[Maternal age as a risk factor for congenital malformations].

We studied 131,899 consecutive births at the Maternity of the University of Chile Clinical Hospital, finding 4887 newborns with congenital malformations (representing a rate of 37.05 per 1000 alive newborns). Between January 1982 and December 1992 there were 41,344 births and 295 stillbirths (0.7%). Among the latter, 41 were malformed (13.9%). A graphic comparing the mean annual rates of malformations and maternal ages, shows a sustained increase in malformations form 1972 to 1988, that decreases thereafter and stabilizes since 1982. There is a marked parallelism between the curves of malformation rates and maternal age (t21 = 1.057, p < 0.1). It is concluded that the risk of congenital malformations increases along with maternal ages.