Non-invasive Prenatal Test (NIPT) for chromosomal abnormality
無創性胎兒染色體篩查 (NIPT)

Down syndrome screening
唐氏綜合症

Down syndrome is caused by an extra copy of Chromosome 21 in the human cells. It is the most common chromosomal abnormality and the most common genetic cause of mental retardation. The local incidence is around 1 in 800. The first-trimester combined Down syndrome screening test (fetal nuchal translucency NT measurement plus maternal biochemical blood test) detects around 90 out of 100 Down syndrome, but around 5 out of 100 normal babies would be reported as high risk. A more accurate screening test called NIPT (non-invasive prenatal test) is now available.

唐氏綜合症是由於人體細胞內第21對染色體 多出一條所致，它的發病率為1/800，是最 常見的染色體異常及遺傳性智力障礙疾病。 早孕期唐氏綜合症篩查（超聲量度胎兒頸皮 厚度+孕婦血液生化檢查）可以檢出約90% 的唐氏綜合症，但每100個正常胎兒中就有5 個會被列為高風險。現時有一種更準確的篩 查方法已供臨床應用，就是「無創性胎兒染色 體篩查」(NIPT)

What is NIPT?
什麽是 NIPT?

The test
篩查方法

People normally have 23 pairs of chromosomes in each cell. Each chromosome is made up of a coil of DNA. Besides her own DNA, mother’s blood also contain small amount of fetal DNA. Therefore, it allows accurate screening for fetal Down syndrome using mother’s blood. If the baby has Down syndrome, the test will show increased amount of DNA from chromosome 21.

每個正常人體細胞內都有23對由DNA組成 的染色體。母體的血液中，除了自己的DNA 外，還含有小量的胎兒DNA，NIPT就是藉 著這些胎兒DNA來作唐氏綜合症篩查。如果 胎兒患有唐氏綜合症，化驗結果就會顯示第21對染色體DNA的數量比正常增加。

NIPT detects around 99 out of 100 Down syndrome, and only around 1 out of 1000 normal babies would be reported as high risk. It also detects Edward syndrome (an extra copy of chromosome 18), Patau syndrome (an extra copy of chromosome 13) and Turner syndrome (only 1 copy of chromosome X).

NIPT可以檢出約99%的唐氏綜合症，而每1000個正常胎兒中只有約1個會被列為高風 險。除此之外，它還可以檢出愛德華氏綜合症（第18條染色體多出一條），巴陶氏綜合 症（第13對染色體多出一條）及特納氏綜合症（只有一條性染色體[X]）。

NIPT is not currently available in Hospital Authority, but is available in The Chinese University of Hong Kong Fetal Medicine Private Clinic as well as other private clinics and hospitals in Hong Kong.

現時醫院管理局並未提供此項篩查服務，閣 下可於香港中文大學胎兒醫學組私家症診所或 其他私家診所和醫院自費進行此項篩查。

There are several brands of NIPT presently available in the market, e.g., SafeT21express, Panorama, NIFTY, verifi, Harmony, Prenetics V.

Gestational age for NIPT
篩查孕週

From 10 gestational weeks onwards
胎兒孕週滿10週便可進行篩查

Reporting time
報告發出時間

Around 7 working days after blood taking
抽血後大约7個工作天便可發出篩查報告

Charge (consultation, ultrasound and blood test)
篩查費用（包括諮詢、超聲波檢查及抽血）
HKD$5,700 單胞胎 singleton pregnancy
HKD$6,400 雙胞胎 twins pregnancy
– Chromosome 21 (Down syndrome) 13 18 X Y + 7 microdeletion syndromes
– 包括染色體 21[唐氏] 13 18 X Y + 7種染色體微缺失症候群

Other information about NIPT
其他NIPT相關資料

Dating Scan
超聲波確定孕週

Pregnant women are recommended to have a dating scan to determine the exact gestational age which is important for all forms of Down syndrome screening. This service is also available in The Chinese University of Hong Kong Fetal Medicine Private Clinic. NIPT can be done at the same time if the gestational age is beyond 10 weeks.

針對各項唐氏綜合症篩查，準確的孕週計 算是十分重要的，所以建議孕婦先進行早 孕期超聲波檢查確定胎兒的孕週。香港中文 大學胎兒醫學組私家症診所亦可提供此項 服務，如胎兒孕週滿10週，更可即時進行 NIPT篩查。

How to make an appointment
預約方法

In person :
The Chinese University of Hong Kong Fetal Medicine Private Clinic, Room 30, 2/F, Li Ka Shing Specialist Out-patient Clinic South Wing, Prince of Wales Hospital
親臨 威爾斯親王醫院李嘉誠專科門診南翼二樓三十號房香港中文大學胎兒醫學組辦公室

By phone :
Call The Chinese University of Hong Kong Fetal Medicine Private Clinic direct line (852) 5600 1970 or leave a message at (852) 3505 4219 (Please leave your name and telephone number)
致電 威爾斯親王醫院香港中文大學胎兒醫學 組直線電話 (852) 5600 1970或電話留言(852) 3505 4219 （請留下姓名、電話）

By fax :
Please download the NIPT pamphlet from the link below, complete the form and fax it to The Chinese University of Hong Kong Fetal Medicine Private Clinic at (852) 2632 5065
填妥以下表格，傳真 至香港中文大學胎兒醫 學組 (852) 2632 5065