Magnetic resonance imaging in evaluation of a second-trimester ovarian twin pregnancy.

BACKGROUND: Ovarian pregnancy presents with abdominal pain and menstrual irregularities, and usually results in hemorrhage and hemoperitoneum in the first trimester. We describe the first case of a twin ovarian pregnancy diagnosed in the second trimester. Magnetic resonance imaging (MRI) was used in the preoperative evaluation of this patient.

CASE: A woman presented at 19 weeks' gestation with abdominal pain and irregular bleeding. Her hemoglobin level was 5.9 g/dL, as compared to 10.8 g/dL in early pregnancy. Ultrasound showed a twin gestation with a mass anterior to the pregnancy, thought to be a placenta percreta or a hemorrhagic leiomyoma. An MRI was suspicious for an extrauterine pregnancy, showing the uterus displaced anteriorly by the pregnancy mass. Laparotomy revealed a hemoperitoneum and right twin ovarian pregnancy. A right salpingo-oophorectomy was performed. Pathology confirmed the diagnosis.

CONCLUSION: Although ultrasound is the primary technique of imaging the pelvis during pregnancy, MRI should be considered when the ultrasound findings are limited or confusing.