Haematological biomarkers demonstrating very good sensitivity and specificity, needing to be confirmed in larger cohorts of at least 100 patients to assess potential substitution for OGTT, are Sex hormone binding globulin (SHBG) and metabolomic profiling for phospholipids, though the latter may be too expensive to be used as a screening or diagnostic test for GDM. The gene discussed is SHBG; the disease is gestational diabetes.