Spontaneous Heterotopic Pregnancy: A Case Report of a Potentially Life-Threatening Condition.

Heterotopic pregnancy involves the coexistence of both an intrauterine and an extrauterine pregnancy occurring simultaneously. The spontaneous incidence of heterotopic pregnancy in the general population has been estimated to be 1/30,000. This report discusses the case of a 37-year-old female who presented to the emergency department with vaginal bleeding and lower abdominal pain. Upon workup, a transabdominal and transvaginal ultrasound demonstrated a heterotopic pregnancy with an estimated gestational age of seven weeks. The ultrasounds confirmed an intrauterine pregnancy with fetal cardiac activity and a fetal pole along with a right adnexal ectopic pregnancy with fetal cardiac activity and a fetal pole. Additionally, a right paratubal cyst was incidentally found. The patient subsequently underwent exploratory laparotomy with a right salpingectomy for the removal of the right tubal pregnancy and a right paratubal cyst. This case denotes the significance of a carefully performed ultrasound examination, especially in the early weeks of pregnancy. Even when a standard pregnancy is visualized with ultrasound examination, it remains imperative for the examiner to meticulously examine the adnexa and interstitial portion of the fallopian tube. A heterotopic pregnancy has the potential to be life-threatening and can often go undetected, resulting in missed diagnoses.