Fig. 4. Transvaginal ultrasonography in a pregnant woman presenting with abdominal pain and cramping.

A. Initial ultrasonography shows a gestational sac without a yolk sac or embryo. B. Follow-up ultrasonography 2 weeks later shows a gestational sac measuring greater than 25 mm in diameter without evidence of a yolk sac or embryo. These findings are diagnostic of early pregnancy loss.