The uterus, like most internal organs, is insensitive to touch, but when your baby s movements are strong enough to stretch the wall of the uterus, the feeling is picked up by the abdominal wall. By fifteen weeks, the entire repertoire of movement may be complete.
Exercise continues for minutes at a time, followed by rest periods.
A baby s activity is very individualistic and may continue whether a mother is awake or asleep. A study in Ireland, using ultrasound observation and measured pulses of sound revealed that babies with normal hearing start moving in reaction to sound around 16 weeks gestational age. This was earlier than previous estimates and occurs about two months before completion of the ear, suggesting that there is more to hearing than the ear alone. Babies show that they can be shocked by big, unexpected sounds, although they tend to adapt to constant sounds in the environment. A few indicate that babies prefer quiet, harmonious music.