**Core Concept**
The management of cervical insufficiency, also known as cervical incompetence, involves stabilizing the cervix to prevent preterm birth. This condition is characterized by the cervix opening prematurely, often without a clear cause, and is a major risk factor for preterm labor and fetal loss.

**Why the Correct Answer is Right**
Cervical cerclage, also known as a cervical stitch, is a surgical procedure where a stitch is placed in the cervix to prevent it from opening too early. This procedure is often recommended for women with a history of cervical insufficiency, especially those who have experienced two or more second-trimester miscarriages. The goal of cerclage is to maintain the integrity of the cervix until the pregnancy reaches a more advanced stage, thereby reducing the risk of preterm birth and fetal loss. This is achieved by reducing the diameter of the cervix and preventing the opening of the internal os.

**Why Each Wrong Option is Incorrect**
* **Option A:** Progesterone supplementation is a common treatment for preventing preterm labor, but it does not address the underlying issue of cervical insufficiency.
* **Option B:** Bed rest has been historically recommended for women at risk of preterm labor, but its effectiveness is limited, and cerclage is a more effective intervention for cervical insufficiency.
* **Option C:** Vaginal progesterone suppositories may be used to prevent preterm labor, but they do not provide the same level of cervical support as cerclage.

**Clinical Pearl / High-Yield Fact**
Cervical cerclage is most effective when performed between 12-24 weeks of gestation, and the type of stitch used (e.g., McDonald or Shirodkar stitch) may vary depending on the individual's anatomy and clinical situation.

**Correct Answer: C. Cervical cerclage.**