title: [Low birth weight as an additional indication for chromosomal analysis].
abstract: BACKGROUND
  Even though there are few epidemiological studies evaluating the birth weights of different groups of malformed babies with chromosomal abnormalities, it is widely known that infants with trisomy 18, and to a lesser degree those with trisomy 13 and other chromosomal alterations, have low birth weights.
  
  
  METHODS
  In this study we present the analysis of the birth weights and gestational ages of a large sample of babies (23,155 malformed and a similar number of nonmalformed babies), separating the different groups of chromosomal anomalies and comparing the weight in the clinical groups of malformed infants.
  
  
  RESULTS
  Most of the groups with chromosomal abnormalities present lower birth weights in comparison to the other groups.
  
  
  CONCLUSIONS
  The results of our study support the conclusion that the relationship between chromosomal alterations and low birth weight is sufficiently important that such a low birth weight in children with minor or major anomalies should be considered as one more indication to perform chromosomal analysis.
authors.affiliation: ECEMC, Facultad de Medicina, Universidad Complutense de Madrid.
authors.forename: M L
authors.initials: ML
authors.lastname: Martínez-Frías
authors.forename: E
authors.initials: E
authors.lastname: Bermejo Sánchez
authors.forename: E
authors.initials: E
authors.lastname: Rodríguez Pinilla
authors.forename: A
authors.initials: A
authors.lastname: Villa
mesh_terms: D002869:Chromosome Aberrations / Q000235:genetics*; D025063:Chromosome Disorders; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007621:Karyotyping