IUCD acts as contraceptive through all of the following mechanisms, except :
**Core Concept**
The Intrauterine Contraceptive Device (IUCD) is a long-acting reversible contraceptive method that primarily acts by inducing a local inflammatory response in the endometrium, leading to changes in the cervical mucus and endometrial lining, making it inhospitable for fertilization and implantation. The IUCD releases a small amount of hormones or copper ions that interact with the uterine environment to prevent pregnancy.
**Why the Correct Answer is Right**
The IUCD primarily acts by inducing a local inflammatory response, which causes:
* Thickening of the cervical mucus, making it difficult for sperm to penetrate
* Thin endometrium, which is less receptive to implantation
* Release of pro-inflammatory cytokines, which inhibit sperm motility and fertilization
* Interference with implantation by altering the endometrial receptivity
**Why Each Wrong Option is Incorrect**
* **Option A:** IUCD does not primarily act by inhibiting ovulation. While it may have some indirect effects on ovulation, its primary mechanism is through local inflammation and changes in the uterine environment.
* **Option B:** IUCD does not primarily act by increasing the basal body temperature. While some IUCDs may release hormones that can affect basal body temperature, this is not its primary mechanism of action.
* **Option C:** IUCD does not primarily act by increasing the frequency of menstrual bleeding. While some IUCDs may cause changes in menstrual bleeding patterns, this is not its primary mechanism of action.
**Clinical Pearl / High-Yield Fact**
The IUCD is an effective long-acting reversible contraceptive method that can be used by women of reproductive age, including those with a history of pelvic inflammatory disease (PID) or endometriosis.
**Correct Answer: A. IUCD does not primarily act by inhibiting ovulation.**