Chromosome analysis of 303 pregnancy losses in Mexico.

BACKGROUND: Chromosomal abnormalities are present in 50 to 60% of miscarriages and in 6 to 19% of stillbirths. Although microarrays are preferred for studying chromosomal abnormalities, many hospitals cannot offer this methodology. OBJECTIVE: To present the results of the cytogenetic analysis of 303 products of conception (POC), which included 184 miscarriages, 49 stillbirths and 17 cases of undefined age. MATERIAL AND METHODS: Karyotyping, fluorescence in situ hybridization, short tandem repeats and microarrays were used, depending on the type of loss and available sample. RESULTS: In 29 POCs we found maternal tissue and were eliminated from the analyses. Informative results were obtained in 250 (91.2 %)/274 cases; the karyotyping success rate was 80.7%; that of single nucleotide polymorphism microarrays, 94.5%; and that of fluorescence in situ hybridization and short tandem repeat, 100%. Cytogenetic abnormalities were observed in 57.6% of miscarriages and in 24.5% of stillbirths; 94% of total anomalies were numerical and 6% were submicroscopic. CONCLUSIONS: Karyotyping with simultaneous short tandem repeat study to rule out contamination of maternal cells is effective for studying miscarriages; in stillbirths, microarrays are recommended.

ANTECEDENTES: Las alteraciones cromosómicas están presentes en 50 a 60 % de los abortos espontáneos y en 6 a 19 % de los mortinatos. Aunque se prefieren los microarreglos para estudiarlos, numerosos hospitales no pueden ofrecerlos. OBJETIVO: Presentar los resultados del estudio citogenético de 303 productos de la concepción (POC), 184 se obtuvieron de abortos espontáneos, 49 fueron mortinatos y en 17 no se identificó la de edad gestacional. MATERIAL Y MÉTODOS: Se empleó cariotipo, hibridación in situ con fluorescencia, secuencias cortas repetidas en tándem y microarreglos, según el tipo de pérdida y la muestra disponible. RESULTADOS: En 29 POC se encontró tejido materno, por lo que fueron eliminados de los análisis. En 250 (91.2 %)/274 casos se obtuvieron resultados informativos; la tasa de éxito del cariotipo fue de 80.7 %; la de los microarreglos de SNP, de 94.5 %; y la de la hibridación fluorescente in situ y la repetición corta en tándem, de 100 %. Se observaron anomalías citogenéticas en 57.6 % de los abortos espontáneos y en 24.5 % de los mortinatos; 94 % de las anomalías fueron numéricas y 6 %, submicroscópicas. CONCLUSIONES: El cariotipo en conjunto con el estudio de secuencias cortas repetidas en tándem para descartar contaminación de células maternas es efectivo para estudiar abortos espontáneos; los microarreglos se recomiendan en los mortinatos.

Congenital limb reduction defects in 1.6 million births in Argentina.

The objectives of this study were to describe the birth prevalence of limb reduction defects (LRD) in Argentina, their clinical features, and to review the literature on this topic. The data source was the National Network of Congenital Anomalies of Argentina, a surveillance system that has been operative since 2009. Data were collected from November 1, 2009 to December 31, 2016. 1,663,610 births and 702 affected patients were registered during this period. The prevalence of LRD was 4.22/10,000 births (CI 95%: 3.93-4.54). In 15,094 stillbirths, prevalence was 30.80/10,000 (CI 95%: 22.31-40.65). Perinatal mortality (stillbirths plus early neonatal deaths) was 24.6%, mostly explained by postnatal deaths. LRD were classified according to different variables, including Gold's anatomic classification. Then, 41.0% of patients had transverse terminal defects and 50.2% had longitudinal defects. We found multiple and syndromic clinical presentation to be associated with both preaxial LRD and lethality. The prevalence of LRD was lower and perinatal mortality was higher in our study compared to that of previously published studies. Because there is heterogeneity in the inclusion and exclusion criteria among publications, a greater effort should be made in order to include similar populations and to use a unified anatomic classification and nomenclature.

Clinical, molecular, and pathological findings in a Neu-Laxova syndrome stillborn: A Brazilian case report.

Neu-Laxova syndrome (NLS) is a lethal genetic multiple congenital anomaly syndrome of unknown prevalence representing the severe spectrum of serine biosynthesis defects associated with PHGDH, PSAT1, or PSP gene mutations. The purpose of this study was to describe clinical/molecular and pathologic features of a NLS case caused by novel heterozygous missense variant in PHGDH gene identified in his consanguineous parents.

Trombosis antenatal de aneurisma espontáneo de conducto arterial / Antenatal thrombosis of arterial ductus spontaneous aneurysm

Los aneurismas espontáneos del conducto arterial se detectan inusualmente de forma prenatal. Su incidencia varía entre 1,5 por ciento y 8 por ciento de los embarazos. Usualmente se solucionan espontáneamente; sin embargo, pueden presentarse complicaciones letales como trombosis, embolia y ruptura. Los casos fatales descritos son escasos, la mayoría después del nacimiento. El objetivo es presentar el reporte de autopsia de un mortinato cuya causa de muerte fue la trombosis de aneurisma del conducto arterial. La madre fue una primigesta de 22 años de edad, con embarazo de 40 semanas sin antecedentes de importancia, atendida en un hospital de tercer nivel de Bucaramanga, Santander. Le realizamos una cesárea emergente por perfil biofísico fetal alterado y bradicardia fetal. Se obtuvo un mortinato masculino sin esfuerzo respiratorio, hipotónico, cianótico, que no respondió a maniobras de reanimación. Los hallazgos de autopsia relevantes fueron: dilatación auricular derecha y dilatación preductal con trombosis del conducto cuya luz estaba completamente ocluida por un coágulo. Los aneurismas ductales prenatales son una entidad que merece más estudio para determinar estrategias de diagnóstico precoz y seguimiento, y así disminuir el riesgo de desenlaces fatales(AU)

Introduction: Spontaneous ductus arteriosus aneurysm is a condition rarely diagnosed on prenatal imaging. Literature reveals 1,5 to 8 percent incidence on pregnancies. Most cases have spontaneous resolution, nonetheless, life-threatening complications such thrombosis, embolism and rupture can occur. Fatal cases reports are scarce, most of them presenting on newborns, days to months after birth. Objective: To present the autopsy report of a stillbirth whose cause of death was thrombosis of the arterial duct aneurysm. Methods: A 22-year healthy prime mother with 40-week pregnancy was assisted at a tertiary hospital in Bucaramanga, Santander. She required emergency cesarean section due to low biophysical profile and fetal bradycardia. The newborn had no respiratory effort, was floppy, cyanotic and did not respond to resuscitation maneuvers. The relevant autopsy findings were right atrial dilatation and preductal dilation with thrombosis of the duct whose lumen was completely occluded by a clot. Conclusions: The prenatal ductal aneurysm is an entity that deserves more study to determine strategies for early diagnosis and follow-up thus decrease the risk of fatal outcomes(AU)

[Genetic disease and diagnostic strategies in stillbirth]. / Alteraciones genéticas y estrategias diagnósticas en muerte fetal.

BACKGROUND: Stillbirth occurs in about 1 in 1000 pregnancies. The causes are maternal, fetal, and placental; but in half of the cases, no cause can be determined. Genetic disease, a common cause of stillbirth, is diagnosed in 25-35% of patients with birth defects. OBJECTIVE: Describe birth defects found in stillbirth cases at the Instituto Nacional de Perinatología in a period of 3 years, analyze risk factors in each pregnancy, and propose an adequate approach to effectively reach the proper diagnosis of defined genetic entities related to stillbirth. MATERIAL AND METHODS: All stillbirths cases presenting birth defects and assessed by the Department of Genetics from January 2008 to December 2010 were included in this study. RESULTS: We evaluated 55 stillbirths with birth defects. 31% of them showed multiple defects; 14.5%, single defects; 20%, single gene disorders; 14.5%, chromosomal abnormalities; 9%, disruptive processes; 7%, non-immune fetal hydrops, and 4% twin pregnancy. The karyotype was obtained in all cases from amniocentesis, and in half of them from umbilical cords as well. In 95% of the cases prenatal findings were confirmed through prenatal USG, and necropsy was performed in 74.5% of them. CONCLUSION: Ultrasound, karyotype, autopsy and assessment by a medical geneticist allowed an accurate diagnosis in 81% of cases. Genetic counseling helps reduce parental anxiety and stillbirth from unknown causes.

Chromosomal abnormalities in couples with reproductive disorders.

AIM: To determine the prevalence of chromosomal abnormalities in couples with reproductive disorders. METHODS: A retrospective study was performed in 939 Mexican couples with reproductive disorders (542 with recurrent fetal loss, 356 with malformed/stillborn children, and 41 with sterility) whose karyotype was established on GTG-banded metaphases. RESULTS: A chromosomal aberration was detected in one partner of 52 couples, including a double translocation carrier; therefore, the prevalence of chromosomally abnormal couples was 5.5%; 31 couples with recurrent fetal loss (31/542, 5.7%), 15 with malformed/stillborn children (15/356, 4.2%), and 6 with sterility (6/41, 14.6%). There were 43 couples with structural rearrangements (29 reciprocal translocations, 10 robertsonian translocations, 2 inversions, 1 insertion, and 1 ring) and 9 with gonosomal aneuploidies. The affected partner was female in 28 (53.8%) and male in 24 (46.2%) couples. In addition, 17 couples (1.8%) with the structural variant inversion 9qh were detected. CONCLUSION: The prevalence of chromosomal abnormalities found in our sample is consistent with figures described in several populations around the world.