Chadud Carolina Schneider, Araujo Júnior Edward, Martinhago Ciro Dresh, Andari Viviane Cristina Mello, Tedesco Giselle Darahem, Bussamra Luiz Claudio Silva, Aoki Tsutomu
Department of Obstetrics and Gynecology, Medical College Sciences of Santa Casa of São Paulo (FCMSCSP) , São Paulo-SP , Brazil .
J Matern Fetal Neonatal Med. 2015 Jan;28(2):172-6. doi: 10.3109/14767058.2014.908843. Epub 2014 May 14.
To compare ethylenediamine tetraacetic acid (EDTA) tubes and plasma preparation tubes (PPT) for evaluating maternal plasma during the first trimester of pregnancy.
A cross-sectional study was conducted on 24 male fetuses in women between 6 and 14 weeks of pregnancy. Blood samples (10 mL) were collected and stored in EDTA and PPT tubes. Subsequently, the samples were centrifuged and sent for free fetal DNA extraction by means of the polymerase chain reaction (PCR) technique. The reactions were performed in a real time PCR machine for detecting the amplification products. The genome region chosen for performing the PCR reactions was a target specific for the Y chromosome, in which the DYS-14 marker was amplified only when the DNA was of male sex. The free fetal DNA concentration was given by the threshold cycle (TC). To compare the tubes, the paired Student t-test was used.
The mean gestational age was 11.08 ± 2.30 weeks (range: 6-14). The mean TC for PPT was 30.08 ± 1.05 (range: 27.08-32.61) and for EDTA, 30.23 ± 0.96 (range: 28.01-32.09), but without statistical significance (p=0.357).
We did not observe any statistically significant difference in free fetal DNA concentration between the EDTA and PPT tubes.
比较乙二胺四乙酸（EDTA）管和血浆制备管（PPT）在孕早期评估母血中的应用。
对24例妊娠6至14周女性的男性胎儿进行横断面研究。采集血样（10 mL）并分别储存在EDTA管和PPT管中。随后，对样本进行离心，并通过聚合酶链反应（PCR）技术送去提取游离胎儿DNA。反应在实时PCR仪中进行以检测扩增产物。用于进行PCR反应的基因组区域是Y染色体特异性靶点，其中只有当DNA为男性时DYS-14标记才会被扩增。游离胎儿DNA浓度由阈值循环（TC）给出。为比较两种管，采用配对学生t检验。
平均孕周为11.08±2.30周（范围：6 - 14周）。PPT管的平均TC为30.08±1.05（范围：27.08 - 32.61），EDTA管的平均TC为30.23±0.96（范围：28.01 - 32.09），但无统计学意义（p = 0.357）。
我们未观察到EDTA管和PPT管在游离胎儿DNA浓度上有任何统计学显著差异。
