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.


METHODS
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.


CONCLUSIONS
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.
Lam
Po Mui
PM
Department of Obstetrics and Gynaecology, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, Hong Kong. lampomui@cuhk.edu.hk
Lo
Keith Wing Kit
KW
D000020:Abortifacient Agents, Nonsteroidal / Q000008:administration & dosage* / Q000627:therapeutic use*; D000328:Adult; D002585:Cesarean Section / Q000009:adverse effects*; D002921:Cicatrix / Q000000981:diagnostic imaging / Q000209:etiology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008727:Methotrexate / Q000008:administration & dosage* / Q000627:therapeutic use*; D011247:Pregnancy; D011271:Pregnancy, Ectopic / Q000000981:diagnostic imaging / Q000188:drug therapy*; D014463:Ultrasonography
D000020:Abortifacient Agents, Nonsteroidal; D008727:Methotrexate