Mechanisms of action of depot MPA include all except?

Ans is 'c' i.e., Immobilization of spermsoHigh-dose progestogen-only contraceptives, such as DMPA, inhibit follicular development and prevent ovulation as their primary mechanism of actionoA secondary mechanism of action of all progestogen-containing contraceptives is inhibition of sperm penetration by changes in the cervical mucus. The cervical mucus remains thick and viscid.oInhibition of ovarian function during DMPA use causes the endometrium to become thin and atrophic.Note- There is no medicinal contraceptive available which acts by immobilization of sperms. Various options are still being researched on.Depot medroxyprogesterone acetate (DMPA) (Depo-Provera/ Depo-SubQ Provera 104)oDepot medroxyprogesterone acetate (DMPA) is an injectable progestin-only contraceptive that provides highly effective, private, three-month-long reversible contraception. Use of DMPA eliminates the need for daily user action, action near the time of sexual intercourse, and need for partner cooperation.oIt is given by intramuscular or subcutaneous injection and forms a long-lasting depot from which it is slowly released over a period of several months. It takes one week to take effect if given after the first five days of the period cycle, and is effective immediately if given during the first five days of the period cycle. Estimates of first-year failure rates are about 0.3%. MPA is effective in preventing pregnancy, but offers no protection against sexually transmitted infections (STIs).oDMPA is a very effective form of contraception because of its multiple mechanisms of action and slow release into the circulation.Mechanism of actionoHigh-dose progestogen-only contraceptives, such as DMPA, inhibit follicular development and prevent ovulation as their primary mechanism of action by decreasing the pulse frequency of gonadotropin-releasing hormone (GnRH) release by the hypothalamus, which decreases the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) by the anterior pituitary.oA secondary mechanism of action of all progestogen-containing contraceptives is inhibition of sperm penetration by changes in the cervical mucus. The cervical mucus remains thick and viscid.oInhibition of ovarian function during DMPA use causes the endometrium to become thin and atrophic. These changes in the endometrium could, theoretically, prevent implantation.