Actually, everything was so beautifully imagined: the job, the partnership, a good apartment - and finally a child. But if the desire to have children is not fulfilled after one or two years at the latest, many couples see this as a stroke of fate. Every seventh couple in Germany feels like this: Their relationship has adjusted to starting a family and now nature refuses to contribute. How reproductive medicine helps the offspring today (e.g. by fertilizing an egg in a test tube) - that is the subject of this chapter.