Primary prevention of gestational diabetes mellitus through nutritional factors: a systematic review.

Gestational diabetes mellitus (GDM), defined as any degree of glucose intolerance with onset during pregnancy, is increasing worldwide, mostly because obesity among women of reproductive age is continuously escalating. GDM is associated with adverse maternal and fetal outcomes. The aim of this article was to systematically review literature on the effectiveness of nutritional factors before or during pregnancy to prevent GDM.