Background: The purpose of the study is to establish and quantitatively assess protein markers and their combination in association with insulin uptake that may be have value for early prospective recognition of diabetic fetopathy (DF) as a complication in patients with diabetes mellitus during gestation. Methods: Proteomic surveying and accurate quantitative measurement of selected proteins from plasma samples collected from the patients with gestational diabetes mellitus (GDM) and type 2 diabetes mellitus (T2DM) who gave birth of either healthy or affected by maternal diabetes newborns was performed using mass spectrometry. Results: We determined and quantitatively measured several proteins, including CRP, CEACAM1, CNDP1 and Ig-family that were significantly differed in patients that gave birth of newborns with signs of DF. We found that patients with newborns associated with DF are characterized by significantly decreased CEACAM1 (113.18 ± 16.23 ng/mL and 81.09 ± 10.54 ng/mL in GDM and T2DM, p < 0.005) in contrast to control group (515.6 ± 72.14 ng/mL, p < 0.005). On the contrary, the concentration of CNDP1 was increased in DF-associated groups and attained 49.3 ± 5.18 ng/mL and 37.7 ± 3.34 ng/mL (p < 0.005) in GDM and T2DM groups, respectively. Among other proteins, dramatically decreased concentration of IgG4 and IgA2 subclasses of immunoglobulins were noticed. Conclusion: The combination of the measured markers may assist (AUC = 0.893 (CI 95%, 0.785-0.980) in establishing the clinical finding of the developing DF especially in patients with GDM who are at the highest risk of chronic insulin resistance.Cells 2020, 9, 1032 2 of 22 mellitus, type 2 diabetes mellitus (T2DM) or gestational diabetes mellitus (GDM) suffered by pregnant women. Diabetic fetopathy is the cause of premature birth, chronic hypoxia, respiratory depression, asphyxia of the fetus at birth, accompanied by various metabolic disorders, and can also be the cause of newborns death [1][2][3]. This is one of the most common forms of obstetric complications and perinatal losses evoked from hyperglycemia manifested in a disturbance of glucose tolerance and occurred or was first recognized during pregnancy [4]. It is also possible that the disturbance of carbohydrate metabolism could precede pregnancy but has not been previously detected [5,6]. During pregnancy, hyperglycemia is induced by a gradually increased insulin resistance due to both placental hormones and the mother's hormones (prolactin, estrogen and cortisol). The growing concentration of these hormones is compensated by a decrease in the clearance of endogenously produced insulin [2,5].According to the WHO data for 2016, up to 25% of pregnant women are at risk of hyperglycemia during pregnancy [7]. An overwhelming majority (from 75% to 90%) of elevated blood glucose levels during pregnancy emerges from the already progressing GDM [8,9]. Statistics of the IDF for 2017 demonstrate up to 204 million women aged between 20 to 79 years live with different types of diabetes, while up to 21.3 m...