RESUMEN
OBJECTIVES: An increased nuchal translucency (NT) thickness of ≥ 3.5 mm is a well-established marker for congenital anomalies and adverse pregnancy outcome between 11 and 14 weeks' gestation, but little is known about its performance as a screening tool before 11 weeks. We aimed to investigate, in a prospective setting, whether fetuses with increased NT before 11 weeks are at risk for adverse pregnancy outcome. METHODS: This was a prospective cohort study including pregnant women with a viable fetus with NT ≥ 2.5 mm and a crown-rump length (CRL) < 45 mm. All included women were referred to our fetal medicine unit (FMU) and scheduled for a follow-up scan where the NT was remeasured after 1 week when the CRL was > 45 mm. Two groups were evaluated: cases with a normalized NT (< 3.5 mm) and cases with persistently increased NT (≥ 3.5 mm). The cases were monitored until 4 weeks after delivery. The main outcome was a composite adverse outcome of aneuploidy, other genetic disorders, structural anomalies and pregnancy loss. We performed subgroup analyses of NT thickness at inclusion and normalized or persistently increased NT at follow-up. RESULTS: The study included 109 cases, of which 39 (35.8%) had an adverse pregnancy outcome. Of these, 64.1% (25/39) were aneuploid, corresponding to 22.9% (25/109) of the total study population. In the subgroups of NT thickness at inclusion of 2.5-3.4 mm, 3.5-4.4 mm and ≥ 4.5 mm, an adverse outcome was reported in 22.0% (9/41), 40.0% (18/45) and 52.2% (12/23), respectively. In fetuses with a normalized NT and without ultrasound abnormalities at the follow-up scan, the incidence of adverse outcome was 8.5% (5/59), of which 5.1% (3/59) cases were aneuploid. CONCLUSIONS: Fetuses with an early increased NT thickness are at considerable risk of an adverse pregnancy outcome, even if the NT normalizes after 11 weeks. Not all congenital anomalies can be diagnosed with routine first-trimester screening, such as non-invasive prenatal testing and/or a first-trimester anomaly scan. Therefore, expectant parents should always be referred to a FMU for detailed ultrasonography. Invasive prenatal testing should be offered if an increased NT of ≥ 2.5 mm is observed before 11 weeks' gestation. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.
Resultado adverso del embarazo en fetos con aumento precoz de la translucencia nucal: estudio prospectivo de cohortes OBJETIVOS: El aumento del grosor de la translucencia nucal (TN) de ≥3,5 mm es un marcador bien establecido de anomalías congénitas y resultados adversos del embarazo entre las semanas 11 y 14 de gestación, pero se sabe poco sobre su rendimiento como herramienta de cribado antes de las 11 semanas. El objetivo fue investigar, en un contexto prospectivo, si los fetos con aumento de la TN antes de las 11 semanas corren riesgo de presentar resultados adversos del embarazo. MÉTODOS: Se trató de un estudio prospectivo de cohortes que incluyó a embarazadas con un feto viable con una TN ≥2,5 mm y una longitud céfalocaudal (LCC) <45 mm. Todas las mujeres incluidas fueron remitidas a una unidad de medicina fetal (UMF) y con cita para una prueba de seguimiento en la que se volvió a medir la TN al cabo de 1 semana cuando la LCC era >45 mm. Se evaluaron dos grupos: casos con una TN normalizada (<3.5 mm) y casos con una TN persistentemente aumentada (≥3,5 mm). A los casos se les dio seguimiento hasta 4 semanas después del parto. El resultado principal fue un resultado adverso compuesto de aneuploidía, otros trastornos genéticos, anomalías estructurales y pérdida del embarazo. Se realizaron análisis de subgrupos del grosor de la TN en el momento de la inclusión y de la TN normalizada o persistentemente aumentada en el seguimiento. RESULTADOS: El estudio incluyó 109 casos, de los cuales 39 (35,8%) tuvieron un resultado adverso del embarazo. De ellos, el 64,1% (25/39) eran aneuploides, lo que supone el 22,9% (25/109) de la población total del estudio. En los subgrupos de grosor de la TN en el momento de la inclusión de 2,53,4 mm, 3,54,4 mm y ≥4,5 mm, se notificó un resultado adverso en el 22,0% (9/41), el 40,0% (18/45) y el 52,2% (12/23), respectivamente. En los fetos con una TN normalizada y sin anomalías ecográficas en la ecografía de seguimiento, la incidencia de resultados adversos fue del 8,5% (5/59), de los cuales el 5,1% (3/59) de los casos eran aneuploides. CONCLUSIONES: Los fetos con un aumento precoz del grosor de la TN corren un riesgo considerable de sufrir un resultado adverso del embarazo, incluso si la TN se normaliza después de 11 semanas. No todas las anomalías congénitas pueden diagnosticarse con un cribado rutinario en el primer trimestre, como las pruebas prenatales no invasivas y/o una ecografía de anomalías en el primer trimestre. Por lo tanto, los futuros padres siempre deben ser remitidos a una UMF para una ecografía detallada. Se debería ofrecer una prueba prenatal invasiva si se observa un aumento de la TN de ≥2,5 mm antes de las 11 semanas de gestación.
Asunto(s)
Largo Cráneo-Cadera , Medida de Translucencia Nucal , Resultado del Embarazo , Primer Trimestre del Embarazo , Humanos , Femenino , Embarazo , Medida de Translucencia Nucal/estadística & datos numéricos , Estudios Prospectivos , Resultado del Embarazo/epidemiología , Adulto , Edad Gestacional , Anomalías Congénitas/diagnóstico por imagen , Anomalías Congénitas/embriología , AneuploidiaRESUMEN
OBJECTIVE: To determine whether implementation of cell-free DNA (cfDNA) testing for aneuploidy as a first-tier test and subsequent abolition of first trimester combined testing (FCT) affected the first trimester detection (<14 weeks) of certain fetal anomalies. METHODS: We performed a geographical cohort study in two Fetal Medicine Units between 2011 and 2020, including 705 fetuses with prenatally detected severe brain, abdominal wall and congenital heart defects. Cases were divided into two groups: before (n = 396) and after (n = 309) cfDNA introduction. The primary outcome was the first trimester detection rate (<14 weeks) overall and for non-chromosomal anomalies solely. RESULTS: Overall, gastroschisis, AVSD and HLHS were detected more often in the first trimester in the before group compared to the after group, respectively 54.5% versus 18.5% (p = 0.004), 45.9% versus 26.9% (p = 0.008) and 30% versus 3.4% (p = 0.005). After exclusion of chromosomal anomalies identifiable through cfDNA testing, the detection of AVSD remained higher in the before group (43.3% vs. 9.5%, p = 0.02), leading to a possible earlier gestation at termination. The termination of pregnancy (TOP) rate did not differ among the groups. In the after group, referrals for suspected anomalies following a dating scan between 11 and 14 weeks significantly increased from 17.4% to 29.1% (p < 0.001). CONCLUSION: This study underscores the value of a scan dedicated to fetal anatomy in the first trimester as we observed a decline in the early detection of certain fetal anomalies (detectable in the first trimester) subsequent to the abolition of FCT.