Medical methods

Medical treatments enforce less rest upon the patient and may be cheaper. They may be used when diagnosis can be made without laparoscopy (since combination of transvaginal ultrasound and serum beta hCG can diagnose ectopic pregnancies with confidence) (1), the mother is haemodynamically stable, and the mass is less than 4 cm diameter.

They include:

• systemic methotrexate - inhibits DNA synthesis and cell multiplication in the trophoblast.
  • usually associated with transient pelvic pain three to seven days after the commencement of therapy and may be difficult to distinguish from that of a rupturing ectopic pregnancy (2)
  • a single dose of intramuscular methotrexate is used according to the patients body surface area - 50 mg/m2 (usually between 75-90mg)
  • further doses may be necessary if the hCG levels fail to fall by more than 15% between day four and day seven (1)
  • side effects are less now that lower doses are used but may include bone marrow suppression, hepatotoxicity, stomatitis, gastritis, enteritis, pulmonary fibrosis, photosensitivity and alopecia
  • large uncontrolled studies have reported that
    • 14% of the women needed more than one dose
    • tubal rupture was seen in 7% during follow up
    • less than 10% will require surgical intervention
    • 75% will have abdominal pain after commencement of therapy
• prostaglandin F2 alpha - originally thought to be effective as causes tubular contractions and local vasoconstriction but claims not substantiated by other studies

Women should be adviced about

• refraining from sexual intercourse during therapy
• adequate fluid intake
• using a reliable contraceptive method for three months after methotrexate therapy (due to the teratogenic risk)

Reference:

• (1) Royal College of Obstetricians and Gynaecologists (2004). The management of tubal pregnancy
• (2) Sau A, Hamilton-Fairley D. Nonsurgical diagnosis and management of ectopic pregnancy. The obstetrician & gynaecologist 2003;5:29-3