title: Blood flow Doppler velocimetry measured during active labor.
abstract: OBJECTIVE
  To evaluate blood flow Doppler velocimetry during the first and second stages of active labor.
  
  
  METHODS
  A prospective observational study was performed. Patients at term (37-42 weeks gestation), with normal fetal heart rate tracing patterns (categorized as category I) were examined during the first and second stages of labor. The sonographic parameters that were measured included the blood flow resistance of the maternal uterine artery (UtA) and umbilical artery (UA). Wilcoxon-matched pair test was used for the comparison of flows between the first and the second stages of labor.
  
  
  RESULTS
  UtA and UA Doppler velocimetry measurements were obtained from 31 parturients. The left (LT) and right (RT) UtA pulsatility index (PI) was lower in the second stage of labor as compared with the first stage. However, only the LT side reached a statistically significant difference (0.88 ± 0.32 and 0.73 ± 0.18; P = 0.005). Compared with the first stage of labor, UA PI was significantly higher during the second stage of labor (0.72 ± 0.17 vs. 0.84 ± 0.33; respectively, P = 0.05).
  
  
  CONCLUSIONS
  Significant blood flow resistance changes in maternal as well as in fetal blood vessels occur during the second stage as compared with the first stage of active labor.
authors.affiliation: Department of Obstetrics and Gynecology, Faculty of Health Sciences, Soroka University Medical Center, Ben-Gurion University of the Negev, POB 151, 84101, Beer-Sheba, Israel.
authors.forename: Joel
authors.initials: J
authors.lastname: Baron
authors.forename: Polina
authors.initials: P
authors.lastname: Shwarzman
authors.forename: Eyal
authors.initials: E
authors.lastname: Sheiner
authors.forename: Adi Y
authors.initials: AY
authors.lastname: Weintraub
authors.forename: Efrat
authors.initials: E
authors.lastname: Spiegel
authors.forename: Yael
authors.initials: Y
authors.lastname: Sciaky
authors.forename: Doron
authors.initials: D
authors.lastname: Dukler
authors.forename: Reli
authors.initials: R
authors.lastname: Hershkovitz
mesh_terms: D001783:Blood Flow Velocity; D005260:Female; D005312:Fetal Blood / Q000000981:diagnostic imaging*; D005865:Gestational Age; D006439:Hemodynamics; D018056:Hemorheology; D006801:Humans; D007743:Labor, Obstetric / Q000097:blood* / Q000502:physiology; D010920:Placenta / Q000098:blood supply* / Q000000981:diagnostic imaging; D011247:Pregnancy / Q000502:physiology; D011446:Prospective Studies; D011673:Pulsatile Flow / Q000502:physiology*; D012039:Regional Blood Flow / Q000502:physiology; D018615:Ultrasonography, Doppler, Color / Q000379:methods*; D018617:Ultrasonography, Doppler, Pulsed / Q000379:methods; D014469:Umbilical Arteries / Q000503:physiopathology; D055988:Uterine Artery / Q000000981:diagnostic imaging*