Q.100 The birth control pills contain hormonal formulations that may either arrest the ovulation or prevent
the fertilization of egg. Some of the formulations do both. Which one of the following combinations represents a formulation
that is likely to affect the process of ovulation and fertilization?
(A) Progesterone and estrogen
(B) Prostaglandin and estrogen
(C) Gonadotrophin and estradiol
(D) Prolactin and estradiol
Birth control pills hormonal formulations primarily use synthetic hormones to arrest ovulation and prevent fertilization, with progesterone and estrogen being the standard combination pill that achieves both effects effectively.
Correct Answer
(A) Progesterone and estrogen
Option Analysis
(A) Progesterone and Estrogen
Correct. Combined oral contraceptives contain synthetic progestin (mimicking progesterone) and estrogen. Progestin suppresses FSH/LH to inhibit follicular development and ovulation; both thicken cervical mucus to block sperm and thin endometrium to prevent implantation—dual action on ovulation and fertilization.
(B) Prostaglandin and Estrogen
Incorrect. Prostaglandins induce labor/uterine contractions or cause diarrhea/vomiting as side effects, not contraception. They don’t suppress ovulation or reliably prevent fertilization; no standard birth control uses this combo.
(C) Gonadotrophin and Estradiol
Incorrect. Gonadotrophins (FSH/LH) stimulate ovulation (used in fertility treatments like IVF), directly opposing birth control. Estradiol (estrogen form) alone doesn’t inhibit; this combo would promote, not arrest, ovulation.
(D) Prolactin and Estradiol
Incorrect. Prolactin supports lactation and provides natural postpartum contraception via anovulation, but synthetic prolactin isn’t used in pills due to side effects (e.g., galactorrhea). No dual ovulation/fertilization mechanism; estradiol doesn’t compensate.
| Formulation | Affects Ovulation? | Affects Fertilization? | Used in Birth Control? |
|---|---|---|---|
| Progesterone + Estrogen | Yes (FSH/LH suppression) | Yes (mucus thickening) | Yes |
| Prostaglandin + Estrogen | No | No | No |
| Gonadotrophin + Estradiol | Promotes | No | No (fertility drug) |
| Prolactin + Estradiol | Indirectly (lactation) | Minimal | No |
Mechanism Details
Combination pills mimic post-ovulation hormone levels: constant progestin/estrogen feedback inhibits hypothalamic GnRH pulses, preventing LH surge needed for ovulation. Fertilization blockade occurs via hostile cervical mucus and reduced sperm motility. Progestin-only “mini-pills” focus more on mucus/fertilization with less reliable ovulation inhibition.
