The Perception of a Fetus in the Womb

In the uterus, weight is reduced because fetuses float in the amniotic fluid. In uteri the temperature is constant. A fetus never experiences temperature changes, thus unaware of the discomfort that goes with it. In uteri, there is no vision. Researchers believe that a fetus may detect a reddish glow if the abdominal wall is thin enough and directly exposed to brilliant sunlight. Otherwise, darkness is the rule. There is no smell in uteri, and taste along with touch is monotonous. Because of almost constant food supply, hunger perception is limited.

Sounds, however, are plentiful and the audition of the fetus develops as early as the fourth  month of pregnancy. The sounds from the external world are perceived, filtered by the abdominal and the uterus wall and are transmitted muted through the amniotic fluid. How sounds are changed by transmission through fluid can be experimented by immersing your ears in a bathtub. Some sounds acquire more volume, while others are reduced. Other than sounds of the external world, a fetus also hears sounds from its immediate surrounding. The sounds from the mother, her heartbeat, her respiration and her voice; the sounds of the blood flow through the placenta and the main arteries, and above all the loud noise produced by the maternal bowel moving liquids and gasses. One may say that the uterus is a very loud place.

The fetus experiences constant motion.  He perceives the back and forth swings of his mother's respiration, the regularity of blood flow impulses, as well as the random movement of the mother. The mobility of the fetus is reduced by the proximity of the uterus wall. This restriction increases toward the term of the pregnancy. In uteri, available space is scarce.