Day	Single-dose regimen	Two-dose regimen
1	Verify baseline stability of complete blood count and comprehensive metabolic panel; determine β-hCG level Administer single dose of methotrexate, 50 mg per m2	Verify baseline stability of complete blood count and comprehensive metabolic panel; determine β-hCG level Administer single dose of methotrexate, 50 mg per m2
4	Measure β-hCG level*	Measure β-hCG level Administer second dose of methotrexate, 50 mg per m2
7	Measure β-hCG level If decrease from days 4 to 7 is ≤ 15%, offer choice of readministration of single-dose methotrexate, 50 mg per m2, or refer for surgical management; if β-hCG level does not decrease after two doses of methotrexate, refer for surgical management If decrease from days 4 to 7 is > 15%, measure β-hCG levels weekly until they are undetectable	Measure β-hCG level If decrease from days 4 to 7 is ≤ 15%, offer choice of further methotrexate doses or refer for surgical management; further methotrexate doses should be 50 mg per m2 on day 7 with measurement of β-hCG level on day 11, then another dose of 50 mg per m2 on day 11 if β-hCG level does not decrease ≤ 15% from days 7 to 11; if β-hCG level does not decrease ≤ 15% from days 11 to 14, refer for surgical management If decrease from days 4 to 7 is > 15%, measure β-hCG levels weekly until they are undetectable