1. The first group (n=167) will receive weight management intervention during up to four months prior to IVF treatment.The group randomized to intervention will start an intensive weight reduction plan. The aim of the weight reduction is to reach as close to normal BMI (<25.0 kg/m2) as possible during a time of approximately 4 months. The purpose of the dietary intervention is to create a negative energy balance to induce weight loss. The intervention starts with 12 weeks of a low calorie liquid formula diet (LCD) and thereafter, diet re-introduction and weight control stabilization until IVF treatment begins. Should the patient for some reason be unable to fulfil the LCD-treatment, she will anyhow have an individualized dietary counselling to help her loose weight until the time for her IVF-treatment.