Which statements correctly explain how the hormone-based contraceptives affect female reproductive cycle?

Correct statements about how hormone-based contraceptives affect the female reproductive cycle:

1. Inhibition of Ovulation:

- Combined oral contraceptives (COCs) and progestin-only pills (POPs) prevent ovulation by suppressing the luteinizing hormone (LH) surge, which is necessary for ovulation to occur.

- COCs achieve this by providing synthetic forms of estrogen and progestin, which mimic the natural hormonal feedback mechanisms and suppress LH release from the pituitary gland.

- POPs primarily work by inhibiting LH surges through the action of progestin, but some may also have a slight impact on follicular development.

2. Thickening of Cervical Mucus:

- COCs and POPs can alter the composition of cervical mucus, making it thicker and less receptive to sperm penetration.

- The progestin component in these contraceptives is responsible for this effect. Thickened cervical mucus acts as a physical barrier that makes it harder for sperm to reach and fertilize an egg.

3. Alteration of Endometrial Lining:

- COCs and POPs affect the endometrium (lining of the uterus) by suppressing its development and receptivity to a fertilized egg.

- Progestin in contraceptives thins the endometrium and alters its structure, making it less favorable for implantation of a fertilized egg.

4. Suppression of Follicle Development:

- COCs, in particular, can suppress the development and maturation of ovarian follicles, which contain the eggs.

- The combined effect of estrogen and progestin in COCs influences the hormonal feedback mechanisms and prevents follicle growth and ovulation.

Incorrect statement about hormone-based contraceptives affecting the female reproductive cycle:

- Prolongation of Menstrual Cycle:

- Hormone-based contraceptives typically shorten menstrual cycle lengths rather than prolonging them. The average menstrual cycle is 28 days, but some contraceptives can shorten it to as little as 21 or 24 days.