[Prevalence of congenital malformations at birth in Chilean maternity hospitals]. / Prevalencia al nacimiento de malformaciones congénitas en las maternidades chilenas participantes en el ECLAMC en el período 2001-2010.

BACKGROUND: The Latin American Collaborative Study of Congenital Malformations (ECLAMC) is an epidemiological surveillance system operating in 11 South American countries since 1969. AIM: To analyze the Congenital Malformation prevalence rate at birth from 2001 to 2010 in Chilean Hospitals participating in ECLAMC. To compare these rates with those of the period 1982-1994. MATERIAL AND METHODS: Review of the ECLAMC database, which contains information about 282.568 newborns, 2.110 of them stillbirths (0.75%) from 13 Maternity hospitals. RESULTS: In the study period, 10.925 newborns had congenital malformations (3.9 %). Their frequency was lower in live newborns than stillbirths (3.8 and 15.3%, respectively). Compared with the 1982-1994 period, congenital malformation prevalence rates at birth were higher. They stabilized in approximately 4 %, from 1985 to 2010. The prevalence of some anomalies such as Down syndrome increased significantly. On the other hand, there was a reduction in the prevalence of spina bifida and anencephaly. CONCLUSIONS: Prevalence rates of congenital malformations at birth remained stable in the last 18 years in Chilean Hospitals participating in ECLAMC. However the prevalence of some malformations such as Down syndrome, Polydactyly, anotia-microtia, syndactyly and cleft palate have increased. The prevalence rates of spina bifida and anencephaly have decreased.

[Identification of risk factors for congenital malformations]. / Factores de riesgo de ocurrencia y gravedad de malformaciones congénitas.

BACKGROUND: The relative importance of congenital malformations as a cause of death in the first year of life is increasing along with the control of preventable causes of perinatal mortality. AIM: To identify risk factors for congenital malformations. PATIENTS AND METHODS: Retrospective case-control study of births registered in the database of The Latin American Collaborative Study of Congenital Malformations (ECLAMC), in the period 2001-2010. RESULTS: Birth weight and gestational age were significantly lower in cases than controls, behaving as risk factors and associated with a greater severity of congenital malformations. The risk and severity of congenital malformations increased along with mother's age. Fetal growth retardation, a history of congenital malformations in the family, physical factors and acute illnesses of the mother in the first trimester of pregnancy were also significant risk factors for congenital malformations and their severity. The educational level of the mother was a protective factor for congenital malformations and their severity. CONCLUSIONS: Variables previously identified as risk factors for congenital malformations, were significantly related with the occurrence of congenital malformations and their severity.

[Effects of wheat flour fortification with folic acid on the prevalence of neural tube defects in Chile]. / Resultados del Programa de Prevención de Defectos de Tubo Neural en Chile mediante la fortificación de la harina con ácido fólico: Período 2001-2010.

BACKGROUND: Congenital malformations (CMF) have an important role in infant mortality. Neural tube defects (NTD) have great relevance from both social and public health points of view. The ECLAMC (Collaborative Latin American Study of Congenital Malformations) maintains in Chile an epidemiological surveillance of CMF prevalence rate at birth since 1969. AIM: To assess the effect of wheat flour folic acid fortification on the prevalence of NTD. PATIENTS AND METHODS: Only Anencephaly, Spina bifida and Cephalocele were considered as NTD. All children born in the maternities incorporated to ECLAMC between 1969 and 1999 were considered as belonging to the pre folic acid fortification period and those who were born from 2001 to 2010 were considered as belonging to the post fortification period. RESULTS: The NTD prevalence rate at birth in the pre fortification period was 17.03/10,000. In the second period, there were 291,996 births and among them, 280 newborns were affected by a form of NTD (9.59 in 10,000 births). This represents a 44% decrease (p < 0.01). Anencephaly rate fell from 7.16/10,000 to 3.67/10,000, representing a 49% lower rate (p < 0.01). Spina bifida rate decreased from 8.61/10,000 to 4.49/10,000, representing a 48% lower rate (p < 0.01). Cephalocele had a 20% non-significant reduction. CONCLUSIONS: Wheat flour fortification with folic acid reduced by 44% the prevalence rate of NTD at birth. This means that NTDs were prevented in 185 Chilean newborns each year.

[Congenital malformations among newborns of teenage mothers]. / Prevalencia al nacimiento de malformaciones congénitas en hijos de madres adolescentes. Hospital Clínico Universidad de Chile. Período 2002-2011.

BACKGROUND: The Chilean Ministry of Health has reported a meaningful increase of births from teenager mothers (aged less than 20 years) in the period 1990-2008. On the contrary, there was a decrease of births from teenage mothers at The University of Chile Clinical Hospital (HCUCH). AIM: To compare the prevalence rates at birth of congenital malformations (CMF) in newborns from mothers younger than 20 with those of mothers between 20 and 34 years old. PATIENTS AND METHODS: The Latin American Collaborative Study of Congenital Malformations (ECLAMC) data base of the HCUCH, since 1969 was analyzed. The last ten years (2002-2011) were studied. RESULTS: There were 15,636 births in the period studied, 153 of them were stillbirths (0.97%). There were 1174 newborns from teenage mothers, 82 of them had one or more congenital malformations (7%). We found an association between smoking and drug consumption in mothers and CMF in their newborns. CONCLUSIONS: The rate of congenital malformations among offspring of teenage mothers is lower than the rate for mothers between 20 and 34 years old.

[Congenital malformations in Latin America in the period 1995-2008]. / 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) has performed an epidemiological surveillance of congenital malformations since 1967. This allows to detect any unexpected change in the incidence of malformations, possibly caused by a new environmental teratogenic agent. AIM: To report a summary of the results thus far obtained in this study. MATERIAL AND METHODS: The ECLAMC database was analyzed and all live births and stillbirths of more than 500 grams in the period 1995-2008, were analyzed. RESULTS: There were 2,409,407 births in the nine participant countries. Of these 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 of the countries, the global rates of malformations increased. Venezuela had the higher rate of teenage pregnancies (25%), followed by Colombia (23%). Chile had the higher percentage of women aged 35 years or more giving birth (14%), followed by Uruguay (13%). However, Chile had the higher rate of Down syndrome and Uruguay, the lowest (24.7 and 13.6 per 10000). CONCLUSIONS: There is a tendency towards an increase in the rates of congenital malformations in this sample, with significant differences among countries.

El estrés materno como factor de riesgo para fisuras labio-palatinas / Maternal stress like risk factors for oral clefts

Introduction: several studies have shown an association between stress caused by natural disasters, acts of terrorism and war, which have been corroborated by experimental studies in rats, with presence of oral clefts (FO) in the children of women who suffered stress in the first weeks of pregnancy. Objectives: To demonstrate the relationship between stress caused by the earthquake and tsunami that struck the central and south regions of Chile, on February 27, 2010 and the prevalence rate of FO in the disaster area. Material and Methods: Registration of ECLAMC (Latin American Collaborative Study of Congenital Malformations) Period 2000- 2011. With this information we created two groups: Group 1: Children born before the event, from 2002 to 2009 up to 6 months after earthquake, that means August 2010. Group 2: the post-earthquake period, from the seventh month after the earthquake (September) until the end of 2011. Results: the prevalence of oral clefts of the first group was 0.88 per thousand births (0.57 for cleft lip and cleft palate 0.30) .and the second group of 1.07 per thousand, (0.70 cleft lip and cleft palate 0.37) statistically significant difference (p <0.05). Conclusion: There is a positive, significant association between maternal stress and the risk of having children with FO.

Prevalencia al nacimiento de malformaciones congénitas en las maternidades chilenas participantes en el ECLAMC en el período 2001-2010 / Prevalence of congenital malformations at birth in chilean maternity hospitals

Background: The Latin American Collaborative Study of Congenital Malformations (ECLAMC) is an epidemiological surveillance system operating in 11 South American countries since 1969. Aim: To analyze the Congenital Malformation prevalence rate at birth from 2001 to 2010 in Chilean Hospitals participating in ECLAMC. To compare these rates with those of the period 1982-1994. Material and Methods: Review of the ECLAMC database, which contains information about 282.568 newborns, 2.110 of them stillbirths (0.75%) from 13 Maternity hospitals. Results: In the study period, 10.925 newborns had congenital malformations (3.9 %). Their frequency was lower in live newborns than stillbirths (3.8 and 15.3%, respectively). Compared with the 1982-1994 period, congenital malformation prevalence rates at birth were higher. They stabilized in approximately 4 %, from 1985 to 2010. The prevalence of some anomalies such as Down syndrome increased significantly. On the other hand, there was a reduction in the prevalence of spina bifida and anencephaly. Conclusions: Prevalence rates of congenital malformations at birth remained stable in the last 18 years in Chilean Hospitals participating in ECLAMC. However the prevalence of some malformations such as Down syndrome, Polydactyly, anotia-microtia, syndactyly and cleft palate have increased. The prevalence rates of spina bifida and anencephaly have decreased.

Factores de riesgo de ocurrencia y gravedad de malformaciones congénitas / Identification of risk factors for congenital malformations

Background: The relative importance of congenital malformations as a cause of death in the first year of life is increasing along with the control of preventable causes of perinatal mortality. Aim: To identify risk factors for congenital malformations. Patients and Methods: Retrospective case-control study of births registered in the database of The Latin American Collaborative Study of Congenital Malformations (ECLAMC), in the period 2001-2010. Results: Birth weight and gestational age were significantly lower in cases than controls, behaving as risk factors and associated with a greater severity of congenital malformations. The risk and severity of congenital malformations increased along with mother’s age. Fetal growth retardation, a history of congenital malformations in the family, physical factors and acute illnesses of the mother in the first trimester of pregnancy were also significant risk factors for congenital malformations and their severity. The educational level of the mother was a protective factor for congenital malformations and their severity. Conclusions: Variables previously identified as risk factors for congenital malformations, were significantly related with the occurrence of congenital malformations and their severity.

Prevalencia al nacimiento de malformaciones congénitas en hijos de madres adolescentes. Hospital Clínico Universidad de Chile: Período 2002-2011 / Congenital malformations among newborns of teenage mothers

Background: The Chilean Ministry of Health has reported a meaningful increase of births from teenager mothers (aged less than 20 years) in the period 1990-2008. On the contrary, there was a decrease of births from teenage mothers at The University of Chile Clinical Hospital (HCUCH). Aim: To compare the prevalence rates at birth of congenital malformations (CMF) in newborns from mothers younger than 20 with those of mothers between 20 and 34 years old. Patients and Methods: The Latin American Collaborative Study of Congenital Malformations (ECLAMC) data base of the HCUCH, since 1969 was analyzed. The last ten years (2002-2011) were studied. Results: There were 15,636 births in the period studied, 153 of them were stillbirths (0.97%). There were 1174 newborns from teenage mothers, 82 of them had one or more congenital malformations (7%). We found an association between smoking and drug consumption in mothers and CMF in their newborns. Conclusions: The rate of congenital malformations among offspring of teenage mothers is lower than the rate for mothers between 20 and 34 years old.

Resultados del Programa de Prevención de Defectos de Tubo Neural en Chile mediante la fortificación de la harina con ácido fólico: Período 2001-2010 / Effects of wheat flour fortification with folic acid on the prevalence of neural tube defects in Chile

Background: Congenital malformations (CMF) have an important role in infant mortality. Neural tube defects (NTD) have great relevance from both social and public health points of view. The ECLAMC (Collaborative Latin American Study of Congenital Malformations) maintains in Chile an epidemiological surveillance of CMF prevalence rate at birth since 1969. Aim: To assess the effect of wheat flour folic acid fortification on the prevalence of NTD. Patients and Methods: Only An encephaly, Spina bifida and Cephalocele were considered as NTD. All children born in the maternities incorporated to ECLAMC between 1969 and 1999 were considered as belonging to the pre folic acid fortification period and those who were born from 2001 to 2010 were considered as belonging to the post fortification period. Results: The NTD prevalence rate at birth in the pre fortification period was 17.03/10,000. In the second period, there were 291,996 births and among them, 280 newborns were affected by a form of NTD (9.59 in 10,000 births). This represents a 44% decrease (p < 0.01). Anencephaly rate fell from 7.16/10,000 to 3.67/10,000, representing a 49% lower rate (p < 0.01). Spina bifida rate decreased from 8.61/10,000 to 4.49/10,000, representing a 48% lower rate (p < 0.01). Cephalocele had a 20% non-significant reduction. Conclusions: Wheat flour fortification with folic acid reduced by 44% the prevalence rate of NTD at birth. This means that NTDs were prevented in 185 Chilean newborns each year.

Defectos de la pared abdominal. Estudio comparativo entre onfalocele y gastrosquisis / Abdominal wall defects. A Comparative investigation between omphalocele and gastroschisis

Introducción: Onfalocele y gastrosquisis son los defectos de la pared abdominal (DPA) más frecuentes, que por su importancia y las diferencias entre ellos merecen ser estudiados en forma especial. Objetivos: Establecer las tasas de prevalencia de onfalocele y gastroaquisis al nacimiento. Verificar variaciones de ellas en distintos períodos. Estudiar la morbimortalidad asociada y su sobrevida. Pacientes y Método: Se revisó la base de datos ECLAMC (Estudio Colaborativo Latino Americano de Malformaciones Congênitas) para el período 1996-2010. Resultados: Se pesquizarón 33 recién nacidos (RN) con DPA. (11,6 por 10.000 nacimientos). De ellos 19 fueron onfalocele (6,7 por 10.000) y 14 (4,9 por 10.000) gastrosquisis. Los niños con onfalocele tenían significativamente mayor asociación con otras malformaciones, su frecuencia en el sexo masculino fue mayor y mostró mayor letalidad que la gastrosquisis. Todos los niños con gastrosquisis nacieron vivos, con predominio del sexo femenino, sus madres eran significativamente más jóvenes. Conclusión: Onfalocele y gastros-quisis presentaron una prevalencia al nacimiento mayor que lo publicado, probablemente por ser el HCUCH un Centro de Referencia. Ambas anomalías mostraron un aumento significativo en sus tasas de prevalencia al nacimiento al compararlas con las obtenidas anteriormente por nosotros en el mismo hospital. Se demostró diferencias significativas entre estas dos entidades: Onfalocele tiene mayor mortinatalidad, mortalidad y letalidad, mayor frecuencia de malformaciones asociadas y mayor promedio de edad materna.

Introduction: Omphalocele and Gastroschisis are the two most common congenital abdominal wall (AWD) defects. Objectives: To determine birth prevalence of Omphalocele and Gastroaquisis; to verify variations in different periods and to study the associated morbidity, mortality and survival. Patients and Method: The database of the Latin American Collaborative Study of Congenital Malformations (ECLAMC) was searched between the years 1996 and 2010. Results: 33 newborns (NB) with AWD were investigated (11.6 per 10,000 births). 19 of the cases corresponded to omphalocele (6.7 per 10,000 births) and 14 to gastroschisis (4.9 per 10,000 births). Children with omphalocele had significantly greater association with other malformations and the frequency in males was higher and showed higher mortality rates than gastroschisis. All children with gas-troschisis were born alive; they were predominantly female infants whose mothers were significantly younger. Conclusion: Birth omphalocele and gastroschisis prevalence were higher than published information, perhaps due to the fact that the HCUCH (Clinical Hospital of Universidad de Chile) is a reference center. Both anomalies showed a significant increase in their birth prevalence rates when compared with those previously obtained by us in the same hospital. Significant differences between these two entities were described. Omphalocele presented higher stillbirth, mortality and fatality rates; higher frequency of associated malformations and higher average maternal age.

[Paternal age as a risk factor for congenital malformations]. / La edad paterna como factor de riesgo para malformaciones congénitas.

BACKGROUND: The role of advanced maternal age as a risk factor for congenital malformations in offspring is known. However, the influence of paternal age is not clear. AIM: To evaluate the association between advanced paternal age and the risk for congenital malformations. PATIENTS AND METHODS: Analysis of maternal and paternal age of cases (malformed newborns) and controls from ECLAMC Database (Latin American Collaborative Study of Congenital Malformations) registered at the University of Chile Clinical Hospital during the decade from Jan 1 1997 to Dec 31 2006. Newborns and stillborns were grouped according to maternal age into 6 intervals. In each interval, paternal ages of cases and controls were compared. The inverse procedure was performed to assess maternal age effect. Other variables as gestational age and birth weight were analyzed for the intervals of maternal and paternal ages. RESULTS: No significant differences were observed in paternal age between cases and controls in any of the intervals of maternal age. However, mean maternal age was higher for cases than for controls (p =0,0149). Gestational age and birth weight depend more on being case or control than on the age of parents. CONCLUSIONS: No differences in paternal age were observed between cases and controls in this series of newborns.

Cambios en la distribución etaria de las madres en Chile y en el Hospital Clínico de la Universidad de Chile y su influencia en la morbimortalidad neonatal / Change in the age distribution of mothers in Chile and its influence on neonatal morbidity

Antecedentes: En las últimas décadas en Chile y otros países Sudamericanos se ha producido un cambio en la distribución etaria de las madres. Objetivos: Obtener la distribución de los nacimientos por grupos de edades maternas en el Hospital Clínico de la Universidad de Chile (HCUCH) y compararlos con iguales grupos en todo Chile. Comprobar que los grupos de edades extremas están aumentando. Estudiar la relación entre estos cambios con algunas patologías del recién nacido, como prematuridad, recién nacidos pequeños para su edad gestacional (PEG) y malformaciones congénitas. Método: Datos de la maternidad del HCUCH (1982-2010) y del Ministerio de Salud (1990-2008). Se distribuye a las madres en 3 grupos: <20, >35 y 20-34 años. Las comparaciones se hicieron con prueba de Chi Cuadrado. Resultados: En Chile el grupo de madres >35 años aumentó en más del 50 por ciento al comparar los años 1990 (10,2 por ciento del total) y 2008 por ciento(15,8 por ciento) (p<10-8). Las madres adolescentes en Chile aumentaron de 13,8 por ciento en 1990 a 16,6 por ciento en 1998 (p<10-8). En el HCUCH las adolescentes disminuyeron de 16,08 por ciento en 1982 a 9,09 por ciento en 2010 (p<10-8). Las >35 años aumentaron significativamente, al igual que en Chile, de 9,8 por ciento en 1982 a 22,17 por ciento en el año 2010 (p<10-8). Esta distribución etaria en el HCUCH (1996-2010) se asoció con otros cambios significativos: disminuyeron los RN PEG (p=0,02) y los prematuros (<37 semanas) aumentaron significativamente (p<0,00001). El grupo de mujeres >35 años se asocia con mayor cantidad de RN femeninos, malformaciones congénitas, síndrome de Down y partos por cesárea.

Introduction: In recent decades, both in Chile and other South American countries there has been a change in the age distribution of mothers. Objectives: To obtain the distribution of births by maternal age groups in the Hospital Clinic of the University of Chile (HCUCH) and compare them with similar groups throughout Chile. Check that the extreme age groups are increasing. To study the relationship between these changes and some diseases of the newborn, such as prematurity, infants small for gestational age (SGA) and birth defects. Methods: We reviewed the database of the Maternity HCUCH (1982-2010) and of the Ministry of Health (19902008). The mothers are distributed in 3 groups: <20, >35 and between 20-34 years. Comparisons were made with chi square test. Results: In Chile, the group of mothers >35 years old has increased by over 50 percent when comparing the 1990 (10.2 percent of total) and 2008 15.8 percent (p<10-8). Teenager mothers in Chile increased from 13.8 percent in 1990 to 16.6 percent in 1998 (p<10-8). In the HCUCH variations were different, adolescents decreased 16.08 percent in 1982 to 9.09 percent in 2010 (p<10-8). The >35 years increased significantly, as in all of Chile, 9.8 percent in 1982 to 22.17 percent in 2010 (p<10-8). The live birth age distribution in the HCUCH (1996-2010) led to significant changes: reducing SGA (p=0.02), the premature (<37 weeks) increased significantly (p<0.00001). The group of women >35 years is associated with increased number of children women, congenital malformations, Down syndrome and cesarean deliveries.

[The association between maternal age and congenital malformations]. / Edad materna y malformaciones congénitas: un registro de 35 años. 1970-2005.

BACKGROUND: There is an association between extreme maternal ages and the risk of congenital malformations. This is specially true for chromosomal abnormalities among women of advanced ages and disruptive malformation among teenage mothers. AIM: To determine the association between maternal ages and incidence of congenital malformations at the obstetric ward of a clinical hospital. To compare these figures with those of Chile. MATERIAL AND METHODS: The hospital registries of the Latin American Collaborative Study of Congenital Malformations (ECLAMC) between 1996 and 2005, were consulted. This is a database of all malformations detected in newborns at the hospital. RESULTS: An overall prevalence of malformations of 8,4% was detected at the hospital. There is a significantly lower frequency of mothers aged less than 20 years than in the rest of Chile. Mothers aged between 20 and 29 years have the lower frequency of malformed children. Women aged less than 20 years and over 39 years of age account for 56% of malformed children. Maternal ages and the rates of malformations, increased in a parallel fashion at a rate of 0.2 years and 2.2 malformed children per 1,000 born alive, per calendar year, respectively. CONCLUSIONS: The association between prevalence rates of congenital malformations and maternal age is U shaped with a higher proportion of malformed children among women aged less than 20 years or more than 39 years.

[Effects of folic acid fortification in the rates of malformations at birth in Chile]. / Efecto de la fortificación de la harina con ácido fólico sobre la evolución de las tasas de prevalencia al nacimiento de malformaciones congénitas en los hospitales chilenos del ECLAMC.

BACKGROUND: The effects of folic acid fortification on neural tube defects is well known. Other reports show a beneficial effect of the fortification on orofacial clefts, urinary malformations and defects caused by limb reduction. AIM: To determine the changes in prevalence of congenital malformations after the start of flour folic acid fortification in Chile. MATERIAL AND METHODS: The rates of 22 malformations occurring in the maternity of the University of Chile Clinical Hospital and other Chilean hospitals participating in the Latin American Collaborative Study of Congenital Malformations (ECLAMC) were compared before and after the start of flour folic acid fortification. RESULTS: After the start of folic acid fortification a significant reduction in the rates of anencephalia, spina bifida and diaphragmatic hernia, was observed. The rates of all other malformations remained stable or increased. The rates of all malformations at the University of Chile Clinical Hospital had a steady increase until 2005 and were significantly higher than in the rest of hospitals participating in ECLAMC. CONCLUSIONS: Folic acid fortification was associated with an expected reduction in rates of spina bifida and anencephalia and an unexpected reduction in the rates of diaphragmatic hernia.

Estudio epidemiológico global del síndrome de Down / Global epidemiological study of Down's syndrome

Introduction: In 1967, the Latin American Collaborative Study of Congenital Malformations (LASCM) was created. Currently, 180 hospitals in 76 cities of 9 Latin American countries participate, accumulating data from over 4.5 M births. The Clinical Hospital of the University of Chile (HCUCH) entered the study in 1967, as did 12 other institutions later on. Objectives: Verify changes (increase) in frequency of Down's Syndrome (DS) in Chile and Latin America, and modification of frequency in those countries where elective abortion is permitted. Patients y Method: Three samples were evaluated: Births at HCUCH, active chilean hospitals and the 180 hospitals in 9 LA countries between 1972 and 2009. DS frequencies in Chile and other countries were compared through the International Clearinghouse for Birth Defects Monitoring System. Results: DS frequency at HCUCH increased significantly from 1.03 per thousand births in 1972 to 2.93 /oo births 2009. Frequencies in all chilean hospitals are fairly homogeneous, all higher than average for LASCM, which is 1.88 per thousand. The chilean average is 2.47/ºº por the period between 1998-2005, with a range of 1.88 at HCUCH to 2.86 at the Hospital of Curicó. In the rest of the world, the rate of DS per birth has diminished significantly, being the lowest in Iran (0.32/o<>) and Spain (0.6/oo live births). Conclusion: Rate of DS births are higher in Chile than LASCM average (2.47/o<>), with a trend to increase. This is true in Latin America, where the average for the period between 2001-2005 was 2.89 per thousand live births. In Europe and Asia, these rates have decreased to very low numbers, such as 0.32/o<> in Iran and 0.6/o<> in Spain.

Introducción: El ECLAMC (Estudio Colaborativo Latino Americano de Malformaciones Congenitas) fue creado en 1967. Actualmente, lo integran 180 hospitales de 76 ciudades de 9 países Latino Americanos y ha acumulado más de 4,5 millones de nacimientos. El Hospital Clínico de la Universidad de Chile (HCUCH) ingresó en 1967 y después otros 12 establecimientos chilenos. Objetivos: Verificar si la frecuencia de síndrome de Down (SD) está aumentando en Chile y Latino América y como se ha visto modificada en los países en que está permitido el aborto electivo. Pacientes y Método: Se estudió 3 muestras: Todos los nacimientos del HCUCH desde 1972 a 2009; de los hospitales chilenos activos y de los 180 hospitales de 9 países Latinoamericanos. Se comparó las frecuencias de SD de Chile y del ECLAMC con otros países que participan en el Internacional Clearinghouse for Birth Defects Monitoring System. Resultados: La frecuencia del SD en el HCUCH aumentó significativamente de 1,03 por mil nacimientos en 1972 a 2,93 por mil en 2009. Las frecuencias en los hospitales chilenos son muy homogéneas, todas más altas que el promedio del ECLAMC: 1,88 por mil. El promedio chileno para el período 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 Curicó. En el resto del mundo se ha asistido a una disminución significativa de las tasas de SD, siendo las más bajas la de Irán: 0,32 por mil y España 0,60 por mil nacimientos vivos. Conclusión: 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 América, donde el promedio para el período 20012005 fue de 2,89 por mil. En Europa y Asia las tasas han disminuido a cifras extremas, Irán 0,32 por mil y España 0,60 por mil.

Malformaciones congénitas en Chile y Latino América: Una visión epidemiológica del ECLAMC del período 1995-2008 / Congenital malformations in Latin America in the period 1995-2008

Background: The Latin American Study of Congenital Malformations (ECLAMC) hasperformed an epidemiológica! 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 datábase 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 percent) were stillbirths. The global rate of congenital malformations in this sample was 2.7 percent. 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 percent), followed by Colombia (23 percent). Chile had the higherpercentage ofwomen aged 35years or moregiving birth (14 percent), followed by Uruguay (13 percent). 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.

[Increasing rates of Down syndrome among newborns in Chile from 1972 to 2005]. / Vigilancia epidemiológica del síndrome de Down en Chile, 1972 a 2005.

BACKGROUND: There are some records shrowing that the frequency of Down syndrome is experiencing an increase over time. AIM: To verify whether the frequency of Down syndrome is increasing in the maternity of the University of Chile Clinical Hospital, or in other Chilean hospitals participating in the Latin American Collaborative Study of Congenital Malformations (ECLAMC) and compare the rates with other world registries of congenital malformations. MATERIAL AND METHODS: The information was obtained from the ECLAMC databases of the maternity. The Down syndrome incidence rates were calculated from 1997 to 2005 and rate curves were constructed. RESULTS: The overall rate of Down syndrome was 3.36 per 10,000 born alive. This rate experienced a significant increase in the study period. These rates differ in the different Chilean regions, being higher in Santiago and lower in the Southern regions of the country. The mean age of mothers of newborns with or without Down syndrome was 36+/-6 and 29+/-6 years, respectively, p >0.001. CONCLUSIONS: The rates of newborns with Down syndrome increased in the period 1972-2005, bearing a close relationship with the increase in maternal ages.

[The frequency of twin pregnancies increased in a Chilean hospital associated with periconceptional flour folic acid supplementation]. / La frecuencia de nacimientos de gemelos aumentó en un hospital chileno coincidiendo con el consumo periconcepcional de harina fortificada con ácido fólico.

BACKGROUND: A significant increase in the frequency of twins has been described in the literature as a secondary effect of perinatal supplementation with folic acid. AIM: To verify if the frequency of twins increased in a Chilean hospital, after the start of flour folic acid supplementation. MATERIAL AND METHODS: The frequency of twins was compared in the University of Chile Clinical Hospital, before and after the start of flour fortification with folic acid. RESULTS: There was a 34% increase in the frequency of twins during the post fortification period (2001-2004) as compared with the previous period (1998-2000). A decrease in the frequency of male twins, when compared with single newborns, was also observed in the post fortification period. There was a higher frequency of stillborns among twins, when compared with single newborns. CONCLUSIONS: The frequency of twin pregnancies increased after flour folic acid supplementation in sample of Chilean population.

Atresia de esófago y sus asociaciones preferenciales / Esophageal atresia and related malformations

Esophageal atresia is a congenital malformation incompatible with life. The incidence is quite variable in Chile and all over the world. Objective: To estimate the prevalence at birth of esophageal atresia, comparing with previously published data. Patients and Methods: All children with congenital anomalies born at the UniversityofChile Clinical Hospital from 1999 to 2009 were included. Results: 19.312 births during the study period were registered, 1710 of them had a congenital anomaly (8,9 percent). Fifteen of the malformed newborns had esophageal atresia (7.8 x 10.000): one stillbirth and 14 alive newborns. 78,6 percent of cases were discharge alive from the hospital, 3 (21,4 percent) died during the hospitalization. Only 1/15 was an isolated esophageal atresia, 6 cases were syndromic and 9 were classified as VACTERL association. Prenatal diagnosis was made in 73,3 percent of the cases. Newborns with esophageal atresia had significantly less birth weight, less gestational age and more malformed relatives, than control newborns. Metrorrhagia during pregnancy in mothers was more frequent in cases than controls. No difference in maternal age between groups was founded. Conclusion: The esophageal atresia prevalence at birth was higher than previously reported local data, and lower than the rest of ECLAMC data; this could be explained because the University of Chile Clinical Hospital is a reference Hospital for prenatal diagnosed cases.

Introducción: Atresia de esófago es una malformación congénita incompatible con la vida, que tiene una frecuencia variable en Chile y en el resto del mundo. Objetivos: Presentar la prevalencia actual y compararla con comunicaciones anteriores. Estudiar las asociaciones más frecuentes con otras malformaciones y la sobreviva al alta hospitalaria. Pacientes y Método: Ingresaron a este trabajo todos los niños que presentaban una o más malformaciones nacidos entre 1999 y 2009 nacidos en la maternidad del Hospital Clínico. Resultados: Durante el período ocurrieron 19.312 nacimientos. Se encontró 1. 710 recién nacidos malformados (8,9 por ciento). A 15 de ellos (7,8 por 10.000) se les diagnosticó Atresia de esófago. Catorce eran nacidos vivos. 78,6 por ciento fueron tratados y dados de alta vivos. Tres (21,4 por ciento) fallecieron. Sólo 1 caso fue catalogado como forma aislada, 6 como formas sindrómicas. Nueve casos fueron catalogados como Asociación VACTERL. En 73,3 por ciento de los casos se hizo el diagnóstico prenatal de la Atresia de esófago. Cuando se los comparó con los controles, los malformados tenían un significativo menor peso de nacimiento y edad gestacional. No se encontró diferencia significativa en edad materna entre casos y controles. Sí había diferencia significativa en "otros malformados en la familia" y "metrorragia del primer trimestre" que eran más frecuentes en casos. Conclusión: La tasa de prevalencia al nacimiento fue mayor que la encontrada anteriormente y menor que el promedio dado por ECLAMC para Latinoamérica, probablemente debido a que el Hospital Clínico es un hospital de referencia de casos diagnosticados prenatalmente.