Next-Generation Sequencing Gene Panels and "Solo" Clinical Exome Sequencing Applied in Structurally Abnormal Fetuses.

OBJECTIVE: The aim of the study was to assess the diagnostic yield of 2 different next-generation sequencing (NGS) approaches: gene panel and "solo" clinical exome sequencing (solo-CES), in fetuses with structural anomalies and normal chromosomal microarray analysis (CMA), in the absence of a known familial mutation. METHODOLOGY: Gene panels encompassing from 2 to 140 genes, were applied mainly in persistent nuchal fold/fetal hydrops and in large hyperechogenic kidneys. Solo-CES, which entails sequencing the fetus alone and only interpreting the Online Mendelian Inheritance in Man genes, was performed in multisystem or recurrent structural anomalies. RESULTS: During the study period (2015-2020), 153 NGS studies were performed in 148 structurally abnormal fetuses with a normal CMA. The overall diagnostic yield accounted for 35% (53/153) of samples and 36% (53/148) of the fetuses. Diagnostic yield with the gene panels was 31% (15/49), similar to 37% (38/104) in solo-CES. CONCLUSIONS: A monogenic disease was established as the underlying cause in 35% of selected fetal structural anomalies by gene panels and solo-CES.

The Contribution of QF-PCR and Pathology Studies in the Diagnosis of Diandric Triploidy/Partial Mole.

OBJECTIVE: the aim of our study was to assess the contribution of quantitative fluorescent polymerase chain reaction (QF-PCR) and pathology studies in the diagnosis of diandric triploidies/partial hydatidiform moles. METHODS: this study included all fet al triploidies diagnosed by QF-PCR in chorionic villi or amniotic fluid in the 2 centers of BCNatal in which a maternal saliva sample was used to establish its parental origin. Pathology studies were performed in products of conception and concordance between a partial hydatidiform mole diagnosis and the finding of a diandric triploidy was assessed. RESULTS: among 46 fetal triploidies, found in 13 ongoing pregnancies and in 33 miscarriages, there were 26 (56%) diandric triploidies. Concordant molecular (diandric triploidy) and pathology results (partial mole) were achieved in 14 cases (54%), while in 6 cases (23%) pathology studies were normal, and in the remaining 6 cases (23%) pathology studies could not be performed because miscarriage was managed medically. CONCLUSIONS: diandric triploidy is associated with partial hydatidiform mole and its diagnosis is crucial to prevent the development of persistent trophoblastic disease. QF-PCR analysis in chorionic villi or amniotic fluid provides a more accurate diagnosis of the parental origin of triploidy than the classical pathology studies.

Prescriptive standards of echocardiographic morphometric and functional parameters in uncomplicated monochorionic diamniotic fetuses.

OBJECTIVE: To create prescriptive standards of cardiac morphometric and functional parameters in a cohort of uncomplicated monochorionic diamniotic (MCDA) twins. METHOD: Fetal echocardiography was performed in a cohort of uncomplicated monochorionic twin fetuses scanned longitudinally, including comprehensive morphometric and functional parameters, using 2-D imaging, M-mode and conventional Doppler. A multilevel polynomial hierarchical model adjusted by gestational age and estimated fetal weight was used to fit each cardiac parameter. RESULTS: The global heart dimensions including the atrial and ventricular areas, the ventricles dimensions and myocardial wall thicknesses and most of the functional parameters, such as the longitudinal myocardial motion and the biventricular cardiac output showed a positive quadratic increment throughout pregnancy. On the other hand, the left ejection fraction, shortening fraction and right fractional area change decreased with gestational age. Scatterplots for the main structural and functional parameters and ratios by gestational age, with mean, 5th, 10th, 90th, and 95th percentiles are provided. Regression equations by estimated fetal weight are also created. CONCLUSION: We provide specific comprehensive echocardiographic prescriptive standards for uncomplicated MCDA twin fetuses following current standardized methodology. The implementation of these charts will potentially help to better identify abnormal cardiovascular parameters associated to monochorionic complications.

Gender-Specific Antenatal Growth Reference Charts in Monochorionic Twins.

OBJECTIVE: To create antenatal gender-specific reference growth charts in uncomplicated monochorionic diamniotic twins. MATERIALS AND METHODS: This is a prospective longitudinal study in which uncomplicated monochorionic (MC) twin pregnancies were included from 23 + 4 weeks of gestation onwards. Estimated fetal weight (EFW) and biometric parameters (biparietal diameter, head circumference, abdominal circumference, and femur length) were evaluated in both fetuses every 2 weeks using standardized methodology. Maternal and fetal complications were excluded. Charts were fitted for each biometric parameter and EFW in relation to gestational age and fetal gender using multilevel mixed models. RESULTS: The final analysis included a total of 456 ultrasound examinations in 62 MC twins, with a mean of 7 scans per pregnancy (range 5-8). The mean as well as 5th and 95th percentiles of each biometric parameter and EFW were adjusted in relation to gender and gestational age between 24 and 37 weeks of gestation. Male fetuses have higher reference values than females, and the disparity is larger in the upper centiles of the distribution. DISCUSSION: We provide gender-specific reference growth charts for MC twins. We suggest that these charts will improve prenatal MC twin assessment and surveillance, with a more accurate classification of normal or growth-restricted fetuses adjusted per sex.

Accuracy of Fetal Echocardiography in the Differential Diagnosis between Truncus Arteriosus and Pulmonary Atresia with Ventricular Septal Defect.

OBJECTIVES: To report on the accuracy of fetal echocardiography in the distinction between truncus arteriosus communis (CAT) and pulmonary atresia with ventricular septal defect (PA-VSD) and to describe the association with extracardiac and chromosomal anomalies. METHODS: This was a retrospective study on 31 fetuses with a single arterial trunk overriding a VSD with a nonidentifiable right ventricle outflow tract with anterograde flow. Data on the type of cardiac defect, gestational age, characteristics of the arterial trunk valve, presence of additional vascular, chromosomal and extracardiac abnormalities and postnatal outcome were obtained. Misdiagnosed cases were reevaluated by four-dimensional spatiotemporal image correlation (4D-STIC) echocardiography. RESULTS: The overall diagnostic accuracy was 81% and increased to 93.5% with 4D-STIC. Chromosomal and extracardiac anomalies were detected in 40 and 27%, respectively. In the PA-VSD group, patent ductus arteriosus and major aortopulmonary collateral arteries (MAPCAs) were present in 70 and 50% of the cases, respectively, coexisting in 1 of 5 cases. MAPCAs were significantly associated with a right aortic arch and with a 22q11 microdeletion in 50% of cases. CONCLUSIONS: A prenatal distinction between CAT and PA-VSD can currently be achieved in most cases. MAPCAs should be actively searched for when PA-VSD is suspected, as they are associated with a higher risk of 22q11 microdeletion and potentially complicate postnatal treatment.

Factores etiopatogénicos de la prematuridad en el hospital universitario Sant Joan de Déu de Barcelona / Etiopathogenic factors of prematurity in the Sant Joan de Déu Hospital in Barcelona (Spain)

Objetivo. Determinar la tasa de partos prematuros durante el 2010 en el Hospital Universitario Sant Joan de Déu de Barcelona, y clasificarlos según la causa principal utilizando un algoritmo de asignación etiológica para establecer las principales causas de parto prematuro. Sujetos y métodos. Se revisan todos los partos prematuros de menos de 37 semanas de gestación que se producen en el Hospital Universitario Sant Joan de Déu de Barcelona durante 2010 (396 casos), y se les asigna un grupo de etiología principal. Resultados. La tasa de parto prematuro es de 9,8%. Las causas inflamatorias representan el 36% de todos los partos prematuros seguidas de las causas idiopáticas (29%). En los partos prematuros de gestaciones múltiples las causas inflamatorias alcanzan el 44%. Conclusiones. Las causas inflamatorias son la principal etiología de parto prematuro, siendo más frecuente en las gestaciones múltiples (AU)

Objective. To determine the rate of preterm births in 2010 at the Sant Joan de Déu University Hospital in Barcelona, and classify them according to the main cause by using a mapping algorithm to establish the main etiological causes of preterm birth. Subjects and methods. All preterm births at less than 37 weeks’ gestation occurring in the Sant Joan de Déu University Hospital in 2010 (n=396) were reviewed and assigned to a group according to their primary etiology. Results. The preterm birth rate was 9.8%. Inflammatory causes accounted for 36% of all preterm births followed by idiopathic causes (29%). In preterm deliveries of multiple gestations, inflammatory causes accounted for 44%. Conclusions. Inflammatory causes are the main etiology of preterm births and are more common in multiple gestations (AU)