What's an Ultrasound?
Ultrasounds are sound-wave pictures that help doctors see internal fetal and maternal structures. The ultrasound probe scans across the mother's abdomen or inside her vagina. The transducer transmits high-frequency sound waves that echo back and are transformed into a picture on a video screen. This picture shows the fetus inside the womb. Often, parents will be given a printout of the ultrasound to keep.
At six weeks' gestation, it's possible to see the baby's heartbeat. For many expectant parents, it's an added bonus that an ultrasound given after 20 weeks can sometimes identify the sex of the baby. However, in some cases it's not possible to see the baby's genitalia and parents are kept guessing.