[The association between maternal age and congenital malformations]. / Edad materna y malformaciones congénitas: un registro de 35 años. 1970-2005.

ABSTRACT

BACKGROUND: There is an association between extreme maternal ages and the risk of congenital malformations. This is specially true for chromosomal abnormalities among women of advanced ages and disruptive malformation among teenage mothers. AIM: To determine the association between maternal ages and incidence of congenital malformations at the obstetric ward of a clinical hospital. To compare these figures with those of Chile. MATERIAL AND METHODS: The hospital registries of the Latin American Collaborative Study of Congenital Malformations (ECLAMC) between 1996 and 2005, were consulted. This is a database of all malformations detected in newborns at the hospital. RESULTS: An overall prevalence of malformations of 8,4% was detected at the hospital. There is a significantly lower frequency of mothers aged less than 20 years than in the rest of Chile. Mothers aged between 20 and 29 years have the lower frequency of malformed children. Women aged less than 20 years and over 39 years of age account for 56% of malformed children. Maternal ages and the rates of malformations, increased in a parallel fashion at a rate of 0.2 years and 2.2 malformed children per 1,000 born alive, per calendar year, respectively. CONCLUSIONS: The association between prevalence rates of congenital malformations and maternal age is U shaped with a higher proportion of malformed children among women aged less than 20 years or more than 39 years.