title: Ultrasound assessment of placental function: the effectiveness of placental biometry in a low-risk population as a predictor of a small for gestational age neonate.
abstract: OBJECTIVE
  The aims of the study were to establish reference ranges for placental length and thickness in a low-risk obstetric population and to assess the likelihood of a small for gestational age (SGA) neonate on the basis of placental length at 18-24 weeks' gestation.
  
  
  METHODS
  Placental length and thickness were measured by two sonographers in 520 singleton pregnancies. Uterine artery Doppler studies and a placental morphological assessment were also performed. Placental size was correlated with the birthweight centiles at delivery.
  
  
  RESULTS
  A placental length <10th centile between the gestational age of 18 and 24 weeks is a significant factor associated with SGA neonate [odds ratio (OR) = 2.8, 95% CL, 1.1-6.9]. An abnormal uterine artery Doppler is a significant factor for SGA neonate (OR = 3.4, 95% CL, 1.6-7.4). There was a weak relationship between cord insertion <2 cm from the placental margin and an SGA neonate (OR = 1.8, 95% CL, 0.4-8.2).
  
  
  CONCLUSIONS
  We have provided reference ranges for placental length and thickness from 18 to 24 weeks' gestation. A single measurement of placental length incorporated into the anatomy scan may assist in the early detection of a group at risk of delivering an SGA neonate.
authors.affiliation: Ultrasound and Fetal Medicine Centre, Coombe Women & Infants University Hospital, Dublin, Ireland.
authors.forename: Patricia
authors.initials: P
authors.lastname: McGinty
authors.forename: Nadine
authors.initials: N
authors.lastname: Farah
authors.forename: Vicky O
authors.initials: VO
authors.lastname: Dwyer
authors.forename: Jennifer
authors.initials: J
authors.lastname: Hogan
authors.forename: Amanda
authors.initials: A
authors.lastname: Reilly
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Turner
authors.forename: Bernard
authors.initials: B
authors.lastname: Stuart
authors.forename: Máireád M
authors.initials: MM
authors.lastname: Kennelly
mesh_terms: D000328:Adult; D001699:Biometry; D001724:Birth Weight; D005260:Female; D005865:Gestational Age; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D008137:Longitudinal Studies; D009929:Organ Size; D010920:Placenta / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011446:Prospective Studies; D016216:Ultrasonography, Prenatal / Q000379:methods*; D014470:Umbilical Cord / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D055988:Uterine Artery / Q000033:anatomy & histology / Q000000981:diagnostic imaging