Joaquin E. Paz

Hand and foot postaxial polydactyly: Two different traits

The aim of this work was to test whether postaxial hexadactyly had different clinical and epidemiological characteristics depending on hand or foot involvement. In the period 1967-1993, the Latin-American Collaborative Study of Congenital Malformations (ECLAMC) enrolled 1,582,289 births, and 2,271 cases with isolated (nonsyndromal) postaxial polydactyly (5th-digit hexadactyly). The prevalence was 14.3/10,000 births. Postaxial polydactyly (PP) of the hand (HPP) was the most frequent type (N:1,733; 76.3%; prevalence: 11.0/10,000), followed by foot PP (FPP=N:351; 15.5%; prevalence: 2.2), and hand and foot PP (BPP=N:187; 8.2%; prevalence: 1.2). Unlike HPP (55.0% bilateral; 77.2% left), FPP was less frequently bilateral (19.4%), with lower preference for the left side (55.5%). As expected, HPP was associated with African Black ethnicity, male sex, twinning, low maternal education, parental consanguinity, and there was frequent recurrence in 1st-degree relatives. Conversely, FPP was associated with Amerindian racial background, parental subfertility, and bleeding in the 1st trimester of pregnancy. BPP displayed the highest frequency of associated congenital defects (23.4%, vs HPP:6.6%, FPP: 15.4%). In its isolated form, BPP resembled HPP more than FPP with respect to left preference (90.9%), familial recurrence (11.0% of 1st degree relatives), and low maternal education. Although male sex preference and high frequency of twinning was observed in the 3 PP subtypes, statistical significance was present only in HPP. None of the 3 PP subtypes showed abnormal values for perinatal mortality, birth weight, length of gestation, parental ages, or parity. A logistic regression analysis showed Black race only to be associated with HPP, parental subfertility with FPP, parental consanguinity with BPP, and non-Black race with both FPP and BPP. The data presented here are the first indication that HPP and FPP are 2 different entities, with a larger genetic component in HPP than in FPP.

Previous miscarriage and stillbirth as risk factors for other unfavourable outcomes in the next pregnancy

Objective To look for associations between previous fetal loss and fetal malformation or low birthweight in a subsequent pregnancy.

Survival of children with Down syndrome in South America

The first step of all healthcare actions aimed at promoting an appropriate quality of life for infants affected by Down syndrome (DS) is to ensure their survival. This investigation was aimed at estimating the infant mortality rate of infants affected with DS in urban populations of South America. Thirty-three hospitals included in the Latin American Collaborative Study of Congenital Malformations (ECLAMC) distributed in 23 cities of 5 South American countries followed 360 liveborn DS cases born during the 1988-1992 period. Families were recontacted after the infant should have reached the age of one year. The collected data included information about health status; i.e., frequency and dates of diagnosed illnesses and hospital admissions, and, in case of death, information on date, place and cause of death, and illness immediately before death. Information about the interviews included place, date, and name of the interviewer. A closed questionnaire was employed by the interviewers, mostly physicians, nurses, and social workers. Life table analysis up to the age of one year was performed by the actuarial survival method. The overall mean survival at age one year was 0.736 (SE=0.023). Thirty-three (9.2%) of the 360 cases died neonatally, and 62 (17.2%) within the remaining 2-to-12-month interval. The probability of survival at one year of age did not differ between public (209 cases; mean 0.718; SE=0.031) and private (151 cases; mean: 0.762; SE=0.035) (chi2:0.87; df:1; P >0.05) health systems. The 150 DS cases with a congenital heart defect (CHD) had a significantly lower P robability of survival at the age of one year (mean: 0.660; SE: 0.039) than did the 210 cases without CHD (mean: 0.790; SE: 0.028) (chi2:6.67; df:1; P <0.01). The death rate in the first year of life for DS cases without a detected cardiac defect (21%) is significantly higher than that reported in developed countries; namely, 16% from Italy, 11% from Canada, 10% from England, and 7% from Denmark.

VATERL : An epidemiologic analysis of risk factors

This work analyzed the incidence of risk factors in 138 cases presenting two or more of five components defining VATERL, with no other recognized unrelated anomalies: vertebral anomalies, anal atresia, esophageal atresia with or without tracheoesophageal fistula, renal anomalies, and preaxial defects of the upper limbs, including polydactyly of the thumb. The 138 infants were ascertained among 1,811,461 births examined in the 1967-1994 period by the Latin-American Collaborative Study of Congenital Malformations: ECLAMC. One healthy and one malformed control newborn infant were matched to each VATERL case. The birth prevalence rates (per 100,000 births) for VATERL were significantly lower in Venezuela (3.1) than in the other eight countries (8.8) (P < 0.001). Venezuela also had lower rates for all five VATERL defects, even after excluding the 138 VATERL cases. VATERL cases were preferentially males (male proportion 0.6261) (P < 0.02), and, when compared with healthy controls, they had a higher perinatal mortality rate (63.7%) (P < 0.005), a higher frequency of fetal losses in previous pregnancies (12.6%) (P < 0.05), and lower mean birthweights (2,361.79 +/- 809.63 g) (P < 0.005). VATERL cases showed a higher rate than matched malformed controls for prenatal exposures to drugs and physical agents (P < 0.02 and P < 0.05, respectively), although no specific pharmacological or physical group was involved. The lower birth prevalence rates found in Venezuela, for VATERL as well as for each of the five congenital anomalies involved in this association, seem to be biologically meaningful. Since we could not identify a potential risk factor, nor a common cause of underascertainment unique to the Venezuelan subsample and common to all six hospitals, no hypothesis can be advanced here for this phenomenon. Nevertheless, this unequal geographic distribution strongly suggests a common etiopathogenicity for the five congenital anomalies involved in the VATERL association.

Knowledge of likely time of ovulation and contraceptive use in unintended pregnancies.

This investigation analyzed social and demographic characteristics of women having an unwanted or mistimed pregnancy (unintended pregnancies at the current time) in South America.A sample of 5135 women having had a normal non-malformed live-born infant were interviewed immediately postpartum at 18 hospitals participating in the Latin American Collaborative Study of Congenital Malformations (Spanish acronym: ECLAMC). Half (2568/5135 = 50%) reported that their pregnancies had been unintended, and, of those, 59.3% (1522/2568 = 59.3%) declared that they were trying to avoid conception. The latter group (n = 1522) was the main sample for this study.Patients were asked about their knowledge of when during the menstrual cycle conception is most likely to occur, their biomedical and social characteristics, the type of contraceptive methods used, their opinion of reasons for contraceptive failure, and their reasons for not using contraceptive methods.Women with unintended pregnancies who had not attempted to avoid conception were younger, often primigravid, less educated, and less knowledgeable concerning when during the cycle pregnancy is most likely to occur. Thus, reproductive health policies should be aimed at this target group.

Prenatal Detection of Chromosome Aberrations after Intercontinental Transport of Amniotic Fluid

Prenatal examination for chromosome anomalies was performed in nine families through a collaborative program between the Center for Medical Genetics in Buenos Aires and The New York Hospital–Cornell Medical Center in New York, using a simplified technique for cultivation of amniotic fluid cells. The indication in three out of nine cases was a balanced translocation present in one of the parents, two of a type which have not previously been reported. Two fetuses were also found to have the same balanced translocation as one of their parents. Some special conditions regarding the indications and techniques used for prenatal diagnosis influenced by local situations are pointed out.

Congenital malformations in hospital admissions in Ribeirão Preto, State of S. Paulo, Brazil

Sao apresentados os dados sobre internacoes por malformacoes congenitas registradas pelo Centro de Processamento de Dados Hospitalares do Departamento de Medicina Social da Faculdade de Medicina de Ribeirao Preto, USP, desde 19 de janeiro de 1970 a 30 de julho de 1974 em sete estabelecimentos hospitalares. Tais internacoes participam com 1,48% no total de internacoes, excluindo-se as causas acidentais. Encontrou-se que as distribuicoes de diagnosticos principais e secundarios classificados por tipo de malformacao sao significantemente diferentes; descreveu-se a participacao de cada estabelecimento nestas internacoes. Do mesmo modo, encontrou-se um incremento significativo na percentagem de internacoes por malformacoes congenitas com o transcurso de tempo, o que e atribuido ao Hospital das Clinicas exclusivamente. Apresentou-se a percentagem de mortalidade por diagnostico, as razoes de sexo e a duracao media das internacoes, encontrando-se nesta ultima que e maior que a media do total de internacoes. Descreveu-se tambem a realizacao de procedimentos cirurgicos, a distribuicao por idades e a procedencia dos pacientes com malformacoes congenitas, sugerindo que os hospitais de Ribeirao Preto funcionem como centros de referencia para o tratamento e a correcao dessas anomalias.Sao apresentados os dados sobre internacoes por malformacoes congenitas registradas pelo Centro de Processamento de Dados Hospitalares do Departamento de Medicina Social da Faculdade de Medicina de Ribeirao Preto, USP, desde 19 de janeiro de 1970 a 30 de julho de 1974 em sete estabelecimentos hospitalares. Tais internacoes participam com 1,48% no total de internacoes, excluindo-se as causas acidentais. Encontrou-se que as distribuicoes de diagnosticos principais e secundarios classificados por tipo de malformacao sao significantemente diferentes; descreveu-se a participacao de cada estabelecimento nestas internacoes. Do mesmo modo, encontrou-se um incremento significativo na percentagem de internacoes por malformacoes congenitas com o transcurso de tempo, o que e atribuido ao Hospital das Clinicas exclusivamente. Apresentou-se a percentagem de mortalidade por diagnostico, as razoes de sexo e a duracao media das internacoes, encontrando-se nesta ultima que e maior que a media do total de internacoes. Descreveu-se tambem a realizacao de procedimentos cirurgicos, a distribuicao por idades e a procedencia dos pacientes com malformacoes congenitas, sugerindo que os hospitais de Ribeirao Preto funcionem como centros de referencia para o tratamento e a correcao dessas anomalias.