Low-dose methotrexate treatment for interstitial pregnancy. A case report.
BACKGROUND
Only a small number of case reports have described medical treatment of interstitial ectopic pregnancies. Almost all of the reported patients were treated with repeated high doses (1 mg/kg) of methotrexate.


METHODS
At 6 weeks of gestation, a 31-year-old woman, gravida 5, para 4, was diagnosed with a 0.96 x 1.36-cm right cornual pregnancy. As the patient desired future fertility, she received 100 mg of intramuscular methotrexate (50 mg/m2). She was then followed on an outpatient basis, with serum human chorionic gonadotropin values appropriately declining. Serial ultrasound also showed decreasing size of the gestational sac. Twenty-one days after the methotrexate dose, the patient experienced rupture of the right posterior cornu, necessitating exploratory laparotomy.


CONCLUSIONS
Extreme caution should be used when treating interstitial gestations with single-dose methotrexate. All patients should be extensively counseled regarding the significantly increased risk of failure, possibility of rupture and need for emergency surgery.
Gherman
R B
RB
Department of Obstetrics and Gynecology, Naval Medical Center Portsmouth, Virginia, USA. ghermtoo@aol.com
Stitely
M
M
Larrimore
C
C
Nevin
K
K
Coppola
A
A
Wiese
D
D
D000020:Abortifacient Agents, Nonsteroidal / Q000008:administration & dosage* / Q000494:pharmacology / Q000627:therapeutic use; D000328:Adult; D005187:Fallopian Tubes / Q000473:pathology*; D005260:Female; D006801:Humans; D007273:Injections, Intramuscular; D008727:Methotrexate / Q000008:administration & dosage* / Q000494:pharmacology / Q000627:therapeutic use; D011247:Pregnancy; D011274:Pregnancy, Tubal / Q000188:drug therapy*; D012307:Risk Factors; D012421:Rupture
D000020:Abortifacient Agents, Nonsteroidal; D008727:Methotrexate