The double corpus luteum: A novel sonographic sign of heterotopic pregnancy.

Heterotopic pregnancy is a rare and highly morbid condition with simultaneous intrauterine and extra-uterine pregnancies. The early diagnosis of heterotopic pregnancy is difficult, owing to rarity of the condition and nonspecific clinical and laboratory findings. This case report introduces the "double corpus luteum" sign, a new sonographic and magnetic resonance imaging sign which is easily detectable and should raise the index of suspicion for heterotopic pregnancy.