Obesity and overweight are becoming a major problem in medicine. Obesity impairs the prognosis of many conditions, including pregnancy. Adipose tissue is not only a passive reservoir of energy but also produces hormones and cytokines, which interfere with the regulation of the whole organism. Obesity adversely affects not only the mother and her reproductive health but also the health and the development of the child. In addition to well-known complication issues such as neuropsychological development of the child or a higher risk of astma are now discussed. Many of these negative effects are attributed to inflammation associated with obesity.