title: Fetomaternal Doppler sonography nomograms.
abstract: OBJECTIVE
  To constitute Doppler flow velocity nomograms for use in obstetric clinics and to analyse the technical infrastructure of constructing Doppler sonography nomograms for clinical use.
  
  
  METHODS
  On a cross-sectional study plan basis 602 flow results of 370 pregnant women were used. Pregnancy gestational ages were confirmed with an early sonogram prior to the 14th gestational week. Patients in whom primary section for placental insufficiency had to be done, who had pathological fetal heart rate monitoring, signs of intrauterine asphyxia, multiple pregnancy or a fetal anomaly were excluded. Every two gestational weeks patients were grouped and for these groups the 5th, 10th, 50th, 90th and 95th percentiles were calculated to represent the umbilical artery, fetal aorta, middle cerebral artery (MCA) and uterine artery S/D ratio, resistence index (RI) and pulsatility index (PI) Doppler flow velocity nomograms.
  
  
  RESULTS
  In normal pregnancies, after the 22nd-24th gestational week, the uteroplacental flow velocities were constant, but at the fetal vessels there were changes in velocity waveforms after this period. With advancing gestation in the third trimester, umbilical artery and middle cerebral artery impedance was lower and the resistance in the descending fetal aorta remained nearly constant.
  
  
  CONCLUSIONS
  With growing gestational age the Doppler velocity forms change. In fact because of this, for Doppler velocity studies and to differentiate between normal and abnormal pregnancy status, nomograms adapted to gestational age should be used. For practical use in different obstetrics clinics, we are presenting our Doppler velocity norm-curves.
authors.affiliation: Saarland University Medical School, Department of Obstetrics and Gynecology, Homburg/Saar, Germany. ertan@uniklinik-saarland.de
authors.forename: A K
authors.initials: AK
authors.lastname: Ertan
authors.forename: H J
authors.initials: HJ
authors.lastname: Hendrik
authors.forename: H A
authors.initials: HA
authors.lastname: Tanriverdi
authors.forename: M
authors.initials: M
authors.lastname: Bechtold
authors.forename: W
authors.initials: W
authors.lastname: Schmidt
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D005328:Fetal Viability / Q000502:physiology; D005865:Gestational Age; D006801:Humans; D008431:Maternal-Fetal Exchange / Q000502:physiology*; D011247:Pregnancy; D011295:Prenatal Care; D012016:Reference Values; D012680:Sensitivity and Specificity; D013997:Time Factors; D018608:Ultrasonography, Doppler; D016216:Ultrasonography, Prenatal; D014655:Vascular Resistance