Study Type of the study Intervention Population Inclusion criteria Outcomes Corrado et al., 2011 [8 ] Randomized controlled open-label study 2 g myoinositol +200 mcg folic acid vs. 200 mcg folic acid (placebo) twice/day MI group: 24 Control group: 45 GDM (OGTT between 24 and 28 weeks) HOMA-IR decreased significantly greater in MI group ( ) Adiponectin levels increased in the MI group and decreased in the placebo group ( ) D’Anna et al., 2013 [9 ] Randomized controlled open-label study 2 g myoinositol +200 mcg folic acid vs. 200 mcg folic acid (placebo) twice/day MI group: 110 Control group: 110 First-degree relatives affected by type 2 diabetes Single pregnancy Prepregnancy kg/m2 Fasting plasma mg/dL and random mg/dL The incidence of GDM reduced in MI group compared with the placebo group ( ) Mean fetal weight at delivery reduced in MI group. D’Anna et al., 2015 [19 ] Randomized controlled open-label study 2 g myoinositol +200 mcg folic acid vs. 200 mcg folic acid (placebo) twice/day MI group: 110 Control group: 110 Prepregnancy kg/m2 Age 18-45 Fasting mg/dL The incidence of GDM reduced in the MI group compared with the placebo group ( ) Matarrelli et al., 2013 [17 ] Randomized controlled double-blind study 2 g myoinositol +200 mcg folic acid vs. 200 mcg folic acid (placebo) twice/day MI group: 36 Control group: 39 Single pregnancy Elevated fasting glucose ( mg/dL and 126 mg/dL) in the first or early second trimester The incidence of GDM reduced in MI group compared with placebo group ( ) Less necessary of insulin therapy at a later gestational age, higher gestational age at delivery in the MI group Malvasi et al., 2014 [18 ] Randomized controlled double-blind study 2 g myoinositol +400 mcg D-chiroinositol +400 mcg folic acid +10 mg manganese vs. placebo daily Study group: 24 Control group: 24 Healthy pregnancies 13-24 weeks kg/m2 and <30 kg/m2 Age 30-40 Reduction of triglycerides, total cholesterol, LDL-, and HDL-cholesterol Santamaria et al., 2016 [20 ] Randomized controlled open-label study 2 g myoinositol +200 mcg folic acid vs. 200 mcg folic acid (placebo) twice/day MI group: 110 Control group: 110 Single pregnancy Prepregnancy kg/m2 and <30 kg/m2 First trimester fasting mg/dL and/or random mg/dL The incidence of GDM reduced in the MI group compared with the placebo group ( )