The method developed and adapted by the authors of this work for determining and analysing the peculiarities of mass imbalance of water, organic and inorganic components in “medium (water)-substance” systems under the influence of harmful exo- and endogenous factors is proposed. The recommended method will help to objectively determine and assess the degree of harmful influence of individual factors on mass homeostasis. In addition, it will allow to characterization of the features of the relationship between the separately taken components of the substances in amniotic and allantois fluids. The presence of long-term effects of inflammatory factors in the fetal membrane fluids of the amnion and allantois is reflected in the functional and placental barrier of the uterus in gestating cows. The direction of the displaced parts of the mass of water, organic and inorganic substances vary depending on the circumstances, either in the direction of increase or in the direction of decrease. It is quite possible that the unequal ability of organic and inorganic substances to bind water is associated with changes in the parameters of the mass of nutrients assimilated by the fetus in the amniotic fluid and accumulation of their breakdown products in the allantois fluid. It has been established that long-term inflammatory processes in the genital organs of pregnant cows alter the manner and quantity of water, organic, and inorganic substances mass parts transferred into the fluid of the fetal membranes of the amnion and allantois through the placental barrier of the uterus. This negatively affects the ability of chemical and biochemical compounds to bind water molecules and alters the intensity of nutrient assimilation processes, converting them into simpler compounds. The strength and method of harmful action determine whether components in the ‘water-substance’ system move towards an increase or decrease in their mass parameters. The consequence of this redistribution is an imbalance in mass homeostasis, negatively impacting the viability, growth, and development of the embryo and newborn fetus.