Prevalencia al nacimiento de aberraciones cromosómicas en el Hospital Clínico de la Universidad de Chile. Período 1990-2001 / Prevalence of chromosomal aberrations at birth in the Clinical Hospital of Universidad de Chile, 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 per cent). 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 per cent 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.

Test de Apgar. Después de medio siglo. Sigue vigente? / The Apgar Score. Is it still valid after a half century?

In 1952, Virginia Apgar MD, proposed to assess the clinical condition of newborns, during the first minutes of life and to evaluate anesthetic and obstetrical practices. She proposed five objectives and easily measured clinical signs: cardiac frequency, respiratory effort, muscle tone, irritability and color. The test was later named Apgar Score Test. Since then, all newborns are evaluated using Apgar score. This article reviews the uses and abuses of Apgar test. It has been used to assess asphyxia, predict neurological damage, to identify newborns that require reanimation and as a survival predictor. It is concluded that Apgar score is useful to know the vitality of a newborn during his first minutes of life. It is a background, that along with acid base state and evolution, allows the diagnosis of asphyxia and predicts survival. Therefore, after half a century of use, it still remains useful.