Chen Min, Lee Chin Peng, Leung Kwok Yin, Hui Pui Wah, Tang Mary Hoi Yin
Department of Obstetrics and Gynaecology, The University of Hong Kong, Tsan Yuk Hospital, Hong Kong SAR, PR China.
Prenat Diagn. 2004 Feb;24(2):87-91. doi: 10.1002/pd.793.
Hypoplasia of the nasal bone of fetuses affected by trisomy 21 and other aneuploidies could be detected by prenatal ultrasound examination and was an important new marker in the detection of Down syndrome in the second trimester. Racial differences in fetal nasal bone length have been reported. However, there was no reference range for the fetal nasal bone length (NBL) in the Chinese population. We conducted a pilot study to investigate the reproducibility of the measurement of fetal NBL in the mid second trimester and to determine whether there is any difference in NBL between the Chinese and the Caucasian population.
From June 2002 to February 2003, 198 Chinese women were examined. Ultrasound measurements of NBL were performed on a strictly midsagittal plane in normal singleton fetuses at 15 to 23 weeks' gestation.
The mean difference in the NBL between the two investigators was small (mean = 0.043 mm; 95% CI, -0.033 to 0.12), and there was substantial agreement between the measurements for each observer. Limits of agreement were -0.48 to 0.35 and -0.29 to 0.22 mm in the two investigators respectively. It was found that the median length of the nasal bones increased from 3.5 mm at 15 weeks to 6.7 mm at 23 weeks' gestation. There was a linear relationship between the length of the nasal bone and the gestational age.
It was demonstrated that the measurement of nasal bone length was feasible and reproducible in the second trimester. The fetal nasal bone length in Chinese population appeared shorter than that of Caucasian and African-Americans. There is a need to establish a reference range of fetal NBL for the Chinese population.
21三体综合征及其他非整倍体胎儿的鼻骨发育不全可通过产前超声检查检测到,这是孕中期唐氏综合征检测中的一项重要新指标。已有报道称胎儿鼻骨长度存在种族差异。然而,中国人群中胎儿鼻骨长度(NBL)尚无参考范围。我们进行了一项初步研究,以调查孕中期胎儿NBL测量的可重复性,并确定中国人群与白种人群的NBL是否存在差异。
2002年6月至2003年2月,对198名中国女性进行了检查。在妊娠15至23周的正常单胎胎儿中,于严格的正中矢状面上进行NBL的超声测量。
两位检查者之间NBL的平均差异较小(平均值 = 0.043毫米;95%可信区间,-0.033至0.12),且每位检查者的测量结果之间具有高度一致性。两位检查者的一致性界限分别为-0.48至0.35毫米和-0.29至0.22毫米。发现鼻骨的中位数长度从妊娠15周时的3.5毫米增加到妊娠23周时的6.7毫米。鼻骨长度与孕周之间存在线性关系。
结果表明,孕中期测量鼻骨长度是可行且可重复的。中国人群的胎儿鼻骨长度似乎比白种人和非裔美国人的短。有必要为中国人群建立胎儿NBL的参考范围。