Rectal Ectopic Pregnancy Managed Successfully by Minimally Invasive Treatment Using Local Methotrexate Injection and Systemic Methotrexate Administration: An Extremely Rare Case at Tu Du Hospital in Vietnam and Literature Review

Rectal ectopic pregnancy (REP) is one of the most extremely rare forms of ectopic pregnancy that strongly leads to maternal mortality higher than common types. An early diagnosis of unruptured REP remains a challenge and its management ought to be individualized depending on the clinical scenario. Currently, owing to the paucity of data, there are no practical guidelines for an appropriate treatment until today. We hereby present a very unusual case at our maternity care center. A 30-year-old pregnant woman (gravidity: 2, parity: 2) complained with abdominal pain and retard menstrual cycle. After serum beta-human chorionic gonadotropin (β-hCG) levels and ultrasonic examinations, a diagnosis of ovarian ectopic pregnancy was established. Thus, the patient underwent explanatory laparoscopy for confirming the diagnosis and for the treatment. However, on the 5th day postoperative course, her β-hCG level continued to increase every 48 hours. By magnetic resonance imaging and pelvic ultrasonography, a gestational sac adherent to the rectal wall was clearly detected. After counseling with multidisciplinary team, a minimally invasive laparoscopy followed by a local injection of methotrexate under ultrasound guidance for gestational sac access and a systemic multidose methotrexate regimen were indicated. In result, her serum β-hCG declined substantially. Although it is very rare, extrauterine pregnancy involving the rectum may be presented. Early diagnosis helps in avoiding the fatal complications and a proper management should be counseled carefully. Conservative treatment with minimally surgical intervention could be an alternative option in appropriate condition. Further data are required to summarize this occult entity.