PID1 and preeclampsia: The results of univariate analysis showed that age ≥3 days, birth weight ≤ 2500 g, prematurity, mother suffering from gestational hypertension, total bilirubin ≥ 15 mg/dl, ACA_PSVd3/PSVd1 ≥ 1, ACA_RId3/RId1 ≥ 1, ACA_PId3/PId1 ≥ 1, MCA_PSVd3/PSVd1 ≥ 1, MCA_RId3/RId1 ≥ 1, and MCA_PId3/PId1 ≥ 1 were risk factors for the development of GMH-IVH in neonatal hyperbilirubinemia (P < 0.05) (Table 2).