Spontaneous angular dichorionic diamniotic twin pregnancy: a case report

Objective: To report a peculiar case of ultrasound diagnosis of spontaneous angular twin pregnancy. In literature, the terms "angular," "interstitial," and "cornual" pregnancies are often used inappropriately. Confusion in terminology may have contributed to difficulties in developing diagnostic ultrasound criteria to differentiate these ectopic pregnancies.

Design: Case report.

Setting: Obstetrics and Gynecology, Community Hospital "S. Maria delle Croci."

Patient: A 28-year-old patient with a previous cesarean delivery was admitted to our hospital for management of a presumed angular ectopic pregnancy. Transvaginal ultrasound confirmed an ectopic dichorionic diamniotic twin pregnancy eccentrically located in the right superior angle of the uterine cavity: the first gestational sac appeared to have right angular implantation, whereas the second gestational sac seemed to deepen inside the myometrium, with a thin myometrial margin of only 3 mm.

Interventions: After discussing the risks, the patient requested to proceed with termination. A single intramuscular injection of 75 mg of methotrexate was administered, followed by ultrasound-guided hysterosuction after 19 days due to severe vaginal bleeding.

Main outcome measures: An early and accurate ultrasound diagnosis of a high-risk condition allowed for conservative medical treatment.

Results: The serum beta-human chorionic gonadotropin levels progressively decreased. After 1 month, a clinical and ultrasound examination showed a regular endometrial line with a regular reappearance of menstrual bleeding.

Conclusions: Although there are remarkable advances in ultrasound techniques, angular pregnancy remains a condition of difficult diagnosis and management; it is potentially dangerous and may lead to severe complications. An early and accurate diagnosis of this condition is necessary to avoid complications and individualize the subsequent management.