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

Prenat Diagn. 2012 Jul;32(7):620-6. doi: 10.1002/pd.3870. Epub 2012 Apr 30.

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).

Conclusion: 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.

MeSH terms

  • Adult
  • Biometry
  • Birth Weight
  • Female
  • Gestational Age*
  • Humans
  • Infant, Low Birth Weight*
  • Infant, Newborn
  • Infant, Small for Gestational Age*
  • Longitudinal Studies
  • Organ Size
  • Placenta / anatomy & histology*
  • Placenta / diagnostic imaging
  • Pregnancy
  • Pregnancy Trimester, Second
  • Prospective Studies
  • Ultrasonography, Prenatal / methods*
  • Umbilical Cord / anatomy & histology*
  • Umbilical Cord / diagnostic imaging
  • Uterine Artery / anatomy & histology
  • Uterine Artery / diagnostic imaging