title: First-trimester fetal limb biometry in Chinese population.
abstract: OBJECTIVE
  To establish reference ranges for fetal limb biometry obtained by transabdominal ultrasound examination at 12-14 weeks of gestation in Chinese women.
  
  
  METHODS
  A total of 1489 normal singleton fetuses between 12(+0) and 14(+6) weeks of gestation were examined transabdominally by two experienced observers. The gestation was ascertained by measurement of fetal crown-rump length (CRL) or biparietal diameter (BPD) and head circumference (HC). The lengths of the humerus and femur were prospectively worked out.
  
  
  RESULTS
  Gestation-specific reference ranges for limb measurements were calculated. The femur length (FL) (mean +/- SD) was 9.15 +/- 1.44 mm at 12-12(+6) weeks, 11.45 +/- 1.35 mm at 13-13(+6) weeks, and 13.64 +/- 1.60 mm at 14-14(+6) weeks; the corresponding humerus length (HL) (mean +/- SD) was 9.63 +/- 1.44 mm, 12.01 +/- 1.41 mm, 14.29 +/- 1.48 mm, respectively.
  
  
  CONCLUSIONS
  There was a general increase in fetal limb biometry with gestation. Fetal limb length can be an early marker of early growth restriction as well as fetal skeletal dysplasia among women in the local population.
authors.affiliation: Department of Obstetrics and Gynaecology, The University of Hong Kong, Queen Mary Hospital, Hong Kong, China. drchenm2003@yahoo.com.hk
authors.forename: Min
authors.initials: M
authors.lastname: Chen
authors.forename: Chin Peng
authors.initials: CP
authors.lastname: Lee
authors.forename: Yung Hang
authors.initials: YH
authors.lastname: Lam
authors.forename: Chun Quan
authors.initials: CQ
authors.lastname: Ou
authors.forename: Mary Hoi Yin
authors.initials: MH
authors.lastname: Tang
mesh_terms: D000328:Adult; D044466:Asian People; D001699:Biometry / Q000379:methods*; D047108:Embryonic Development / Q000502:physiology*; D005121:Extremities / Q000000981:diagnostic imaging / Q000196:embryology*; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000196:embryology; D047109:Fetal Development / Q000502:physiology*; D006801:Humans; D006811:Humerus / Q000000981:diagnostic imaging / Q000196:embryology; D008875:Middle Aged; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D012016:Reference Values; D016216:Ultrasonography, Prenatal