During the 5th week of interuterine life a ~blood~ vessel will form in the center of the |embryo| which will soon become the primitive |heart|. In the 6th week the primitive |heart| starts to beat, although it does not yet look like the |heart| of a baby. During the 7th week ~blood~ vessels extend throughout the body and the |heart| now has a more complex shape. An ultrasound scan done at the end of the 7th week shows the |heart| of the |embryo| beating at about 160 beats per minute. The |heart| is completely formed by the end of the 12th week and is pumping ~blood~ around the fetal body and down the two arteries in the |umbilical cord| to the |placenta|. By 18 weeks the fetal |heart| can be heard with a special stethoscope. As of the 24th week every examination of the mother will include checking the fetal |heart|.
