Which condition describes simultaneous intrauterine and extrauterine gestations?

• A. Heterotopic pregnancy
• B. Ectopic pregnancy
• C. Blighted ovum
• D. Pseudocyesis

Answer: (A)

A heterotopic pregnancy describes simultaneous intrauterine and extrauterine gestations. In this scenario, two separate pregnancies exist at once: one implanted inside the uterus and another implanted outside the uterine cavity, most commonly in the fallopian tube. This pattern is what sets it apart from a typical ectopic pregnancy, which involves only an extrauterine gestation, and from a blighted ovum, where the intrauterine sac is present but contains no embryo, or from pseudocyesis, which is a false pregnancy with no gestation at all. On ultrasound, you may see a living intrauterine fetus alongside an additional adnexal mass or gestational sac outside the uterus, with the clinical nuance that the ectopic component can rupture and cause hemoperitoneum if not managed.