Pregnancy is aspecial state for the expectant mother. Not only is ahuman being growing, but the pregnant woman's body is also constantly changing during the 40-week pregnancy. One organ that is frequently affected by these changes is the skin. As diagnosis and treatment during pregnancy can present treating physicians with particular challenges, it is important to know the relevant pregnancy dermatoses, to recognize and diagnose them reliably, and to observe red flags in order to protect the pregnant women and the unborn child. In this article, the most important changes in the skin of pregnant patients are explained and potential warning signs are presented. In addition to aspects of altered pigmentation, the influence of pregnancy on pre-existing inflammatory dermatoses and their improvement or worsening is also described. The occurrence of so-called specific pregnancy dermatoses over the course of pregnancy is also explained. Finally, the extent to which autoimmune diseases of the mother can also affect the unborn child and to what extent skin changes in the newborn can indicate adisease of the mother are described. The respective "red flags" are presented as leading symptoms and their relevance is discussed.