Gynaecology & Obstetrics Apoptosis can occur by change in hormone levels in the ovarian cycle. When there is no fertilization of the ovum, the endometrial cells die because: A The involution of corpus luteum causes estradiol and progesterone levels to fall dramatically B LH levels rise after ovulation C Estradiol levels are not involved in the LH surge phenomenon D Estradiol inhibits the induction of the progesterone receptor in the endometrium 💡 Explanation Apoptosis can occur by change in hormone levels in the ovarian cycle. When there is no fertilization of the ovum, the endometrial cells die because: ✓ Correct Answer: A. The involution of corpus luteum causes estradiol and progesterone levels to fall dramatically