Objectives: Pancreatic duodenal homeobox factor-1 ( PDX - 1 ) and neurogenin-3 ( NGN-3 ) are progenitor cell markers in the pancreas. The aim was to compare their serum levels in women with and without gestational diabetes mellitus (GDM). Material and Methods: This prospective, cross-sectional study included two groups: (a) Women with normal gestation and (b) with GDM. PDX-1 and NGN-3 serum expression was determined by qRT-PCR. Student’s t -test or the Mann–Whitney U-test was used to contrast both groups and the Pearson or Spearman correlation was used. A multiple regression was done introducing body mass index and the relative expression of both genes as independent variables and glucose as dependent variable. Statistical significance was tested at P ≤ 0.05 level. Results: Thirty-eight patients (mean age was of 29.00 ± 7.74 years) were included, 22 belonged to the normal pregnancies, and 16 to GDM. Using the ΔΔCt method, the expression fold change for PDX-1 was 0.458 and for NGN-3 it was 0.361. There was a significant positive correlation between the expressions of both genes. The multiple regression was significant for both genes expression and glucose levels in case of having normal weight. Conclusion: PDX-1 and NGN-3 low serum expression could be predictors of higher glucose levels in normal pregnancies.