Gynaecology & Obstetrics Mechanism of action of oral contraceptive pill can be all except ? A Hostile to sperm penetration B Anovulatory cycle C Failure of blastocyst implantation D Blockade of fimbrial ostia 💡 Explanation Mechanism of action of oral contraceptive pill can be all except ? ✓ Correct Answer: D. Blockade of fimbrial ostia