Protein:creatinine ratio in uncomplicated twin pregnancy

Women with twin pregnancies may have higher rates of isolated proteinuria than do those with singletons. We compared protein-to-creatinine (P:C) ratios longitudinally through gestation in uncomplicated twin and singleton pregnancies.

P:C ratios were compared at 3 times points in 102 (51 twins, 51 singletons) healthy gravid patients who did not have preeclampsia develop, using linear and logistic regression techniques.

P:C ratio increased significantly over gestation in all patients. This increase was significantly greater in twins than in singletons. The odds of P:C ratio >0.19 was 3.5 times higher in twins between 34 and 38 weeks.

Women with uncomplicated twin pregnancies have greater protein excretion as measured by P:C ratios than do those with singletons. In early pregnancy, protein excretion is similar, but it diverges significantly by the latter third trimester. We suggest that normal values for proteinuria in twins may differ from those in singletons, and warrant further evaluation.