Multiple-dose methotrexate for pregnancy in a cesarean section scar. A case report

BACKGROUND: Pregnancy developing in a cesarean section scar is a very rare but possibly life-threatening condition because of the risk of rupture and excessive hemorrhage. CASE: A woman with previous cesarean section had transvaginal sonography performed at 7 weeks of gestation that showed a gestational sac implanted in the anterior isthmus wall of the uterus with 3 mm of myometrium between the sac and bladder wall. A diagnosis of pregnancy in the cesarean section scar was made. The patient was asymptomatic, and her hemodynamic condition was stable. Two courses of multiple-dose systemic methotrexate-folinic acid (1 mg/kg methotrexate intramuscularly on days 1, 3, 5 and 7 with 0.1 mg/kg folinic acid intramuscularly on days 2, 4, 6 and 8) were given. The patient tolerated it and remained stable during treatment. The serum hCG dropped to < 5 IU/L on day 56. CONCLUSION: Treatment with methotrexate is a non-surgical option that can improve preservation of the uterus in patients who desire fertility. A multiple-dose regimen causes rapid interruption of the pregnancy. This is very important because the risk of rupture and hemorrhage directly correlates with the duration of the pregnancy.