Antioxidants/pharmacology; Apoptosis/drug effects; Diabetes Mellitus, Experimental/drug therapy; Folic Acid/pharmacology; Oxidoreductases/metabolism; Pregnancy in Diabetics/drug therapy; Vascular Endothelial Growth Factor A/metabolism; Yolk Sac/drug effects; Animals; Antioxidants/therapeutic use; Caspase 3/metabolism; Catalase/metabolism; Diabetes Mellitus, Experimental/embryology; Diabetes Mellitus, Experimental/genetics; Diabetes Mellitus, Experimental/metabolism; Diabetes Mellitus, Experimental/pathology; Female; Folic Acid/therapeutic use; Gene Expression Regulation, Developmental/drug effects; Gestational Age; Glutathione Peroxidase/metabolism; Glycine N-Methyltransferase/metabolism; Oxidoreductases/genetics; Pregnancy; Pregnancy in Diabetics/genetics; Pregnancy in Diabetics/metabolism; Pregnancy in Diabetics/pathology; Proto-Oncogene Proteins c-bcl-2/metabolism; RNA, Messenger/metabolism; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species/metabolism; Superoxide Dismutase/metabolism; Vascular Endothelial Growth Factor A/genetics; Yolk Sac/enzymology; Yolk Sac/pathology; bcl-2-Associated X Protein/metabolism