title: A Thai reference for normal fetal nasal bone length at 11-13(+6) weeks gestation.
abstract: OBJECTIVE
  The purpose of this study was to establish a Thai reference for normal fetal nasal bone length (NBL) at 11-13(+6) weeks gestation.
  
  
  METHODS
  The fetal nasal bone was measured by sonography in pregnant women at 11-13(+6) weeks gestation. All neonates who showed normal karyotypes were examined after delivery to confirm the absence of congenital abnormalities.
  
  
  RESULTS
  A total of 255 pregnant women were recruited. Forty-seven pregnant women were excluded from the analysis because of technically unsatisfactory examination or absent nasal bone and chromosomal abnormalities. The mean ± SD of NBL was 1.79 ± 0.33 mm and increased significantly with crown-rump length (CRL) and gestational age (p < 0.001). The best-fit equation for NBL in euploid fetuses in relation to CRL was: NBL (mm) = (0.030 × CRL (mm)) - 0.016.
  
  
  CONCLUSIONS
  NBL in Thai fetuses at 11-13(+6) weeks was found to be on average shorter than that in Caucasian, African-American and Chinese populations, but similar to those reported in Korean and Latin-American populations.
authors: Department of Obstetrics and Gynecology, Faculty of Medicine, Prince of Songkla University, Hat Yai, Thailand.
authors: N
authors: N
authors: Pruksanusak
authors: C
authors: C
authors: Suwanrath
authors: O
authors: O
authors: Kor-anantakul
authors: T
authors: T
authors: Suntharasaj
authors: T
authors: T
authors: Hanprasertpong
authors: S
authors: S
authors: Pranpnus
authors: A F
authors: AF
authors: Geater
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D018568:Crown-Rump Length; D005260:Female; D047109:Fetal Development; D005865:Gestational Age; D006801:Humans; D009295:Nasal Bone / Q000000981:diagnostic imaging* / Q000196:embryology*; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D012016:Reference Values; D013785:Thailand; D016216:Ultrasonography, Prenatal / Q000379:methods*