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

RESUMO

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)