[Nasal bone biometry in the second trimester of gestation].
OBJECTIVE
To determine physiological variability range of the analyzed biometrical parameters and to establish optimal circumstances for fetal nasal ultrasound biometry. To evaluate preliminarily the value of fetal nasal biometry in the screening for aneuploidy.


METHODS
Ultrasound measurement of nasal bones length and nasal width in healthy fetuses and in fetuses with common aneuploidies.


METHODS
Measurements of the analyzed parameters were undertaken in 681 euploid fetuses and 9 fetuses with common aneuploidies. Nasal bones length was measured with accordance to the same set of rules as determined by Cicero et al. in their publication relating to the first trimester nasal bones assessment. Nasal width was measured in the coronal plane between the alae.


RESULTS
Relationship between the examined parameters and gestational age was described. The normal variability range of the analyzed parameters was determined and percentile charts created. In three out of five examined fetuses with trisomy 21 the nasal bones length was below the 5th percentile. In one out of five trisomy 21 fetuses the nasal width was over the 95th percentile. Regrettably the paucity of data obtained from affected fetuses does not allow drawing statistically founded conclusions.


CONCLUSIONS
Fetal nasal biometry seems to be a valuable screening marker of trisomy 21 in the second trimester, requiring further studies.
Dudarewicz
Lech
L
Zakład Genetyki Instytutu CZMP w Lodzi. dudarew@yahoo.com
Nowakowska
Dorota
D
Jakubowski
Lucjusz
L
Wilczyński
Jan
J
D000886:Anthropometry; D004314:Down Syndrome / Q000000981:diagnostic imaging* / Q000196:embryology*; D005260:Female; D006801:Humans; D009295:Nasal Bone / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000196:embryology*; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D012016:Reference Values; D015203:Reproducibility of Results; D016216:Ultrasonography, Prenatal