Chronic kidney disease may increase certain risks during pregnancy

Even mild kidney disease during pregnancy may increase certain risks in the mother and baby, according to a study appearing in an upcoming issue of the Journal of the American Society of Nephrology (JASN). The findings may be helpful for guiding prenatal counseling and for monitoring women during pregnancy.

Chronic kidney disease (CKD) is on the rise, and studies suggest that even early stages of the disease can affect pregnancy outcomes. An Italian research team led by Giorgina Barbara Piccoli, MD, Rossella Attini, MD, PhD (University of Torino), and Gianfranca Cabiddu, MD (Azienda Ospedaliera Brotzu) recently conducted a study—called the TOCOS (TOrino-Cagliari Observational Study)—that compared pregnancy outcomes of 504 pregnancies in women with CKD with outcomes of 836 low-risk pregnancies in women without CKD.

The researchers found that the risk for adverse pregnancy outcomes—such as preterm delivery, the need for neonatal intensive care, or the development of hypertension in the mother—increased across CKD stages. However, the risk was not merely linked to reduced kidney function because stage 1 CKD patients and healthy controls differed significantly, despite the fact that patients with stage 1 CKD are asymptomatic and have kidney function within the normal range. The team also found that the risks of intrauterine death or fetal malformations did not differ between patients and healthy controls.

"The findings indicate that any kidney disease—even the least severe, such as a kidney scar form a previous episode of kidney infection, with normal kidney function—has to be regarded as relevant in pregnancy, and all patients should undergo a particularly careful follow-up," said Dr. Piccoli. "Conversely, we also found that a good outcome was possible in patients with advanced CKD, who are often discouraged to pursue pregnancy," she added.

The investigators hope that the new findings may help establish dedicated programs for the early diagnosis and follow up of pregnancy in CKD. "We are presently working on a model for 'grading' the risks that will provide patients and physicians with information when making choices about undergoing and monitoring pregnancies," said Dr. Piccoli.