What do you see at four weeks in an ultrasound?

At four weeks of pregnancy, an ultrasound can show:

- The gestational sac, which is a fluid-filled sac surrounding the developing embryo.

- The fetal pole, which is a small, bean-shaped structure that will develop into the fetus.

- The yolk sac, which provides nourishment for the developing embryo.

- The amniotic sac, which is a fluid-filled sac surrounding the fetus.

Other important things that may be visible at four weeks:

- Cardiac activity, or a heartbeat, may be visible in the fetal pole.

- The embryo may be starting to develop rudimentary structures, such as the head and tail.

- The placenta may be starting to form.

The appearance and visibility of these structures may vary depending on the quality of the ultrasound equipment and the skill of the technician performing the scan.