Introduction: Recently vitamin D showed greater importance in reproduction. Vitamin D affects cellular proliferation and differentiation, angiogenesis, fetal bone formation and immune modulation. There is increased number of pregnant women with vitamin D deficiency worldwide. Vitamin D deficiency (VDD) has been related to pregnancy complications such as preeclampsia, gestational diabetes mellitus and preterm birth.
Objectives: To evaluate histological changes in placentas of vitamin D deficient mothers.
Material and Methods: Twenty placentas of term live births were divided into two groups; normal vitamin D level (control) and VDD (n = 10 in each group). The morphology of placental villi of control group and VDD group were subjected to light microscopic (LM) examination using H&E, Masson's trichrome and PAS stains, and transmission electron microscopic (TEM) examination. Quantitative parameters of the placenta in the selected sections were estimated and statistically analyzed.
Results: LM examination of placenta of VDD group showed collagen fibers deposition in the villous core, stromal edema, increased syncytial knots, irregularities and thickening of basement membrane of fetal capillaries, and deposition of fibrin around the villi. On TEM, syncytiotrophoblast of VDD group exhibited fragmented heterochromatic nuclei, dilated profiles of rough endoplasmic reticulum, disrupted mitochondria and disorganized and separated microvilli. Cytotrophoblasts of VDD group showed irregular nuclear outline among numerous intracytoplasmic vacuoles. Concerning the histopathological grading, the VDD group showed a higher score in trophoblast degenerative knots compared to control. Edema and collagen fibers deposition were present in VDD group in 70% and 60% of the examined sections respectively.
Conclusion: Maternal VDD is likely to be responsible for placental barrier impairment that disrupts transplacental transport and exchange which could be associated with some pregnancy complications and might affect development of the fetus and even future life.