Lucía Cifuentes O

Malformaciones congénitas en Chile y Latino América: Una visión Epidemiológica del ECLAMC del período 1995-2008

Background: The Latin American Study of Congenital Malformations (ECLAMC) hasperformed an epidemiologica! surveillance of congenital malformations since 1967. This allows to detectany unexpected change in the incidence of malformations, possibly caused by a new environmental teratogenic agent. Aim: To report a summary ofthe results thusfar obtained in this study. Material ana Methods: The ECLAMC database was analyzed and all Uve births and stillbirths ofmore than 500 grams in the period 1995-2008, were analyzed. Results: There were 2,409,407 births in the nine participant countries. Ofthese 31,516 (1.3%) were stillbirths. The global rate of congenital malformations in this sample was 2.7%. In the studied period, there was a significant reduction in the rates of anencephaly and spina bifida in Chile and Argentina. In the rest ofthe countries, the global rates of malformations increased. Venezuela had the higher rate of teenage pregnancies (25%), followed by Colombia (23%). Chile had the higherpercentage ofwomen aged 35years or moregiving birth (14%), followed by Uruguay (13%). However, Chile had the higher rate of Down syndrome and Uruguay, the lowest (24.7 and 13.6per 10000). Conclusions: There is a tendency towards an increase in the rates of congenital malformations in this sample, with significant differences among countries.

Incidencia de labio leporino y paladar hendido en la Maternidad del Hospital Clínico de la Universidad de Chile y en las maternidades chilenas participantes en el Estudio Colaborativo Latino Americano de Malformaciones Congénitas (ECLAMC) período 1991-1999

Background: ECLAMC is a registry, aimed to assess the incidence of congenital malformations, that started in 1967 and Chile incorporated to it in 1969. Aim: To report the incidence of cleft lip/palate, updated to 1999 in the University of Chile Maternity Hospital and other Chilean hospitals participating in the ECLAMC. Patients and methods: A review of the ECLAMC database that registers all births or stillbirths of more than 500 g. Results: The incidence of orofacial cleft, at the University of Chile Maternity Hospital, in the period 1991-1999 was 17.8 per 10000 (12.6 for cleft lip and 5.2 for cleft palate). The incidence in the rest of participating hospitals was 12.04 and 4.6 respectively. Males had a higher incidence of cleft lip and 80% of children with cleft palate, had other malformations, most of them as part of a syndrome (13 and 18 trisomy, holoproscencephalia, Pierre Robin, Apert en EE syndromes, anencephaly etc). In three of 12 children with cleft lip but without cleft palate, there was a relative with the same malformation. Conclusions: It is proposed that both entities, cleft lip with or without cleft palate and cleft palate without cleft lip, are two etiopathogenically different conditions (Rev Med Chile 2001; 129: 285-93).

Effects of folic acid fortification in the rates of malformations at birth in Chile

After the start of folic acidfortification a significant reduction in the rates of anencephalia, spina bifida anddiaphragmatic hernia, was observed. The rates of all other malformations remained stable orincreased. The rates of all malformations at the University of Chile Clinical Hospital had asteady increase until 2005 and were significantly higher than in the rest of hospitalsparticipating in ECLAMC.

The association between maternal age and congenital malformations

An overallprevalence of malformations of 8,4% was detected at the hospital. There is a significantly lowerfrequency of mothers aged less than 20 years than in the rest of Chile. Mothers aged between 20and 29 years have the lower frequency of malformed children. Women aged less than 20 yearsand over 39 years of age, account for 56% of malformed children. Maternal ages and the ratesof malformations, increased in a parallel fashion at a rate of 0.2 years and 2.2 malformedchildren per 1,000 born alive, per calendar year, respectively.

Prevalencia al nacimiento de malformaciones congénitas y de menor peso de nacimiento en hijos de madres adolescentes

:The births occurred in a hospital between 1982 and 2001, were analyzed using the Latin Amer-ican Collaborative Study for Congenital Malformations (ECLAMC) data base. Mothers were clas-sified as teenagers when their age ranged between 10 and 19 years old and older when their agewas over 20 years old. All women were subdivided as cases and controls.

Estudio epidemiológico global del síndrome de Down

Introduccion: El ECLAMC (Estudio Colaborativo Latino Americano de Malformaciones Congenitas) fue creado en 1967. Actualmente, lo integran 180 hospitales de 76 ciudades de 9 paises Latino Americanos y ha acumulado mas de 4,5 millones de nacimientos. El Hospital Clinico de la Universidad de Chile (HCUCH) ingreso en 1967 y despues otros 12 establecimientos chilenos. Objetivos: Verificar si la frecuencia de sindrome de Down (SD) esta aumentando en Chile y Latino America y como se ha visto modificada en los paises en que esta permitido el aborto electivo. Pacientes y Metodo: Se estudio 3 muestras: Todos los nacimientos del HCUCH desde 1972 a 2009; de los hospitales chilenos activos y de los 180 hospitales de 9 paises Latinoamericanos. Se comparo las frecuencias de SD de Chile y del ECLAMC con otros paises que participan en el Internacional Clearinghouse for Birth Defects Monitoring System. Resultados: La frecuencia del SD en el HCUCH aumento significativamente de 1,03 por mil nacimientos en 1972 a 2,93 por mil en 2009. Las frecuencias en los hospitales chilenos son muy homogeneas, todas mas altas que el promedio del ECLAMC: 1,88 por mil. El promedio chileno para el periodo 1998-2005 fue de 2,47 por mil. Con un rango de 1,88 por mil del HCUCH y 2,86 por mil del Hospital de Curico. En el resto del mundo se ha asistido a una disminucion significativa de las tasas de SD, siendo las mas bajas la de Iran: 0,32 por mil y Espana 0,60 por mil nacimientos vivos. Conclusion: En Chile, las tasas de SD son mayores al promedio del ECLAMC 2,47 por mil existiendo una tendencia al aumento de ellas lo mismo que en Latino America, donde el promedio para el periodo 20012005 fue de 2,89 por mil. En Europa y Asia las tasas han disminuido a cifras extremas, Iran 0,32 por mil y Espana 0,60 por mil.

Malformaciones congénitas en Chile.: Un problema emergente (período 1995-1999)

Background: The Latin American collaborative study of congenital malformations (ECLAMC) is a surveillance program designed to monitor the frequency of congenital malformations and detect abrupt changes in their frequency, look for the cause of such change and implement primary prevention measures. Aim: To construct a secular trend curve with the frequency of congenital malformations in Chile. Material and methods: Using the ECLAMC protocol, every malformed newborn or stillbirth, weighting more than 500 g at birth is registered using a standard protocol, and the next non malformed child of the same sex born in the same hospital is assigned as control. Using the gathered data, secular trend curves of congenital malformations were constructed. Results: Between 1982 and 1999, there is a secular tendency in the rate of congenital malformations and maternal age, with a correlation coefficient of 0.8 and slope of 13.5 (p<0.05). The rates of congenital malformations at the moment of birth are higher at the University of Chile Clinical Hospital than in the rest of Chilean hospitals and other Latin American Hospitals. Anencephalia is a defect with a high frequency in Concepcion and spina bifida has a high frequency in Rancagua, Vina del Mar, Concepcion and Valdivia. There is an impressive increase in malformations dependent on prenatal diagnosis such as kidney agenesis, polycystic kidney and diaphragmatic hernia. Conclusions: Congenital malformations are having an increasing importance as causes of morbidity or mortality in the newborn. (Rev Med Chile 2001; 129: 895-904).

Prevalencia de nacimiento de microtia-anotia: Maternidad del Hospital Clínico de la Universidad de Chile, período 1983-2005

The prevalence of microtia-anotia in the period 1982-2001 was 8.7 per10,000 born alive. Chilean hospitals have an uniform prevalence of 5.2 per 10,000 born alive. Thirtyseven percent presented as isolated malformations and the rest were associated to other defects. Eightysix percent of non isolated cases were part of a syndrome. Sixty eight percent were mild or moderateforms and the rest, severe forms. Two cases were stillborns and two newborns died before hospitaldischarge.

Prevalencia al nacimiento de aberraciones cromosómicas en el Hospital Clínico de la Universidad de Chile: Período 1990-2001

Background: A cytogenetical study should be performed to every newborn with malformations. If a chromosomal aberration is found, parents must be studied to give an adequate genetic advise. Aim: To study the frequency of chromosomal aberrations in newborns with malformations. Patients and methods: In the Clinical Hospital of the University of Chile all malformations in newborns are registered, as part of the Collaborative Latin American Study of Congenital Malformations (ECLAMC). The frequency of chromosomal aberrations, determined by cytogenetical studies, was determined in newborns with malformations. Results: In the study period, there were 32,214 births. Of these, 2,268 live newborns and 43 stillbirths had malformations. Ninety nine children with malformations had chromosomal aberrations (4.3%). Trisomy 21 was the most common aberration with a rate of 23/10,000 births, followed by trisomy 18 with a rate of 4/10,000 and trisomy 18 with a rate of 1.2/10,000. Ninety four percent of these children were born alive and 16.1% died before discharge from the hospital. The masculinity indexes for Down syndrome and for trisomy 18 were 0.38 and 0.61 respectively. Conclusions: A higher frequency of female gender for trisomy 21 and male gender for trisomy 18 has not been reported previously (Rev Med Chile 2003; 131: 651-658)

Malformaciones congénitas anorrectales y sus asociaciones preferentes. Experiencia del Hospital Clínico de la Universidad de Chile. Período 1979-1999

Background: Anorectal atresia is a relatively frequent malformation in the newborn. According to the Latin American Collaborative Study for Congenital Malformations (ECLAMC), its frequency is 4.1 per 10,000 born alive. Aim: To determine the frequency of anorectal malformations at birth, and compare the figures with those of other maternity hospitals in Chile participating in ECLAMC, with the figures of the whole ECLAMC and with figures from other worldwide monitoring systems. Patients and methods: All births occurred in the University of Chile Clinical Hospital between January 1979 and August 1999, were reviewed. Results: During the study period, 70,242 children were born, 4,486 had a malformation and 54 had an anorectal malformation (7.7 per 10,000 born alive). Fifty nine percent had other associated malformations (of the urinary tract in 42.5%, skeletal in 26% and cardiovascular in 18.5%). Five stillborn babies had other severe malformations. Twenty one children had a fistula. Forty three % were male, 39% female and 18% had ambiguous sex. When compared with normal controls, malformed newborns had a lower birth weight, lower gestational age and a higher mean maternal age, a higher frequency of metrorrhagia during the first trimester of pregnancy, a higher number of siblings with malformations and a higher degree of consanguinity among parents. Conclusions: The participation of recessive genes in the etiology of anorectal malformations is suggested. (Rev Med Chile 2000; 128: 519-25)