Feasibility of extended ultrasound examination of the fetal brain between 24 and 37 weeks' gestation in low-risk pregnancies.

OBJECTIVES: To assess the feasibility of identifying fetal brain structures and anatomic landmarks included in the anterior complex (AC) and posterior complex (PC), as well as the proximal hemisphere (PH). METHODS: This was a prospective observational multicenter study of healthy pregnant women evaluated by ultrasound screening at 24 to 36 + 6 weeks' gestation. Six physicians performed transabdominal ultrasound, to obtain the planes required to visualize the AC, PC, and PH. Blind analysis by an expert and non-expert operator in fetal neurosonography was used to assess the structures included in each plane view. RESULTS: In the population studied (n=366), structure detection rates for AC were over 95 %, with an agreement of 96 % when comparing expert and non-expert examiners. Visualization of the corpus callosum crossing the midline was detected in over 97 and 96 % of cases for the AC and PC, respectively, with an agreement of over 96 %. The PH plane, particularly through the posterior access via the mastoid fontanelle, enabled visualization of the proximal anatomical structures in almost 95 % of cases. Detection of the corpus callosum through the AC and PC, both proximal/distal germinal matrix (AC) and proximal Sylvian fissure through the anterior access (PH) in the 24-25 + 6, 26-31 + 6 and 32-36 + 6 weeks' gestation groups were successful in over 96 % of cases with high level of agreement. CONCLUSIONS: Inclusion of AC, PC, and PH later in pregnancy proves feasible with a high level of agreement between both expert and non-expert operators.

Detección rápida de aneuploidías para la definición de incompatibilidad con la vida extrauterina independiente / Rapid detection of aneuploidies for definition of incompatibility with independent extrauterine life

OBJETIVO: Analizar la implementación de la prueba rápida de reacción en cadena de la polimerasa cuantitativa y fluorescente (QF-PCR) para la detección de aneuploidías. MÉTODO: Se incluyeron todas las pacientes que se realizaron una QF-PCR entre septiembre de 2017 y mayo de 2021. En todos los casos se consignaron los datos clínicos, ecográficos y de laboratorio, y se efectuó un seguimiento de quienes se realizaron además cariograma y su resultado fue normal. RESULTADOS: Se realizaron 213 procedimientos invasivos genéticos prenatales, siendo 72 para detección rápida de aneuploidía mediante QF-PCR. El promedio de edad de las madres con QF-PCR fue de 37 años y 48 pacientes (67%) tenían menos de 15 semanas de gestación. La QF-PCR demostró aneuploidía de los cromosomas 18, 13 y de triploidía en 21 de 49 casos informados como anormales. De los 22 casos sin sugerencia de alteración, 17 accedieron a proseguir el estudio con cariotipo, que resultó anormal en 6 casos. Hubo 4 casos de discordancia entre la QF-PCR y el cariotipo, que pudo afectar el manejo clínico de la gestación. En 25/72 casos (34,7%) la aneuploidía era letal. CONCLUSIONES: Considerando la necesidad de tener un diagnóstico rápido, pero también completo y que permita un consejo genético apropiado, debería integrarse la QF-PCR a un protocolo de diagnóstico que considere variables clínicas y ecográficas.

OBJECTIVE: To analyze the performance of QF-PCR test for the detection of aneuploidies. METHOD: All patients who underwent QF-PCR from September 2017 to May 2021, were included. Clinical, ultrasound and laboratory data were recorded in all cases, as well as follow-up of the cases, including those performing karyotype and the result was normal. RESULTS: 213 prenatal genetic invasive procedures were performed in the study period, 72 for rapid detection of aneuploidy by QF-PCR. 48 patients (67%) were less than 15 weeks at the time of ultrasound diagnosis. The QF-PCR test demonstrated aneuploidy of chromosomes 18, 13, and triploidy in 21/49 cases reported as abnormal. Of the cases without suggestion of alteration (22), 17 agreed to continue the study with a karyotype, which was abnormal in 6 cases. There were 4 cases of discrepancy between QF-PCR and karyotype, which could affect the clinical management of pregnancy. 25/72 cases (34. 7%) corresponded to lethal aneuploidy. CONCLUSIONS: Our results justify the use of QF-PCR. Considering the need to have a rapid diagnosis, but also complete and that allows appropriate genetic counseling, it is that QF-PCR should be integrated into a protocol that considers clinical and ultrasound variables.

New Insights into the Anterior Complex.

OBJECTIVE: To introduce visualization of the germinal matrix (GM), external angle of the frontal horn, and periventricular white matter while evaluating the anterior complex (AC) during basic ultrasound assessment of the fetal brain. CASE PRESENTATIONS: This is a retrospective observational study of healthy women with singleton pregnancies, with no increased risk of fetal central nervous system anomalies, attending routine ultrasound screening at 20-32 weeks' gestation. Seventeen cases are presented in which an abnormal aspect of the GM or external angle of the frontal horn or periventricular white matter on AC evaluation has allowed a prenatal diagnosis of peri-intraventricular hemorrhage, subependymal cysts, connatal cysts, periventricular venous hemorrhagic infarction, and white matter injury. CONCLUSION: An extended AC evaluation could significantly improve the -diagnosis of hemorrhagic/cystic/hypoxic-ischemic lesions during the performance of a basic ultrasound study of the fetal brain.

Feasibility and agreement of including anterior-posterior complexes and landmarks of the proximal hemisphere into basic examination of the fetal brain: A prospective study.

OBJECTIVE: To assess the feasibility of identifying structures included in anterior complex (AC) and posterior complex (PC), as well as a series of anatomic landmarks that could help to demonstrate the integrity of the cerebral proximal hemisphere (PH). METHODS: This was a prospective observational multicenter study of healthy pregnant women attending routine ultrasound screening at 20 + 0 to 33 + 6 weeks' gestation. Six physicians performed transabdominal (TA) ultrasound, in order to obtain the planes required to visualize the AC, PC, and PH. Blind analysis by a nonexpert and two experts in fetal neurosonography was used to assess the structures included in each plane view. RESULTS: In the population studied (n = 747), detection of the structure rates for AC, PC, and proximal hemisphere was of 94%, 93%, and 96%, respectively, with an agreement of 97%, 94%, and 98% when comparing an expert and a nonexpert in fetal brain examiner. Detection of structures in the proximal hemisphere was significantly higher when observed through the proximal hemisphere plane rather than the transventricular plane. CONCLUSION: Our results suggest that inclusion of AC and PC complexes visualization, as well as real-time access to the proximal hemisphere, is feasible and could improve the prenatal detection of fetal cerebral anomalies.