[Evolution of the frequency of congenital defects in newborn infants and fetuses from terminations of pregnancy after prenatal diagnosis in the period 1982-2009]. / Defectos congénitos en recién nacidos y fetos procedentes de interrupción del embarazo tras diagnóstico prenatal en el período 1982-2009.

BACKGROUND AND OBJECTIVE: The study of congenital defects (CD) must include termination of pregnancy (TOP) for CD and evaluate risk factors that modify their frequency. PATIENTS AND METHODS: Consecutive series of 517 newborn and 202 TOP with CD among 38,191 childbirths, between 1982-2009 years. RESULTS: The mean frequency for newborns with CD is 13.54‰ and for newborn and TOP with CD is 18.73‰. Single CD are 61.12% in newborns and 52.17% in TOP. The 18.37% of CD in newborn and 40.58% of TOP are syndromic. Mean gestational age for TOP is 17.92 weeks. Overall frequency of anencephaly is 2.62‰ for newborns and 6.77 for 10,000 for newborns and TOP. Spina bifida is 3.14 for 10,000 newborns and 5.99 for 10,000 newborns and TOP. Overall frequency of Down syndrome (DS) is 10.74 for 10,000 newborns and 22.14 for 10,000 newborns and TOP. The percentage of foreign mothers was 35.9% in 2009 and the mean maternal age significantly increased in this period. CONCLUSION: We observe a significant decrease of CD in newborns but not in their conception. We have not detected primary prevention for neural tube defects. The decrease in DS in newborns is not statistically relevant but ethnic diversity and maternal aging may be modifying the frequency. The 53% of CD were TOP in the period 2007-2009. It is mandatory a complete study for CD in TOP in order to offer serious reproductive counselling.