Progestogens in infertility practice

Abstract

The role of Progestogens is gaining more importance and clinical relevance in infertility practice. The use of progestogens for luteal phase support in infertility is not controversial. However there are debates and reviews on the type of progestogens to be used, the route of administration and duration of treatment once pregnancy is confirmed. Progesterone is secreted primarily from the corpus luteum of the ovary during the second half of the menstrual cycle, and from the placenta during pregnancy. Inadequate or deficient progesterone production, commonly associated with luteal phase deficiency, has been claimed to be responsible for subfertility, implantation failures and recurrent miscarriages. As more knowledge accumulates regarding immunomodulation and cytokine changes in early pregnancy, infertility specialists and research scientist are using this knowledge to improve implantation and pregnancy rates in infertility treatment particularly in IVF/ICSI cycles. The progestogens used in infertility practice have been shown to induce changes in a number of immunocompetent cells by different molecular and cellular mechanisms. Progesterone use for endometrial ripening and implantation is also discussed with reference to the window of receptivity, cytokine changes and progesterone induced changes brought about by nitric oxide synthesis causing local vasodilation and uterine muscle quiescence. This chapter attempts to connect the endocrine effects of progestogens with the immunomodulatory and cytokine changes associated with progesterone.