Síndrome de Andersen Tawil en una embarazada con alto riesgo de muerte súbita. Reporte de caso / Andersen Tawil syndrome in a pregnant woman at high risk of sudden death

Resumen ANTECEDENTES: El síndrome de Andersen Tawil es una canalopatía multisistémica genética, muy rara, sin alteración cardiaca estructural, heredada de manera autosómica dominante y causada por mutación en el gen KCNJ2. Este síndrome se caracteriza por una triada de parálisis muscular periódica, cambios en el electrocardiograma y estructurales corporales. El rasgo distintivo es la taquicardia ventricular bidireccional, las contracciones ventriculares prematuras y raramente taquicardia polimórfica tipo torsade de pointes. En la actualidad se carece de guías para el peri y postparto y para la prevención de arritmias. CASO CLÍNICO: Paciente de 21 años, embarazada, con síndrome de Andersen Tawil diagnosticado a esta edad, con base en los antecedentes de síncope de repetición y debilidad en las extremidades desde los 11 años. Recibía tratamiento con un beta-bloqueador y un desfibrilador automático implantable. La ecocardiografía fetal a las 23 y 33 semanas de gestación reportó una comunicación interventricular apical de 1.6 mm. A las 39 semanas de embarazo se practicó una cesárea electiva, con evolución posoperatoria satisfactoria. El estudio molecular dirigido al recién nacido descartó el síndrome de Andersen Tawil congénito. CONCLUSIÓN: En pacientes con síndromes de arritmia congénita, el embarazo puede ser seguro siempre y cuando un grupo de especialistas esté pendiente para tomar decisiones de atención y tratamiento durante todo el proceso del embarazo y puerperio.

Abstract BACKGROUND: Andersen Tawil syndrome is a very rare genetic multisystemic channelopathy without structural cardiac alteration, inherited in an autosomal dominant manner and caused by mutation in the KCNJ2 gene. This syndrome is characterised by a triad of periodic muscle paralysis, electrocardiogram and body structural changes. The hallmark is bidirectional ventricular tachycardia, premature ventricular contractions and rarely polymorphic torsade de pointes tachycardia. Currently there is a lack of guidelines for peri- and postpartum and arrhythmia prevention. CLINICAL CASE: 21-year-old pregnant patient with Andersen-Tawil syndrome diagnosed at this age, based on a history of repeated syncope and weakness in the extremities since the age of 11. She was being treated with a beta-blocker and an implantable cardioverter defibrillator. Fetal echocardiography at 23 and 33 weeks gestation reported an apical ventricular septal defect of 1.6 mm. Elective caesarean section was performed at 39 weeks of pregnancy, with satisfactory postoperative evolution. Molecular study of the newborn ruled out congenital Andersen-Tawil syndrome. CONCLUSION: In patients with congenital arrhythmia syndromes, pregnancy can be safe as long as it is managed by a group of experts to make decisions and optimise care throughout the pregnancy and postpartum period.

Anomalías congénitas disruptivas asociadas con misoprostol. Reporte de un caso / Disruptive congenital anomalies associated with misoprostol. Case report

Resumen ANTECEDENTES: La exposición prenatal al misoprostol puede asociarse con un espectro de defectos congénitos que varían desde anomalías del sistema nervioso central, secuencia de Moebius, defectos en la pared abdominal, defectos transversales en las extremidades hasta alteraciones fetales. Esos defectos se observan más comúnmente con esquemas de solo misoprostol para inducción del aborto. Por esos antecedentes es importante que la historia clínica de toda paciente obstétrica sea exhaustiva para permitir identificar el antecedente de la exposición prenatal luego de un aborto fallido. CASO CLINICO: Paciente de 21 años, con 32 semanas de embarazo, con diagnóstico de feto con ventriculomegalia. En la evaluación ecográfica destacó la ventriculomegalia triventricular severa, simétrica y la angulación de ambas extremidades inferiores en varo. La resonancia magnética reportó: ventriculomegalia no comunicante severa, bilateral, simétrica, por probable estenosis del acueducto de Silvio. Cariotipo 46,XY y perfil TORCH negativo. El embarazo finalizó mediante cesárea, por indicación fetal a las 35 semanas. La evaluación al nacimiento reportó: parálisis facial bilateral, macrocefalia y pie equino varo bilateral. Al volver a interrogar a la paciente refirió haber sido tratada con misoprostol en el primer trimestre del embarazo, con fines abortivos. Al descartar las alteraciones cromosómicas e infecciosas se estableció el diagnóstico de secuencia Moebius. CONCLUSIONES: La exposición prenatal al misoprostol está relacionada con la aparición de defectos vasculares en algunos fetos expuestos. Aún no se ha determinado el espectro preciso ni la estimación potencial de teratogenicidad. La historia clínica es el pilar para la asociación en estos casos.

Abstract BACKGROUND: Prenatal misoprostol exposure can be associated with a spectrum of birth defects, ranging from central nervous system abnormalities, Moebius sequence, abdominal wall defects, as well as transverse limb defects, fetal abnormalities are more commonly seen with the use of the misoprostol-only regimen for induction of abortion, such that a thorough medical history is essential to detect a history of prenatal exposure after a failed abortion. CLINICAL CASE: A 21-year-old patient, with a 32-week pregnancy, who attended the institute with a diagnosis of a fetus with ventriculomegaly, the ultrasound evaluation highlighted severe symmetric triventricular ventriculomegaly and angulation of both lower extremities in varus, magnetic resonance imaging reported severe non-communicating ventriculomegaly Symmetric bilateral, due to probable stenosis of the aqueduct of Silvio, the karyotype reported 46, XY, as well as a negative TORCH profile, however, a cesarean section was performed for fetal indication at 35 weeks, the evaluation at birth showed bilateral facial paralysis, macrocephaly and foot Bilateral equinus varus, upon re-examination the patient referred the use of misoprostol in the first trimester of pregnancy for abortive purposes, so as there were no chromosomal or infectious alterations, a Moebius sequence was suggested. CONCLUSIONS : Prenatal exposure to misoprostol is related to the appearance of vascular disruption defects in some exposed fetuses, the precise spectrum and potential estimation of teratogenicity have not yet been determined, the clinical history is the mainstay for the association in these cases.

AZFa, AZFb, AZFc and gr/gr Y-chromosome microdeletions in azoospermic and severe oligozoospermic patients, analyzed from a neural network perspective.

AIM: Analysis of male infertility by molecular methods has increased since recognition of genetic risk factors. The AZFa, AZFb, AZFc, and gr/gr regions on the Y-chromosome can cause male infertility. The aim of this study was to determine the prevalence of Y-chromosome microdeletions in these regions in infertile Mexican patients. MATERIAL AND METHODS: We recruited 57 infertile patients with abnormal sperm count (26 azoospermic and 31 oligozoospermic) and 55 individuals with normal sperm count. Analysis of the regions of interest was performed by PCR. RESULTS: 15.8% of infertile patients presented Y-chromosome microdeletions, whereas no deletions were found in the control group. Deletions were observed in all the analyzed regions except in AZFa. Additionally, the neural network model revealed a mild genotype-phenotype correlation between deletion of the sY1191, sY1291 and sY254 markers with oligozoospermia, azoospermia and cryptozoospermia, respectively. CONCLUSIONS: Our data show that AZFb, AZFc, and gr/gr microdeletions are significantly associated with infertility in Mexican population. In addition, the neural network model revealed a discrete genotype-phenotype correlation between specific deletions and a particular abnormality. Our results reinforce the importance of the analysis of AZF regions as part of the clinical approach of infertile men.

OBJETIVO: La utilización de técnicas moleculares para estudiar la infertilidad masculina se ha incrementado desde el reconocimiento de factores genéticos. Las regiones AZFa, AZFb, AZFc, y gr/gr del cromosoma Y son causa de infertilidad masculina. El objetvo de este estudio fue determinar la prevalencia de microdeleciones en estas regiones en pacientes infértiles Mexicanos. MATERIAL Y MÉTODOS: Reclutamos 57 pacientes infértiles con cuentas espermáticas anormales (26 con azoospermia y 31 con oligozoospermia) y 55 individuos con cuentas espermáticas normales. El análisis de las regiones se realizó mediante PCR. RESULTADOS: 15.8% de los pacientes infértiles presentó microdeleciones, no se encontraron microdeleciones en el grupo control. Las microdeleciones fueron observadas en todas las regiones excepto en AZFa. Adicionalmente, el modelo de red neuronal reveló una leve correlación genotipo-fenotipo entre microdeleciones de los marcadores sY1191, Sy1291 y sY254 con oligozoospermia, azoospermia y criptozoospermia, respectivamente. CONCLUSIONES: Nuestros datos muestran que las microdeleciones en AZFb, AZFc, y gr/gr se asocian significativamente con infertilidad en la población Mexicana. Además, el modelo de red neuronal reveló una discreta correlación genotipo-genotipo entre microdeleciones específicas con una anormalidad en particular. Nuestros resultados refuerzan la importancia del análisis de las regiones AZF en el abordaje de la infertilidad masculina.

COVID-19 Infection in Pregnancy: PCR Cycle Thresholds, Placental Pathology, and Perinatal Outcomes.

(1) This study aimed to evaluate characteristics, perinatal outcomes, and placental pathology of pregnant women with or without SARS-CoV-2 infection in the context of maternal PCR cycle threshold (CT) values. (2) This was a retrospective case-control study in a third-level health center in Mexico City with universal screening by RT-qPCR. The association of COVID-19 manifestations, preeclampsia, and preterm birth with maternal variables and CT values were assessed by logistic regression models and decision trees. (3) Accordingly, 828 and 298 women had a negative and positive test, respectively. Of those positive, only 2.6% of them presented mild to moderate symptoms. Clinical characteristics between both groups of women were similar. No associations between CT values were found for maternal features, such as pre-gestational BMI, age, and symptomatology. A significantly higher percentage of placental fibrinoid was seen with women with low CTs (<25; p < 0.01). Regarding perinatal outcomes, preeclampsia was found to be significantly associated with symptomatology but not with risk factors or CT values (p < 0.01, aOR = 14.72). Moreover, 88.9% of women diagnosed with COVID-19 at <35 gestational weeks and symptomatic developed preeclampsia. (4) The data support strong guidance for pregnancies with SARS-CoV-2 infection, in particular preeclampsia and placental pathology, which need further investigation.

Prevalence, clinical features, and outcomes of SARS-CoV-2 infection in pregnant women with or without mild/moderate symptoms: Results from universal screening in a tertiary care center in Mexico City, Mexico.

The perinatal consequences of SARS-CoV-2 infection are still largely unknown. This study aimed to describe the features and outcomes of pregnant women with or without SARS-CoV-2 infection after the universal screening was established in a large tertiary care center admitting only obstetric related conditions without severe COVID-19 in Mexico City. This retrospective case-control study integrates data between April 22 and May 25, 2020, during active community transmission in Mexico, with one of the highest COVID-19 test positivity percentages worldwide. Only pregnant women and neonates with a SARS-CoV-2 result by quantitative RT-PCR were included in this study. Among 240 pregnant women, the prevalence of COVID-19 was 29% (95% CI, 24% to 35%); 86% of the patients were asymptomatic (95% CI, 76%-92%), nine women presented mild symptoms, and one patient moderate disease. No pregnancy baseline features or risk factors associated with severity of infection, including maternal age > 35 years, Body Mass Index >30 kg/m2, and pre-existing diseases, differed between positive and negative women. The median gestational age at admission for both groups was 38 weeks. All women were discharged at home without complications, and no maternal death was reported. The proportion of preeclampsia was higher in positive women than negative women (18%, 95% CI, 10%-29% vs. 9%, 95% CI, 5%-14%, P<0.05). No differences were found for other perinatal outcomes. SARS-CoV-2 test result was positive for nine infants of positive mothers detected within 24h of birth. An increased number of infected neonates were admitted to the NICU, compared to negative neonates (44% vs. 22%, P<0.05) and had a longer length of hospitalization (2 [2-18] days vs. 2 [2-3] days, P<0.001); these are potential proxies for illness severity. This report highlights the importance of COVID-19 detection at delivery in pregnant women living in high transmission areas.

Estrategia combinada en fertilización in vitro: mínima estimulación y transferencia de embrión único con diagnóstico genético. Experiencia de 3 años en dos centros de reproducción en México / A combined in-vitro fertilization strategy: minimal stimulation IVF, PGT-A and SET. Results from 3 years' experience at two IVF centers in Mexico

Resumen OBJETIVO: Evaluar los desenlaces de una estrategia combinada para fertilización in vitro: mínima estimulación ovárica, diagnóstico genético preimplantación para aneuploidias y transferencia de un solo embrión. MATERIALES Y MÉTODOS: Estudio de cohorte, retrospectivo, efectuado en dos centros de reproducción de México, en un periodo de tres años. Se incluyeron pacientes entre 25 y 45 años, en protocolo de fertilización in vitro, con mínima estimulación, diagnóstico genético preimplantación para aneuploidias (PGT-A) y transferencia de embrión único. El diagnóstico genético preimplantación se estableció mediante microarreglos y secuenciación de nueva generación (NGS). Para el análisis estadístico se integraron 5 grupos, según la edad de las pacientes: menores de 35 años; 35 a 37 años; 38 a 40 años; 41 a 42 años; y mayores de 42 años. Mediante estadística descriptiva se analizaron las variables numéricas y categóricas. RESULTADOS: Se analizaron 175 ciclos, en 125 pacientes (edad promedio: 39 años ± 5). Se obtuvieron, en promedio, 5 óvulos por ciclo. La tasa de fertilización fue de 86.5% y la de blastocisto por óvulo fertilizado de 50.7%. Se tomó biopsia para diagnóstico genético preimplantación para aneuploidias a 404 embriones. La tasa general de euploidia fue de 33%. Se efectuaron 69 transferencias de embrión único, con una tasa de embarazo por transferencia de 71%. La tasa de nacimiento por transferencia fue de 60.8% (42 nacimientos). CONCLUSIONES: La combinación de mínima estimulación, diagnóstico genético preimplantación para aneuploidias y transferencia de embrión único, es un procedimiento adecuado para alcanzar una tasa de nacimiento alta.

Abstract OBJECTIVE: To evaluate results of a combined approach in IVF, using minimal stimulation, preimplantation genetic testing for aneuploidy, and single blastocyst transfer. MATERIALS AND METHODS: Retrospective cohort study over a three years' period in two fertility centers in Mexico. A total of 125 patients were included, between 25 and 45 years old, with minimal stimulation IVF, preimplantation genetic testing for aneuploidy (PGT-A) and single euploid embryo transfer. PGT was performed using microarrays and next generation sequencing (NGS). RESULTS: A total of 175 cycles (mean age: 39 years old) were analyzed in 125 patients. On average, five eggs were collected per cycle; fertilization rate was 86.57%; blastocyst rate was 50.7% per fertilized egg. Only 33% of embryos were euploid. Pregnancy rate per transferred embryo was 71%. Live birth rate was 60.8% (42 births). CONCLUSIONS: A combination of minimal stimulation, PGT-A and single blastocyst embryo transfer can yield a high live birth rate.

Clinical and genetic description of patients with prenatally identified cardiac tumors.

OBJECTIVE: Rhabdomyomas are the most common type of prenatal cardiac tumors. When isolated, 50% to 70% are related to the tuberous sclerosis complex (TSC). The aim of this study was to reinforce the importance of additional clinical data in patients with prenatal heart tumors. METHODS: From 2010 to 2017, 10 prenatally detected cardiac tumors were referred to the Genetics Department, and a complete family history was taken. Postnatal echocardiographic and full clinical evaluation were completed. Next generation sequencing (NGS) of the TSC1 and TSC2 genes was performed. RESULTS: The 10 cases were postnatally confirmed as rhabdomyomas. Four de novo and four family cases were detected, and only one patient was previously aware of the TSC diagnosis. Molecular analysis by NGS was performed in four patients with three TSC2 mutations, two of which were previously reported and one not. DISCUSSION: Prenatal cardiac tumors are associated with TSC in 60% of cases. Prenatal diagnosis of cardiac tumors permits a further analysis of family members using the fetus as a clue for familial disease diagnosis.

Giant left ventricular rhabdomyoma treated successfully with everolimus: case report and review of literature.

IntroductionIntracardiac rhabdomyomas can cause severe ventricular dysfunction and outflow tract obstruction.Case reportA term newborn infant with antenatal diagnosis of giant left ventricle rhabdomyoma presented with cardiac failure and duct-dependent systemic circulation after birth. She was treated successfully with everolimus, showing decrease in tumour size and improvement in left ventricular ejection fraction.DiscussionTumour regression rate was 0.32 cm2/day and improved to 0.80 cm2/day with the use of everolimus. Herein we report a newborn with inoperable giant left ventricular cardiac rhabdomyoma and significant regression of the tumour. To our knowledge, this is the largest left ventricular rhabdomyoma reported. A review of the literature was undertaken for comparison. CONCLUSION: Everolimus has proven to be efficacious in size reduction of cardiac rhabdomyomas in cases when surgical resection is not possible.

Mortality from Congenital Heart Disease in Mexico: A Problem on the Rise.

BACKGROUND AND OBJECTIVES: Temporal trends in mortality from congenital heart disease (CHD) vary among regions. It is therefore necessary to study this problem in each country. In Mexico, congenital anomalies were responsible for 24% of infant mortality in 2013 and CHD represented 55% of total deaths from congenital anomalies among children under 1 year of age. The objectives of this study were to analyze the trends in infant mortality from CHD in Mexico (1998 to 2013), its specific causes, age at death and associated socio-demographic factors. METHODS: Population-based study which calculated the compounded annual growth rate of death rom CHD between 1998 and 2013. Specific causes, age at which death from CHD occurred and risk factors associated with mortality were analyzed for the year 2013. RESULTS: Infant mortality from CHD increased 24.8% from 1998 to 2013 (114.4 to 146.4/ 100,000 live births). A total of 3,593 CHD deaths occurred in 2013; the main causes were CHD with left-to-right shunt (n = 487; 19.8/100,000 live births) and cyanotic heart disease (n = 410; 16.7/100,000). A total of 1,049 (29.2%) deaths from CHD occurred during the first week of life. Risk factors associated with mortality from CHD were, in order of magnitude: non-institutional birth, rural area, birth in a public hospital and male sex. CONCLUSIONS: Mortality from CHD has increased in Mexico. The main causes were CHD with left-to-right shunt, which are not necessarily fatal if treated promptly. Populations vulnerable to death from CHD were identified. Approximately one-third of the CHD occurred during the first week of life. It is important to promote early diagnosis, especially for non-institutional births.

[Clinical implementation of non-invasive prenatal study for detecting aneuploidies by fetal DNA based on single nucleotide polymorphisms: two years in Mexico]. / Implementación clínica del estudio prenatal no invasivo para Ia detección de aneuplodías mediante ADN fetal con base en polimorfismos de nucleótido único: dos años en México.

BACKGROUND: Recent data have shown that non invasive prenatal test (NIPT) for the detection of fetal aneuploidies (chromosomes 13, 18, 21, X, Y, and triploidy) by cell free fetal DNA in maternal blood (cfDNA) is a clinical reality, with detection rates > 99% and false positive rates of 0.1%. Results that exceed the first trimester screening. OBJECTIVE: To describe our experience of 2 years integrating NIPT by cfADN in its variant of single nucleotide polymorphism (SNPs) as a screening method for the detection of common aneuploidies, since nine weeks of gestation. PATIENTS AND METHODS: Observational prospective study from March 2013 to February 2015. Women with a singleton pregnancy were offered conventional prenatal screening fetal aneuploidy and or new alternative NIPT-SNPs. RESULTS: 270 women were included,the mean maternal age was 35.3 years with a mean gestational age of 11.85 weeks. The result was obtained in 98.5%, with an average report time of 7.5 working days. Blood collection was repeated in fifteen patients, obtaining the result in eleven. The NIPT tested positive for ten cases, 8 for trisomy 21, one for trisomy 18 and one trisomy 13. CONCLUSIONS: We describe our first two years of integrating NIPT-SNPs to obstetric private practice, that is an alternative screening with the potential to be incorporated into theexisting algorithms in prenatal care, from the ninth week of gestation. We expect this information will motivate a debate on the issue of prenatal screening and get to improve obstetric care and genetic counseling in Mexico.

Microtia-atresia: aspectos clínicos, genéticos y genómicos / Microtia-atresia: clinical, genetic and genomic aspects

En México, la microtia presenta una prevalencia de 7.37/10,000 recién nacidos, la cual es más alta que la reportada en otras poblaciones; por ejemplo, en Estados Unidos es de 2-3/10,000 recién nacidos. Se define como la malformación congénita del oído externo caracterizada por un pabellón auricular pequeño y con alteración en su forma. Se observa más frecuentemente de manera unilateral de lado derecho y en varones, y puede presentarse como defecto aislado o asociada con otras alteraciones como atresia y estenosis del conducto auditivo. Representa una de las principales causas de atención en la consulta externa del departamento de genética de instituciones de tercer nivel. Se considera como una malformación mayor con profundas repercusiones en la función auditiva, y que requiere de una atención multidisciplinaria. En una minoría de casos ha sido posible identificar una causa puramente genética o puramente ambiental, ya que en la mayoría la presentación es multifactorial. Debido a la importancia que representa esta alteración para los diferentes servicios de salud en México, es importante que se conozcan sus bases clínicas, moleculares y hereditarias.

Mexico has a prevalence of microtia of 7.37/10,000 (newborns), 3 times higher than the prevalence reported in other populations (USA 2-3/10,000). Microtia is defined as a congenital malformation of the external ear characterized by a small auricular lobe with an abnormal shape. It is more often unilateral and on the right side. Males are more frequently affected than females. It can occur as an isolated defect or can be associated with other abnormalities such as stenosis of the external auditory canal. In three of the main pediatric hospitals in Mexico, microtia is among the most important causes of attendance in the Genetics Department. Microtia-atresia must be considered as a major malformation with important repercussions in hearing function requiring multidisciplinary medical care in order to limit the disability associated and to provide genetic counseling. Its etiology is complex. Only in a minor number of cases it has been possible to identify a main genetic component (as in monogenic presentations) or a main environmental cause (as in fetal alcohol syndrome or pregestational diabetes). In most cases this malformation is multifactorial. Due to the relevance that the frequency of microtia atresia has in different health services in Mexico, it is important that all medical professionals are aware of its clinical, molecular and inherited characteristics.

[Microtia-atresia: clinical, genetic and genomic aspects]. / Microtia-atresia: aspectos clínicos, genéticos y genómicos.

Mexico has a prevalence of microtia of 7.37/10,000 (newborns), 3 times higher than the prevalence reported in other populations (USA 2-3/10,000). Microtia is defined as a congenital malformation of the external ear characterized by a small auricular lobe with an abnormal shape. It is more often unilateral and on the right side. Males are more frequently affected than females. It can occur as an isolated defect or can be associated with other abnormalities such as stenosis of the external auditory canal. In three of the main pediatric hospitals in Mexico, microtia is among the most important causes of attendance in the Genetics Department. Microtia-atresia must be considered as a major malformation with important repercussions in hearing function requiring multidisciplinary medical care in order to limit the disability associated and to provide genetic counseling. Its etiology is complex. Only in a minor number of cases it has been possible to identify a main genetic component (as in monogenic presentations) or a main environmental cause (as in fetal alcohol syndrome or pregestational diabetes). In most cases this malformation is multifactorial. Due to the relevance that the frequency of microtia atresia has in different health services in Mexico, it is important that all medical professionals are aware of its clinical, molecular and inherited characteristics.

Amniotic band sequence: prenatal diagnosis, phenotype descriptions, and a proposal of a new classification based on morphologic findings.

OBJECTIVE: The aim of this study is to describe the phenotype of fetuses affected by amniotic band sequence (ABS) that were diagnosed at the Instituto Nacional de Perinatología Isidro Espinosa de los Reyes and to propose a new classification based on morphologic findings. MATERIAL AND METHODS: Cases with a final diagnosis of amniotic band sequence, diagnosed between January 1993 and July 2010 in the Department of Maternal Fetal Medicine, were reviewed. Demographic, clinical, and periconceptional data were collected, and the defects were described and classified. The association frequencies of the defects were also determined. RESULTS: We included 50 cases with prenatal diagnosis of amniotic band sequence. The mean maternal age was 25.7 ± 6.9 years. Of these patients, 54% (27/50) were primiparous compared to 22% (11/50) who had three or more previous pregnancies. Craniofacial defects were seen in 78% (39/50) of the cases, followed by defects of the extremities 70% (35/50), abdominal wall, spine, and/or thorax 52% (26/50). The most frequent defects were the following: a) Encephalocele and facial clefts in the craniofacial group. b) Shortening at any level in the limb defects group, and c) Alterations of the spinal column curvature in the group of "other" defects. CONCLUSIONS: The amniotic band sequence shows a tendency to affect women who are in their earlier years of reproduction. We observed an inverse relationship between the number of pregnancies and the frequency of presentation of this pathology. The majority of affected fetuses showed a phenotype that fit into one of many groups. Therefore, we propose classifying the amniotic band sequence phenotypes into the following groups: I. Craniofacial defect + limb defect. II. Craniofacial defect + limb defect + abdominal wall, spinal column, and/or thoracic defects. III. Limb defect + abdominal wall, spinal column, and/or thoracic defects; and IV. Isolated defect (craniofacial, limb, or thoraco-abdominal wall). This classification system will be helpful in diagnosing amniotic band sequence. Based on future research studies, we hope that we can use this classification system as a prognosis fetal factor to establish a more accurate fetal prognosis and recurrence probability. Finally, we created a flowchart describing all of the steps that were followed by our Department from the moment an amniotic band was found by ultrasound until the definitive diagnosis was made and the follow up according to the fetal findings.

[Current indications for invasive prenatal diagnosis. New proposals based on the experience of Institute Nacional de Perinatología]. / Indicaciones actuales para el diagnóstico prenatal invasivo. Nuevas propuestas basadas en la experiencia del Instituto Nacional de Perinatología.

BACKGROUND: Invasive prenatal diagnosis (IPD) allows identification of fetal diseases, mainly aneuploidy. With the addition of first-trimester prenatal screening and structural ultrasound, IPD indications have changed. OBJECTIVE: To describe the current indications for IPD in pregnant patients at INPer. METHODS: Descriptive and retrospective study. We reviewed medical records of patients in which IPD was performed during a period of 2.5 years. RESULTS: A total of 339 studies were performed: 81% by amniocentesis (AC), 13% by chorionic villus sampling (CVS) and 6% by cordocentesis or somatocentesis. The most common indications for AC were: advanced maternal age (AMA) (43%), fetuses with multiple defects by ultrasonido (23%) and presence of soft markers for aneuploidies (9%). For CVS were: cystic hygroma (24%). Increased nuchal translucency (NT) (24%), and AMA (18%). When the indication was only AMA, 1.5% of fetus presented aneuploidy. In women under 38 years and normal ultrasoud, chromosomal abnormalities were not detected. The increased NT in women <35 years had a 21% detection and in patients > 35 years it increased to 33%. CONCLUSIONS: We observed that the group who had normal translucencia nucal and AMA presented a low risk of chromosomal abnormalities. In the presence of an increased NT, 33% of fetuses were affected, so that measuring TN is considered the best non invasive PD tool. The average age with cytogenetic abnormalities was above 38 years, so we suggest to offer IPD in women above 38 years-old.

Association between selected structural defects and chromosomal abnormalities.

OBJECTIVE: To determine the association between some major structural abnormalities detected prenatally by ultrasound and chromosomal abnormalities. MATERIAL AND METHODS: The present study was a retrolective, transversal study. We analyzed case records of patients during the fetal follow-up at the Department of Maternal Fetal Medicine from January 1994 to May 2010 to identify fetal patients with a diagnosis of holoprosencephaly, diaphragmatic hernia, omphalocele, cystic hygroma, hydrops and cardiac defects. We analyzed patients who had a prenatal invasive diagnosis procedure to obtain the odds ratio (OR) for some major isolated anomalies and their different combinations with respect to chromosomal abnormalities. RESULTS: We examined 280 patients with ultrasonographic markers for chromosomal alteration, 197 met inclusion criteria, from which 88 had chromosomal abnormalities. The most frequent diagnosis was trisomy 18 (31.8%), which was followed by trisomy 21 (21.6%), trisomy 13 (21.6%), Turner syndrome (monosomy X) (14.8%) and other chromosomal abnormalities (10.2%). Among the fetuses with nonisolated holoprosencephaly, we obtained an OR of 4.9 95% CI (0.99-24.2) for aneuploidy. Associated omphalocele had an OR of 7.63 95% CI (2.07-46.75), p < 0.01. Interestingly, 62% of aneuploidy cases had associated cardiac defects [OR = 7.7 95% CI (1.4-41.7)]. In addition, associated cystic hygroma had an OR of 2.5 95% CI (0.59-10.91). Heart defects were the most common defects in fetuses with trisomy 18 (57.1%), when they were associated with facial cleft, we had an OR of 11.08 95% CI (2.99-41.11), p < 0.0001. Statistical potency was calculated for each analyzed defect and it was over 80% for all of them but diaphragmatic hernia. CONCLUSIONS: The association of 2 or more structural defects increased the probability of a fetus to be a carrier of a chromosomal disorder; however this was not statistically significative except for associated omphalocele. Heart defects showed the greatest association with all chromosomal abnormalities. The most important association was among heart defect, facial cleft and trisomy 13.

El papel de la genética en la restricción del crecimiento intrauterino / The role of genetics in fetal growth restriction

Se define como restricción del crecimiento intrauterino (RCIU) a la alteración en el crecimiento fetal que determina un peso por debajo de la percentila 10 para la edad gestacional. Las causas genéticas de RCIU pueden dividirse en: cromosómicas, alteraciones de la epigenética o impronta y síndromes génicos. Se presenta el caso de una paciente con RCIU referida por sospecha de displasia ósea, en la que se descartó disfunción vascular placentaria por ultrasonido prenatal, infecciones, patología materna y displasias óseas por estudio radiológico normal. Se realizó cariotipo en el cordón umbilical y en tres diferentes sitios de la placenta por la posibilidad de un mosaico placentario, obteniéndose un resultado normal. Al nacimiento presentó peso y talla por debajo de la percentila 3, cráneo dolicocéfalo con frontal prominente, fontanela anterior amplia, cara pequeña, triangular con mentón en punta y clinodactilia bilateral. A los dos meses de edad se observó asimetría de extremidades inferiores y se refirió reflujo gastroesofágico. Con base en los criterios clínicos y resultados obtenidos se realizó el diagnóstico de síndrome de Silver-Russell.

Intrauterine growth restriction (IUGR) is an alteration in fetal development in which the fetal weight is below the 10th percentile for gestational age. The genetic causes of IUGR can be classified as: chromosomal, epigenetic and other imprinting disorders and monogenic syndromes. We report a patient with IUGR referred to our hospital with the prenatal diagnosis of achondroplasia. Vascular malfunction of the placentae, maternal pathology, and skeletal dysplasia were discarded. A karyotype in umbilical cord and in three different placental spots was performed, with a normal result in all of them, ruling out placentae mosaicism. At birth, the weight and height were below the 3th percentile. Physical examination showed: dolicocephaly, frontal prominence, large fontanels, small and triangular face, pointed chin and incurved bilateral fifth fingers. Two months later a lower limb asymmetry was noticed and gastroesophageal reflux was referred. With these clinical abnormalities and the studies performed the diagnosis of Silver-Russell syndrome was established.

Discordancia de defectos congénitos en recién nacidos de embarazos múltiples en el Instituto Nacional de Perinatología / Discordance in birth defects in multiple gestations at the Instituto Nacional de Perinatología

Introducción: Los embarazos gemelares representan menos del 3% de los recién nacidos; sin embargo, constituyen el 12% de las muertes perinatales. Presentan una alta frecuencia de complicaciones que se clasifican en: propias del embarazo gemelar, defectos congénitos aislados y anomalías cromosómicas. Material y métodos: Se revisaron los expedientes clínicos de los recién nacidos en embarazos múltiples que recibieron interconsulta por el Departamento de Genética del INPer de enero de 2009 a septiembre de 2011. Se incluyeron 76 casos; 56 fueron de embarazos dobles y 20 de triples. Resultados: Se registraron 619 recién nacidos de embarazos múltiples; 76 fueron valorados por genética, lo que corresponde al 12.2% de los embarazos múltiples con defectos, los cuales fueron: a) En los gemelares dobles: tres deformaciones, siete disrupciones, nueve malformaciones, 10 anomalías propias de gemelos (dos fetos acárdicos), cuatro síndromes (Holt-Oram y espectro facio-aurículo-vertebral y dos con síndrome de Down), tres defectos menores y 20 recién nacidos sanos. b) En los triples: una deformación, una malformación, tres síndromes (Walker-Warburg, Goldenhar y Down), tres anomalías propias de gemelos (toracoonfalópagos) y un síndrome de Down, tres con defectos menores y nueve recién nacidos sanos. Conclusiones: Los defectos congénitos encontrados en este estudio son similares a lo reportado en la literatura mundial. Observamos discordancia en presentación y severidad en defectos congénitos de todos los gemelos, siendo mayor en los monocoriales. Varios procesos durante la división de un óvulo fertilizado pueden predisponer al desarrollo de una anomalía congénita, o bien presentarse como resultado de una alteración en la placenta.

Introduction: Twin pregnancies represent less than 3% of newborns and up to 12% of perinatal deaths, with a high frequency of complications such as: characteristic of twin pregnancy, isolated birth defects and chromosomal abnormalities. Materials and methods: We reviewed the clinical records of newborns from multiple pregnancies evaluated by the Genetics Department at INPer between January 2009 and September 2011. We included 76 cases, 56 were twin pregnancies and 20 triplets. Results: There were 619 infants of multiple pregnancies, 76 were assessed by a geneticist, corresponding to 12.2% of multiple pregnancies with congenital defects, which were: a) In twins: three deformations, seven disruptions, nine birth defects, 10 defects characteristic of multiple gestation (two acardic fetuses), four syndromes (Holt-Oram and oculo auriculo vertebral spectrum and two Down syndrome), three minor defects and 20 healthy neonates. b) In triplets: one deformation, one malformation, three syndromes (Walker-Warburg, Goldenhar and Down), three defects of twins (thoracopagus), three minor defects and nine healthy neonates. Conclusions: Birth defects found in this study are similar to those reported in the world literature. We observed discordance in the presence and severity of congenital defects in all the twins studied, this observation was higher in monochorionic pairs. Several processes in the division of a fertilized egg may predispose to the development of a congenital abnormality, or it can result as an alteration in the placenta.

[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.

Mortalidad neonatal en 2007 y 2008 en un centro de tercer nivel de atención / Newborn mortality in 2007 and 2008 in a tertiary level care center

Introducción. La mortalidad neonatal es un indicador sensible y específico que nos permite conocer el estado de salud de un país y plantear estrategias para mejorarlo. Resulta de una cadena compleja de determinantes como los biológicos, los socioeconómicos y los de salud. El objetivo de este trabajo fue conocer la tasa de mortalidad neonatal general, por peso y edad gestacional, en un instituto de tercer nivel de atención durante 2007 y 2008. Métodos. Se analizaron todos los casos provenientes del comité de mortalidad perinatal y neonatal, de 2007 y 2008, desde 22 semanas de gestación en adelante. El análisis estadístico se realizó mediante medidas de tendencia central y dispersión para las variables cuantitativas y para las variables cualitativas frecuencia, porcentaje, χ² y razón de momios con nivel de significación estadística < 0.05. Resultados. La tasa de mortalidad para el año 2007 fue de 17.7 × 1000 nacidos vivos y para el 2008 de 19.7 × 1000 nacidos vivos. En relación con el peso y con la edad gestacional no se encontró aumento de riesgo al comparar los resultados de ambos años. Las malformaciones ocuparon el mayor porcentaje entre las causas de defunción. Conclusiones. Las tasas de mortalidad en 2007 y 2008 fueron de 17.7 y 19.7 × 1000 nacidos vivos, respectivamente. Las principales causas de defunción fueron las malformaciones cardiacas.

Background. Mortality is a sensitive and specific indicator for determining the health status of a country in order to implement improvement strategies. It is the result of biological, social, economic and health factors. The aim of this study was to determine neonatal general mortality and its relationship with weight and gestational age at a third-level health institution from 2007 to 2008. Methods. We analyzed all patients >22 weeks of gestational age from the perinatal mortality service. Statistical analysis was done using measures of central tendency and dispersion for quantitative variables and χ2, percentage and frequency for qualitative variables; odds ratios were calculated with significance level <0.05. Results. The mortality rate for 2007 was 17.7 per 1000 live births, and for 2008 it was 19.7 per 1000 live births. When we compared both years, we did not find an increased risk for weight and gestational age. Malformations occupied the largest causes of death. Conclusions. For years 2007 and 2008, mortality rates were 17.7 and 19.7 per 1000 live births, respectively, and the main cause of deaths were cardiac malformations.

[Birth defects associated with increased nuchal translucency]. / Defectos congénitos asociados con translucencia nucal aumentada.

BACKGROUND: Nuchal translucency is widely used to screen for trisomy 21 in the first trimester of pregnancy. It has also been associated with other chromosomal abnormalities, genetic syndromes and congenital defects. OBJECTIVE: To evaluate the perinatal outcome of patients who showed nuchal translucency greater or equal to 95th percentile during the first trimester ultrasound screening, which underwent fetal karyotype. MATERIAL AND METHOD: Case series. Fetuses with nuchal translucency greater or equal to 95th percentile were evaluated by fetal karyotype, second-trimester structural ultrasound scan, fetal echocardiography and postnatal clinical genetic evaluation, attended in the servicio de Genética of the Instituto Nacional de Perinatología Isidro Espinosa de los Reyes. RESULTS: 48 fetuses were evaluated. The karyotype was normal in 39 (81%) and abnormal in 9 (19%) cases of which three had trisomy 21, three monosomy X, two trisomy 18 and one 47,XYY In the cases with normal karyotype, 13 (33%) showed an abnormal second trimester ultrasound scan; among them, 12 had major congenital defects, 5 of them had abnormal cardiac findings that were confirmed by fetal echocardiography. In the group of 26 fetuses with normal karyotype and ultrasound, only 2 patients had minor birth defects. CONCLUSIONS: Increased fetal nuchal translucency is frequently associated with chromosomal abnormalities and several congenital defects, mostly heart defects and genetic syndromes. Our findings are in accordance with other published reports where a complete follow-up of all patients with increased nuchal translucency is recommended even if they have a normal karyotype, due to the increased risk of having other congenital defects or syndromic entities.