The fetus is 14.5 cm long from crown to rump. It is now possible to distinguish between female and male genitalia. The heartbeat is now audible through a wooden stethoscope or a fetal doppler (a prenatal heart monitor which uses ultrasound to enable you to listen to your baby’s heartbeat through a loudspeaker). The heart beats at a rate of 120 to 140 beats per minute. The skin is thin, but continues to thicken.