A trend for higher odds of maternal morbidity was seen for women with Hb concentration <90 g/L during pregnancy compared with women with Hb concentration ≥90 g/L (OR (95% CI); 1.80 (0.99−3.26)).131 A second study reported on a composite adverse maternal outcome defined as preeclampsia, GDM, preterm birth, PPH, puerperal morbidity, or surgical wound complication. The gene discussed is GSTM1; the disease is gestational diabetes.