Results
Fetal fraction was positively correlated with the difference of birth weight (β=0.004, 95%CI: 0.001~0.006). Higher fetal fraction was significantly associated with the increased risk of birthweight discordance of 20% (adjusted OR:1.073, 95%CI: 1.009~1.142) and 25% (adjusted OR:1.092, 95%CI: 1.006~1.185) and sIUGR(adjusted OR:1.130, 95%CI: 1.038~1.231). We obtained the optimum cut-off point of fetal fraction ≥ 11.790, ≥ 14.800 and ≥ 14.800 for birthweight discordance of 20% and 25% and sFGR, respectively.