[Prenetal diagnosis: analysis of combined screening for first trimester].

Nowadays we are wittness of an outstanding increment in social demand related to prenatal diagnosis and genetic counsuelling. New life-style features have determined the sharp rise in pregnancies in women over 35 years of age. In this context, a recent interest on the risk of hereditary syndromes has developed. Only a few years ago, prenatal screening depended exclusively on epidemiologic data: age, and clinical past history. Due to a poor efficacy of these parameters, a new screening method based on sonographic and biochemical features is now considered to be mandatory. We describe our results of San Carlos Clinical Hospital including 4886 patients submitted to sonographic and biochemical screening during the first trimester of gestation, with a high sensitivity, acceptable false positive rate and a low cost/benefit rate. This information will determine an earlier decision making proccess, which will benefit both the mother and the fetus.