In recent years, intramuscular methotrexate has gained attention as an alternative to sal-pingostomy for management of ectopic pregnancy. In addition, there is also interest in using serum human chorionic gonadotropin (hCG) or progesterone levels to monitor resolution of ectopic pregnancy after intervention. Saraj and associates compared methotrexate and salpingostomy in the treatment of ectopic pregnancy and evaluated the role of serum hCG and progesterone levels as markers for resolution.

The study included 75 patients with ectopic pregnancy; 37 underwent laparoscopic salpingostomy and 38 received an intramuscular injection of methotrexate (1 mg per kg). Patients were eligible for the study if the hCG level was greater than 2,000 mIU per mL, no gestational sac was visualized on ultrasound examination and the adnexal mass was less than 3.5 cm in size. Progesterone and hCG levels were determined at baseline, on days 4 and 7 after treatment, and weekly thereafter until the hCG level fell to less than 15 mIU per mL and the progesterone level declined to less than 1.5 ng per mL (4.5 nmol per L). A second methotrexate injection was administered if the hCG level on day 7 had not decreased by 15 percent from the level on day 4. Six (16 percent) of the 38 patients required a repeat injection.

Serum hCG levels in patients receiving methotrexate decreased to less than 15 mIU per mL in 27.2 ± 2.3 days, compared with 20.2 ± 2.7 days in patients undergoing salpingostomy. Initially, hCG levels increased from 3,162 ± 772 mIU per mL at baseline to 3,547 ± 808 mIU per mL four days after methotrexate injection. In contrast, hCG levels sharply decreased in the surgical group, from 3,356 ± 776 mIU per mL at baseline to 276 ± 90 mIU per mL four days after surgery.

In both treatment groups, serum progesterone levels decreased more rapidly than the hCG levels. They returned to less than 1.5 ng per mL in 17.6 ± 2.2 days in the methotrexate group and in 7.8 ± 1.7 days in the surgery group. Unlike serum hCG levels, serum progesterone levels did not show an increase on the fourth day after treatment.

Success rates were similar in the two groups: 95 percent (36 of 38) of the patients with methotrexate and 91 percent (33 of 36) of the patients with salpingostomy. Ipsilateral tubal patency rates three months after ectopic pregnancy were similar with either treatment, as were pregnancy rates among patients who were trying to conceive. Nine months after treatment, pregnancy had occurred in five (28 percent) of 18 patients treated with methotrexate and in four (29 percent) of 14 patients who had undergone salpingostomy.

The authors conclude that a single dose of intramuscular methotrexate is comparable to laparoscopic salpingostomy for the treatment of a small, unruptured ectopic pregnancy. That serum progesterone levels resolved faster than serum hCG levels suggests that serum progesterone may be a better marker for monitoring resolution of ectopic pregnancy.