Acute pelvic pain following miscarriage heterotopic pregnancy must be excluded: case report

Heterotopic pregnancies are increasing in prevalence and this case highlights the importance of excluding the diagnosis in patients with pelvic pain following miscarriage. A known pre-existing intrauterine pregnancy can be falsely reassuring and delay the diagnosis of a potentially life-threatening concurrent ectopic pregnancy.

In this report, we describe a case of spontaneous heterotopic pregnancy in a woman who had initially presented with pelvic pain and vaginal bleeding, and was diagnosed on pelvic ultrasound with a missed miscarriage; a non-viable intrauterine pregnancy. She re-presented 7 days later with worsening pelvic pain and bleeding, and a repeat pelvic ultrasound identified a ruptured tubal ectopic pregnancy in addition to an incomplete miscarriage of the previously identified intrauterine pregnancy. She underwent an emergency laparoscopy where a ruptured tubal ectopic pregnancy was confirmed.

Being a time critical diagnosis with the potential for an adverse outcome, it is important that the emergency physician considers heterotopic pregnancy as a differential diagnosis in patients presenting with pelvic pain following a recent miscarriage. The same principle should apply to pelvic pain in the context of a known viable intrauterine pregnancy or recent termination of pregnancy. A combination of clinical assessment, beta human chorionic gonadotropin levels, point of care ultrasound and formal transvaginal ultrasound must be utilized together in these situations to explicitly exclude heterotopic pregnancy.