Drug used for midtrimester abortion is –
## **Core Concept**
The question pertains to the pharmacological management of midtrimester abortion, focusing on the drugs used for inducing abortion during the second trimester of pregnancy. Midtrimester abortion typically refers to termination of pregnancy between 13 and 26 weeks of gestation.
## **Why the Correct Answer is Right**
Mifepristone (**Option C**) is a **prostaglandin receptor antagonist** and a **progesterone receptor antagonist**. It works by blocking the action of progesterone, which is essential for maintaining pregnancy. By inhibiting progesterone receptors in the uterus, mifepristone prepares the uterus for the action of prostaglandins, which then induce uterine contractions and lead to the expulsion of the pregnancy. Mifepristone is often used in combination with prostaglandin analogues like misoprostol for medical abortion, including during the midtrimester.
## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is not specified, but generally, other prostaglandin analogues like **dinoprostone (PGE2)** and **misoprostol (PGE1 analogue)** are used for inducing labor or abortion. However, they are usually not the primary choice when considering a drug specifically for midtrimester abortion without mentioning a combination.
- **Option B:** This option is not specified, but drugs like **methotrexate** are used for ectopic pregnancy and sometimes for early medical abortion, not typically for midtrimester abortion.
- **Option D:** This option is not specified, but drugs like **laminaria** (a type of seaweed) are used for cervical dilation but are not pharmacological agents for inducing abortion.
## **Clinical Pearl / High-Yield Fact**
A key point to remember is that for midtrimester abortion, **mifepristone** combined with **misoprostol** is a highly effective regimen. This combination is critical for preparing and inducing uterine evacuation. Mifepristone's role in blocking progesterone receptors facilitates the effectiveness of misoprostol in inducing contractions.
## **Correct Answer:** C. Mifepristone.