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Abstract
Infertility is defined as inability to conceive after 1.5 years of unprotected intercourse. Infertility is classified into primary infertility without any previous pregnancy and secondary infertility with at least one previous pregnancy. The prevalence of infertility does not differ among racial or cthnic groups. The incidence of infertility is about 7 -15% of all married couples at the reproductive age group. The female factor of infertility is responsible for 40-60% of causes of infertility. Uterine
causes of infertility are uncommon.
Progesterone, a steroid hormone secreted from the corpus luteum during the luteal phase of the menstrual cycle, acting as a central coordinator of all female reproductive functions. It is synthesized from circulating cholesterol, metabolized in the liver, having a plasma half- life of about 5 minutes, carried in the blood with plasma proteins, excreted in urine.
The physiological effects of progesterone are mediated through interactions ’between the two intracellular nuclear progesterone receptors (PRA., PRS). They arise from a single gene and acting asa ligandactivating transcription factors for expression ofprogesterone functions at
target tissues. Estrogen is a very important stimulating factor for their synthesis.
Luteal phase defect ansing either from defect in progesterone secretion or defect in progesterone receptors. Defects in the progesterone secretion occur in the form of delay in secretion, gradual rather than rapid increase ill secret inn, secret ion is not reaching high levels, prcmuturc decline in progesterone levels towards the end of the cycle (short luteal phase), abnormal persistence of an active corpus lutcum or relative decrease in progesterone secretion associated with hyperestrogenism.