21. Mifepristone and progesterone.
| a. | progesterone is mainly secreted by the corpus luteum | |
| b. | falling levels of progesterone in the last days of the cycle trigger menstruation | |
| c. | trophoblastic HCG causes the corpus luteum to persist in the early weeks of pregnancy | |
| d. | trophoblastic progesterone production takes over from the corpus luteum at about eight weeks | |
| e. | progesterone reduces uterine sensitivity to prostaglandins | |
| f. | Mifepristone is the main anti-progesterone drug | |
| g. | Mifepristone binds competitively to progesterone receptors and has greater affinity for them than has progesterone | |
| h. | Mifepristone has to be given parenterally | |
| i. | Mifepristone during the luteal phase effectively stops pregnancy occurring | |
| j. | Mifepristone given in the first 7 weeks of pregnancy effectively induces abortion | |
| k. | Mifepristone plus a prostaglandin produces abortion in >95% of pregnancies before eight weeks | |
| l. | Mifepristone plus prostaglandin is equally effective in the first and second trimesters in inducing abortion | |
| m. | medical abortion with Mifepristone carries a higher risk of infection that vacuum aspiration | |
| n. | Mifepristone has been used to shrink fibroids | |
| o. | Mifepristone has been used in some types of psychiatric illness |