Prevalencia de la arteria umbilical única en gestantes: su relación con otras malformaciones y el bajo peso al nacer

Introducción: La arteria umbilical única tiene una incidencia del 1 % en los recién nacidos. Se le asocia frecuentemente con gemelaridad, malformaciones y crecimiento intrauterino retardado, y constituye un factor de riesgo de prematuridad, muerte fetal y neonatal. Objetivos: Determinar la prevalencia de la arteria umbilical única en gestantes, y la asociación de esta entidad con otras malformaciones y el bajo peso al nacer. Materiales y métodos: Estudio descriptivo retrospectivo, con datos obtenidos de las historias clínicas y del modelo de seguimiento lineal existente en las consultas de genética comunitaria del municipio Matanzas, de enero de 2015 a diciembre de 2019. Resultados: La prevalencia de la arteria umbilical única fue del 0,3 %. Las malformaciones más frecuentes fueron las renales; el 27,7 % de los nacimientos fueron pretérmino y el 33,3 % de los nacidos fue con un peso inferior a 2500 g. Conclusiones: La arteria umbilical única constituye un marcador para otras malformaciones. Cuando coexisten ambas existe riesgo de prematuridad y bajo peso al nacer. Se recomienda realizar examen clínico posnatal a todo recién nacido con arteria umbilical única, pesquisando defectos renales y cardíacos.

Introduction: The single umbilical artery has an incidence of 1% in newborns. It is frequently associated with twinning, malformations and delayed intrauterine growth, and is a risk factor of prematurity, fetal and neonatal death. Objective: To determine the prevalence of single umbilical artery in pregnant women and the association of this entity with other malformations and low birth weight. Materials and methods: Retrospective descriptive study, with data obtained from medical records and the linear follow-up model existing in the community genetic clinics of the municipality of Matanzas, from January 2015 to December 2019. Results: The prevalence of the single umbilical artery was 0.3%. The most frequent malformations were renal ones; 27.7% of births were pre-term and 33.3% of those born weighed less than 2500g. Conclusions: The single umbilical artery is a marker for other malformations. When both coexist there is a risk of prematurity and low birth weight. Postnatal clinical examination is recommended for all newborns with single umbilical artery, checking for renal and heart defects.

Should fetal growth be a matter of concern in isolated single umbilical artery? / Artéria umbilical única isolada e restrição do crescimento fetal

Objective: To examine birth weight in pregnancies with isolated single umbilical artery (ISUA). Methods: Case control study with retrospective review of 131 singleton pregnancies with isolated single umbilical artery diagnosed before birth. Control group consisted of 730 singleton pregnancies recruited prospectively, that had histological confirmation of a 3 vessels cord. Pregnancies were classified as uncomplicated or high-risk according to the presence of diseases that increase the risk of placental insufficiency during pregnancy. Mean birth weight and frequency of low birth weight (< 2.500 g), very low birth weight (< 1.500 g) and fetal growth restriction below the 5th and 10th centiles were compared between groups. Results: Mean birth weight difference between ISUA (n=131, 2840±701g) and control (n=730, 2.983 ± 671g) pregnancies was 143g (95% CI= 17-269; p=0.04) and birth weight below the 5thcentile was significantly more common in ISUA group [28/131 (21.4%) versus 99/730 (13.6%), p=0.02]. When only uncomplicated pregnancies were considered in both groups, no birth weight differences were observed. Amongst high-risk subgroups, birth weight below the 5th centile remained significantly more common in ISUA compared to control pregnancies [10/35 (28.6%) versus 53/377 (14.1%), p=0.04]. Conclusion: Isolated single umbilical artery does not increase the risk of fetal growth restriction in uncomplicated singleton pregnancies. .

Objetivo: Examinar a frequência de peso ao nascer abaixo dos percentis 5 e 10, em gestações únicas com artéria umbilical única isolada (AUUI), de acordo com a presença de complicações maternas. Métodos: Estudo caso-controle. De acordo com a presença de doenças maternas prévias à gestação, ou ocorrência de complicações obstétricas, as gestações foram classificadas em "não complicadas" ou de "alto risco". As frequências de peso ao nascer abaixo dos percentis 5 e 10 foram comparadas entre os subgrupos. Resultados: O peso ao nascer foi significativamente menor em gestações com AUUI (n=134, 2840 ± 701 g) quando comparado com o grupo controle (n= 730, 2983 ± 671 g, p= 0,04; média da diferença=143 g, IC 95% = 17-269). Em gestações de alto risco, peso ao nascer abaixo do 5º percentil foi significativamente mais frequente no subgrupo com AUUI [10/35 (28,6%) versus 53/377 (14,1%), p= 0,04; razão de chances= 2.45 (IC 95% = 1,11- 5,38)]; não foi observada diferença em relação ao peso abaixo do 10º percentil (p= 0,11). Em gestações não complicadas, não foram observadas diferenças na frequência de peso ao nascer abaixo do 5º e 10º percentis entre os subgrupos com AUUI e cordão com 3 vasos (p= 0,21). Conclusão: Em gestações de alto risco, a frequência de peso ao nascer abaixo do percentil 5 é significativamente aumentada. .

Incidencia y asociaciones de arteria umbilical única en recién nacidos: maternidad del Hospital Clínico de la Universidad de Chile, 1998-2010 / Incidence and associations of single umbilical artery in newborns: of Hospital Clínico de la Universidad de Chile maternity, 1998-2010, 1998-2010

ANTECEDENTES: La presencia de 2 vasos en el cordón umbilical es una anomalía con incidencia de 1% de todos los recién nacidos. Se asocia frecuentemente con restricción del crecimiento intrauterino (RCIU), malformaciones estructurales mayores y cromosómicas y prematuridad. Constituye un factor de riesgo que aumenta la mortalidad fetal tardía y neonatal. OBJETIVOS: Establecer la prevalencia al nacimiento de arteria umbilical única (AUU), la magnitud de las asociaciones con malformaciones congénitas (MFC), RCIU, prematuridad y su influencia en la morbimortalidad neonatal. MÉTODO: Se usó la base de datos que el Estudio Colaborativo Latino Americano de Malformaciones Congénitas (ECLAMC) tiene en la maternidad del Hospital Clínico de la Universidad de Chile. Incluyó a todos los recién nacidos vivos (RN) y mortinatos con peso de nacimiento 500 gramos o más en el período mayo 1998 a junio 2010. Se comparó algunas variables demográficas entre los casos y sus controles. RESULTADOS: En 22.011 nacimientos ocurridos hubo 65 RN con AUU (0,3%), 9 eran mortinatos (13,8%), 88,9% de ellos presentaban RCIU. Eran prematuros 55,4% de los RN. El 60% de los casos de AUU estaban asociados a MFC mayores, destacando las del aparato genitourinario (35,3%) y las cardiovasculares (29,4%); 23,8% eran parte de un síndrome, donde dominaban latrisomía 13 y 18 (12 casos, 18,5%). De los RN vivos fallecieron 13 (23,2%), 8 (61,5%) presentaban RCIU. CONCLUSIÓN: La AUU es un factor de alto riesgo de asociación con RCIU, MFC mayores estructurales y/o cromosómicas, prematuridad y de un aumento de la morbimartalidad neonatal.

BACKGROUND: The presence of only two blood vessels in the cord blood is a congenital anomaly that has an incidence about 1% among all newborns. Frequently, it is associated with intrauterine growth restriction (IUGR), major congenital malformations (MCMF), chromosome anomalies and prematurity. It represents a risk factor that increases late foetal and neonatal mortality and morbidity. AIMS: To estímate the prevalence at birth of unique umbilical artery (UUA), to know its association with congenital anomalies, IUGR, prematurity and to evaluate its influence in neonatal morbidity and mortality. METHODS: We studied data registered in the Latin American Study of Congenital Malformations (ECLAMC) from the Maternity of the Clinical Hospital of University of Chile from May 1998 and June 2010. All newborns (alive and stillbirths) with a birth weigh >500 g were included. Demographic variables were compared between cases and controls. RESULTS: 65 newborns with UUA (0.3%) was found among the 22.011 births registered: 9 was stillbirths (13.8%), 88.9% of them had IUGR and 55.4% were premature. 60% of cases has another MCMF (35.3% of the genitourinary system and 29.4% involved the cardiovascular system). 23.8% of cases were part of a syndrome, 13 and 18 trisomy were the most common (12 cases, 18.5%). 13 newborns died (23.2%), 8 of them (61.5%) had IUGR. CONCLUSION: The presence of UUA in a foetus or newborn represents a high risk for IUGR, MCMF, chromosome anomalies, prematurity and increase of neonatal morbidity and mortality.

Arteria umbilical única y malformaciones asociadas en una serie de 5500 autopsias: implicancia en conductas perinatales / Single umbilical artery and associated malformations in a series of 5500 autopsies: implication in perinatal conducts

Con una incidencia del 1% de nacimientos, la arteria umbilical única (AUU) es, de todos los defectos congénitos, el más frecuente. Se asocia reconocidamente a una variedad de malformaciones pero existen controversias acerca de su condición de predictora de un resultado perinatal adverso y de constituir una indicación para descartar otras malformaciones. Objetivos: establecer las frecuencias de malformaciones asociadas a AUU, determinar si existen asociaciones preferenciales y cuantificar el riesgo de otras malformaciones en presencia de AUU en una serie de autopsias perinatales. Material y métodos: en 5.539 autopsias del Hospital Materno Infantil Ramón Sardá y del Laboratorio Privado de Patología Perinatal se calculó la frecuencia de cada malformación (agrupadas por aparato) asociada a la AUU y los riesgos de malformaciones asociadas. Se estableció el riesgo para anomalías cromosómicas en casos con AUU sin otras malformaciones asociadas. Resultados: la AUU fue 10 veces más frecuente en presencia de otras malformaciones. El riesgo para malformaciones se incrementó significativamente entre tres y nueve veces en presencia de AUU. Las anomalías renales y digestivas mostraron una asociación preferencial con la AUU. En ausencia de otras malformaciones agregadas, la AUU presentó un bajo riesgo para anomalías cromosómicas. Conclusiones: el diagnóstico de AUU es indicación para realizar un exhaustivo monitoreo fetal y para descartar anomalías renales y cardiovasculares. No sería indicación para realizar un estudio cromosómico fetal si no se detectan otras malformaciones.

With a birth prevalence rate of about 1%, single umbilical artery (SUA) is the most frequent congenital anomaly. It recognizably associates with a variety of birth defects but its ability to predict an adverse perinatal outcome is unclear, as well as if other malformations should be ruled out when a SUA is diagnosed. Aims: to estimate the association between SUA and other birth defects in a series of perinatal autopsies, to establish if preferential associations between SUA and certain birth defects exist, and to quantify the risks for other birth defects when a SUA is diagnosed. Material and methods: in a series of 5.539 perinatal autopsies, from the Hospital Materno Infantil Ramón Sardá and the Private Laboratory of Perinatal Pathology, Buenos Aires, the rate of each malformation (grouped by organ/system) associated with SUA and the risks of associated malformations were estimated. Results: the rate of SUA showed a 10-fold increase when other malformations were present. The risk for other malformations increased significantly, from 3 to 9-fold, when a SUA was present. Urinary and gut anomalies showed a preferential association with SUA. The absence of other birth defects lowered the risk of SUA for chromosome anomalies in almost 60 per cent. Conclusions: prenatal diagnosis of SUA should lead to an exhaustive fetal monitoring, and urinary and cardiovascular defects should be ruled out. The diagnosis of a SUA is not an indication for a fetal chromosome analysis, if no other malformations are present.