Gynaecology & Obstetrics Which of the following mechanisms best explains the contraceptive effect of birth control pills that contain both synthetic estrogen and progestin? A Direct inhibition of oocyte maturation B Inhibition of ovulation C Production of uterine secretions that are toxic to developing embryos D Impairment of implantation hyperplastic changes of the endometrium 💡 Explanation Which of the following mechanisms best explains the contraceptive effect of birth control pills that contain both synthetic estrogen and progestin? ✓ Correct Answer: B. Inhibition of ovulation