SAN DIEGO – Pregnant women with kidney disease face an increased risk of adverse maternal outcomes including maternal mortality independent of underlying comorbid conditions that can occur with kidney disease, according to Dr. Shailendra Sharma.
"Any degree of kidney disease during pregnancy should be recognized and should be treated promptly with respect because we now know that can lead to bad outcomes down the road," Dr. Sharma said in an interview during a poster session at the Kidney Week 2012. "This is not something that should be underestimated."
Dr. Shailendra Sharma
Dr. Sharma, a second-year renal fellow at the University of Colorado, Aurora, and his associates retrospectively studied the records of 646 women with kidney disease who gave birth in Colorado and Utah between 2000 and 2011 at facilities operated by Intermountain Health Care. For comparison, the researchers randomly selected the records of 62,757 pregnancies from women without kidney disease.
Kidney disease was defined by ICD-9 code, and adverse maternal outcomes were defined as preterm delivery (prior to 37 weeks’ gestation), delivery by cesarean section, length of hospital stay, and maternal death. The researchers used multivariate logistic regression analysis to examine the association between kidney disease and adverse maternal outcomes. Covariates included in the fully adjusted model were maternal age, race, history of diabetes, chronic hypertension, liver disease, and connective tissue disorders.
The mean age of patients was 28 years. Compared with women who did not have kidney disease, those who did were significantly more likely to have comorbid conditions including diabetes (12% vs. 1%, respectively); chronic hypertension (2% vs. 7%); liver disease (9% vs. 1%); and connective tissue disorders (7% vs. 0.4%). They also were more likely to have preeclampsia/eclampsia (11% vs. 3%), to have a longer hospital stay (a mean of 3 vs. 2 days), and to give birth to a lower-weight infant (a mean of 3,067 g vs. 3,325 g).
After the investigators adjusted for age, race, history of diabetes, hypertension, liver disease, and connective tissue disorders, Dr. Sharma and his associates found that pregnant women with kidney disease had a significantly increased risk of death (OR, 3.38); preterm delivery (OR, 1.95); delivery via C-section (OR, 1.38); and longer length of hospital stay (OR, 1.39). "The most striking finding was the association of kidney disease with maternal mortality," Dr. Sharma said at the meeting, which was sponsored by the American Society of Nephrology. "The magnitude of this association surprised us."
He said that the retrospective design of the study is a limitation. "If there’s a prospective study moving forward, specifically designed to answer these questions, then it probably would help us establish the causality."
The study was funded by the National Institute of Diabetes and Digestive and Kidney Diseases. Dr. Sharma said he had no relevant financial conflicts to disclose.