The most rare type of ectopic pregnancy with an incidence of 1 out of 2500 pregnancies.
Risk factors include a prior dilatation and curettage (D & C) surgery. Painless vaginal bleeding with an enlarged cervix are the most common findings. Diagnosis can then be confirmed with transvaginal ultrasound examination. Conservative treatment using methotrexate is preferred over D & C surgery because of the risk of severe uterine bleeding.