Pregnancy and chronic kidney disease: a challenge in all CKD stages.

BACKGROUND AND OBJECTIVES: Chronic kidney disease (CKD) is a challenge for pregnancy. Its recent classification underlines the importance of its early phases. This study's aim was to evaluate outcomes of pregnancy according to CKD stage versus low-risk pregnancies followed in the same center.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The prospective analysis was conducted from January 2000 to May 2009 with the start of observation at referral and end of observation 1 month after delivery. Ninety-one singleton deliveries were studied; 267 "low-risk" singleton pregnancies served as controls. Because of the lack of hard end points (death, start of dialysis), surrogate end points were analyzed (cesarean section, prematurity, neonatal intensive care).

RESULTS: CKD outcome was worse than physiologic pregnancies: preterm delivery (44% versus 5%); cesarean section (44% versus 25%); and need for neonatal intensive care (26% versus 1%). The differences were highly significant in stage 1 CKD (61 cases) versus controls (CKD stage 1: cesarean sections = 57%, preterm delivery = 33%, intensive care = 18%). In CKD, proteinuria and hypertension were correlated with outcomes [proteinuria dichotomized at 1 g/24 h at referral: need for intensive care, relative risk (RR) = 4.16 (1.05 to 16.46); hypertension: preterm delivery, RR = 7.24 (2.30 to 22.79); cesarean section, RR = 5.70 (1.69 to 19.24)]. Statistical significance across stages was reached for preterm delivery [RR = 3.32 (1.09 to 10.13)].

CONCLUSIONS: CKD is a challenge for pregnancy from early stages. Strict follow-up is needed for CKD patients, even when there is normal renal function.