Additional file 1 of Association between lower uterine wall thickness measured at 18–22 weeks of gestation and risk of Preterm Birth: a prospective cohort study

Additional file 1: The reliability of LUW thickness measurement. Figure 1. Bland-Altman plot showed the difference of LUWthickness measurement between two operators (Inter-observer reliability)(N=40)]. Figure 2. Bland-Altman plot showed the differenceof LUW thickness measurement between two measurements of the same operator(Intra-observer reliability) (N=46)].