Audibert F, Dommergues M, Benattar C, Taieb J, Thalabard J C, Frydman R
Department of Obstetrics and Gynecology, Hopital Antoine Beclere, Université Paris XI, Paris, France.
Ultrasound Obstet Gynecol. 2001 Jul;18(1):26-31. doi: 10.1046/j.1469-0705.2001.00457.x.
To compare nuchal translucency and second-trimester maternal serum measurements as alternative methods of antenatal screening for Down syndrome in a low-risk population and to evaluate the consequence of combining the results in the estimation of risk.
In a consecutive series of 4130 women aged less than 38 years with a singleton pregnancy, we examined both the detection rate of Down syndrome by nuchal translucency measurement at 10-14 weeks and maternal serum screening by human chorionic gonadotrophin and alpha-fetoprotein at 14-18 weeks. Women with a nuchal translucency measurement of > or = 3 mm and women with a maternal serum screening-derived risk > or = 1/250 were recommended to have amniocentesis. A second-trimester detailed ultrasound scan was also performed in all women. The outcome of all pregnancies was recorded prospectively and the detection rate and false-positive rate of different screening strategies were retrospectively analyzed.
Out of the 4130 pregnancies that were followed (mean maternal age, 30.1 years), 12 cases of Down syndrome were observed (0.28%), all detected prenatally. Seven of 12 cases had a nuchal translucency measurement of > or = 3 mm (58%), and six out of 10 cases with available maternal serum screening had a calculated risk of > or = 1/250 (60%). Four of the five Down syndrome cases with a nuchal translucency measurement of < 3 mm were detected by subsequent maternal serum screening. At a threshold giving 5% of positive tests, the sensitivity of nuchal translucency, maternal serum screening and combined risk screening were 75%, 60% and 90%, respectively.
In screening for Down syndrome, an approach which combines the results from first-trimester nuchal translucency and second-trimester biochemistry is effective and increases the detection rate compared to the use of any single test. However, this strategy is likely to raise the false-positive rate and the interpretation of maternal serum screening-derived risk should be combined with the first-trimester nuchal translucency measurement.
比较颈后透明带厚度及孕中期母体血清检测作为低风险人群唐氏综合征产前筛查替代方法的效果，并评估在风险评估中合并检测结果的影响。
在连续纳入的4130名年龄小于38岁的单胎妊娠妇女中，我们分别检测了孕10 - 14周时通过测量颈后透明带厚度筛查唐氏综合征的检出率，以及孕14 - 18周时通过检测人绒毛膜促性腺激素和甲胎蛋白进行母体血清筛查的检出率。颈后透明带厚度测量值≥3 mm的妇女以及母体血清筛查风险≥1/250的妇女被建议进行羊水穿刺。所有妇女均在孕中期进行了详细的超声检查。前瞻性记录所有妊娠结局，并回顾性分析不同筛查策略的检出率和假阳性率。
在随访的4130例妊娠中（平均产妇年龄30.1岁），观察到12例唐氏综合征病例（0.28%），均在产前被检测出。12例中有7例颈后透明带厚度测量值≥3 mm（58%），10例可进行母体血清筛查的病例中有6例计算风险≥1/250（60%）。颈后透明带厚度测量值<3 mm的5例唐氏综合征病例中有4例通过后续的母体血清筛查被检测出。在设定5%阳性检测率的阈值时，颈后透明带厚度筛查、母体血清筛查及联合风险筛查的灵敏度分别为75%、60%和90%。
在唐氏综合征筛查中，将孕早期颈后透明带厚度和孕中期生化检测结果相结合的方法是有效的，与单独使用任何一种检测方法相比，可提高检出率。然而，这种策略可能会提高假阳性率，并且母体血清筛查风险的解读应与孕早期颈后透明带厚度测量结果相结合。
