The HAPO study found a continuous association between hyperglycemia at 24-32 weeks of gestation, below the diagnostic levels of gestational diabetes mellitus (GDM), and adverse pregnancy outcomes, suggesting the need to reconsider the diagnostic criteria for GDM. Recently, a consensus for diagnosis of diabetes in pregnancy was published, based on the results of the HAPO study. Diagnosing for diabetes is considered already in the first trimester with fasting plasma glucose (FPG), but oral glucose tolerance test is recommended to be performed only at 24-28 weeks of gestation. Identifying all pregnant women at risk for GDM in the first trimester would allow an individualization of obstetric care and establishment of a dietetic and exercise plan since earlier stages of pregnancy with potential benefits for both mother and fetus.
The glycemic metabolism varies throughout pregnancy, as insulin resistance increases during pregnancy. However the cut-off values for blood glucose tests in screening and diagnosing GDM are independent of gestational age.
The objectives of this study are to verify if the pregnant women with and without GDM diagnosed in the second/third trimester are already different from each other in the first trimester regarding FPG levels and to study the evolution of the FPG throughout pregnancy