title: Cerebellar Doppler velocimetry in the appropriate- and small-for-gestational-age fetus.
abstract: OBJECTIVE
  To compare superior cerebellar artery flow velocity waveforms in the appropriate-for-gestational-age (AGA) and the small-for-gestational-age (SGA) fetus.
  
  
  METHODS
  Superior cerebellar artery velocity waveforms were obtained prospectively from 172 AGA fetuses at 17-41 weeks' gestation. The pulsatility index (PI) was used to quantify the waveforms. Superior cerebellar artery velocity waveforms were also obtained from 30 SGA fetuses divided into group A (n = 15), with a normal umbilical artery PI, and group B (n = 15), with an abnormal umbilical artery PI. The transverse cerebellar diameter was measured in all SGA fetuses.
  
  
  RESULTS
  The superior cerebellar artery PI was best represented by a second-order polynomial equation [PI = 0.145 + 0.101 x (gestational age) - 0.00197 (gestational age)2]. Small-for-gestational-age fetuses of group A had a superior cerebellar artery PI in the normal range, whereas 13 of 15 fetuses of group B (86.7%) had a PI value less than the individual 95% confidence interval. The transverse cerebellar diameter in group A fetuses was in the normal range in ten of 15 cases, whereas it was in the normal range for all group B fetuses.
  
  
  CONCLUSIONS
  Small-for-gestational-age fetuses with an abnormal umbilical artery PI have "cerebellar-sparing effect," as suggested by a superior cerebellar artery PI less than the normal range and a normal transverse cerebellar diameter.
authors.affiliation: Department of Obstetrics and Gynecology, Yale University School of Medicine, New Haven, Connecticut, USA.
authors.forename: B
authors.initials: B
authors.lastname: Uerpairojkit
authors.forename: L
authors.initials: L
authors.lastname: Chan
authors.forename: A E
authors.initials: AE
authors.lastname: Reece
authors.forename: E
authors.initials: E
authors.lastname: Martinez
authors.forename: G
authors.initials: G
authors.lastname: Mari
mesh_terms: D001158:Arteries / Q000000981:diagnostic imaging; D001783:Blood Flow Velocity; D002531:Cerebellum / Q000098:blood supply* / Q000000981:diagnostic imaging; D005314:Embryonic and Fetal Development; D005260:Female; D005317:Fetal Growth Retardation / Q000000981:diagnostic imaging*; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D011247:Pregnancy; D011446:Prospective Studies; D018608:Ultrasonography, Doppler; D016216:Ultrasonography, Prenatal; D014469:Umbilical Arteries / Q000503:physiopathology