13A - Corticosteroid Therapy Is Useful in Assisting Implantation

Summary

Implantation is a complex biological process and for the maternal tolerance of an antigenically different fetus, controlled inflammation and activation of immune response in the peri-implantation period is essential. Elevated follicular cortisol:cortisone ratio is associated with good follicular development, oocyte maturation and successful implantation. However, as the follicles are unable to biosynthesise cortisol, corticosteroid therapy has been tested and shown to improve clinical pregnancy in women having stimulated IVF/ICSI cycles. Corticosteroid gradient at the feto-maternal interface is essential and is facilitated by progesterone induced 11βHSD-I activity. In women with recurrent miscarriage, expression of 11βHSD-I in decidualising endometrium is blunted by high uterine natural killer (uNK) cell density, which also has a negative impact on decidualisation marker genes and endometrial cytokines, suggesting that local steroid deficiency leads to impaired decidualisation. Prednisolone has been shown to reduce uNK cell density and although a pilot RCT suggested possible clinical benefit, validation from larger trials is awaited.