Myth: The Fetus Has Little Sensory Perception
Fact: Perception and consciousness emerge long before the moment of birth. Sensation is present within the first weeks as the emerging neural network forms the organs of sensation and the brain.
While most believe that the human fetus is a blank slate, lacking true sensation, emotional affect, or the ability to feel pain, pregnant women through the ages have known what scientists today have proven to be true: a mother's unborn child hears her voice and senses her love. The unborn can see, hear, and feel.
Note: Below are many references to gestational age in weeks. For reference, the first trimester ends at 14 weeks, the second at 28 week, and birth is usually week.
Scientists have understood some things about fetal sensation for a long time. At 28 days, when the embryo measures a quarter inch and the tiny blood vessel that is the precursor of the heart begins to beat, the three primary parts of the brain have already formed. At 6 weeks, and approximately a half-inch in length, eyes, nose, and ears have started to form, and the unborn child can respond to touch. At 19 to 20 weeks, she has primitive brainwave patterns, and by 22 weeks, has patterns similar to those of adults. By the fourth month she plays with her umbilical cord and sucks her thumb. If foul tasting iodinated poppy seed oil is introduced into the womb, she will grimace and cry; a sweet substance will cause her to swallow amniotic fluid at twice the normal rate--she likes it! At 22 weeks she will react to a loud sound by raising her hands and covering her ears. The brain structures necessary for learning form sometime between the fifth and sixth month. During the final trimester the prenate experiences periods of wakefulness and sleep, even exhibiting brainwaves associated with dream sleep.
Experiences, both positive and negative, enter through the unborn child's rapidly developing senses--hearing, taste, smell, touch, motion, and sight. At 8 weeks, he begins to make movements in response to being touched. At 20 weeks gestation he can respond to sound, and at 28 weeks discriminate between different tones.
Vision also develops in the womb. Although fetal eyelids remain fused from week 10 to 26, the unborn, aware of light and dark, responds to a flashlight shined on mother's abdomen. The human auditory system is as advanced at 20 weeks as it is in the adult. At 27 weeks the unborn is especially sensitive to mother's voice. The mother's language is intimately bound to her experiences, and the fetus experiences that binding and builds it into the brain's neural makeup.
A growing body of evidence indicates that the unborn child feels pain. From the eighth week of gestation, the nervous system begins to develop pain pathways. By week 16, connections for pain are in place, and by week 28 that wiring is more or less complete. In fact, anatomical evidence suggests that the unborn is more sensitive to pain that those outside the womb; the inhibitory pathways that block incoming pain do not develop until after birth--a disturbing finding in view of fact that the fetus is often treated as though it feels no pain, and given no analgesia or anesthesia for potentially painful interventions.
It appears that some form of consciousness--a rudimentary awareness of the world beyond--exists from the earliest days in womb; even that the emotional circumstances of the child's conception matter. It makes a difference whether a child is conceived in love or in fear, or whether the mother wants to be pregnant.
Although the experience of the embryo remains shrouded in mystery, she nonetheless begins to record and react to events on a cellular level from conception on. Between the third and sixth months of gestation, the unborn child begins responding to variety of stimuli and seems capable of volitional acts, such as moving away from a source of light or even attempting to push aside an amniocentesis needle. Somewhere between the fifth and sixth months of gestation, the unborn child changes from a largely sensate being--one who receives, processes, and reacts to sensations--to a sensible being, one who is mentally alert, conscious, and capable of primitive recognition.
There is not doubt in my mind that at six months after conception the unborn child is a sensing, feeling, aware, and remembering human being.
--Thomas R. Verny, MD
Thomas R. Verny, Preparenting: Nurturing Your Baby from Conception
Thomas R. Verny, The Secret Life of the Unborn Child*