Publication: Birinci trimester tarama programı kromozomal anomalileri ne kadar etkindir?
Abstract
Amaç: 11-14 hafta erken tarama testinin trizomi 21 ve diğer kromozomal anomalileri saptamadaki başarısını araştırmak ve bu testin duyarlılık ve özgüllüğünü hesaplamak. Çalışmanın Yapıldığı Yer: Marmara Üniversitesi Tıp Fakültesi Hastanesi Kadın Hastalıkları ve Doğum AD, Fetal - Maternal Tıp Ünitesi. Materyal ve Metod: Temmuz 2000 ile Nisan 2002 tarihleri arasında erken tarama testi uygulanan 453 gebe çalışmaya alındı. Tüm hastaların son adet tarihine göre gestasyon haftası 11-13 hafta 6 gün arasında iken nukal saydamlık ölçümü ve anne serum biokimyası (serbest beta-HCG ve PAPP-A düzeyleri) ile riskleri belirlendi. Riski yüksek olanlara (>1:300) 16-18. gebelik haftalarında amniyosentez yapıldı. Hastalar doğum sonuna kadar takip edildiler ve veriler retrospektif olarak değerlendirildi. Bulgular: Çalışmaya alınan hastaların ortalama yaşı 29.07 ± 4.57 yıl (18-40 yıl arasında) idi. 453 hastadan 18'ine invazif test (amniyosentez) yapıldı ve bir trizomi 21 (Down sendromu), bir de Robertsonian translokasyonu (45 XX robt(13;15)pat.) tespit edildi. Erken tarama testinin duyarlılığı %100, özgüllüğü %96, doğruluk oranı %96, yalancı negatiflik oranı %0, yalancı pozitiflik oram %3.5, pozitif test sonucunun olasılık oranı 25, pozitif prediktif değer %11 ve negatif prediktif değer % 100 olarak bulundu. Sonuç: 11-14 hafta erken tarama testi yüksek sensitivite, spesifisite ve doğruluk oranları ile kromozomal anomali riskini belirlemede kullanılabilecek güvenli bir test olup düşük yalancı pozitiflik oranları ile de daha az girişimsel testle daha fazla anomalili fetüs saptamamıza imkan vermektedir.
Objective: The aim of this study is to calculate the sensitivity and specificity of the first trimester screening programme for the detection of trisomy 21 and other chromosomal abnormalities. Setting: Marmara University Hospital Department of Obstetrics and Gynecology, Fetal - Maternal Unit. Materials and Method: 453 pregnancies with the gestational age of 11-13weeks6days have been enrolled into the study between July 2000 and April 2002. According to the nuchal translucency measurements and maternal free beta-HCG and PAPP-A levels, risks of each patient have been calculated and for those with a high calculated risk (>1:300) amniocentesis have been performed. All the pregnancies have been followed till birth. The data have been analyzed retrospectively. Results: The mean age of the patients enrolled in the study was 29.07 ± 4.57 years (with the range of 18-40 years). Of the 453 pregnancies 18 had a high calculated risk (> 1:300). Amniocentesis is performed for those 18 patients and one trizomy 21 (Down's syndrome) and one Robertsonian translocation (45 XX robt(13;15)pat.) have been identified. Sensitivity, specificity, accuracy, false negative ratio, false positive ratio, positive predictive and negative predictive values for the first trimester screening programme were calculated to be 100%, 96%, %96, %0, %3.5,11% and 100% respectively. Conclusion: First trimester screening programme which incorporates maternal age, nuchal translucency and maternal bio-chemistry (free beta-HCG and PAPP-A) has a high sensitivity, specificity and accuracy to detect chromosomal abnormali-ties and with the low false positive ratio it saves us from unnecessary invasive tests and abortions of normal fetuses as a result of these tests.
Objective: The aim of this study is to calculate the sensitivity and specificity of the first trimester screening programme for the detection of trisomy 21 and other chromosomal abnormalities. Setting: Marmara University Hospital Department of Obstetrics and Gynecology, Fetal - Maternal Unit. Materials and Method: 453 pregnancies with the gestational age of 11-13weeks6days have been enrolled into the study between July 2000 and April 2002. According to the nuchal translucency measurements and maternal free beta-HCG and PAPP-A levels, risks of each patient have been calculated and for those with a high calculated risk (>1:300) amniocentesis have been performed. All the pregnancies have been followed till birth. The data have been analyzed retrospectively. Results: The mean age of the patients enrolled in the study was 29.07 ± 4.57 years (with the range of 18-40 years). Of the 453 pregnancies 18 had a high calculated risk (> 1:300). Amniocentesis is performed for those 18 patients and one trizomy 21 (Down's syndrome) and one Robertsonian translocation (45 XX robt(13;15)pat.) have been identified. Sensitivity, specificity, accuracy, false negative ratio, false positive ratio, positive predictive and negative predictive values for the first trimester screening programme were calculated to be 100%, 96%, %96, %0, %3.5,11% and 100% respectively. Conclusion: First trimester screening programme which incorporates maternal age, nuchal translucency and maternal bio-chemistry (free beta-HCG and PAPP-A) has a high sensitivity, specificity and accuracy to detect chromosomal abnormali-ties and with the low false positive ratio it saves us from unnecessary invasive tests and abortions of normal fetuses as a result of these tests.