Pregnancy induces longitudinal changes in urinary C-peptide creatinine ratio in women with type 1 diabetes

Changes in maternal serum C-peptide have been described during pregnancy in women with Type 1 diabetes. We aimed to determine whether in these women, C-peptide, as measured by the urinary C-peptide creatinine ratio (UCPCR), display changes during the course of pregnancy and in the postpartum period.

In this longitudinal study including 26 women, UCPCR was measured in the first, second, and third trimester of pregnancy, and postpartum, using a high sensitivity two-step chemiluminescent microparticle immunoassay.

UCPCR was detectable in 7/26 (26.9%) participants in the first trimester, 10/26 (38.4%) in the second trimester, and 18/26 (69.2%) in the third trimester. Changes in UCPCR concentrations were observed throughout pregnancy, significantly increasing from first to third trimester. UCPCR concentration in the three trimesters was associated with a shorter duration of diabetes and in the third trimester also with first trimester UCPCR.

UCPCR detects longitudinal changes during pregnancy in women with type 1 diabetes mellitus, more marked in those with shorter diabetes duration.