**Question:** Drug used for the management of ectopic pregnancy:

A. Methotrexate
B. Saline Infusion Sonography (SIS)
C. Oral Contraceptives
D. Laparotomy

**Core Concept:** Ectopic pregnancy is a life-threatening condition that occurs when a fertilized egg implants itself outside the uterus, most commonly in the fallopian tube. Methotrexate, a folic acid antagonist, is often used as a first-line treatment due to its anti-proliferative effects on rapidly dividing cells.

**Why the Correct Answer is Right:** Methotrexate is chosen as the correct answer because it is a potent folic acid antagonist that inhibits dihydrofolic acid reductase, an enzyme necessary for DNA synthesis. By doing so, methotrexate interferes with the rapid cell division occurring in the ectopic pregnancy site, leading to its regression.

**Why Each Wrong Option is Incorrect:**

**Option A (Saline Infusion Sonography - SIS):** This is a diagnostic procedure used to locate the ectopic pregnancy site, not a therapeutic intervention. SIS involves injecting saline into the uterine cavity to create a pressure gradient that guides ultrasound imaging, aiding in identifying the site of ectopic pregnancy.

**Option B (Oral Contraceptives):** Oral contraceptives are a form of hormonal therapy used for contraception and do not directly target ectopic pregnancies. They are not suitable for treating ectopic pregnancies and should be used for prophylactic purposes only.

**Option C (Laparotomy):** Laparotomy is a surgical procedure involving an incision into the abdominal cavity to access the peritoneal organs. It is an invasive and major surgical intervention, typically reserved for cases where conservative management with medications fails or when a life-threatening condition is present.

**Clinical Pearl:** Ectopic pregnancies can be managed conservatively with methotrexate, particularly in non-ruptured, unifocal pregnancies. Methotrexate treatment involves a single intramuscular injection followed by a second injection 48 hours later. Folic acid supplementation is typically administered to counteract methotrexate's toxic effects on rapidly dividing cells, such as those in the gastrointestinal tract.

**Why Each Wrong Option is Incorrect:**

**Option A (Saline Infusion Sonography - SIS):** SIS is a diagnostic procedure for locating the site of ectopic pregnancy but is not an appropriate treatment option.

**Option B (Oral Contraceptives):** Oral contraceptives are used for contraception, not for treating ectopic pregnancies. They are not suitable for treating ectopic pregnancies and should be used for prophylactic purposes only.

**Option C (Laparotomy):** Laparotomy is a major surgical intervention, typically reserved for cases where conservative management with medications fails or when a life-threatening condition is present.

**Clinical Pearls:**

1. **Ectopic pregnancies can