title: [The measurement of umbilical artery flow velocity waveforms in normal late pregnancy by Doppler ultrasound].
abstract: Doppler ultrasound was adopted in a study of fetal umbilical artery flow velocity waveforms in 81 cases of late pregnancies (28-41 gestational weeks). The peak systolic/end-diastolic ratio (A/B) and the Pourlot index were used as indices for assessing placental resistance. Both the A/B ratio (2.34 +/- 0.44) and Pourlot index (0.56 +/- 0.07) decreased while the gestational week was increasing, and they had a good correlation with the gestational week (r1 = -0.90, r2 = -0.93). The results indicated that the placental resistance became lower when the gestational week was increasing. This method has been documented a useful noninvasive technique for the exam of placental resistance.
authors.affiliation: Department of Ulirasonics, First Affiliated Hospital, MCH Center of Sichuan Province.
authors.forename: H
authors.initials: H
authors.lastname: Tang
authors.forename: C
authors.initials: C
authors.lastname: Huang
authors.forename: Y
authors.initials: Y
authors.lastname: Tian
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity; D015150:Echocardiography, Doppler; D005260:Female; D006801:Humans; D011247:Pregnancy / Q000502:physiology*; D011263:Pregnancy Trimester, Third; D016216:Ultrasonography, Prenatal; D014469:Umbilical Arteries / Q000000981:diagnostic imaging*