Materials and methods
non-GDM, GDM, diabetic, Diabetes
GDM, WEST, SECONDARY, DIABETES
We conducted a secondary analysis of a randomized, non-inferiority trial among Iranian pregnant women. The protocol was approved by the national ethics committee of the National Institute for Medical Research Development (Approval number: IR.NIMAD.REC.1394.013). In addition, the Iranian Ministry of Health and Medical Education (MoHME) approved the study protocol, and pre-specified GDM modalities were made available to all those provinces as mandatory guidelines. Detailed methods have been described elsewhere (Cluster randomization was stratified by five geographic regions (North, East, West, South, and Center) of Iran. One province in each stratum was randomly selected (Golestan, South Khorasan, Kurdistan, Bushehr, and Yazd, respectively); in the next step, all cities in each province were classified in two clusters of the center of the province and other cities and after that four cities were randomly selected from the list of other cities in each province. Finally, five different protocols were randomly allocated to each provincial center. Also, in the cluster of other cities, four other cities in each province were randomly allocated to the rest of the protocols (For the current study, all pregnant women who classified as non-GDM in the first trimester of pregnancy were randomized for GDM re-screening between 24 and 28 weeks, using either a One-step (n = 14611) or Two-step (n = 14160) approach. In this respect, One-step screening was based on a 75 gram 2-h oral glucose tolerance test (75 g 2h-OGTT). Participants were labeled as GDM if at least one values exceeded the cut-off, including fasting plasma glucose ≥ 92mg/dl, but <126 mg/dl and/or 2-h OGTT ≥153 mg/dl. The Two-step approach was as follows: firstly, a 50 g oral glucose challenge test (GCT) was performed regardless of the fasting status. One-hour plasma glucose level ≤140 mg/dl was considered negative and needed no further test. Otherwise, women underwent 100-g 3h-OGTT. GDM was diagnosed if two glucose values were above the thresholds including: FPG >95 mg/dl; 1-h glucose level >180 mg/dl; 2-h glucose level >155 mg/dl; and 3-h glucose level >140 mg/dl.It should be noted that we excluded all those pregnant women who assigned to the protocol B in original study (All study participants were followed until delivery, and their outcomes were recorded in detail. Those pregnant women with a GDM diagnosis, either with a One- or Two-step approach, received specific prenatal and diabetic care, as recommended by the ACOG and the American Diabetes Association (2016) (Flowchart of the study. *We excluded protocol B since it was not exact comparable with other standard approaches. In this protocol, GDM was defined as 