Strengths and Limitations
To the best of our knowledge, our study is the first to evaluate 1st trimester FPG levels and its association with T2DM up to 5-year follow-up. The strengths of this study include the large cohort and the linkage of two detailed databases with systematic data collection measured rather than reported. Our results were based directly on the laboratory glucose levels and INDR solid criteria and not on reported GDM or T2DM diagnosis. Nevertheless, our study was not free of limitations, mainly derived from its retrospective nature. 1) our study did not involve a structured GDM or T2DM screening, therefore, it may be biased by women selected to be screened. 2). The Meuhedet HMO pregnancy registry has been limited to the last five years, therefore we lack data on longer postpartum follow-ups. Also, the registry lacked data on other major GDM and T2DM risk factors, such as gestational weight gain, ethnicity, a family history of T2DM, lipid profile, or possible after-pregnancy interventions including weight reduction or lifestyle modifications that might have interfered with the risk for T2DM. 3) we did not account for women who might have been offered self-monitoring of glucose values and therefore were excused from the oGTT for the diagnosis of GDM. This shortcoming could have led to an underestimation of the size effect.