“…Between the years 2000 and 2016, 48 articles were published with a total sample of 3,594,803 pregnant women (range: 1038–1,824,913) in 7 countries. Of the 48 studies, 21 were conducted in China [ 41 – 43 , 45 , 48 – 64 ], 8 in the Republic of Korea [ 65 , 68 , 70 – 72 , 74 , 75 , 77 ], 6 in Thailand [ 37 , 46 , 79 – 81 , 83 ], five in Japan [ 39 , 47 , 73 , 76 , 78 ], five in Taiwan (China) [ 38 , 44 , 66 , 67 , 69 ], one in Malaysia [ 82 ], one in Singapore [ 40 ], and one in Vietnam [ 36 ]. Two-thirds of the studies ( n = 32) used a two-step screening procedure, that is, women underwent a 1-hour glucose challenge test (GCT) and a 3-hour glucose tolerance test (GTT) if GCT were abnormal.…”