In addition, the levels of serum SIRT1 was decreased in patients with preeclampsia combined with fetal growth restriction, compared with the combined group (p < 0.0001) (Figure 2A); the peak-to-trough ratio of arterial blood flow velocity, pulsatility index and resistance index were all increased in patients with preeclampsia combined with fetal growth restriction, compared with the uncombined group (p < 0.0001) (Figure 2B-D). This evidence concerns the gene SIRT1 and preeclampsia.