3 | RESULTS
We included 42 DC twin pregnancy cases, with the DCDA-D group (14 total pairs) and the DCDA-C group (28 randomly selected pairs matched for maternal age and BMI). The larger BW of each twin pair in the DCDA-D group was referred to as DCDA-D-L, and the smaller BW DCDA-D-S. To evaluate the metabolic perturbations of intrauterine growth discordance of DC twin pregnancies, we performed the following three comparisons: DCDA-D-L and DCDA-D-S twins versus control twins (DCDA-C) respectively as comparison 1 and comparison 2. DCDA-D-S vs DCDA-D-L within pair analysis used for comparison 3 (Figure 1 ).