我們收集了懷孕婦女當作研究樣本，總樣本數是3819其中62位被剔除。 因為沒有有效的染色體檢查，時間是從1999年1越至2002年1月，總共3年期間，我們使用1/270當作唐氏症候群增加危險機率的切入值。3819為懷孕婦女接受篩檢，其中陽性有146位，在146位中，102位有染色體結果，所以合於標準的樣本數為3757，在篩檢呈陽性婦女中，沒有一位不正常。陽性預測值為0，我們也收集了另外850位婦女接受羊膜穿刺檢查，適應症包括467位超齡婦女，107位有不正常超音波檢查結果，27位先前有先天性異常胎兒，20位有家庭遺傳史，其中3位的家庭中，父母之中有一位有遺傳疾病，經過羊膜穿刺檢查，分析染色體的結果，其中6位有trisomy21，他們都是因為年齡超過34歲接受羊膜穿刺檢查，2位有trisomy18，2位有klinefelter’s症候群，他們的年紀超過34歲，在這10個案例當中，只有1位是自願接受羊膜穿刺檢查，其餘均是超齡的關係，在我們的研究中，超齡似乎是有關胎兒偵測唐氏症候群很強烈的適應症，也就是說羊膜穿刺檢查應該用在超齡婦女，不論其血糖檢測為陽性與否。 We collected the pregnant women as the population of our research. The total population in our study was 3891.Among these women,62 were excluded from the general population because of no available chromosome study results.The time interval from Jan.1999 to Jan.2002 was three- year interval.We use 1/270 as the cut-off value for increasing risk of Down’s sydrome.A total of 3819 pregnancies were screened of which screening positive pregnancies was 146.Among these 146 screening positive pregnancies,102 women had chromosomal result.The adjusted total population was 3757.There was no abnormal chromosomal result among those screen positive women .Positive predictive value of the screening positive result is zero.We also collected another 850 pregnant women who received amniocentesis on many indications including 467 of advanced age,107 of abnormal sonographic finding, 27 of previous congenital abnormal fetus.20 had history of familial hereditary disease,three of them had a family history that one of their parents is with hereditary disease.After analyzing the chromosome from amniocentesis,trisomy21 was found in six women who were all performed amniocentesis because of advanced maternal age,that is age over 34 years .Trisomy 18 was found in two women.Klinefelter’s syndrome was found in two women who were older than 34 years old.Among these ten cases only one received amniocentesis electively,while the others were all because of advanced age. In our study.Advanced maternal age seemed to be a strong indication in prenatal detection of Down’s syndrome .That is amniocentesis should be performed to those women who were at this age or old.Whatever the serum screening is positive or not.
