title: Reproducibility of fetal ductus venosus blood flow velocity waveforms during first stage of labor.
abstract: OBJECTIVE
  Fetal ductus venosus (DV) blood flow velocity waveforms are significantly altered during contractions in first stage of labor. We have evaluated the reproducibility of these waveforms during and between contractions.
  
  
  METHODS
  90 women between 37th and 41st week of gestation were included in the study. The measurements of the DV were obtained by three different investigators during and between contractions. The pulsatility index for veins (PIV), peak velocity index for veins (PVIV), and fetal heart rate (FHR) were calculated offline. Furthermore, differences in PVIV (PVIVdiff) and PIV (PIVdiff) and a mean of FHR (FHRmean) were calculated. Statistical analysis was used to verify differences in the PIV, PVIV and FHR during and between contractions of each subgroup as well as for the PVIVdiff, PIVdiff and FHRmean between the subgroups.
  
  
  RESULTS
  Investigator 1 examined 49 patients (group 1); investigator 2, 17 patients (group 2) and investigator 3, 24 patients (group 3), respectively. In all subgroups, there was a significant difference for the PVIV and PIV during and between contractions, but not for FHR. There was a correlation between gestational age and PVIVdiff, PIVdiff and FHRmean as well as for maternal age and PVIVdiff and PIVdiff. PVIVdiff and PIVdiff showed significant differences in group 1 compared to groups 2 and 3 (p < 0.001), but not between groups 2 and 3.
  
  
  CONCLUSIONS
  Significant differences in the measurements in the three subgroups have been revealed, which may be due to different timing of measurement during the contraction. For future studies further standardization of the measurement protocol should be established.
authors.affiliation: Center for Endocrinology, Reproductive and Prenatal Medicine, amedes Hamburg, Mönckebergstr. 10, 20095, Hamburg, Germany. martin.krapp@amedes-group.com
authors.forename: Martin
authors.initials: M
authors.lastname: Krapp
authors.forename: Anja
authors.initials: A
authors.lastname: Kühn
authors.forename: Kristin
authors.initials: K
authors.lastname: Baumann
authors.forename: Ulrich
authors.initials: U
authors.lastname: Gembruch
mesh_terms: D000293:Adolescent; D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology; D005260:Female; D005318:Fetal Heart / Q000000981:diagnostic imaging / Q000502:physiology; D005333:Fetus / Q000098:blood supply*; D005865:Gestational Age; D006340:Heart Rate, Fetal / Q000502:physiology; D006801:Humans; D007747:Labor Stage, First; D011247:Pregnancy; D011673:Pulsatile Flow; D015203:Reproducibility of Results; D016216:Ultrasonography, Prenatal; D014680:Veins / Q000000981:diagnostic imaging; D055815:Young Adult