The Marvelous Womb

WHAT would you regard as the greatest construction job on earth? You will likely agree that, of the millions of structures built, nothing can compare with the building of a human body. And, amazingly, the major part of this work is done in the small female organ called the womb or “uterus.” In fact, we can only begin to grasp the least fraction of the operation of this marvelous “cradle” of life.

This organ, having the shape of an inverted pear, consists of two parts, the main body and the “cervix,” the “neck” of the womb. The womb of the average unmarried woman is about three inches long and is somewhat elliptical at the top or widest part, which is about two and a half inches by two inches in diameter. It is formed of a thick wall of strong muscles, so that the inside volume of the uterus is not much greater than that of a thimble. On the sides, near the top, the two Fallopian tubes branch out, about four and a half inches in length. At a slight angle, under these tubes, ligaments also branch to the two ovaries, each situated near the entrance to the Fallopian tubes. The ovaries are about the size of unshelled almonds, and the inner canal of the Fallopian tubes is about the diameter of a hair bristle.

The first stage toward the construction of a new human begins when the ovaries produce a mature egg or “ovum.” This takes place about every twenty-eight days, the ovaries normally alternating. The tiny pinpoint-size egg, barely visible, finds the trumpetlike entrance to the Fallopian tube and starts a slow journey down its canal toward the uterus. This is the time when conception can take place. At such time sexual intercourse will result in male sperm cells (in the millions) traveling through the cervix, up through the womb and the Fallopian tube, “swimming” toward the ovum. Small as the ovum is, it is 85,000 times as large as a sperm cell! One sperm finally succeeds in penetrating the ovum and reaching its nucleus; there nuclei of sperm and ovum combine to start the life of a new human. The millions of other sperm cells die. Since the life-span of sperm and ovum is only about two days, conception must occur, if at all, within this narrow period.

A New Life Begins

It is to be noted that a new life begins when the cells begin to divide to form the new individual. And the sperm and ovum unite, not in the womb, but in the Fallopian tube, or sometimes during the short journey from the ovary into the Fallopian tube. Conception takes place very rarely, if at all, in the womb. The fertilized ovum reaches the womb about the fourth to the eighth day after conception. Any act that stops the process after conception occurs, or that gets rid of the fertilized ovum, is abortion.

Meanwhile, activity goes on in the womb. A thick, soft, spongy lining, rich in blood vessels, has been made ready. This will form a “bed” for the fertilized ovum. In the case where no fertilization occurs, the blood vessels in the lining begin to be constricted. The lining eventually breaks down and is expelled through the cervix, manifesting itself in a period of bleeding, usually from four to seven days. This is called menstruation.

If conception has taken place, the fertilized ovum multiplies by cellular division, becoming a cluster of cells, but this cluster is extremely small as it travels down the tube. On reaching the womb, this cell cluster, now called a “blastocyst,” imbeds itself in the soft lining. Scar tissue from the wound thus made in the lining closes over the site, protecting the tiny object. Later the growing embryo will protrude farther into the womb cavity, on a “body stalk” that eventually becomes the “umbilical cord.” A bubblelike sac called the “amnion” forms around the embryo and the body stalk. This sac is filled with fluid, which serves as a shock absorber and also provides some nourishment for the forming baby.

The Amazing Placenta

Now marvelous things take place in the womb’s soft lining. The “placenta” begins to form. This is a round, flat organ fastened to the womb wall that, as we shall see, performs amazing functions. As the placenta is forming, blood “islands” appear in the body stalk and the soft lining. Around these islands vascular walls soon appear. The baby’s own circulatory system is formed. By the end of the first month the embryo has simple kidneys, a digestive tract, a liver, a bloodstream and a heart​—a small U-shaped tube two millimeters (about one tenth of an inch) long. Thus the circulatory systems of mother and baby are entirely separate and are never directly mixed.

In the few months that it is active the placenta does a stupendous work indeed. From its formation early in the gestation period until birth the baby is wholly dependent on the placenta for oxygen, nourishment and a host of other things. At four months the placenta is a little over three inches in diameter. By the time of birth, it has an eight-inch diameter and weighs about a pound. At birth it becomes detached from the lining of the uterus, to be discarded. For this reason it is sometimes called the “afterbirth.”

How does the placenta get its life-giving supplies to the baby? This is accomplished by the circulation of the baby’s blood through the body stalk, which develops into the umbilical cord. This cord has two arteries leading from the baby to the placenta, and a vein from the placenta to the baby. These blood vessels branch out into the placenta like a group of trees, and leaflike “fingers” made up of cells surround these branches. The mother’s blood flowing by means of other blood vessels from the womb wall into the placenta bathes these “fingers” so that they can dispose of wastes from the embryo and pick up nourishment to carry back through the umbilical cord to the baby.

The placenta serves the baby as lungs, liver, kidneys and intestines until the baby enters the world to be on its own. The placenta also performs some of the functions of a hormone gland. Additionally it produces substances that can combat infections. How does it function as all these organs for the baby’s benefit?

In doing the work of a lung the placenta exchanges carbon dioxide from the baby’s bloodstream for oxygen from the mother’s. As a “kidney” the placenta filters urea out of the baby’s blood and transfers it to the mother’s blood, where it is passed out through her kidneys. As a “liver,” the placenta processes some of the mother’s blood cells, transferring certain necessary components, such as iron, to the baby’s circulatory system. In performing the functions of intestines the placenta digests the food molecules by means of enzymes. These exchanges are made through the pores of the embryo’s branched-out blood vessels. The placenta also does a work similar to the glands by producing certain hormones, both for the baby and for the mother. It serves to protect the baby by manufacturing certain blood ingredients that prevent infection. All of this enables the baby to function fully on its own and prepares it to do all these things for itself after birth.

Since what the placenta supplies comes from the mother’s blood, what the mother takes into her system has an effect on the baby. If she smokes a cigarette, the baby’s blood gets a certain amount of nicotine. If she takes a drug, some of the drug reaches the baby. Many infections the mother develops can affect the baby. The venereal disease syphilis can result in danger to the mother and extreme damage and even death to the baby during gestation or at birth.

There is also a danger in anesthetics given to the mother in childbirth. When a baby is born it needs to be awake and lively, not anesthetized or tranquilized. This is especially so because a baby’s first breath of air requires about five times the effort of an ordinary breath.

The Amniotic Sac​—Watery Home During Gestation

During the gestation period the baby lives in the amniotic sac, which is a tough, shiny, transparent membrane. It keeps full of fluid, but this is by no means stagnant. More than a third of its volume is removed and replaced every hour. This amounts to a total daily exchange equivalent to six gallons! In about the third month the baby begins to practice inhaling and exhaling exercises. Breathing in the amniotic fluid may help in formation of its lung sacs. The baby does not drown, because its blood gets oxygen from the mother through the placenta’s action. Also, the baby swallows much of this fluid, from which it apparently gets some nourishment.

The amniotic sac renders another fine service to the baby. It provides the baby with an even temperature in its temporary “home.” Moreover, the baby is almost weightless in its liquid surroundings and is therefore free to kick, to move about and even to turn somersaults, all this strengthening its muscles for when it enters the world of atmosphere and will have to move about without the liquid support.

Marvelous Events at Time of Birth

At the end of nine months the womb has expanded to many times its normal size so that the baby of seven to ten pounds or more can be accommodated. At the time of birth it must contract so as to expel the baby. This is called “labor.” The womb is adequately equipped for this by having a complex system of muscle fibers spiraling around it in both clockwise and counterclockwise directions. Peristaltic waves, initiated in the Fallopian tubal walls, act as lateral pacemakers for uterine contractions that sweep down from the top to the cervix. An interesting fact is that this arrangement might give rise to irregular contraction patterns were it not that the uterus exhibits independently a certain measure of rhythmicity.

After the baby’s birth the umbilical cord is delivered, with the placenta attached to it. If left alone, it would dry up in about a week. But usually the attending doctor cuts the cord after tying it off. Is there danger of profuse bleeding? Not normally. This is because a jellylike substance in the umbilical cord automatically expands to close down the blood vessels like a tourniquet. Also, a valve closes inside the heart so that it can perform its new function of pumping blood to the baby’s now functioning lungs. Were it not for this provision the baby would immediately die.

The baby is usually born head first. The amniotic sac breaks but its fluid still protects the baby from localized injuries by creating a hydrostatic balance so that the pressure of the womb’s contractions are on all parts of its body equally. When the baby is born it is clean and not blood-covered. It will have some amniotic fluid on it. Also, when the placenta breaks free from the womb’s lining, the womb then rapidly contracts to its original or nearly its original size without appreciable blood loss.

Reproductive Organs Deserve Respect

It is indeed a wonder to contemplate the work accomplished in the womb. In this consideration only a mere “fringe” has been explored. Biologists and medical men can explain very little of the operations. Who does understand them fully? The One who designed the entire operation​—the Creator, Jehovah God. Note how truthfully the Bible psalmist wrote under inspiration (Psalm 139:13, 15, 16):

“You yourself produced my kidneys.”

Yes, each organ in the body was predesigned by the Creator and directly fashioned in the womb for its specific function.

“You kept me screened off in the belly of my mother.”

Even today many birth processes cannot be observed by men. God arranged matters so that the structural process, some of which is not pleasing to the human eye, would not be seen. The baby is brought forth from the womb a finished product, clean, beautiful, lovable.​—Compare 1 Corinthians 12:23, 24.

“My bones were not hidden from you When I was made in secret, When I was woven in the lowest parts of the earth.”

In the sixth week the embryo gains a complete skeleton, not yet of bone, but of flexible cartilage, which later turns to bone. The psalmist speaks of the ‘weaving’ of sinews, muscles, tissues​—the thousands of different ‘threads’ that are woven into a most intricate pattern of color, beauty and function. It is done in the complete darkness of the womb, as hidden and mysterious to men as the depths of the earth.

“Your eyes saw even the embryo of me, And in your book all its parts were down in writing, As regards the days when they were formed And there was not yet one among them.”

Scientists now know that the genetic code is primarily contained in the “genes” located in the nucleus of the fertilized ovum. God, who designed the pattern for mankind, can also know beforehand the specific physical and mental traits a child will have by inheritance.​—Compare Genesis 16:11, 12; 25:23; Romans 9:10-12.

The psalmist goes on to say:

“So, to me how precious your thoughts are! O God, how much does the grand sum of them amount to!”​—Ps. 139:17.

Knowing the wonderful complexity of our bodies and their reproductive qualities, and God’s high regard for them, men and women should indeed avoid their misuse. Deliberate, unnecessary sterilization would certainly reflect disrespect for God’s creation. (Compare Deuteronomy 23:1.) On the other hand, diseases may require operations sacrificing certain organs in order to save one’s life. This situation occurs at times with respect to the female reproductive organs. Christians leave these matters up to the consciences of those involved. The decision would be based on their own knowledge of the problem and the advice of physicians as to the need or urgency of such an operation. At all times, however, it ought to be kept in mind that this “cradle” of life is the handiwork of God, and is to be treated with great respect.

[Diagram on page 12]

(For fully formatted text, see publication)

1. Cervix

2. Uterine cavity

3. Fallopian tube

4. Fertilization

5. Ovary