What is the first-line treatment for a hemodynamically stable ectopic pregnancy?

Methotrexate is the first-line treatment for a hemodynamically stable ectopic pregnancy due to its effectiveness in managing early, unruptured ectopic pregnancies without the need for surgical intervention. This medication, which is a cytotoxic agent, works by inhibiting the growth of rapidly dividing cells, including the trophoblastic tissue associated with the ectopic pregnancy. When administered appropriately, methotrexate can successfully cause the ectopic tissue to resorb, thereby allowing for preservation of the fallopian tube and reducing the risks associated with surgery.

In cases where the patient is hemodynamically stable and without indications for immediate intervention, such as significant pain or probable rupture, methotrexate is preferred as it is less invasive and associated with a quicker recovery.

Other management strategies like laparoscopic salpingotomy and immediate surgery are typically reserved for hemodynamically unstable patients or those with severe symptoms. Expectant management may be considered under very specific circumstances, usually when the ectopic pregnancy is tiny and the patient is closely monitored, but it is not the first approach for a stable patient. Thus, methotrexate remains the established first-line therapy in managing stable ectopic pregnancies.