Medicine and psychology are just distinguished from many other scientific disciplines by the same object and subject, but only in medicine exists obligatory active care of another man. However physics is a basic natural discipline going about characteristics and motions of the matter, therefore these days perinatology can not be reduced to calendar periods, because today we can documate fetal maturity progress in real time by enzymatic and ultrasound methods, and see in third trimester how fetuses in multifetal pregnancies compete with each other for existence. In spite of that recently fetuses in such pregnancies were supposed to grow identically in the same conditions. Their competition has not been taken into consideration. Each fetus has its own thermodynamic system, and another twin belongs to surroundings not to his/her system. Therefore fundamental question is not: what to do in case of death one of them, but how to diagnose this danger competition between themselves. Thanks to physics and uniform rights of the nature we can assess this competition in real time by estimation speed of changes in fetal spatial parameters. The aim of our study was pay attention to fact, that fight for existence between people, who have own feelings, experiences and memory, may start intrauterine. The 20th century medicine categories, has been absolutely predominated by wrongly programmed technology expense of man and the advertising of apparent successes but negligence of self-education.