Case report: Granulocytopenia induced by local injection of MTX for abdominal pregnancy

Abdominal ectopic pregnancies(APs) is a rare type of ectopic pregnancy, most commonly implanting in the rectouterine pouch. The treatment methods include surgical treatment and drug therapy. In the surgical treatment of ectopic pregnancy, local injection of methotrexate(MTX)at the site of pregnancy can reduce the occurrence of persistent ectopic pregnancy(PEP). However, there is no unified standard for the treatment dosage. We report a case of an AP patient who received local injection of MTX during surgery and developed neutropenia postoperatively.

A 29-year-old woman with a 45-day history of missed menses and rectal pressure presented with suspected ruptured ectopic pregnancy. Intraoperative exploration revealed no abnormalities in the appearance of both ovaries and fallopian tubes. Upon careful examination, the pregnancy tissue was found to be located on the inner side of the right sacral ligament and the pregnancy tissue was removed. To prevent the occurrence of PEP, MTX was locally injected at a dose of 50 mg/m² during the surgery. Postoperatively, the patient developed leukopenia, with a white blood cell (WBC) count of 3.22 × 10⁹/L on day 4, which further decreased to 2.59 × 10⁹/L with a neutrophil (NEUT)count of 1.19 × 10⁹/L by day 10. The patient was treated with Di Yu Sheng Bai tablets, 3 tablets orally three times a day. On the 17th postoperative day, the WBC count was 3.1 × 10⁹/L and the absolute neutrophil(NEUT) count was 1.21 × 10⁹/L. The patient received recombinant human granulocyte colony-stimulating factor (G-CSF) at a dose of 200 μg for three days. Granulocytes returned to normal levels.

APs is a rare form of ectopic pregnancy that can be treated with laparoscopy in the early stages of pregnancy. It is well known that local injection of MTX at the site of pregnancy during surgery can reduce the occurrence of PEP. There are documented cases of local MTX injection reducing the occurrence of PEP in special locations such as retroperitoneal pregnancy and cervical pregnancy. However, there is no unified standard for the therapeutic dosage. The minimum effective dose of locally injected MTX to prevent PEP needs further exploration. There have been no reports on the occurrence of granulocytopenia due to the local injection of MTX during surgery for ectopic pregnancy to prevent the PEP.

Ectopic pregnancy patients, such as those with abdominal pregnancy, if treated with a combination of local MTX injection during surgery, require close postoperative monitoring of blood routine. The minimum effective dose still needs further exploration.