Influence of hypokinesia applied during different periods of pregnancy in female rats on the dynamics of the number and survival of the progeny

The influence of chronic hypokinesia in certain periods of pregnancy of female rats on the number of progenies was studied and their survival in the early stages of individual development up to a three-month period was traced. It has been shown that hypokinesia of pregnant female rats contributes to a significant decrease in their fertility. At the same time, the most vulnerable are the embryonic and prefoetal periods of pregnancy, where the number of born rat pups is reduced by 40-50% compared with the control. It was revealed that the most stable in terms of the number of progenies born is the third decade of pregnancy in female rats. The fecundity of animals subject to hypokinesia in this period of pregnancy was close to the control and was about 70%. Hypokinesia, which affects the prefoetal period of pregnancy (E8-E15), increases the risk of death of about 30% of individuals from the total number of progenies obtained. It was found that the restriction of the motor activity of female rats during pregnancy contributes to a decrease in the number of offspring and increases the risk of their premature death. It should be borne in mind that in our experiments, hypokinesia conditions were applied after fertilization (mating) and the reason for the decrease in the fertility of female rats and the viability of their progeny is profound changes in the relationship in the “mother-foetus” system. It is more likely that the limitation of the motor performance of rats during certain periods of their pregnancy, in addition to discomfort, which contributes to various stressful conditions, directly affects the state of the blood supply of the litters and the resulting hypoxic state disrupts the dynamics of the energy supply of the developing organism, as a result of which the survival of the progeny is significantly reduced.