Leung Tak Yeung, Chan Lin Wai, Law Lai Wa, Sahota Daljit Singh, Fung Tak Yuen, Leung Tse Ngong, Lau Tze Kin
Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong, China SAR.
J Matern Fetal Neonatal Med. 2009 Apr;22(4):300-4. doi: 10.1080/14767050802430842.
To examine the effectiveness of first trimester fetal Trisomy 21 (T21) screening using a combination of maternal age, nuchal translucency, maternal serum levels of free beta-hCG and PAPP-A in a predominantly Chinese population in Hong Kong.
Consecutive women who underwent the combined screening for T21 between 11 and 13 + 6 weeks of gestation between 2003 and 2007 were recruited. Risk of T21 was calculated using Fetal Medicine Foundation algorithm and karyotyping was advised when the risk was 1:300 or above. All women were followed up for pregnancy and fetal outcome.
10,363 fetuses underwent screening. 99% of the women were Chinese and 27.4% were at or above 35 years old. 618 fetuses were screened positive (5.9%), which included 31 cases of T21, 14 cases of T18, 7 cases of T13, 10 cases of 45XO and 7 cases of other chromosomal abnormalities. Among the 9745 screened negative fetuses all but 50 (0.5%) had a known outcome, which included three T21 and four other chromosomal abnormalities. All were subsequently identified at the morphology scan except for one case of T21. The detection rate and false positive rates for T21 were 91.2% and 5.4%, respectively and the positive predictive value for all chromosomal abnormalities was 1 in 9.
Combined screening for T21 is highly effective among Chinese women. Training, quality control, regular auditing and follow up are essential to maintain screening standards.
探讨在香港以华人为主的人群中，联合应用孕妇年龄、颈部透明带厚度、孕妇血清游离β-人绒毛膜促性腺激素（β-hCG）和妊娠相关血浆蛋白-A（PAPP-A）水平进行孕早期胎儿21-三体综合征（T21）筛查的有效性。
招募2003年至2007年间孕11至13⁺⁶周接受T21联合筛查的连续孕妇。采用胎儿医学基金会算法计算T21风险，当风险为1:300及以上时建议进行染色体核型分析。所有孕妇均随访妊娠及胎儿结局。
10363例胎儿接受筛查。99%的孕妇为华人，27.4%的孕妇年龄在35岁及以上。618例胎儿筛查阳性（5.9%），其中包括31例T21、14例T18、7例T13、10例45,XO及7例其他染色体异常。在9745例筛查阴性的胎儿中，除50例（0.5%）外均有已知结局，其中包括3例T21及4例其他染色体异常。除1例T21外，其余均在形态学超声检查时被发现。T21的检出率和假阳性率分别为91.2%和5.4%，所有染色体异常的阳性预测值为1/9。
T21联合筛查在华人女性中非常有效。培训、质量控制、定期审核及随访对于维持筛查标准至关重要。
