ABSTRACT
OBJECTIVE: To analyze the results of contingent screening for common aneuploidies at our center from June 2017 to June 2019. MATERIALS AND METHODS: Traditional screening tests were performed using a combination of biochemical markers and ultrasound measurements in the first and second trimesters to assess the risk of trisomies 21 (T21), 18 (T18) and 13 (T13). Cell-free DNA (cf-DNA) testing was offered (Harmony test) to pregnant women at high risk (>1/280 for T21 and > 1/150 for T13 and T18) and a normal early morphology scan. In positive cases, prenatal sampling was strongly recommended to confirm the results by gold standard methods (QF-PCR and karyotyping). Newborns' phenotypes were corroborated after birth in all cases. RESULTS: In this prospective study, 8153 pregnant women were enrolled, resulting in 390 at high risk according to traditional screening tests. cfDNA testing was offered to 383 women. Traditional screening tests showed a false negative rate of 9.68% for T21. Traditional test sensitivity for T21 was 90.3%, for a false positive rate of 4.17% and a positive predictive value of 7.6%. The positive and negative predictive value for cfDNA testing was 100%. The approach used avoided invasive procedures in 91.3% of women at high risk. The prevalence of chromosomal abnormalities in the population analyzed was 1 in 164, and 1 in 210 for T21. CONCLUSIONS: Our results show that offering cf-DNA testing to women at high risk in traditional tests (including those with risks >1 in 50) significantly reduces false positives and, therefore, the number of invasive tests. Extending the use of cf-DNA testing to intermediate risk categories may be cost effective.
Subject(s)
Aneuploidy , Cell-Free Nucleic Acids/analysis , Congenital Abnormalities/diagnosis , Genetic Testing/methods , Prenatal Diagnosis/methods , Adult , Congenital Abnormalities/embryology , Cost-Benefit Analysis , Down Syndrome/diagnosis , Down Syndrome/embryology , Female , Genetic Testing/economics , Humans , Predictive Value of Tests , Pregnancy , Prenatal Diagnosis/economics , Prospective Studies , Trisomy 13 Syndrome/diagnosis , Trisomy 13 Syndrome/embryology , Trisomy 18 Syndrome/diagnosis , Trisomy 18 Syndrome/embryology , Young AdultABSTRACT
El tracto genital femenino ejecuta un análisis de semen particular, identificando y seleccionando el mejor espermatozoide para la fecundación. Este análisis in vivo trata de asegurar que la descendencia reciba el material genético de mejor calidad. La selección artificial de espermatozoides implica eliminar las barreras naturales con las que se encuentra el gameto masculino en su largo recorrido. Las técnicas convencionales de selección de espermatozoides que se emplean en reproducción asistida (swim-up y gradientes de densidad específicos), se fundamentan en la recuperación o selección de los espermatozoides con mejor movilidad y morfología, pero no distinguen espermatozoides funcionalmente capaces de fecundar ni genéticamente normales. El objetivo de las técnicas avanzadas es seleccionar el espermatozoide con las mejores características funcionales para ICSI o FIV y conseguir una progenie sana. La introducción de nuevas técnicas en el Laboratorio de Andrología podría suponer un salto cualitativo en los resultados en reproducción (AU)
The female genital tract performs a particular sperm analysis, identifying and selecting the best sperm for fertilization. This in vivo analysis seeks to ensure that the offspring receives the best genetic material. Through artificial sperm selection, natural barriers along the female tract are skipped. Conventional selection techniques used in assisted reproduction are based on sperm motility and morphology, not distinguishing between fecundating ability or genetic normality. The object of advanced sperm selection techniques is to retrieve the spermatozoa with better functional characteristics for intracytoplasmic sperm injection or in vitro fertilization. The introduction of these techniques in the andrology laboratory might represent a qualitative leap in assisted reproduction results (AU)
