<qa>  What is a modifiable risk factor?The aim of this project is to perform a randomized controlled trial RCT in order to evaluate the effects of life-style intervention psycho-education by a midwife during 4 prenatal sessions on pregnancy and birth outcomes. Main dependent variables are gestational weight gain and anxiety and depression. Obesity is a modifiable risk factor and optimizing an adequate gestational weight gain with attention to psycho-social factors, can reduce the need for adverse perinatal outcomes. 