Kidney injury during pregnancy: associated comorbid conditions and outcomes

To investigate the characteristics of women who have kidney injury during pregnancy.

Medical records of all women who gave birth at our institution between January 1, 2005, and December 31, 2010, were retrospectively reviewed electronically. We identified those who incurred a kidney injury [defined by modified Acute Kidney Injury Network (AKIN) criteria: serum creatinine (sCr) increase ≥0.3 mg/dL] during pregnancy or within 30 days postpartum. Identified case records were reviewed in detail.

During the study period, 54 women had a kidney injury (0.4 % estimated incidence) with a mean (SD) increase in sCr of 0.46 (0.29) mg/dL; most injuries were AKIN stage 1 with transient increases in sCr. Most of the women (n = 48, 87.3 %) had substantial preexisting or pregnancy-associated comorbid conditions (e.g., kidney disease, hypertension, diabetes), complications (e.g., preeclampsia, HELLP syndrome), or a complicated obstetric course (hemorrhage, infections) that could have contributed to the development of a kidney injury. Two patients had AKIN stage 3 injuries: a previously healthy patient who had a massive hemorrhage during cesarean delivery, and a patient with a renal transplant who had deterioration and eventual postpartum failure of her transplanted kidney.

The majority of pregnancy-associated kidney injuries were transient and occurred in women with substantial comorbid conditions or complicated pregnancies.