Abstract
Cohort studies involving more than 500,000 transfers have shown that having an endometrial lining less than 7 or 8 mm at the time of IVF trigger or cryo-defrost progesterone cycle start is associated with having a lower clinical pregnancy and live birth rate than for women with cycles having thicker endometrial linings. The use of platelet-rich plasma has been proposed as a therapy to compensate for having a thin endometrial lining. Its use is purported to increase the thickness of the endometrial linings of affected women or otherwise increase their endometrial receptivity.
Casper hypothesized that the diminished endometrial receptivity seen in women with thin endometrial linings was due to their having a higher oxygen concentration in the lumen of their uterus than they would have had with a thicker endometrial lining. This hypothesis is examined in the context of uterine anatomical arguments, accepted chemical/physiological principles, and mechanistic biochemical data.
Platelet-rich plasma (PRP) may enhance endometrial growth and receptivity through vascular endothelial growth factor (VEGF) and other platelet-derived growth factors. PRP can deliver supraphysiologic concentrations of these factors directly to the basal endometrium, augmenting angiogenesis and indirectly promoting glandular development during endometrial repair. Increased glandular development and the associated more hypoxic oxygen environment may further stimulate endogenous VEGF and other growth factors, potentially altering midcycle endometrial luminal secretions and improving the environment for implantation and early embryonic development. PRP will be most effective when the epithelial surface is disrupted, permitting greater access of platelet-derived factors to underlying tissues before degradation or clearance.
Keywords
Casper's hypothesis, Endometrial lining, Gynecology, Implantation, Infertility and medicine, Platelet Rich Plasma (PRP), Receptivity, Reproductive medicine and endocrinology, Thin endometrial lining, Vascular Endothelial Growth Factor (VEGF)