From the XVII century on, new anatomically knowledge will create conditions to medical doctors to understand human conception that lead to the self-confidence that is held today in the field of medicine. Portugal is integrating that new medical knowledge and, during the XVIII century, sees more and more generalizing the idea that men participated in the conception through the semen that fecundated the women's egg, creating a rupture with prior knowledge, coming from Antiquity. Despite some novelty in the anatomically knowledge and a medical reasoning more based on systematically observation, the idea that arises is the impotency to respond to the normal expectations from the general public, and the poor capacity to undo myths that have been long created, like the possibility of the influence of imagination on conception. One of the most important contributions of this rationality seems to be the rising of a developmental consciousness that stressed the necessity to act preventively in the promotion of health. Than, the importance of looking at children health care from the very beginning, that is, from conception.
child; history; conception