Slide show: Fetal ultrasound
Image of a fetal ultrasound showing the chambers of baby's heart
Previous Next 3 of 13 Baby's heart

This slide offers a four-chamber view of a baby's heart as well as the heart valves. A baby's cardiovascular system begins developing five weeks into pregnancy, or three weeks after conception. The heart starts to beat shortly afterward.

See more Multimedia Oct. 10, 2015