5.3.0.0 Di­ag­no­sis

5.3.1.0 Overview

GDM car­ries risks for the moth­er, fetus, and neonate. Not all ad­verse out­comes are of equal clin­i­cal im­por­tance. The Hy­per­glycemia and Ad­verse Preg­nan­cy Out­come (HAPO) study (74), a large-‍scale multi­na­tion­al co­hort study com­plet­ed by more than 23,000 preg­nant women, demon­strat­ed that risk of ad­verse ma­ter­nal, fetal, and neona­tal out­comes con­tin­u­ously in­creased as a func­tion of ma­ter­nal glycemia at 24–28 weeks of ges­ta­tion, even with­in ranges pre­vi­ous­ly con­sid­ered nor­mal for preg­nan­cy. For most com­pli­ca­tions, there was no thresh­old for risk. These re­sults have led to care­ful recon­sid­er­a­tion of the di­ag­nos­tic cri­te­ria for GDM. GDM di­ag­no­sis (Table 2.6) can be ac­com­plished with ei­ther of two strate­gies:

1. “One-‍step” 75-g OGTT or
2. “Two-‍step” ap­proach with a 50-g (nonfast­ing) screen fol­lowed by a 100-g OGTT for those who screen pos­i­tive

Dif­fer­ent di­ag­nos­tic cri­te­ria will iden­tify dif­ferent de­grees of ma­ter­nal hy­per­glycemia and ma­ter­nal/fetal risk, lead­ing some ex­perts to de­bate, and dis­agree on, op­ti­mal strate­gies for the di­ag­no­sis of GDM.

Table 2.6 - Screen­ing for and di­ag­no­sis of GDM