CYP17A1 and gestational diabetes: Since in the cord blood there were three 5α/β-reduced metabolites of 17-hydroxyprogesterone and one 5α-reduced androgen, which showed lower levels in the GDM+ group, it can be concluded that GDM may be associated with lower activity of CYP17A1 in the C17-hydroxylase step at least (Figure 1, Table S2).