title: Reference charts and equations of fetal biometry for normal singleton pregnant women in Shaanxi, China.
abstract: OBJECTIVE
  To construct reference charts and equations of fetal biometry for singleton pregnant women in Shaanxi, China.
  
  
  METHODS
  This was a cross-sectional study involving 6,832 singleton pregnant women. One set of fetal ultrasonographic measurement data between the 16th to 41st gestational weeks (GW) was randomly selected from each pregnant woman, and biparietal diameter (BPD), abdominal circumference (AC), and femur length (FL) were recorded. Mean and standard deviation (SD) of BPD, AC, and FL were fitted by polynomial. Centile = Mean + Z(alpha) x SD was used to calculate centiles. Differences in the 50th centile of BPD, AC, and FL between Hong Kong, Korean, Italian and Shaanxi fetuses were compared.
  
  
  RESULTS
  Mean of BPD, AC, and FL were well-fitted by quadratic polynomial, SD of BPD, AC and FL were fitted by linear regression. Equations for estimating mean and SD for BPD, AC, and FL from GW were obtained. Centiles for BPD,AC, and FL were calculated. From the 21st GW, the differences in BPD,AC, and FL between Hong Kong, Korean, Italian, and Shaanxi fetuses became larger.
  
  
  CONCLUSIONS
  Fetal biometry reference charts and equations for estimating fetal size and GW could be used in obstetrics practice and research in Shaanxi, China.
authors.affiliation: Department of Paediatrics, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China.
authors.forename: X
authors.initials: X
authors.lastname: Jiang
authors.forename: Y H
authors.initials: YH
authors.lastname: Zhang
authors.forename: Y
authors.initials: Y
authors.lastname: Li
authors.forename: X
authors.initials: X
authors.lastname: Ma
authors.forename: Y S H
authors.initials: YS
authors.lastname: Zhu
authors.forename: L
authors.initials: L
authors.lastname: Shang
mesh_terms: D000328:Adult; D000818:Animals; D044466:Asian People; D001699:Biometry; D002681:China; D003430:Cross-Sectional Studies; D005260:Female; D005269:Femur / Q000033:anatomy & histology; D005333:Fetus / Q000033:anatomy & histology*; D005865:Gestational Age; D006801:Humans; D011247:Pregnancy; D012016:Reference Values; D016216:Ultrasonography, Prenatal; D055105:Waist Circumference