RESUMO
OBJECTIVE: To compare ethylenediamine tetraacetic acid (EDTA) tubes and plasma preparation tubes (PPT) for evaluating maternal plasma during the first trimester of pregnancy. METHODS: 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. RESULTS: 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). CONCLUSION: We did not observe any statistically significant difference in free fetal DNA concentration between the EDTA and PPT tubes.
Assuntos
Anticoagulantes/farmacologia , Preservação de Sangue/métodos , Coleta de Amostras Sanguíneas/métodos , DNA/sangue , Ácido Edético/farmacologia , Feto/metabolismo , Primeiro Trimestre da Gravidez/sangue , Proteínas de Ciclo Celular/análise , Proteínas de Ciclo Celular/genética , Estudos Transversais , DNA/análise , Feminino , Idade Gestacional , Humanos , Masculino , Projetos Piloto , Reação em Cadeia da Polimerase , Gravidez , Primeiro Trimestre da Gravidez/genéticaRESUMO
A infertilidade pode ser definida como a incapacidade de se conseguir uma gravidez dentro de um determinado período ou a falha repetida em levar uma gravidez a termo. Os fatores mais comuns associados com o abortamento habitual são de ordem genética, hormonal ou anatômica. O aumento da heterocromatina encontrado nos cromossomos humanos autossomos 1, 9, 16 e no cromossomo sexual Y tem sido comumente definido como sendo uma variação da normalidade. Todavia, têm-se alguns relatos da frequência aumentada dessas alterações em pais de crianças com anomalias cromossômicas, casais com abortos recorrentes e em conceptos cromossomicamente anormais. Sabe-se que os genes responsáveis pela fertilidade e viabilidade são encontrados presentes na heterocromatina, sugerindo que tais variantes não podem ser ignoradas.(AU)
Infertility can be defined as the inability to achieve pregnancy within certain time frame, or the repetitive failure to carry pregnancy through completion. The most common factors associated with habitual abortion have a genetic, hormonal, or anatomical cause. The increase found in heterochromatin at chromosomes 1, 9 and 16 as well as in the sex chromosome Y has been implicated as a variation of normality. However, some reports have highlighted cases of children having chromosomal abnormalities from parents carrying a higher alteration frequency, cases of repetitive abortions, and also some chromosomal abnormal conceptions. It is known that genes for fertility and viability are now thought to reside in heterochromatin, which suggests that variants should not be ignored.(AU)