Gastrosquisis: ¿una pandemia con tasas en aumento? Experiencia del estudio colaborativo latino americano de malformaciones congénitas (ECLAMC) en Chile. Período 1982-2014 / Gastroschisis: A pandemic with increasing rates? ECLAMC experience in Chile 1982-2015

Introducción: Numerosas publicaciones han alertado sobre el aumento sostenido de las tasas de prevalencia al nacimiento de gastrosquisis en todo el mundo, catalogado este hecho como una «pandemia¼ fuertemente asociada a edad materna baja. Objetivos: Comprobar si en Chile se ha producido también un aumento significativo de la tasa de prevalencia al nacimiento de gastrosquisis y si se relaciona con edad materna baja. Pacientes y método: Se usó la base de datos ECLAMC de 26 hospitales chilenos participantes. Las tasas de prevalencia entre hospitales y las categorías de edad materna se compararon con prueba de Chi cuadrado o prueba exacta de Fisher. Se estudió la serie temporal mediante comparación de tendencias lineales, usando comparaciones de medias vía t-test y Wilcoxon-test. Resultados: En el período 1982-2014 nacieron 721.901 niños, entre los que se encontró 107 casos de gastrosquisis (1,49/10.000), el 75,7% de ellos eran hijos de mujeres menores de 25 años. El promedio de edad materna de los casos fue de 21,6 años, y el promedio nacional es cercano a 28 años, según el Ministerio de Salud. A partir de 1995 esta tasa mostró una tendencia ascendente significativamente distinta de cero (p = 0,00714), con un aumento de 0,1591 cada año. Este incremento fue alrededor del 300% entre 1995 y 2014, respecto del período anterior (p < 0,00001). Conclusión: En Chile se ha producido un aumento significativo de las tasas de gastrosquisis después del año 1995, y esta anomalía se asocia fuertemente con baja edad materna.

Introduction: Several communications have reported a significant increase in the prevalence of gastroschisis at birth in the last three decades. In many Countries it is referred to as "a pandemic strongly associated to low maternal age". Objective: To verify if there has been a significant increase in the prevalence of gastroschisis at birth in Chile, and if this rate is associated with a low maternal age. Patients and methods: The study was performed using the ECLAMC data base from 26 Chilean Hospitals. Comparison between prevalence rates and maternal age categories were made using the X² test or Fisher exact Test. The time series was studied comparing average tendencies using the Student t test and Wilcoxon-test. Results: There were 721,901 newborns in the period 1982-2014, among which 107 were diagnosed with gastroschisis (1.48/10,000). Around three-quarters (75.7%) of them were born from mothers younger than 25. The mean maternal age was 21.6 years in mothers of children with gastroschisis, while the mean maternal age of all mothers from Chile was almost 28 years old. The gastroschisis prevalence at birth rate was constant at around 1/10,000 until 1994. From 1995 this rate has a significant increasing tendency of 0.1591 by year (P = .00714). This increase is about a 300% on average for the 1995-2014 period, compared with the previous one (P < .00001). Conclusion: There has been a significant increase in the gastroschisis prevalence at birth in Chile from 1995, and this anomaly is associated with a low maternal age.

[Gastroschisis: A pandemic with increasing rates? ECLAMC experience in Chile 1982-2015]. / Gastrosquisis: ¿una pandemia con tasas en aumento? Experiencia del estudio colaborativo latino americano de malformaciones congénitas (ECLAMC) en Chile. Período 1982-2014.

INTRODUCTION: Several communications have reported a significant increase in the prevalence of gastroschisis at birth in the last three decades. In many Countries it is referred to as "a pandemic strongly associated to low maternal age". OBJECTIVE: To verify if there has been a significant increase in the prevalence of gastroschisis at birth in Chile, and if this rate is associated with a low maternal age. PATIENTS AND METHODS: The study was performed using the ECLAMC data base from 26 Chilean Hospitals. Comparison between prevalence rates and maternal age categories were made using the X2 test or Fisher exact Test. The time series was studied comparing average tendencies using the Student t test and Wilcoxon-test. RESULTS: There were 721,901 newborns in the period 1982-2014, among which 107 were diagnosed with gastroschisis (1.48/10,000). Around three-quarters (75.7%) of them were born from mothers younger than 25. The mean maternal age was 21.6 years in mothers of children with gastroschisis, while the mean maternal age of all mothers from Chile was almost 28 years old. The gastroschisis prevalence at birth rate was constant at around 1/10,000 until 1994. From 1995 this rate has a significant increasing tendency of 0.1591 by year (P=.00714). This increase is about a 300% on average for the 1995-2014 period, compared with the previous one (P<.00001). CONCLUSION: There has been a significant increase in the gastroschisis prevalence at birth in Chile from 1995, and this anomaly is associated with a low maternal age.

[Frequency of holoprosencephaly in Chile]. / ECLAMC: 41 años de vigilancia de la holoprosencefalia en Chile. Período 1972-2012.

BACKGROUND: Holoprosencephaly is a structural anomaly of the brain that consists in a defect of the prosencephalon development that leads to face and neurological defects of variable intensity. AIM: To estimate holoprosencephaly prevalence at birth. PATIENTS AND METHODS: All cases of holoprosencephaly, born alive or stillbirths, registered in the 15 Chilean Hospitals of the Latin American Collaborative Study of Congenital Malformations (ECLAMC) between 1972 and 2012, were studied. Craniofacial and other anomalies found in newborns affected by holoprosencephaly are described. RESULTS: Fifty five cases of holoprosencephaly (58% males) were found among the 798.222 registered births (rendering a prevalence at birth of 0.69 per 10.000 newborns). The most common cranial defect was medial cleft lip with cleft palate (27.3%), bilateral cleft lip (11%) or both (38.2%), cyclopia (14%), single nostril (10.9%) and proboscis (9.1%). Eleven percent cases had a trisomy 13. A slight increase in prevalence over time was observed. CONCLUSIONS: Holoprosencephaly has a low frequency in Chile and is associated to trisomy 13. The increase in prevalence could be explained by a better prenatal diagnosis (ultrasonography).

ECLAMC: 41 años de vigilancia de la holoprosencefalia en Chile. Período 1972-2012 / Frequency of holoprosencephaly in Chile

Background: Holoprosencephaly is a structural anomaly of the brain that consists in a defect of the prosencephalon development that leads to face and neurological defects of variable intensity. Aim: To estimate holoprosencephaly prevalence at birth. Patients and Methods: All cases of holoprosencephaly, born alive or stillbirths, registered in the 15 Chilean Hospitals of the Latin American Collaborative Study of Congenital Malformations (ECLAMC) between 1972 and 2012, were studied. Craniofacial and other anomalies found in newborns affected by holoprosencephaly are described. Results: Fifty five cases of holoprosencephaly (58% males) were found among the 798.222 registered births (rendering a prevalence at birth of 0.69 per 10.000 newborns). The most common cranial defect was medial cleft lip with cleft palate (27.3%), bilateral cleft lip (11%) or both (38.2%), cyclopia (14%), single nostril (10.9%) and proboscis (9.1%). Eleven percent cases had a trisomy 13. A slight increase in prevalence over time was observed. Conclusions: Holoprosencephaly has a low frequency in Chile and is associated to trisomy 13. The increase in prevalence could be explained by a better prenatal diagnosis (ultrasonography).

Prevalencia de malformaciones congénitas en hijos de madres mayores de 34 años y adolescentes: Hospital Clínico de la Universidad de Chile, 2002-2011 / prevalence rate of congenital malformations among newborn of teenagers mothers and older than 34 years old: Hospital Clínico de la Universidad de Chile, 2002-2011

Antecedentes: Las madres mayores de 34 años han aumentado en Chile. La mayor edad materna aumenta el riesgo de malformaciones congénitas (MFC) Objetivos: Determinar la tasa de prevalencia de MFC entre adolescentes y mayores de 34 años. Método: Se utilizó la base de datos de la Maternidad del Hospital Clínico Universidad de Chile (2002-2011). Se estudió todos los nacimientos, vivos, mortinatos y malformados de 500 gramos o más, de madres menores de 20 y mayores de 34 años. Se calculó y comparó las tasas de prevalencia al nacer de todas las malformaciones de cada grupo etario. Resultados: Hubo 15.636 nacimientos, 0,98 por ciento fueron mortinatos, 7,5 por ciento hijos de madres menores de 20 años y 27,7 por ciento de mayores de 34 años. La tasa global de MFC fue 8,8 por ciento; 7 por ciento en menores de 20 años y 9,6 por ciento en mayores de 34 años (p=0,007). Síndrome de Down fue 12 veces más frecuente en los hijos de madres mayores de 34 años que en las adolescentes. Las mayores de 34 años presentaron significativamente más mortineonatalidad en sus hijos malformados que las adolescentes, pero menor frecuencia de bajo peso, menor consumo de tabaco, alcohol y mariguana. Conclusión: El grupo de madres mayores de 34 años es significativamente diferente al grupo de adolescentes, tanto en prevalencia de MFC como en mortalidad neonatal de malformados, bajo peso al nacer y hábitos de vida...

Background: Mothers older than 34 years have increased trend in Chile. The maternal age increases the risk of congenital malformations (CMF). Objectives: Determine the prevalence rate of CMF among newborn of teenagers mothers and older than 34 years old. Method: We used the database of the Maternity Hospital, University of Chile (2002-2011). We studied all births, live, stillbirths and malformed newborn of 500 grams or more, from mothers under 20 and over 34 years. We calculated and compared the birth prevalence rates of all malformations for each age group. Results: There were 15,636 births, 0.98 percent were stillbirths, 7.5 percent children of mothers under 20 years and 27.7 percent older than 34 years. The overall rate of CMF was 8.8 percent; 7 percent in under 20 years and 9.6 percent in mothers over 34 years (p=0.007). Down syndrome was 12 times more common in children of mothers older than 34 years than in adolescents. The older than 34 years had significantly more neonatal mortality in malformed children than adolescents, but lower frequency of low birth weight, lower consumption of snuff, alcohol and marijuana. Conclusion: The group of mothers older than 34 years is significantly different from the group of teenagers, both in prevalence of CMF as neonatal mortality, low birth weight and lifestyle habits...

[Congenital malformations among offspring of diabetic women]. / Malformaciones congénitas en hijos de madres con diabetes gestacional.

BACKGROUND: The risk of congenital malformations is two to three times higher among women with diabetes mellitus before pregnancy. Gestational diabetes is emerging as a risk factor for malformations. AIM: To study the rate and type of congenital malformations among offspring of women with pre-gestational or gestational diabetes. MATERIAL AND METHODS: A search in the databases of the Collaborative Latin American Study for Congenital Malformations and of the Neonatology Unity of The University of Chile Clinical Hospital. All births from January 1998 through June 2004 were investigated. RESULTS: In the study period, 13,965 births occurred, of which 0.7% were stillbirths and 8.1% had malformations. A total of 295 women (2.1%) had diabetes (gestational diabetes in 1.8% and pre gestational diabetes in 0.3%). The prevalence of congenital malformations was 14% and 18.3% among offspring of mothers with pre-gestational and gestational diabetes, respectively (p=NS). The prevalence of congenital malformations among offspring of non diabetic women was 7.9% (p <0.001 with respect to diabetic women). Major malformations were found in 83% and 70% of malformed offspring of women with pre-gestational and gestational diabetes, respectively. CONCLUSIONS: Pregnant women with pre-existing or gestational diabetes have a higher risk of giving birth a child with malformations.

Malformaciones congénitas en hijos de madres con diabetes gestacional / Congenital malformations among offspring of diabetic women

Background: The risk of congenital malformations is two to three times higher among women with diabetes mellitus before pregnancy. Gestacional diabetes is emerging as a risk factor for malformations. Aim: To study the rate and type of congenital malformations among offspring of women with pre-gestational or gestational diabetes. Material and methods: A search in the databases of the Collaborative Latin American Study for Congenital Malformations and of the Neonatology Unity of The University of Chile Clinical Hospital. All births from January 1998 through June 2004 were investigated. Results: In the study period, 13,965 births occurred, of which 0.7% were stillbirths and 8.1% had malformations. A total of 295 women (2.1%) had diabetes (gestational diabetes in 1.8% and pre gestational diabetes in 0.3%). The prevalence of congenital malformations was 14% and 18.3% among offspring of mothers with pre-gestational and gestational diabetes, respectively (p=NS). The prevalence of congenital malformations among offspring of non diabetic women was 7.9% (p <0.001 with respect to diabetic women). Major malformations were found in 83% and 70% of malformed offspring of women with pre-gestational and gestational diabetes, respectively. Conclusions: Pregnant women with pre-existing or gestational diabetes have a higher risk of giving birth a child with malformations.

Reduction of birth prevalence rates of neural tube defects after folic acid fortification in Chile.

To verify whether the decreasing neural tube defects birth prevalence rates in Chile are due to folic acid fortification or to pre-existing decreasing trends, we performed a population survey using a network of Estudio Colaborativo Latino Americano de Malformaciones Congenitas (ECLAMC, Latin American Collaborative Study of Congenital Malformations) maternity hospitals in Chile, between the years 1982 and 2002. Within each maternity hospital, birth prevalence rates of spina bifida and anencephaly were calculated from two pre-fortification periods (1982-1989 and 1990-2000), and from one fortified period (2001-2002). There was no historical trend for spina bifida birth prevalence rates before folic acid fortification, and there was a 51% (minimum 27%, maximum 66%) decrease in the birth prevalence rates of this anomaly in the fortified period. The relative risks of spina bifida were homogeneous among hospitals in the two period comparisons. There was no historical trend for the birth prevalence of anencephaly comparing the two pre-fortified periods, but the relative risks were heterogeneous among hospitals in this comparison. There was a 42% (minimum 10%, maximum 63%) decrease in the birth prevalence rate of anencephaly in the fortified period as compared with the immediately pre-fortified period, with homogeneous relative risks among hospitals. Within the methodological constraints of this study we conclude that the birth prevalence rates for both spina bifida and anencephaly decreased as a result of folic acid fortification, without interference of decreasing secular trends.

Preliminary data on changes in neural tube defect prevalence rates after folic acid fortification in South America.

Several South American countries are fortifying wheat flour with folic acid. However, only Chile started in 2000 to add 2.2 mg/kg, providing 360 microg daily per capita, an acceptable dosage for preventing the occurrence of some neural tube defect (NTD) cases. ECLAMC (Spanish acronym for the Latin American Collaborative Study of Congenital Malformations) routinely monitoring birth defects in South America since 1976, surveyed the impact of this fortification. Data from 361,374 births occurred in 43 South American hospitals, distributed in five different countries, active throughout the 1999-2001 triennium, were selected from the ECLAMC network. Birth prevalence rates for three different congenital anomalies with similar expected prevalence rates, were surveyed by the Cumulative Sum Method (CUSUM) method. They were NTD, oral clefts (OC), and Down syndrome (DS). Expected values were derived from observations made in 1999, and CUSUM was applied to the consecutive series of 24 months covering years 2000 and 2001. Only one of three congenital anomaly types, NTDs, in only one of five sampled out countries, Chile, showed a significant decrease, of 31%, during the 2000-2001 biennium, corresponding to the birth of the periconceptionally fortified infants. The level of significance (P < 0.001) was reached in the 20th month after fortification started, corresponding to August 2001. This is the first observation of a significant decrease in the occurrence of NTD after folic acid food fortification in a population little influenced by confounders common in the developed world as pre-existing secular decreasing trends, and partially unregistered induced abortions.

Malformaciones congénitas y patología crónica de la madre: estudio ECLAMC 1971-1999 / Association between congenital malformations and chronic diseases of the mother

Background: Several maternal diseases, such as diabetes mellitus or high blood pressure, are associated with a higher risk for fetal or neonatal problems. Aim: To study the association between chronic diseases of the mother and congenital malformations. Material and methods: Review of the records of the Latin American Collaborative Study of Congenital Malformations (ECLAMC) at the University of Chile Clinical Hospital. A sample of 383 mothers with a chronic disease was compared with 297 healthy mothers. The presence of congenital malformations in the newborns was studied. The odds ratio (OR) of a mother to have a child with a congenital malformation was calculated. Results: Mothers with bronchial asthma, diabetes mellitus, hypertension and hypothyroidism had an OR over 1 of having a child with a congenital malformation. No association between maternal obesity and offspring malformations was observed. Offspring of diabetic mothers had 8.95 times more probabilities of having a major malformation and 4.95 times more probabilities of having a minor defect. Conclusions: Offspring of mothers with diabetes mellitus, bronchial asthma, hypertension or hypothyroidism have a higher risk of presenting a congenital malformation, when compared with offspring of healthy mothers

Malformaciones congénicas del sistema digestivo: maternidad Hospital Clínico de la Universidad de Chile: período 1991-2001 / Frequency of digestive system congenital malformations detected at the University of Chile hospital in the period 1991-2001

There were 26,617 births attended at the University of Chile Clinical Hospital, of which 0.63 percent were stillborn. A frequency of malformations of 7.2 per born alive and of 22.1 per stillborn was detected in this population. Aim: To report the frequency of digestive system congenital malformations in this population. Material and methods: Analysis of data from the births that occurred at the University of Chile Hospital, that was gathered using codified form for the Latin American Collaborative Study for Congenital Malformations. Results: Ninety seven digestive congenital malformations were detected, with a rate of 26.4 per 10,000 born alive and 12.2 per 10,000 stillborn. Diaphragmatic hernia was the most frequent malformation found, followed by imperforated anus, onphalocele and esophageal atresia. There was a secular increase in the frequency of these malformations. Conclusions: The frequency of digestive system malformations is higher than in the rest of hospitals participating in the Latin American Collaborative Study for Congenital Malformations

Malformaciones del sistema nervioso central en el Hospital Clínico de la Universidad de Chile y maternidades chilenas participantes en el estudio colaborativo lationamericano de malformaciones congénitas, ECLAMC / Central nervous system malformations in Chilean hospitals participating in the Latin American collaborative study of congenital malformations, ECLAMC

Background: In Chile, the rates of central nervous system congenital malformations at birth remain high, when compared with the rest of the world. Aim: To report the rates of central nervous system congenital malformations in Chilean hospitals. Material and methods: Using the ECLAMC protocol, every malformed newborn or stillbirth, weighing 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. Results: The rates of central nervous system congenital malformations are higher at the University of Chile Clinical Hospital than in the rest of Chilean hospitals or Latin American Hospitals. There are significantly higher rates of anencephalia in Concepcion and spina bifida in Valdivia, Rancagua and Concepcion. In the University of Chile Clinical Hospital, global annual rates have a negative slope of -0.0259 per 1000 born alive, with a correlation coefficient of -0.125 (p <0.05). The slope is positive among children born alive, with an annual rate increase of 0.071. Among stillbirths, the slope is -0.47 per 1000 born alive. Sixty two percent of malformed children were female. Among children with neural tube defects, 30 per cent had a malformed relative and, of these, 66 per cent had the same malformation. Conclusions: Family clustering of neural tube defects, supports the influence of a genetic factor influencing their appearance

Malformaciones congénitas en Chile: un problema emergente período 1995-1999 / Congenital malformations in Chile: an emergent problem at 1995-1999 period

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 Concepción and spina bifida has a high frequency in Rancagua, Viña del Mar, Concepción 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

Sexo ambiguo: prevalencia al nacimiento en la maternidad del Hospital Clínico de la Universidad de Chile / Ambiguous sex: prevalence at birth in a university obstetric service in Santiago, Chile

Background: Ambiguous sex has a great phenotypic variability and is a serious medical and social problem. Aim: To study the prevalence of ambiguous sex among newborns. Material and methods: As part of the ECLAMC (Cooperative Latin American Study of Congenital Malformations) all newborns with malformations are registered and the next normal newborn is considered as a control. Results: 50.253 births occurred (between 1982 and 1999) in the University of Chile Maternity Hospital. The rate of congenital malformations was 6.78 percent and the prevalence of ambiguous sex was 4.7 per 10.000 births. Affected children had a lower birth weight, lower gestational age and a lower maternal age than controls. The most frequent associated malformations were of the urinary (64 percent) and cardiovascular systems (60.7 percent). Thirty two percent of affected children had specific syndromes. Conclusions: The prevalence of ambiguous sex in this study was 4.7 per 10.000 births, which is higher than that reported in the ECLAMC (1.9 per 10000)

ECLAMC: estudio de 30 años de vigilancia epidemiológica de defectos de tubo neural en Chile y en Latinoamérica / ECLAMC: results of 30 years of epidemiological surveillance of neural tube defects in Chile and Latin America

Background: There is an urgent need to assess the impact, on the incidence of neural tube defects, of the recently implanted flour fortification with folic acid in Chile. The Collaborative Study of Congenital Malformations in Latin America (ECLAMC) has carried out an uninterrupted register of congenital malformations in the last thirty years Aim: To assess the epidemiology of neural tube defects in Chile and determine the most adequate base period to evaluate the effects of Folic acid fortification. Material and methods: analysis of ECLAMC database that has registered all births over 500 g from 1967. Results: From 1967 to 1999, there were 434.624 births in 18 hospitals in Chile and 3.586.569 births in 155 hospitals in the rest of Latin America. The rate of neural tube defects in Chile was 17.03 per 10.000, significantly higher than the rest of ECLAMC (14.88 per 10.000). The prevalence of neural tube defects has a statistically significant secular tendency to increase in the study period and is higher among stillbirths, newborns with a birth weight of less than 1500 g, women and offspring of mothers aged less than 19 years old. Conclusions: The period 1982-1999 is considered the best period for reference comparisons of the effects folic acid supplementation

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 / Incidence of orofacial cleft at Universidad de Chile maternity hospital and other hospitals participating in the Latin American collaborative study of congenital malformations, ECLAMC

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 percent 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

Malformaciones invalidantes en Chile: estudio ECLAMC 1982-1997 / Disabling congenital defects in Chile: ECLAMC 1982-1997

Background: The ECLAMC (Estudio Colaborativo Latinoamericano de Malformaciones Congénitas) is an epidemiological surveillance program for congenital defects that operates in Chile since 1969. Aim: To communicate the frequency of disabling congenital defects in Chile in the period 1982-1997. Material and methods: A review of the ECLAMC registry, choosing 12 congenital defects: amelia, limb amputations, limb reductions, arthrogryposis, hip luxation and subluxation, spina bifida, hydrocephaly, microcephaly, cephalocele, talipes equinovarus, Down syndrome and multiple abnormalities. Results: In the study period, 283,403 births occurred and 7,917 newborns were malformed (7,654 born alive and 263 stillbirths). The congenital defects prevalence rates appeared higher in Chile than in other Latin American countries, specially among stillbirths. Among the studied maternity hospitals, the Clinical Hospital of the University of Chile, showed the higher prevalence of congenital defects. Rancagua and the Navy Hospital in Valparaiso have a high frequency of Down syndrome. Global rates in Chile and in the rest of ECLAMC for specific defects, do not have significant differences, except for hip subluxation, that has a lower incidence in Chile. Conclusions: The ECLAMC allows to have a good knowledge of the prevalence of congenital malformations in Latin America

Malformaciones congénitas en los hijos de madres diabéticas / Congenital malformations in the offspring of diabetic mothers

The offspring of diabetic mothers have a 10 times higher frequency of congenital malformations and 5 times higher frequency of spontaneous abortions. Since the discovery of insulin, the prognosis of pregnancies has improved, both for the mother and the offspring. However, the prevalence of congenital malformations at birth has not decreased significantly. The embriological process that leads to anomalies in the offspring of diabetic mothers probably occurs between 6 and 8 weeks of gestation. According to animal experiments, hyperglycemia, ketones and free radicals may be involved in the genesis of malfomations, but different strains of rats respond differently to these potential teratogenic agents. Possibly, a higher genetic susceptibility towards congenital malformations also plays a role in diabetic women. Therefore, although the intimate mechanism producing malformations in the offspring of diabetic women is not known, several strategies to decrease the prevalence of malformations in these women, such as the use of antioxidants, are being tested

Malformaciones congénitas anorrectales y sus asociaciones preferentes: experiencia del Hospital Clínico de la Universidad de Chile, período 1979-1999 / Anorectal congenital malformations and their associations in a Chilean University Hospital between 1979 and 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 percent, skeletal in 26 percent and cardiovascular in 18.5 percent). Five stillborn babies had other severe malformations. Twenty one children had a fistula. Forty three percent were male, 39 percent female and 18 percent 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

Prevalencia de malformaciones congénitas al nacer y factores asociados en Isla de Pascua, Chile: 1988-1998 / Prevalence of congenital malformations and associated factors in Easter Island, Chile

Background: Consanguinity plays an important role in the genetic etiology of congenital malformations. In Easter Island the degree of consanguinity could be higher than in continental Chile. Therefore the study of the prevalence of congenital malformations in this island seems worthwhile. Aim: To study the prevalence of congenital malformations at birth in Easter Island. Material and methods: A review of personal and family features of all children born alive between 1988 and 1998 in the Rapa Nui Hospital of Easter Island. Results: During the study period, 772 newborns were reviewed and 22 were found to have congenital malformations. Among the latter, birth weight fluctuated between 3001 and 4000 g and the male/female ratio was 0.54. No differences in maternal age between children with and without malformations was observed. Heart and circulatory malformations, hemangiomas and Down syndrome were the predominant malformations. Conclusions: The prevalence of congenital malformations at birth in Easter Island is similar to that of continental Chile. No neural tube defects were detected in this sample