The fascinating world of the unborn
Major advances in ultrasound scanning began opening a window to the womb; doctors could view every movement of the baby on a screen. The pictures show unborn babies yawning, sucking, grasping, stretching, blinking and making faces – in short, all the things they will do after birth. Foetal surgery has unveiled the amazing fact that the unborn baby is completely interactive and responsive to stimuli.
Baby Samuel about 5 months' gestation undergoing surgery in the womb
reaches out and holds the surgeon's finger
The unborn baby trains for life after birth like an athlete preparing for a race. He doesn’t need to breathe, yet his diaphragm practises breathing motions. He doesn’t need to eat or drink, yet he drinks his amniotic fluid.
The amniotic sac, the fluid-filled bubble that encloses him, cushions him from shock and temperature changes. Its lubrication allows him free movement, essential for bone and muscle development.
The placenta, long believed to be a protective barrier between baby and mother, is nothing of the kind. The poisons in cigarette smoke, alcohol and drugs, as well as stress-related hormones, all pass from the mother’s bloodstream through the placenta and umbilical cord to the baby. Diseases relatively harmless to the mother, such as rubella or toxoplasmosis can threaten a baby’s health or development – and so can many chemicals in the home or workplace.
Normally an unborn baby never experiences hunger or thirst. But if a mother does not consume sufficient nutrients, the baby’s diet will not be adequate either. When a foetus is severely malnourished – for instance, because his mother’s heavy smoking restricts blood flow to the placenta, on the ultrasound screen can be seen the baby’s chest and throat making crying motions.
By the last few weeks of pregnancy the baby can use all of his senses. Vision is perhaps the least important one within the womb. Nonetheless, when a bright light is shined on the mother’s bare belly, a foetus with his eyes open will turn his face towards the light. He sees a faint glow, like shining a torch through your hand.
Taste buds are well-developed by the end of pregnancy, and the baby prefers a sweet taste. A doctor injected saccharin and a dye into the wombs of women with excessive amounts of amniotic fluid. He hoped the foetus would drink more, passing the excess liquid into the mother’s circulation system. It worked – more dye appeared in the mother’s urine when the amniotic fluid was sweet – but only until the baby became sated with the sweet taste and stopped drinking.
In the womb.
A baby lives in a sea of sound. Researchers have eavesdropped on him by inserting a tiny microphone into the uterus. Daphne and Charles Maurer, authors of The World of the Newborn, describe the racket the baby hears from his mother’s heart, lungs and digestive system. “In engineering terms, these are a pulsating water pump with flap valves, a seven and a half metre long sludge pump and a double bellows.”
Dr Jeffrey Phelan, a specialist in maternal-foetal medicine, played tapes to a pregnant woman of everything from bird songs to a passing train. A microphone in her uterus picked up almost every sound. When he played back a tape of how an argument sounded in the womb, Phelan found it uncomfortably loud. He wonders about the possible injurious effects of mothers working amid excessive noise.
Does an unborn baby know his mother’s voice? Psychology professor Anthony DeCasper devised an ingenious experiment to find out. He placed padded earphones over a newborn’s ears and gave him a bottle nipple attached to a closed rubber tube. Pressure changes in the tube switched channels on a tape recorder. If the baby paused for a time between bursts of sucking he heard one channel, if he paused shorter than average, he heard the other. The baby now had the ability, in effect, to change channels.
DeCasper found that newborns choose the recording of their mother’s voice over that of another woman’s. The baby, however, has no innate interest in his father’s voice, which is heard in the womb only now and again, while the mother’s voice is ever-present. Within two weeks after birth, however, the baby can recognise Dad’s voice too.
A newborn is even attuned to the cadence and rhythm of his native language. In a French study using a setup similar to DeCasper’s, French babies given the choice between French or Russian words responded more to the sound of French.
Brian Satt, a research specialist in clinical psychology, has parents sing a lullaby-like “womb song” to their baby. The unborn baby often develops a specific, consistent movement pattern when its song is sung. According to Satt, most parents can calm a fussy newborn with the song most of the time, which is a prize worth more than rubies to a new parent.
Can a mother’s stress, anger, shock or grief harm her baby? The normal stresses and strains of life won’t hurt him. As the Maurers put it, such periods are the womb equivalent of a spell of ‘bad weather’. Ups and downs may even be beneficial because change stimulates the unborn. Foetuses are startled when exposed to a series of loud buzzes, but some then turn an ear to listen.
Severe, unremitting stress may be another story. It remains unclear whether problems arise from the stress itself or from the poor nutrition, smoking, drinking or drug-taking that likely accompany it. In any case the baby is affected.
The timing of labour is not something forced on an unwilling baby by the mother, nor is it an arbitrary event. It is a culmination of a dance in which, for the most part, the baby leads. Changes in his body contribute to readying her uterus and cervix for labour, while changes in hers help him prepare for life outside the womb.
Embedded in Western psychology is the belief that birth is traumatic for the baby, but it is unlikely that babies find labour painful. Sensors taped to the foetus during labour show that ‘massage’ is an accurate description of the experience.
Stress during labour comes from the periodic reduction in the oxygen supply when the pressure of the contraction stops blood flow through the placenta. But for a healthy, full-term baby this is not a problem. In fact, the stress of labour prepares the unborn for life in the outside world. Adrenaline in the foetus shunts blood towards vital internal organs that may be damaged by a reduction in oxygen supply. Adrenaline also causes absorption of liquid in the lungs and a surge in the production of surfactants, chemicals that make the lungs easy to inflate.
This adrenaline rush helps produce the quiet-alert, wide-eyed state of a baby after birth. As Dr Marshall Klaus, co-author of The Amazing Newborn, says “It is as though newborns had rehearsed the perfect approach to the first meeting with their parents.”
Countdown to birth – moving day!
His umbilical cord drifts by his questing fingers. He plays with it briefly, brings his hands up to his mouth and sucks his thumb. Over his mother’s heartbeat and the gurgles of her digestive tract, he can hear her talking. Interested, he stops sucking to listen. She begins to walk, and the motion rocks him gently back to sleep.
He rests against the texture of the silken pillow of his placenta, to which he is moored by his umbilical cord like a boat to a jetty. He drinks some of his amniotic fluid, which resembles seawater. The swallowing triggers a bout of hiccups, which his mother feels as a series of small rhythmic jumping motions. The hiccups stop and he settles himself into his favourite position – bottom tucked under his mother’s ribs, back along her left side – for another nap.
A radio startles him awake. He blinks and grimaces at the new sensation, but then becomes interested in the music. He turns his head to bring his ear closer to the outside world. He notices the pressure of the book his mother is resting on her belly. He kicks at it. Her laugh comes to him as a dull, echoing rumble. She pats the spot he kicked, and entering into the spirit of the game, he kicks back. They play several rounds before he loses interest and falls asleep.
He is roused by a heavy jolt. His mother has tripped and fallen heavily on one hip. He is much too well cushioned to experience any injury, but her pain and the fear that she may have hurt him floods both their bodies with adrenaline and other stress-related hormones. He cries and kicks vigorously, a cry never heard because there is no air to make sound. As she recovers, the stress hormones ebb away, and he calms down too.
For the past few months, he has been feeling his little home tighten round him, as if his mother were hugging him. Today hugs are coming more frequently and growing stronger. The rhythmic massage continues and there is growing pressure round his head.
Suddenly that pressure is released as his head is born. The rest of his body emerges. Assaulted by the light, cold and lack of constriction, he lets out a wail, arms and legs flailing, eyes tightly shut.
His distress is short-lived. He finds himself lying on a warm, soft surface gently rising and falling beneath him. Hands are stroking and cradling him. Eyes still shut, he can hear his mother’s soothing familiar heartbeat, as well as her familiar voice, much closer and clearer than it ever was. His body relaxes.
After a while he begins to blink, and finally opens his eyes, looking about him with a wide, shiny-eyed gaze. Above him, just within his limited ability to focus, is a human face. Fascinated, he struggles to keep his wandering eyes on it, frowning from his efforts. Then he realises that the voice he knows so well is coming from that face, and his own face flowers into an expression of wonder.
His mother smiles down at him. “Welcome to the world, little man” she says softly.