title: Umbilical artery Doppler studies in small for gestational age babies reflect disease severity.
abstract: OBJECTIVE
  To determine: 1. whether abnormal umbilical artery Doppler studies were independently associated with newborn morbidity; and 2. whether small for gestational age babies with normal umbilical artery Doppler studies had small mothers and a low rate of newborn malnutrition and morbidity.
  
  
  METHODS
  Prospective observational study.
  
  
  METHODS
  National Women's Hospital, a tertiary referral centre, Auckland, New Zealand.
  
  
  METHODS
  One hundred eighty-six women and their small for gestational age babies (birthweight < 10th%) who had been participants in one of two randomised controlled trials of small for gestational age pregnancies between 1993 and 1997.
  
  
  METHODS
  Newborn morbidity and morphometry were compared between small for gestational age babies with normal and abnormal umbilical artery Doppler studies (resistance index > 95th%). Maternal demographic characteristics and morbidity were also compared.
  
  
  RESULTS
  Compared with small for gestational age babies with normal umbilical artery Doppler studies (n = 109), small for gestational age babies with abnormal umbilical artery Doppler studies (n = 77) were diagnosed earlier in pregnancy as being small for gestational age (30.3 vs 32.9 weeks, P < 0.001), were smaller in all body proportions at birth (median Z score birthweight -1.82 vs -1.70, P = 0.004, Z score length -1.86 vs -1.36, P < 0.0001, Z score head circumference -1.31 vs -0.89, P < 0.0001) and were more likely to experience newborn morbidity. When birthweight and gestation were entered into a logistic regression model, an abnormal umbilical artery Doppler study was not an independent predictor of prolonged newborn nursery admission or hypoglycaemia. Of small for gestational age babies with normal umbilical artery Doppler studies, 53 (49%) had low ponderal indices, 26/98 (26%) were hypoglycaemic and 38 (35%) required admission to the newborn nursery. There was no difference in maternal height, weight and ethnicity between the abnormal and normal umbilical artery Doppler groups.
  
  
  CONCLUSIONS
  Abnormal umbilical artery Doppler studies reflect earlier onset and more severe growth restriction and are not independently associated with newborn morbidity. Small for gestational age babies with normal Doppler studies have a high rate of newborn nursery admission and malnutrition at birth and are not all just normal small babies.
authors.affiliation: Department of Obstetrics and Gynaecology, University of Auckland School of Medicine, New Zealand.
authors.forename: L M
authors.initials: LM
authors.lastname: McCowan
authors.forename: J E
authors.initials: JE
authors.lastname: Harding
authors.forename: A W
authors.initials: AW
authors.lastname: Stewart
mesh_terms: D000328:Adult; D001724:Birth Weight / Q000502:physiology; D001783:Blood Flow Velocity; D001824:Body Constitution; D005260:Female; D005865:Gestational Age; D006760:Hospitalization; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D008297:Male; D009748:Nutrition Disorders / Q000151:congenital; D011247:Pregnancy; D011446:Prospective Studies; D016216:Ultrasonography, Prenatal; D014469:Umbilical Arteries / Q000000981:diagnostic imaging*