Postpartum human breast milk levels of neutrophil gelatinase-associated lipocalin (NGAL) and matrix metalloproteinase-9 (MMP-9)/NGAL complex in normal and pregnancies complicated with insulin-dependent gestational diabetes mellitus. A prospective pilot case-control study.

Neutrophil gelatinase-associated lipocalin (NGAL) and its complex with matrix metalloproteinase-9 (MMP-9) are present in a variety of human tissues and extracellular fluids. The aim of this pilot prospective case-control study was to detect NGAL and MMP-9/NGAL complex in human breast milk postpartum in women with normal and pregnancies that developed insulin-depended gestational diabetes mellitus (iGDM). We detected both biomarkers in human breast milk and concentrations were determined at the first day of colostrum secretion and two days after, in 22 normal pregnancies and 13 pregnancies with iGDM. Mean NGAL concentration decreased significantly from the first to the second sample, in both groups. Mean MMP-9/NGAL complex concentration decreased also significantly from the first to the second sample in normal pregnancies. Mean complex concentration was significantly higher in diabetic pregnancies compared to normal ones in the second sample.IMPACT STATEMENT