Final answer:
A missed abortion, early intrauterine pregnancy, and ectopic pregnancy can only be confirmed through ultrasound imaging, which is a safe and non-invasive method to examine pregnancy-related conditions.
Step-by-step explanation:
A missed abortion, early intrauterine pregnancy, and ectopic pregnancy can only be confirmed by ultrasound imaging. Ultrasound is the technique of choice for examining conditions related to pregnancy due to its safety profile and ability to provide real-time images. It is widely used to monitor fetal growth and development, and to diagnose ectopic pregnancies and other complications. Ultrasound utilizes high-frequency sound waves that generate echoes when they bounce off tissues in the body; these echoes are then converted into visual images. This non-invasive technology is particularly favorable because it does not involve ionizing radiation, which could be harmful to the developing fetus.