Throughout their lives, women are confronted with tales of experiences and stories that are continually passed on from parents to children and which, except in rare cases, contribute to the formation of beliefs and myths that determine their behavior. These beliefs and myths generate fears and worries upon which women base the representation of their pregnancies. The main objective of this study conducted in the northwest region of Portugal is to ascertain whether or not pregnant women who use public health services are influenced by myths or beliefs. The study also aims to identify behaviors presented by these woman that are directly dependent on beliefs. The main conclusion that we can draw from this study is that 82 percent of the women interviewed mentioned having been influenced, to a greater or lesser extent, by myths and beliefs.