Methotrexate treatment helps resolve ectopic pregnancies after a median of 22 days, a recent study has found. Baseline levels of human chorionic gonadotrophin (hCG) may help predict the timing of resolution.
Researchers conducted a 14-year retrospective cohort analysis of 216 women (mean age 32.1 years) who had received a single intramuscular dose of methotrexate for tubal ectopic pregnancy. Serum hCG levels were measured at days 1, 4, and 7 of treatment and then weekly thereafter until resolution (defined as hCG <IU/L). The primary study outcome was the time to resolution.
At baseline, women had an average body mass index of 25.4 kg/m2 and median pretreatment hCG concentration was 758.8 IU/L. Between days 4 and 7, 20.4 percent women did not see a ≥15-percent decline in hCG and thus required a second methotrexate dose. Nearly a quarter (24.5 percent) needed rescue surgery.
The median time to resolution was 22 days in the remaining women who did not undergo surgery. Those who had hCG <1,000 IU/L at baseline had the shortest resolution time at 20.0 days. This jumped to 31.5 days in women with hCG levels 1,000–1,999 IU/L, and to 34.5 days in those with hCG 2,000–2,999 IU/L.
Of note, when looking at women who only needed a single dose of methotrexate, the median time to resolution was 17 days when baseline hCG was <1,000 IU/L.
The likelihood of rescue surgery was also associated with hCG, with such risk increasing by nearly fourfold (odds ratio [OR], 3.66, 95 percent confidence interval [CI], 1.47–9.07) and over eightfold (OR, 8.53, 95 percent CI, 2.86–25.42) in women with hCG 2,000–2,999 and ≥3,000 IU/L, respectively.