However, IGFBP1 levels in the second trimester were associated only with insulin-resistant GDM (OR = 0.28 (0.16–0.47) per s.d. increase in IGFBP1 levels; P < 0.001); there was no statistically significant association between second trimester IGFBP1 plasma levels and insulin-deficient GDM (Table 3). Here, IGFBP1 is linked to gestational diabetes.