Braithwaite J M, Morris R W, Economides D L
University Department of Obstetrics & Gynaecology, Royal Free Hospital School of Medicine, London, UK.
Br J Obstet Gynaecol. 1996 Dec;103(12):1201-4. doi: 10.1111/j.1471-0528.1996.tb09629.x.
To investigate nuchal translucency variation with crown-rump length (CRL) in the first trimester in normal fetuses.
A prospective observational study.
Department of obstetrics in a London teaching hospital.
One thousand seven hundred and seven pregnant women (1685 singleton and 22 twin pregnancies) with chromosomally normal fetuses between 9+zero and 14+6 weeks of gestation were recruited sequentially from a dating scan clinic. Nuchal translucency was measured in 94.9% by transabdominal sonography (TAS) and by transvaginal sonography (TVS) if difficulty was encountered with TAS (5.1%). Nuchal translucency measurement was repeated in 136 fetuses: the first scan between between 9+zero-11+6 weeks and the second over 12 weeks of gestation.
Of this general population, 4.2% had a nuchal translucency (NT) measurement > or = 2.5 mm, but this proportion varied significantly between gestational age groups (P = 0.011). The repeatability coefficients for NT measurements were 0.44 mm and 0.23 mm for TAS and TVS, respectively. The cross-sectional data demonstrate an increase in nuchal translucency measurement between 9 and 12 weeks of gestation and then a decrease at 13-14 weeks. This relation is best modelled using the quadratic equation: log10 (NT) = -1.03 + (0.0314 x CRL) - (2.20 x 10(-4) x CRL2). Longitudinal data confirmed an increase of nuchal translucency measurements with increasing gestation.
Nuchal translucency measurements increase significantly with increasing gestation. The use of a single threshold nuchal translucency measurement throughout the first trimester is inappropriate. We propose reference ranges of nuchal translucency measurements with gestation, aiming to improve the performance of nuchal translucency screening for chromosomal abnormalities.
研究正常胎儿孕早期颈部透明带厚度随头臀长（CRL）的变化情况。
一项前瞻性观察性研究。
伦敦一家教学医院的产科。
从一家预产期扫描诊所连续招募了1707名孕妇（1685名单胎妊娠和22例双胎妊娠），其胎儿染色体正常，孕周在9周零天至14周6天之间。94.9%的孕妇通过经腹超声（TAS）测量颈部透明带厚度，若TAS测量困难，则通过经阴道超声（TVS）测量（5.1%）。对136例胎儿重复测量颈部透明带厚度：第一次扫描在9周零天至11周6天之间，第二次扫描在妊娠12周以上。
在这一总体人群中，4.2%的孕妇颈部透明带（NT）测量值≥2.5 mm，但该比例在不同孕周组之间差异显著（P = 0.011）。TAS和TVS测量NT的重复性系数分别为0.44 mm和0.23 mm。横断面数据显示，妊娠9至12周期间颈部透明带测量值增加，然后在13至14周时下降。这种关系用二次方程log10（NT） = -1.03 +（0.0314×CRL） - （2.20×10⁻⁴×CRL²）能得到最佳拟合。纵向数据证实，随着孕周增加，颈部透明带测量值增加。
颈部透明带测量值随孕周增加而显著增加。在整个孕早期使用单一的颈部透明带测量阈值是不合适的。我们提出了不同孕周颈部透明带测量的参考范围，旨在提高颈部透明带筛查染色体异常的效能。
