Mechanism of action of oral contraceptive pill can be all except ?
Ans. is 'd' i.e., Blockade of fimbrial ostia Mechanism of action of OCPs 1nihibition of gonadotropin release from pitutary by reinforcement of normal feedback inhibition - No prevulatory LH surge - No ovulation This is the most impoant mechanism. Thickening of cervical mucus secretion (due to progesterone) - hostile to sperm penetration. Even if ovulation and feilization occur, the blastocyte fails to implant because endometrium is either hyperproliferative or hypersecretory - not suitable for nidation - Impoant in case of postcoital pill. Uterine and tubal contractions may be modified to disour feilization. Postcoital pills may dislodge a just implated blastocyte or may interfere feilization/implantation.
Hostile to sperm penetration
Anovulatory cycle
Failure of blastocyst implantation
Blockade of fimbrial ostia