Objective: To explore diagnostic value of prenatal ultrasound screening in velamentous umbilical cord insertion (VCI) and its influence on perinatal outcomes, and to provide theoretical basis for clinical practice. Methods: Fifty-eight pregnant women diagnosed with VCI before or after delivery admitted to the First Affiliated Hospital of Xi'an Jiaotong University were selected from January 2012 to December 2022. The clinical features and perinatal outcomes of 45 women finally with VCI after delivery (VCI group) were retrospectively analyzed, and 225 women with normal umbilical cord attachment were selected as the control group during the same period. Results: (1) Among 58 women, 54 (93.1%, 54/58) were diagnosed with VCI by prenatal ultrasound screening, 4 patients (6.9%, 4/58) were missed; and 13 (22.4%, 13/58) were misdiagnosed. Finally, a total of 45 women were confirmed by postpartum placental examination, and 11 (24.4%,11/45) were combined with vasa previa. (2) There were no differences in age, number of pregnancies, and number of induced abortions between the two groups (all P>0.05). Compared with the control group, the rate of assisted reproductive technology [13.3% (6/45) vs 0.4% (1/225); P<0.01], and twin pregnancy rate [8.9% (4/45) vs 0.4% (1/225); P<0.01] in the VCI group were significant higher. (3) Compared with the control group, the rate of placenta previa, succenturiate placenta, vasa previa, postpartum hemorrhage, prenatal hemorrhage and postpartum intrauterine remainder in the VCI group were significant higher (all P<0.05); there was no significant difference in the incidence of placental abruption, premature rupture of membranes, fetal distress and single umbilical artery between the two groups (all P>0.05). The incidence of fetal structural abnormalities in the VCI group (4.4%, 2/45) was higher than that in the control group (1.3%, 3/225), but there was no significant difference between the two groups (P=0.195). (4) The cesarean section rate [75.0% (33/44) vs 45.1% (101/224); P<0.01], preterm birth rate [29.5% (13/44) vs 5.4% (12/224); P<0.01], rate of small for gestational age [20.5% (9/44) vs 5.4% (12/224); P<0.01] in the VCI group were significant higher. However, neonatal birth weight [(2 928±552) vs (3 353±498) g; P<0.01], and 1-minute Apgar score (median: 10 vs 10; P<0.01) in the VCI group were lower than those in the control group. Conclusions: Prenatal ultrasound screening is an important method to diagnose VCI. VCI is more prone to adverse pregnancy outcomes, such as postpartum hemorrhage, premature delivery, small for gestational age, et al. Its risk factors include twin pregnancy, assisted reproductive technology, placenta previa, and para-placenta.