Steroid metabolome and multiple pregnancy.

Steroid biosynthesis occurs in adrenal, gonadal, brain, liver, and placental tissues. Depending on the location of their activity, steroids can be divided into two groups - intracellular and extracellular. Intracellular ones act as transcription factors, suppressing or activating gene expression - they have a so-called genomic effect and therefore their onset of action is slow. Steroids acting extracellularly (non-genome effect) bind to neurotransmitter receptors located on the cytoplasmic cell membrane and thus affect the permeability of the ion channels, the effect of which is much faster, and we refer to them as neuroactive steroids or neurosteroids. While neuroactive steroids can be produced in different tissues of the body, or can be administered externally, neurosteroids are synthetized in cells of the nervous system. Some neuroactive steroids whose levels are extremely elevated in pregnancy (progesterone and its metabolites) are crucial in stabilizing pregnancy and changes in their concentration may influence the onset of parturition. Steroidogenic disorders may be involved in a number of pregnancy pathologies such as premature birth, pre-eclampsia, intrahepatic cholestasis in pregnancy, etc. Our research in collaboration with the Department of Steroids and Proteofactors of the Institute of Endocrinology in Prague also focuses on the investigation of multiple pregnancies in terms of biosynthesis, transport, and the effects of steroids. Studies available in the literature so far have not provided a comprehensive analysis of the steroidome in children and mothers in multiple pregnancies. The aim of our research is therefore to clarify the relationships between fetuses and mothers and between fetuses from the point of view of steroid synthesis and transport as well as the physiology and pathophysiology of human pregnancy and childbirth.