant risk for mortality and severe morbidity,” Kucirka’s group suggested.

Along with the care and outcome disparities these women faced, racial disparities were emphasized in pregnancy-related end-stage kidney disease. While Black patients made up 16.2% of the general U.S. birthing population, they made up 31.9% of all patients with pregnancy-related ESKD.

“[A]cute kidney injury and other risk factors for [pregnancy-related end-stage kidney disease] may be underdiagnosed [in at-risk women] due to physicians’ historical use of biased race-based kidney function estimation equations which could have inappropriately labeled individuals included in this study cohort as having better kidney function,” said Dinushika Mohottige, MD, MPH, of Icahn School of Medicine at Mount Sinai in New York, and L. Ebony Boulware, MD, MPH, of Wake Forest University School of Medicine in Winston Salem, North Carolina, in an accompanying commentary, while also praising the researchers for being among the first in the U.S. to quantify these health inequities.

“Pregnancy-related knowledge among nephrologists has also been demonstrated to be low, and many women may experience missed opportunities for proteinuria and other screenings,” they added.

Despite significantly lower access to care and transplants, ESKD survival was actually highest amongst patients with pregnancy-related causes and glomerulonephritis or cystic kidney disease, and was lowest for those with diabetes or hypertension as the primary cause of ESKD.

For the study, Kucirka’s group drew data on reproductive-age women with incident ESKD from the U.S. Renal Data System paired with CDC maternal-birth data from 2000 to 2020. Pregnancy-related primary cause of ESKD was identified via ICD-9 and -10 codes reported by the primary nephrologist on CMS form 2728.

The average age for women with pregnancy-related ESKD was 30.2 and BMI was 27.1. These women had higher rates of diabetes (5.3%) and hypertension (68.8%) compared with the general birthing population in 2020 (1.1% and 2.5%, respectively).

Compared with people with other causes of ESKD, those with pregnancy-driven disease were younger, more likely to report Hispanic ethnicity, have Medicaid only for insurance, and be currently employed or in school.

The researchers pointed out that the study likely only included “the most extreme cases of pregnancy-related ESKD” where the nephrologist thought pregnancy was the main driver of the disease. Therefore, the “true burden of ESKD related to pregnancy” may have been underestimated.

The editorialists agreed with this, adding that existing categories on the 2728 form — used to identify these patients — lacks data regarding diagnostic evaluation, time of diagnosis in the context of pregnancy, or any additional categorization of this condition into those with underlying chronic kidney disease or predisposing conditions like preeclampsia and glomerular disease.