The relation between fetal nasal bone length and biparietal diameter in the Korean population.
OBJECTIVE
To evaluate the relation between fetal nasal bone length (NBL) and biparietal diameter (BPD) at 15-19.9 (20) weeks of gestation by ultrasonography in the Korean population.


METHODS
The study population included 1268 Korean women (aged between 19 and 45 years) with a singleton pregnancy who registered at the Maternal Fetal Medicine Unit of Samsung Cheil Hospital between September 2003 and February 2005. Ultrasound measurements of NBL were performed using a strict sagittal plan of the fetal head. Other fetal biometry profiles were conducted before amniocentesis for fetal karyotyping.


RESULTS
NBL and fetal biometry profiles were measured successfully in 77.9% (988/1268) of the fetuses. NBL was found to increase linearly as a function of BPD (P < 0.001) with a median NBL of 4.4 mm (range 1.9-7.9). NBL increases through 15-19.9 (20) weeks of gestation were given by the equation NBL (mm) = 0.0836 x BPD (mm) + 1.368 (R2 = 0.1, P < 0.001).


CONCLUSIONS
Fetal NBL and BPD are linearly related in the second trimester. Fetal NBL in the Korean population is likely to be shorter than that reported for Caucasians and African-Americans.
Department of Obstetrics and Gynecology, Samsung Cheil Hospital and Women's Healthcare Center, Sungkyunkwan University School of Medicine, Jung-gu, Seoul, Korea.
Joong Sik
JS
Shin
Jae Hyug
JH
Yang
Jin Hoon
JH
Chung
Moon Young
MY
Kim
Hyun Mee
HM
Ryu
Jung Yeol
JY
Han
June Seek
JS
Choi
D000328:Adult; D005260:Female; D005865:Gestational Age; D006801:Humans; D007723:Korea; D008875:Middle Aged; D009295:Nasal Bone / Q000000981:diagnostic imaging / Q000196:embryology*; D010296:Parietal Lobe / Q000000981:diagnostic imaging / Q000196:embryology*; D011247:Pregnancy; D011446:Prospective Studies; D012016:Reference Values; D016216:Ultrasonography, Prenatal