Multiple pregnancies in CKD patients: an explosive mix.

Background And Objectives: CKD and multiple pregnancies bear important risks for pregnancy outcomes. The aim of the study was to define the risk for adverse pregnancy-related outcomes in multiple pregnancies in CKD patients in comparison with a control group of "low-risk" multiple pregnancies.

Design, Setting, Participants, & Measurements: The study was performed in the Maternal Hospital of the University of Turin, Italy. Of 314 pregnancies referred in CKD (2000-2011), 20 were multiple (15 twin deliveries). Control groups consisted of 379 low-risk multiple pregnancies (314 twin deliveries) and 19 (15 twin deliveries) cases with hypertension-collagen diseases. Baseline data and outcomes were compared by univariate and logistic regression analyses.

Results: The prevalence of multiple pregnancies was relatively high in the CKD population (6.4%); all referred cases were in early CKD stages (I-II); both creatinine (0.68 to 0.79 mg/dl; P=0.010) and proteinuria (0.81 to 3.42 g/d; P=0.041) significantly increased from referral to delivery. No significant difference in demographic data at baseline was found between cases and low-risk controls. CKD was associated with higher risk of adverse pregnancy outcomes versus low-risk twin pregnancies. Statistical significance was reached for preterm delivery (<34 weeks: 60% vs 26.4%; P=0.005; <32 weeks: 53.3% vs 12.7%; P<0.001), small for gestational age babies (28.6% vs 8.1%; P<0.001), need for Neonatal Intensive Care Unit (60% vs 12.7%; P<0.001), weight discordance between twins (40% vs 17.8%; P=0.032), and neonatal and perinatal mortality (6.6% vs 0.8%; P=0.032).

Conclusion: This study suggests that maternal-fetal risks are increased in multiple pregnancies in the early CKD stages.