[Stress as an explanatory model for spontaneous abortions and recurrent spontaneous abortions]

Abstract

In this reviews uterine article stress shall be outlined as a possible psychobiological model for interpretation of spontaneous and recurrent spontaneous abortions by emphasis on physiological explanation theories. Results refer to the fact that stress can cause via neuro-endocrinologic processes in the uteroplacental area a rejection of the fetus. The role of neurotransmitters adrenaline, noradrenaline and acetylcholine on uterine vascularization and contractility and fetal oxygenation and the influence of progesterone, glucocorticoids and other hormones have been discussed. Stress induces in loading situations a changing action of elevated stress hormones adrenaline, noradrenalin++ and cortisol on the metabolism of other hormones, e.g. a decrease of serum progesterone and an increase of estrogen and thyroxine-level. Therefore the physiological balance of the organism is disturbed. Because informations of the nervous system are transmitted to the utero-placental unit in this way there are disturbances e.g. reduction of fetal oxygenation, advancement of uterine contractility and possible stimulation of labor. Troubles of the immunologic protection of pregnancy by stress have been considered. Nevertheless the question for the reason of elevated abortion tendency caused by stress is still open. Constitutional factors as motility and other uterine and feto-placental factors may be explanations for interindividual differences in this area. Additionally stress modulation factors like efficient stress coping and social support are able to reduce stress effects.