The goals are to help overweight and obese women (BMI ≥ 27) who are considering pregnancy to adopt improved dietary and physical activity habits and lose weight prior to becoming pregnant, and then help them maintain those habits and prevent excessive weight gain during their pregnancy. We model this intervention after successful, frequent-contact interventions designed by ourselves and other investigators. We start with face-to-face counseling followed by frequent telephone counseling contacts. The expected outcomes for mothers include reduced pregnancy-related weight gain (primary) and lower weight at the start of pregnancy (secondary) and for babies, decreased risk of exceeding national norms for weight at birth (secondary).