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【medical-news】鼻骨发育与发育异常————春节
2/12/2007
By: Reuters Health
http://www.auntminnie.com/index.asp?Sec=sup&Sub=wom&Pag=dis&ItemId=74587
NEW YORK (Reuters Health), Feb 12 - New study results confirm that documenting total absence of a nasal bone on a fetus during the second trimester can identify nearly half of all fetuses affected by Down syndrome, investigators report in the February issue of Obstetrics and Gynecology. The research team also reports that hypoplasia of the nasal bone is also a predictor of trisomy 21.
Dr. Carolyn M. Zelop, at St. Francis Hospital in Hartford, CT, and her associates first conducted a retrospective analysis to establish the expected normal distribution of fetal nasal bone length, using ultrasound records of 732 pregnancies during the second trimester. They excluded pregnancies affected with Down syndrome or other significant chromosome abnormalities.
Nasal bone lengths were converted to "multiples of the median" (MoM) with adjustment for maternal race and ethnicity and week of gestation. They then converted nasal bone length of the 10 fetuses with Down syndrome into race or ethnicity-adjusted MoM using the same method.
To confirm their analysis, they prospectively evaluated 1,794 women referred for second-trimester ultrasound, with nasal bone measurements converted to MoM based on the formula established in the first cohort. Results indicated that 11 fetuses had Down syndrome.
With the two cohorts combined, nasal bone absence had a sensitivity of 47.6% and specificity of 100%.
When they used a cutoff of 0.80 Mom, sensitivity and specificity were 95.2% and 92.7%, respectively. Corresponding values when they used a cutoff of less than 0.75 Mom were 85.7% and 97.1%.
Dr. Zelop and her colleagues do not advocate using nasal bone length to predict an individual patient's risk. "However, we do suggest that careful second-trimester scanning of the midsagittal plane of the fetal facial profile specifically looking for presence or absence of a nasal bone be carried out," they write.
Dr. Joshua A. Copel, an obstetrician at Yale School of Medicine in New Haven, CT, and president-elect of the American Institute of Ultrasound in Medicine, told Reuters Health that "it is challenging to make sure that the 'right place' is found for measuring nasal bone length."
Still, he said, "It's a work in progress. We need to find ways of using ultrasound to perform a physical examination of the fetus and identify diagnostic characteristics."
By Karla Gale
Last Updated: 2007-02-09 15:00:37 -0400 (Reuters Health)
Obstet Gynecol 2007;109:371-375.
真的是很惊讶，猪年马上就到了，生猪的特别多，春节后，将会迎来妇产科最繁忙的一年。这篇新闻来得稍微晚了一些，不过希望能够在健康报之类的报纸上印出来，搞计划生育，b超的同志一定要看看。 1: Obstet Gynecol. 2007 Feb;109(2 Pt 1):371-5.
Absent or shortened nasal bone length and the detection of down syndrome in
second-trimester fetuses.
Gianferrari EA, Benn PA, Dries L, Brault K, Egan JF, Zelop CM.
Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology,
University of Connecticut Health Center, 114 Woodland Street, Farmington, CT
06105, USA.
OBJECTIVE: To estimate the accuracy of evaluating nasal bone length, expressed
as multiples of the median (MoM), for the detection of Down syndrome in second-
trimester fetuses. METHODS: Expected normal median nasal bone measurements were
established for an initial cohort of women receiving fetal ultrasound
examinations at 15-24 weeks of gestation. Nasal bone lengths were converted to
MoM with adjustment for maternal race and ethnicity using whites as the referent
group. Nasal bone MoM were compared in euploid and Down syndrome fetuses. The
sensitivity and specificity were evaluated in this initial cohort and in a
second cohort in which all ultrasound measurements were carried out
prospectively. RESULTS: For the combined data set, 10 of 21 affected pregnancies
had an absence of the nasal bone (sensitivity 47.6%), but absence was noted in
only 1 of 2,515 unaffected pregnancies (false-positive rate 0.04%). Using less
than 0.80 MoM as a cutoff, the sensitivity was 20 of 21 (95.2%), and the
false-positive rate was 185 of 2,515 (7.4%). Changing the cutoff to 0.75 MoM
resulted in 18 of 21 (85.7%) sensitivity and 74 of 2,515 (2.9%) false-positive
rate. Using medians derived from whites to calculate MoM for the entire
population resulted in higher false-positive rates. CONCLUSION: Nasal bone
length expressed as MoM seems to be an useful ultrasound marker for Down
syndrome in second-trimester fetuses with a high sensitivity and a low
false-positive rate. LEVEL OF EVIDENCE: III.
PMID: 17267838 [PubMed - in process] 本人已认领该文编译，48小时后若未提交译文，请其他战友自由认领。 Short fetal nasal bone predicts increased likelihood of Down syndrome
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