The contemporary world despite its enough developed medicine and generally highly enlightened population faces a great problem of vitamin, micro-element and nutrient deficiency turning to become the XXI century pandemic. Along with that significant growth of interest can be seen towards vitamin D importance for reproductive physiology. The fact is that vitamin D receptors (VDR) have been detected in women's ovarium tissue, fallopian tubes, decidua and placenta. Some recent years studies have proven that vitamin D may act as immune regulator during implantation. During early pregnancy the trophoblast release vitamin D, which produces anti-inflammatory reaction and also induce decidual tissue growth for successive pregnancy. It was a comparison between the expression of Vitamin D and VDR in chorionic villous in cases of normal pregnancy and missed abortion groups. 64 samples of chorionic villous were taken: 32 from missed abortion and 32 from the induced abortion group. Abortive material was taken from two groups of women residing in North-West region of Russia: missed abortion and pregnancy terminated at woman's wish (induced abortion); 6-12 weeks of gestation, singleton pregnancy. Immune histochemical examination showed homogenous distribution of vitamin D and VDR expression in syncytiotrophoblasts, cytotrophoblasts and chorion villus stroma.Vitamin D expression relative area was 10,3% which is statistically different from the induced abortion group - 15,4% (p<0,01). VDR expression analysis showed its homogenous distribution in chorionic villus structures in both groups. High VDR expression was detected in chorion villus stromal components. In missed abortion group, the morphometry results showed distinctly lower relative area of vitamin D expression against the comparison group (35,9 ± 1,8; 56,1 ± 2,4 p < 0,01). Also in missed abortion group, positively significant correlation has been determined between the level of vitamin D in blood and VDR relative area expression (r = 0,412). In missed abortion group, definite vitamin D and VDR expression decrease was detected compared to the induced abortion group. The results witness vitamin D importance for pregnancy progress.
Keywords: 1st trimester spontaneous miscarriage; Vitamin D expression; chorion villus; immunohistochemistry; induced abortion; vitamin D receptor expression.