INTRODUCTIONThe most common form of pregestational diabetes in pregnancy is type 2 diabetes, requiring strict metabolic monitoring owing to the risk of adverse pregnancy outcomes. Our study aimed to identify predictors of composite maternal outcome (CMO) and fetal outcome (CFO) separately in pregnant women with early-onset type 2 diabetes (PwEOT2D).METHODSThe cross-sectional pilot study included 60 PwEOT2D by recording age, socioeconomic determinants, preconception body mass index (pBMI), preconception (pHbA1c) and trimester-specific glycated hemoglobin (HbA1c), gestational weight gain (GWG), and pregnancy outcomes. We defined CMO as at least one of the following: gestational hypertension, preeclampsia, eclampsia, preterm delivery, or emergency section. CFO included at least one of the following: small or large for gestational age, macrosomia, neonatal hypoglycemia, or admission to the neonatal intensive care unit.RESULTSCMO was detected in 55% and CFO in 35% of PwEOT2D. The majority of PwEOT2D with CMO lived in suburban areas (73.1%), while those without CMO mostly lived in rural areas (51.9%, p = 0.014). Moreover, PwEOT2D with CMO had comparable pBMI to those without CMO (31.45 ± 6.27 versus 28.99 ± 6.28 kg/m2, p = 0.136). However, PwEOT2D with CMO had higher pHbA1c (7.28 ± 0.95 versus 6.46 ± 0.96%, p = 0.002) and first trimester HbA1c (7.24 ± 1.08 versus 6.42 ± 0.97%, p = 0.003). Similarly, PwEOT2D with CFO had higher pHbA1c (7.84 ± 0.95 versus 6.41 ± 0.67%, p < 0.001) and first trimester (7.29 ± 1.07 versus 6.65 ± 1.07%, p = 0.032) and second trimester HbA1c (6.45 ± 0.87 versus 5.96 ± 0.82%, p = 0.038). Additionally, GWG was higher in the second (4.38 ± 2.01 versus 3.33 ± 1.61 kg, p = 0.032) and third trimester (5.66 ± 2.93 versus 3.89 ± 2.61 kg, p = 0.002) compared with those without CMO. Regression analysis identified pHbA1c, first trimester of pregnancy, and community type as predictors of CMO, while pHbA1c and the occurrence of CMO were predictors of CFO.CONCLUSIONSOur results imply that preconception and first trimester of pregnancy HbA1c, as well as community disparities, are predictors of CMO, while the predictors of CFO were only preconception HbA1c and the occurrence of CMO in pregnant women with EOT2D. Therefore, tailoring preventive strategies, followed by achieving and sustaining trimester-specific metabolic control, might improve pregnancy outcomes in women with EOT2D.