title: Umbilical artery velocity waveforms are not valid indices for assessing growth retardation in utero.
abstract: Blood flow velocity waveforms from the umbilical artery of 126 normal fetuses with no complications at 20-41 weeks and in 31 growth-retarded fetuses, were recorded using pulsed Doppler ultrasound. A total of 140 examinations were performed on normal fetuses and 49 on growth-retarded fetuses. The resistance index (RI) was used as an index of blood flow resistance. In 30 of the 31 growth-retarded fetuses (96.8%), the values of RI were within the mean +/- 2 S.D. of normal fetuses. Placental/fetal weight ratio (P/F ratio) was assessed. All values of P/F ratio of growth-retarded fetuses were within the mean +/- 2 S.D. of normal values. Small placentas expressed as a normal P/F ratio almost always associated with normal RI values. Therefore, measurement of RI on umbilical artery blood flow velocity waveform by Doppler ultrasound cannot serve as a valid diagnostic index to predict growth retardation of the fetus in utero.
authors.affiliation: Department of Obstetrics and Gynecology, Shimane Medical University, Izumo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Hata
authors.forename: S
authors.initials: S
authors.lastname: Katoh
authors.forename: D
authors.initials: D
authors.lastname: Senoh
authors.forename: S
authors.initials: S
authors.lastname: Aoki
authors.forename: O
authors.initials: O
authors.lastname: Takamiya
authors.forename: T
authors.initials: T
authors.lastname: Hata
authors.forename: M
authors.initials: M
authors.lastname: Kitao
mesh_terms: D001783:Blood Flow Velocity; D005260:Female; D005317:Fetal Growth Retardation / Q000175:diagnosis*; D006801:Humans; D011247:Pregnancy; D014465:Ultrasonics; D014463:Ultrasonography; D014469:Umbilical Arteries / Q000502:physiology*