October 9, 2020

Amniotic Fluid, the Water of Life in Mother’s Body


In an advertisement of a milk powder company, a swimming infant has once appeared. Seeing a newborn baby swimming, who cannot even hold its head up yet, most people thought that the scene must have been created.

Surprisingly, however, the scene was real. Under the water, babies are comfortable rather than afraid. Newborn babies are more like that. They can swim very peacefully and open their eyes underwater. If they sink, they even paddle. How can this be possible? It’s because they remember their living in the water called amniotic fluid in their mothers’ wombs for nine months though they forget it three months after birth.

Amniotic fluid that surrounds the fetus for nine months is not simple water. It’s just like a cradle that plays the role of mother’s arms. First of all, the amniotic fluid cushions the fetus from external shocks. For example, if the mother’s abdomen is suddenly pushed or hit by any force, the fluid absorbs the shock and the fetus is not directly affected by the force. Moreover, the amniotic fluid keeps the umbilical cord away from the fetal body; if the umbilical cord is wrapped around the baby’s body, it can hinder the baby’s blood flow and physical development, and at worst it can be even deadly if the coil gets wrapped around the baby’s neck. Furthermore, the fluid protects the fetus from germs. As the amnion that covers amniotic fluid protects the fetus from the invasion of germs, it is just like the fetus is in a bioclean room.

The amniotic fluid fills the space between the mother and the fetus that is connected to the mother by umbilical cord; so it becomes a link between the two. Amniotic fluid, which is heated by the mother’s temperature, surrounds the baby, keeping consistent temperature. It delivers the warmth of the mother to the fetus that is immature in controlling its temperature. Since water rarely changes in temperature because of its high specific heat, the fluid maintains the heat as warm as the mother’s.

There is one more thing that the amniotic fluid delivers to the fetus. It is the sound. As for the way to soothe a crying baby, there is no better one than white noise (a sound frequency or a signal that one hears as a gentle hiss), or vacuum cleaner sound. You may wonder why, but it really is. The reason is simple. It’s because the sounds are similar to what the fetus heard in the womb. Babies feel relaxed at familiar sounds. The sound that is heard through amniotic fluid is usually irregular. Among the sounds heard from outside the womb, the fetus mostly hear the sound of the mother’s rubbing her stomach or the sound of low-pitched tone like the father’s voice. In water, a low voice is transmitted better than a high voice. If the sound is only delivered to the womb from the outside, father’s low voice is transmitted much better than mother’s high voice. However, mother’s voice is directly transmitted by vibration which is carried through bones, passing through her spine and pelvis. The sounds transmitted in this way help the fetus develop hearing, and form strong bonds with its parents.

What makes the fetus grow is also the amniotic fluid. Thanks to buoyancy, water helps people move more freely than they do in the air, and it is resistive enough to increase muscular strength. For this reason, water is used for patients’ rehabilitation. Likewise, the watery environment allows the fetus to practice moving around to strengthen its bones and muscles. Fetal muscles develop and bones grow hard to make the baby ready to come out to the world.

Amniotic fluid also helps the baby’s lungs develop. The fetus fills its lungs with the fluid and then empties them just like breathing; by repeating this, the fetus develops the muscle of its lungs. When the baby is born, it spits out the fluid that has filled the lungs because of the pressure it receives at birth, and breathes in air fully as it practiced in the fluid. In this process, the baby bursts out crying for the first time.

Amniotic fluid that surrounds the fetus is first made up of water that is provided by the mother in early pregnancy. It is a clear colorless liquid just like normal saline solution. As the fetus grows, amniotic fluid becomes cloudy because of fetal hair, vernix caseosa that covers the skin of the fetus, the materials released from fetal lungs, etc. Around week 12, the fetus begins to swallow the amniotic fluid, which then passes through its digestive system, into its kidneys, and backs out again to the amniotic sac as urine, leaving impurities in the large intestine. In this process, the fetus absorbs nutrition melted in the amniotic fluid such as albumin and lecithin. Surprisingly, the amniotic fluid that circulates between the baby and the mother remains incorruptible for nine months.

As the fetus keeps swallowing the amniotic fluid, the fluid’s quantity is adjusted. Around week 23–36, the fluid is at its fullest—about 700–1000ml, and as the mother is near her time, it decreases a little. As the amniotic fluid allows the baby to move around, too little fluid can cause the baby to grow slowly and hinder delivery. On the contrary, too much fluid can also be a problem of premature labor. Even the fluid amount should be in the optimum condition for the fetus.

In fact, amniotic fluid has much information about the fetus. By analyzing fetal cells contained in the fluid, doctors can tell whether or not the baby has a problem such as chromosomal anomaly and malformation, and can assess the level of maturity. This checkup is often carried out when the mother is aged or has family history.

Amniotic fluid protects the baby even to the last point of birth. At the time of delivery, the water breaks and opens the uterus. Then, the fluid washes obstetric canal where the baby passes through and keeps it moist to the end.

In an experiment, when newborn babies smelled the amniotic fluid, all stopped crying, turned toward the smell, and smacked their lips. It turned out they remembered the smell of amniotic fluid.

The amniotic fluid is the water that links the mother and the baby mentally and physiologically. The fetus interacts with its mother through amniotic fluid; the mother feels the fetal movement through amniotic fluid, and the baby grows in amniotic fluid and remembers the sounds, smells, and tastes it had in the fluid. The baby grows safely in the amniotic fluid of the mother for 280 days. What is the reason that life begins through the water coming from the mother?

On that day living water will flow out from Jerusalem, half to the eastern sea and half to the western sea, in summer and in winter. Zec 14:8

Then the angel showed me the river of the water of life, as clear as crystal, flowing from the throne of God and of the Lamb down the middle of the great street of the city. On each side of the river stood the tree of life, bearing twelve crops of fruit, yielding its fruit every month. And the leaves of the tree are for the healing of the nations. Rev 22:1–2

But the Jerusalem that is above is free, and she is our mother. Gal 4:26