To identify dietary patterns in women who are planning immediate pregnancy in preconception, weeks 6, 10, 26 and 38 of pregnancy, and 6 months postpartum, and to describe how particular lifestyles, the body mass index (BMI) and sociodemographic factors are associated to these patterns.Longitudinal study throughout the reproductive cycle of food consumption carried out in a Spanish Mediterranean city.Faculty of Medicine and Health Sciences, Rovira i Virgili University.In total, 80 healthy female volunteers who were planning immediate pregnancy.A seven-consecutive-day dietary record was used to evaluate the dietary intake. Exploratory factor analysis was used to identify the main dietary patterns in each of the periods. Fitted multiple linear regression models were used to study the associations between the lifestyle and sociodemographic variables, and each dietary pattern.The 'sweetened beverages and sugars' pattern was identified from preconception to 6 months postpartum and the 'vegetables and meat' pattern to the end of pregnancy. The 'sweetened beverages and sugars' pattern is positively associated with smoking and negatively associated with physical activity before conception and in the first trimester of pregnancy. The 'vegetables and meat' pattern is negatively associated with the BMI during the preconception period and positively associated with age in weeks 10 and 38 of pregnancy. It is shown that the patterns do not change significantly throughout the period studied.We have identified two stable dietary patterns from preconception to postpartum. The 'sweetened beverages and sugars' pattern is associated with habits of risk for the health of the pregnant woman and her offspring.'Comisión Interministerial de Ciencia y Tecnología' (CICYT: ALI89-0388) and 'Instituto de Salud Carlos III', RCMN (C03/08), Madrid, Spain'.