One of the Greatest Miracles Is When a Person Is Born Again

"Life's Greatest Miracle"

PBS Airdate: Nov xx, 2001
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NARRATOR: People do all sorts of things to go attention. And why? Information technology may be the last thing on his mind, but this man's trunk is working toward this.

Whether we're thinking nigh it or not, our bodies desire to make babies. And our bodies are very good at it. Around the world nearly 365,000 new babies get fabricated every day.

Only as ordinary as it seems, creating a new man being is no unproblematic feat. Just recall of information technology. No affair who y'all are, once upon a time yous looked similar this. From a single cell you lot built a body that has one hundred trillion cells. You made hundreds of different kinds of tissues and dozens of organs, including a encephalon that allows yous to do remarkable things.

How did you lot do it?

Today, nosotros can expect closer than e'er earlier: into the womb, into a cell, into the essence of life itself. Not only can we see what's happening, but now nosotros're first to run into how information technology happens—the forces that build the embryo, the molecules that bulldoze this remarkable change. We're uncovering the most intimate details of how life is created, the secrets behind life's greatest miracle.

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NARRATOR: You might think all the people on this beach are just working on their suntans. But beneath all that sunscreen, nether the skin, there'due south a frenzy of activity. Without even thinking nigh it, almost all the adults hither are busy trying to reproduce. They tin't aid themselves. The urge to procreate is a fundamental part of life, not but for us simply for all life.

Why is this urge so universal? At to the lowest degree some blame can probably go to this: Deoxyribonucleic acid—the molecule that carries our genes, the chemical instructions for building our bodies and keeping us alive, all wrapped upwardly in a tiny winding staircase.

DNA has run the evidence for more than than four billion years for one main reason: information technology's very expert at making copies of itself. The copies can get passed to a new generation in a couple of ways.

If you're a bacterium, you might be into cloning—making verbal replicas of yourself. All your descendents accept the same DNA and, except for an occasional mutant, are merely like you. It's elementary. It works. And genetically information technology'southward extremely boring.

It can likewise be unsafe.

If humans were all clones, everyone would have the exact same immune arrangement, and one successful parasite could wipe u.s. all out.

Fortunately, there's sex, the method of choice for 99.9 per centum of the organisms on World more complex than bacteria. With sexual reproduction, two individuals each provide some DNA. Virtually animals put it into sperm or eggs. If the two can gather, a new being will be created, one that's different from its parents and everybody else.

Where there's sexual practice, there's diversity. And when it comes to survival of the fittest, variety has a definite advantage.

All this comes at a price. Sexual reproduction may be popular, but it's also quite tricky. To get an idea of how tricky, just have a peek inside a human being's testicle.

It'southward packed with tiny tubes coiled into bundles. Stretched out they could cover half a mile. Inside all this tubing, the average human is churning out a one thousand new sperm every second. That'southward near a hundred million new sperm every day and more than two trillion over a lifetime. And here's the tricky office: each and every sperm is one of a kind, carrying a unique genetic package.

How is this possible? How can ane person produce so many dissimilar combinations of genes? The answer lies in the very special way we make sperm and eggs, a process called "meiosis."

In almost every cell of your torso yous have thirty thousand or more than different genes, spread out on very long strands of Dna called "chromosomes." Most cells take ii versions of every factor on a full of 46 chromosomes. Exactly half of those, 23, came from your mom, and 23 came from your dad. They come in pairs where the partners are very like simply not quite the aforementioned. The simply time they get together is during meiosis.

Here's how it works inside a testicle that'due south making sperm. First, each chromosome makes an exact copy of itself, keeping it attached at one bespeak. They condense, creating an X-shape. Now the chromosome partners get together and the two, or actually 4, will embrace. They cling so closely, big chunks carrying whole bunches of genes get exchanged between the partners. The cell then divides twice, each time pulling the pairs apart. The final result is a sperm or an egg cell with 23 chromosomes, one-half the normal number.

Past itself, the cell is incomplete. Only it still holds incredible hope, considering every chromosome at present carries a combination of genes that has never existed before.

All this gene shuffling means that within a unmarried species, at that place can be an enormous amount of diversity. And the more multifariousness, the meliorate the odds are that someone volition survive to create a new generation.

MELINDA TATE IRUEGAS: This is my mom and dad and your mom and dad.

SERGIO IRUEGUS: And my mom and dad on their wedding day. You definitely have your mom'due south eyes. And you can see I definitely accept my dad's eyebrows.

MELINDA TATE IRUEGAS: You do accept your dad's eyebrows.

NARRATOR: Melinda Tate Iruegas and her hubby, Sergio, are expecting their get-go baby.

SERGIO IRUEGUS: Here'southward Mom and Dad with me and my brother.

MELINDA TATE IRUEGAS: Yes.

SERGIO IRUEGUS: My sister hadn't come up along all the same. But this is what our little boy might look like. That's me.

NARRATOR: Their unborn child carries a mixture of genes not just from them, but from all their ancestors.

SERGIO IRUEGAS: That's like the spitting image. You look and then much like your mother here.

NARRATOR: Simply which genes got passed on from whom right now is everyone's judge.

SERGIO IRUEGAS: Because here yous are and this is what our little girl might wait like. I wonder if the babe will accept the feature eyebrows that come from my begetter's side of the family. Nosotros call them the Iruegas eyebrows.

MELINDA TATE IRUEGAS: Or that information technology won't accept my dad's olfactory organ.

SERGIO IRUEGAS: Your nose.

MELINDA TATE IRUEGAS: We talked about having children a lot. He would say, "5, six." I was like, "Well, let'due south kickoff with i. Two, possibly iii."

NARRATOR: In their efforts to pass on their genes, Melinda and Sergio pursued dramatically unlike strategies. Like well-nigh men, Sergio has been constantly producing sperm since puberty.

But Melinda created all her eggs when she looked like this, a fetus in her female parent'south womb. Within a couple of months, she created several one thousand thousand eggs. And so, the eggs began to die. At the age of 31, Melinda may only take a few thousand left. But that's okay, considering inside an ovary, as opposed to a testicle, it's quality, not quantity, that counts.

Every month, one of a woman'due south ii ovaries selects an immature egg cell to lavish with attention. Hundreds of support cells tend the egg, feeding information technology until information technology grows fatty. When information technology's ready, the whole entourage—the egg along with its helpers—oozes out of the ovary.

Waiting for them is the open end of the Fallopian tube, which leads to the uterus. Its tentacles capture the egg and pull it inside. The egg is swept along past muscular contractions of the tube, as well equally the constant swaying of tiny cilia. The egg has everything it needs to start a new life, except for i thing: Deoxyribonucleic acid from a sperm. And information technology has to get it fast. If the egg is not fertilized within a few hours it will die.

With sex, at that place will always be force per unit area to come across and impress a mate. When it comes to actually choosing a partner, at that place's a lot to consider. For us, it might be somewhat more complicated than picking the one that smells all-time, but in that location's no dubiousness that the process can exist heavily influenced by chemistry, natural drugs that alluvion the brain.

When love is in the air, the trunk can undergo some dramatic changes. Signals from the brain speed up the metabolism of glucose. As a result, body temperature rises, skin sweats, heartbeat and breathing get faster. In a man, hormones cue blood vessels to relax, assuasive the spongy tissue in the penis to make full with blood. At the meridian of sexual excitement, millions of sperm are squeezed out of storage and swept up past fluid gushing from several glands, including the prostate. The alluvion carries them into a 15-inch-long tube looping into the abdomen and and so out through the penis. It'southward but about a teaspoon of liquid, but it typically contains nigh three hundred 1000000 sperm.

They are immediately in peril. The vagina is acidic, and then the sperm must escape or dice. They start to swim, at to the lowest degree some of them. Fifty-fifty in a healthy man, 60 percent of the sperm can exist less than perfect. Like this one with two tails. For these guys, the journey is over.

Only what about the rest? What are the chances that i tiny sperm will attain and fertilize an egg? Sperm are frequently portrayed as brave little warriors forging their way through hostile terrain to conquer the egg. Nothing could exist farther from the truth.

For every challenge the sperm face, success is, to a great extent, controlled by the woman'south trunk and even the egg itself.

Accept the sperm's first obstruction, the neck, passageway to the uterus. Virtually of the fourth dimension, it'south locked shut, plugged with mucous that keeps bacteria and sperm out. But for only a few days a calendar month, around ovulation, the mucous becomes watery and forms tiny channels that guide the sperm through.

Arriving inside the uterus, the sperm are still virtually six inches away from their goal—at least a two-mean solar day swim.But undulations of the uterine muscles propel the sperm into the fallopian tube within 30 minutes.

Fifty-fifty a sperm that reaches the tube in record time has no guarantee of fertilizing an egg. There may exist no egg there. Ovulation could yet be days away.

It's the slowpokes, caught upwards in the cilia lining the tube, who may have a meliorate gamble. It's probably hither that chemicals in the woman's trunk alter the sperm'southward outer blanket. Only those sperm that are altered can get a date with the egg. The sperm are released gradually, over the course of a few days, and then at any given time only a couple hundred sperm will move on.

If all goes well, then farther up the tube they'll observe the egg. Just it'south heavily chaperoned past support cells. And the chaperones are picky. Only some of the sperm are allow through.

Those who brand information technology will face yet another challenge. Underneath the cloud of cells, the egg itself is encased in a thick protein shell, called the "zona." To fertilize the egg, the sperm must break through the zona. But fifty-fifty the strongest tin't exercise it by beast force lone. The egg demands a proper introduction. Proteins protruding from the sperm's cap must hook up precisely with a set of proteins on the egg's surface. If they lucifer, the sperm is held fast and undergoes a dramatic transformation. It sheds its outer coating, releasing powerful enzymes that dissolve a hole in the zona, allowing the sperm to push its way through.

The concluding hurdle passed, the sperm still does not thrust its way into the egg itself. Rather, the membranes of the ii cells fuse, and the egg draws the entire contents of the sperm inside.

MELINDA TATE IRUEGAS: I don't know. We weren't being equally careful every bit nosotros should have been. And Oct came around and I was a day late. And really I was having another problems with my wrist. And we went to the medico and the doctor had asked me...he's similar, "Well, are you pregnant?" You know, because he wanted to do an x-ray of my wrist.

SERGIO IRUEGAS: Aye.

MELINDA TATE IRUEGAS: And I said, "No." And and so I thought about it and I was similar, "Well, I don't know." I decided that I better check this out. And sure enough, it was positive. And when he came habitation, I was like...

SERGIO IRUEGAS: I could tell she had something to tell me.

MELINDA TATE IRUEGAS: And I was like, "Well you lot amend sit downwardly."

SERGIO IRUEGAS: It was something that nosotros had discussed...

MELINDA TATE IRUEGAS: Yeah.

SERGIO IRUEGAS: ...just hadn't anticipated until nigh 2 more years downwards the road. And then when she told me...yeah...I was ecstatic.

MELINDA TATE IRUEGAS: Nosotros were set. We were definitely prepare even if it was a little early.

NARRATOR: Gear up or non, in one case sperm and egg go together they have their ain agenda: to create a feasible embryo. Their chances aren't great. Information technology'southward estimated that more than 50 per centum of all fertilized eggs neglect to develop. If information technology's going to survive, the egg has a lot of work to do.

First, it orders the zona to lock out all other sperm. And so the egg must end meiosis, expelling half of its chromosomes into this tiny pouch, chosen a "polar body." With the door closed behind it, the single sperm already within releases its precious cargo.

The sperm'due south 23 chromosomes stretch out in the roomy, welcoming egg. The chromosomes of sperm and egg arroyo each other and then the jail cell divides.

Since the moment the sperm entered the egg, 24 hours have passed. All this time the fertilized egg is moving down the fallopian tube toward the uterus. Every few hours, the cells divide. Four...eight...16...gradually creating the edifice blocks needed to construct an embryo.

On rare occasions, the tiny cluster of cells splits into two groups and creates two embryos—identical twins. But about of the time the cells stick together. They must complete just the right number of cell divisions before they arrive in the uterus about five days afterward fertilization. What started as a large single cell has divided into only over a hundred much smaller cells, but they're still trapped inside the difficult beat out of the zona.

Now chosen a "blastocyst," the package of cells must do ii things to survive: break out of the zona and find a source of nourishment. At the start of the sixth 24-hour interval, it orchestrates an escape. It releases an enzyme that eats through the zona, and the ball of cells squeezes out. Costless at last, the blastocyst lands on the blood-rich lining of the mother's uterus. It has simply passed 1 hurdle, only is immediately presented with some other.

For in fact it is now in very grave danger. Stripped of its protective coating, the blastocyst could be attacked by the female parent's immune system as a foreign invader. White blood cells would swarm in to devour it. In its own self-defense, the ball of cells produces several chemicals that suppress the mother's immune system inside the uterus, in consequence, disarming the female parent to treat it like a welcome guest.

Then it is free to get to work. Searching for food and oxygen, cells from the blastocyst reach down and burrow into the surrounding tissue. Eventually, they pull the unabridged bundle down into the uterine lining. And sooner or afterwards, the mother will notice.

MELINDA TATE IRUEGAS: Even brushing my teeth would make me...the minty flavor was only, like, gross. And information technology made me experience nauseous. And I would go upward and I would try to eat something. And if it...annihilation smelled off slightly, then information technology was...it made me nauseous.

SERGIO IRUEGAS: My mother has told me stories of how my father had gone through morning sickness. And of course that never really registered until the first time information technology started happening to me.

MELINDA TATE IRUEGAS: He literally got...he would get really, really nauseous and upset, and actually get physically ill sometimes.

SERGIO IRUEGAS: There was a couple of times when that...well, more than a couple of times when that actually happened.

NARRATOR: Not everybody gets morning sickness. Sometimes months tin can become past before the female parent gets any sense of the drama unfolding within her trunk.

One milestone event takes identify but two weeks after formulation, when the blastocyst is nearly the size of a poppy seed. This is the moment when the cells start to organize themselves into an embryo. The procedure is chosen "gastrulation."

With animals like frogs, whose embryos develop inside transparent eggs, information technology's easy to see it in action. After the egg becomes a hollow ball of many cells, some cells dive into the heart, forming layers which will go on to develop into different organs.

In humans, gastrulation happens deep inside the mother'southward uterine lining, and then it can't exist photographed. Simply we call back information technology works something like this:the blastocyst creates two oblong bubbling, ane on top of the other. Sandwiched between them is a thin layer of cells. These are the cells which one day may become a babe. At the get-go of gastrulation, some cells begin moving toward the center. Then they dive downwards, creating a new, lower layer. More cells plunge through, squeezing in between, forming a third. The cells in the three layers may not look different, but for each layer, a very dissimilar future lies ahead.

The lower cells are destined to form structures like the lungs, liver, and the lining of the digestive tract. The middle layer will form the heart, muscles, bones and blood. And the top layer will create the nervous system, including the spinal cord and the brain, as well as an outer covering of skin, and eventually, hair.

This is a human embryo three weeks after fertilization. Less than a tenth of an inch long, its neural tube, the beginning of the nervous system, is already in place. A couple of days layer, the top of the tube is jutting outwards on its way to condign a encephalon. With the primitive encephalon cells exposed, we can see some are sending feelers, making connections to their neighbors.

Every bit the days pass, changes keep at a rapid-fire pace throughout the embryo. Everywhere, cells are multiplying. And they're on the move. Some accomplish out to i another, forming blood vessels. A center begins to beat out. As the embryo lengthens the precursor to the backbone forms. Groups of cells bulge out on the sides, the ancestry of arms and legs.

This is the embryo iv and a one-half weeks later fertilization. It is only about a fifth of an inch long. The primitive backbone now curls into a tail, which will disappear in a few weeks. A large brain is developing, and on the side of the head: an middle.

How does this happen? How does the embryo transform itself from a blob of cells into different tissues and organs, and finally into a fully functional infant?

The secret, of course, lies in your genes—in your DNA. Within most every cell in your torso, you have the aforementioned 46 chromosomes, conveying the same genes. Only not all the cells in your trunk are the same. Nervus cells, blood cells, cells lining your intestine, they all look different and they do different jobs.

That's because in each of these cells unlike groups of genes are turned on. And when a factor is turned on, it tells the jail cell to construct a particular protein.Proteins are the molecules that build your body—like collagen, a fiber that makes upward much of your skin, tendons, and basic, or keratin in your pilus. Crystallin is the protein that helps brand the lens of your eye clear.

Some proteins do work. Actin and myosin move muscle fibers. Hemoglobin in the claret carries oxygen from the lungs to the rest of the body.

So when the embryo is developing, how does a cell turn on the right set of genes and create the correct proteins?

Office of the answer seems to be location. In one case the basic body plan is established, with a head on one end, back and front, and left and right sides, cells seem to know exactly where they are and what they are supposed to become. This is because cells talk to each other in the form of chemical messages.

Chemicals in ane prison cell can trigger a reaction in the cell next door that can spread to the cell'south nucleus and plough genes on or off. But what's actually going on in there? How does a gene go turned on?

If all the DNA in a unmarried jail cell were stretched out, it would be about six feet long. But it'south all wound upwardly very tightly, coiled effectually balls of protein. For a cistron to exist turned on, something has to come in and loosen upward the correct section. Then the prison cell's mechanism can latch on and read the Dna, the start step on the long road to building a protein. Those molecules that can turn genes on play a primal function in every aspect of development, including the process that transforms the embryo into a boy or a girl.

SERGIO IRUEGAS: We didn't want to know. We wanted to exercise it, I approximate, the sometime fashioned mode.

MELINDA TATE IRUEGAS: Well, you lot kind of wanted to know. We did a wedding ring test, where you took a slice of your pilus and the hymeneals band and you hold it over the belly and if it moves one way in a circle, then it'due south a girl; if it moves in a straight line information technology's a male child. And that said it was a daughter.

And there was a point when we went into the ultrasound where I was waffling. It was like, "Well, we could look. At this very moment we could expect and we could find out." And I didn't say anything.

SERGIO IRUEGAS: See...but...I was trying to be strong because she was very adamant near not...

MELINDA TATE IRUEGAS: I said, "No, no, no."

NARRATOR: By the fourth dimension most ultrasounds are done, around 18 weeks or so, doctors can sometimes make out the sex. But in the early weeks information technology's impossible.

Have a look at a seven-week-quondam embryo. Endeavor to guess what sex activity it is. Think it's a boy? Believe it or not, this is not a penis, at least not yet. It might get ane, but information technology could just every bit easily turn into a clitoris, the female person sex organ. At this phase boys and girls expect exactly alike.

And not merely on the outside. Inside, there are two gonads which could go testicles or ovaries. And there are 2 sets of tubes, one in case it'southward a male child, the other for a daughter.

Of course at that place is one way to tell the deviation: look at the chromosomes in a cell from the embryo. One pair amidst the 23 determines sex. An embryo with two 10 chromosomes normally becomes a girl. If one of those Xs is a Y, it will about likely be a boy.

Recently, scientists came up with a good thought of how this works. There are only about thirty genes on the Y chromosome. One of them is called SRY. This gene seems to office just one time in a lifetime, late in the sixth week of embryonic evolution. And only in i identify, the gonad.

SRY turns on for a twenty-four hour period or two, and the cells churn out its protein. But in that short time, SRY sets off a chemic chain reaction, turning on other genes, eventually turning the gonads into testicles, which begin to make testosterone. Testosterone travels throughout the body. If it reaches the genitals and so the cells hither will build a penis.

But if there are two X chromosomes and no Y, different genes get turned on and the gonads become ovaries. The embryo becomes a infant girl.

This is the power of genes, creating cascades of chemical reactions, defining the class and role of all the cells in your body.

Sometimes genes send the message to multiply and grow, as with the arm and leg buds. Sometimes the message is to die, as it is a few days later, to the cells between the fingers. Every bit the weeks pass, the embryo's genes send billions of individual messages, constructing new kinds of cells and building organs and limbs.

Ii months afterwards fertilization, the embryo is now called a fetus. Near all its organs are in place though they're not working nonetheless. The whole fetus is just over an inch long and weighs less than a 3rd of an ounce.

Over the next six and half months, it will grow almost four hundred times larger and set up for birth. All of this demands a constant supply of nutrients.

MELINDA TATE IRUEGAS: Serge was a piddling frustrated 'cause he thought he was going to be able to get out and become me whatever I craved and whatever I wanted. And I had the problem of I didn't want anything or crave anything until I smelled it. And I had to odor my food earlier I would eat it. I could cook a whole meal, and if it didn't smell right when I was done with it, y'all know, simply considering I put the incorrect spice in there or something, then I couldn't consume information technology.

SERGIO IRUEGAS: Well, what about this identify here? Let'southward cheque out the menu.

MELINDA TATE IRUEGAS: No.

SERGIO IRUEGAS: No?

MELINDA TATE IRUEGAS: No.

SERGIO IRUEGAS: We would exit on walks sometimes, just around in the Square.

MELINDA TATE IRUEGAS: No.

SERGIO IRUEGAS: No?

MELINDA TATE IRUEGAS: That's non going to work.

SERGIO IRUEGAS: She would have to smell it starting time. But see what caught her fancy at that fourth dimension.

MELINDA TATE IRUEGAS: Yeah.

SERGIO IRUEGAS: Yeah?

MELINDA TATE IRUEGAS: Yes.

SERGIO IRUEGAS: Equally shortly as it did, then that's where we would get.

MELINDA TATE IRUEGAS: And that lasted throughout my entire pregnancy.

SERGIO IRUEGAS: How is it?

MELINDA TATE IRUEGAS: Garlicky. Yum.

SERGIO IRUEGAS: Baby likes it?

MELINDA TATE IRUEGAS: Yeah. I'yard pretty hungry. I'm still like that. I still really want to odor my food, and if I aroma something and I'1000 just similar, "Oh, I have to take that and I have to have information technology now."

NARRATOR: It's no surprise that Melinda might be peculiarly hungry. The fetus she'due south carrying has only one source for all the raw materials it needs to grow into a baby: Melinda'southward claret, which is systematically raided with the assist of the placenta.

The placenta began to form as soon equally the blastocyst burrowed into the mother's uterus, and in the early weeks information technology dwarfed the embryo. The underside of the placenta is covered with thousands of tiny projections, called "villi" which lie in pools of the mother's blood. Without ever mixing the claret of female parent and child, the villi grab oxygen and nutrients. The enriched claret flows about a foot and a one-half through the umbilical cord, back to the fetus, whose eye beats about twice as fast equally an developed's.

The heart is ane of the few organs that actually piece of work during the earliest weeks of development. But with other organs, function comes afterward. With the centre, although the retina and lens are well-formed past the 9th week, the fetus doesn't respond to light until the fifth or 6th calendar month.

And the same for the ear. The outer ear speedily takes shape, but the fetus can't hear yet. Sound conduction relies on the tiny bones of the inner ear, and most of the bones in the fetus commencement out equally cartilage. By the fourth calendar month, hard bone can be seen forming in the paw and the leg. Finally, after five months, the process is complete in the inner ear. And and then, the fetus begins to hear audio.

SERGIO IRUEGAS: I would sing songs, right on her belly, just so that it could hear my voice and get to know my vocalisation. But there was...

MELINDA TATE IRUEGAS: And what else? And brand whale noises.

SERGIO IRUEGAS: Yeah. I of the first times I did that the baby seemed to move its paw across her belly and kind of impact my lips. Or at least I like to remember it was a hand, saying hi or something.

MELINDA TATE IRUEGAS: And I even play music. You lot know, I wanted to see what would happen to what different kinds of music. And, you know, Mozart, you know...was mellow...kind of made some movements. And and then I put salsa music in and it simply started kicking, almost in rhythm. So it was dandy.

SERGIO IRUEGAS: It had a particular beat that it likes.

MELINDA TATE IRUEGAS: Yes.

NARRATOR: Within Melinda'south belly, a remarkable transformation has taken identify, starting with the moment egg and sperm met. Inside the womb, the first few weeks are the nigh dramatic. Later in pregnancy, when the mother'southward body seems to exist irresolute the most, life in the womb can appear, well, a bit uneventful.

All the organ systems are in identify, then during the final trimester the fetus's principal job is to abound. But a few crucial events are unfolding below the pare. Fat deposits are forming, edifice reserves the baby volition rely on later nativity. Simply fifty-fifty more importantly, fat is getting laid down in the encephalon.

In the sixth month, genes in the encephalon order the manufacture of a fatty substance called "myelin," which wraps around the long connections betwixt brain cells. This fatty covering allows nerve impulses to travel up to 100 times faster, profoundly enhancing brainpower. The process will continue for years later on the baby is born.

The encephalon'southward hunger for fat in the final trimester puts an enormous strain on the mother. Over the course of the pregnancy, her body has increased its own blood supply by about 50 percentage, all for the sake of the rapidly growing babe. But late in pregnancy, the baby's need for fat becomes so great the mother tin can't keep up. If it stays inside, the baby will brainstorm to starve. Somehow, information technology'southward got to get out.

MELINDA TATE IRUEGAS: I've only had, similar, one feet set on. And it was the moment I was in the bathroom and I merely had the idea of, similar, "How's this babe going to go out? I just don't remember he'south going to make information technology out." And I hadn't really thought about it upward until that very moment, where I was just like, "No."

SERGIO IRUEGAS: I dearest you.

NARRATOR: Giving nativity is ane of the near amazing experiences a woman tin can have. It can too exist one of the most painful.

SERGIO IRUEGAS: It'south starting to become down.

SHIRLEY TATE (Melinda Tate Iruegas's mother): Think? Think about being in that garden.

NARRATOR: Once again and again the uterus contracts as the cervix opens up. The tiny passageway that in one case allowed the entrance of a single file of sperm now must widen to almost four inches to accommodate a baby's head.

Human births are far more dangerous than those of other mammals or even other primates. The human brain is three to four times bigger than an ape's encephalon. And the pelvis is narrower to allow us to walk upright. A human baby has to go through considerable contortions to make it through the narrow opening. Sometimes, in that location simply is not enough room.

If that happens today, Melinda's infant can be delivered by caesarian section. But not long ago, earlier the rise of modern surgery, decease was a mutual issue for the baby and the mother.

SERGIO IRUEGAS: I can't help but experience a little guilty that I'm responsible for this, merely it'southward role of the natural cycle of life. And I only want to exist there in any fashion that I can to support her through this whole process.

NARRATOR: Because of the hurting and danger of homo labor, nosotros regularly give birth in the presence of others. Today, at 4:25 a.m., Melinda's parents, along with Sergio, will have the privilege of witnessing immediate this extraordinary outcome—life'south greatest miracle.

NURSE: Grab information technology again. All right. That'south it. 1 more time...push it correct down for more...oh good, good, good.

ED TATE (Melinda Tate Iruegas's father): A life! A new life! Look at that little babe!

SHIRLEY TATE: Oh, a little penis! It's a boy!

SERGIO IRUEGAS: Await at our little boy.

MELINDA TATE IRUEGAS: Hi. I was wondering who you were. You're and then handsome.

SERGIO IRUEGAS: Nosotros've been wondering who y'all were. Nosotros've been playing with you.

MELINDA TATE IRUEGAS: Howdy. Oh, there you lot go.

SERGIO IRUEGAS: I honey that little yawn.

MELINDA TATE IRUEGAS: Wake up.

On NOVA's Web site, follow along in real time as an expectant mother chronicles the joys and challenges of her concluding months of pregnancy and the birth of her babe, on PBS.org or America Online, Keyword PBS.

To guild Life's Greatest Miracle on video cassette for $nineteen.98 plus shipping and handling, call PBS Home Video at 1-800-PLAY-PBS.

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PRODUCTION CREDITS

Life'south Greatest Miracle

Medical Photography
Lennart Nilsson

Narrated by
John Lithgow

Written past
Julia Cort

Director of Photography
Sven Nykvist

Produced for NOVA by
Julia Cort

Edited by
Dick Bartlett

Music
Ray Loring

Animation
rhed studio

Additional Animation/Embryonic Imaging
Bradley Smith

Product Assistants
Jennifer Callahan
Christian Rodriguez

Photography
Brian Dowley
Rolf Lindström

Sound Recordists
John Cameron
Erik Reisner

Online Editor
Will Hearn

Colorist
Gary Chuntz

Sound Mix
John Jenkins

Scientific Advisors
Lars Hamberger
Johan Ericson
Kerstin Hagenfeldt
Lars Holmgren
Ulrik Kvist
Hugo Lagercrantz
Urban Lendahl
Jonas Muhr
Åke Seiger
Anita Sjögren
Johannes Wilbertz
Harvey Fineberg
Douglas Melton
Janet Michaud
David Page
Michael Pinette
Doug Powers
Elizabeth Robertson
Hazel Sive
Meredith Small

Archival Material
Cells Alive!
Clouds Hill Imaging
Getty Images/The Paradigm Bank
Alexey Khodjakov
National Geographic Film Library
Natural History New Zealand Limited
Jeremy Pickett-Heaps, Cytographics
Provision AB
Conley Rieder
Rotebro Filmservice AB
Sekani Moving Ideas
Streamline Films, Inc.
Survival Anglia Limited
Sveriges Tv AB
Visuals Unlimited, Inc.
Wild Visuals

Special Thanks
Danderyd Hospital
Göteborg University
Huddinge Academy Hospital
Karolinska Institute
Sahlgrenska University Infirmary
Sophiahemmet Hospital
University of Lund
Uppsala University Hospital
Eastman Kodak Company
Portia Brockway
Patricia Campbell
Marking Cooper
Leonard D'Amico
Harvard-Vanguard Medical Associates
Sylvia Fine
Clarissa A. Henry
Charles Lee
Cynthia Morton
Mt. Auburn Hospital
Michael O'Connell
Picante Mexican Grill
Brian Price
University Lutheran Church building

For Erikson & Nilsson Productions:

Production Supervisor
Lars Rengfelt

Drama Director
Mikael Agaton

Assistants to Lennart Nilsson
January-Åke Andersson
Klaus Biedermann
Mike Mixoff
Lars Pettersson
Malin Rohdin
Abdalla Saleh

Location Manager
Anika Beclijevski

Actors
Lea Boysen
Henrik Dahl

Special Advisor
Catharina Nilsson

Controller/Projection Director
Madeleine Von Rohr

Assistant Producer/Editor
Lars Wiberg

Executive Producer/Writer
Bo G Erikson

For NOVA:

NOVA Series Graphics
National Ministry of Design

NOVA Theme
Mason Daring
Martin Brody
Michael Whalen

Post Product Online Editor
Mark Steele

Airtight Captioning
The Caption Middle

Production Secretaries
Queene Coyne
Linda Callahan

Publicity
Jonathan Renes
Diane Buxton
Katie Kemple

Senior Researcher
Ethan Herberman

Unit Managers
Sarah Goldman
Jessica Maher
Sharon Winsett

Paralegal
Nancy Marshall

Legal Counsel
Susan Rosen Shishko

Business Director
Laurie Cahalane

Mail service Production Assistant
Patrick Carey

Associate Producer, Mail Production
Nathan Gunner

Post Production Supervisor
Regina O'Toole

Post Production Editors
David Eells
Rebecca Nieto

Supervising Producer
Lisa D'Angelo

Senior Scientific discipline Editor
Evan Hadingham

Senior Series Producer
Melanie Wallace

Managing Director
Alan Ritsko

Executive Producer
Paula South. Apsell

A NOVA Production past ERIKSON & NILSSON Production in association with WGBH/Boston and ZDF Germany, ARTE France and Germany, RAI 3 Italy, NHK Japan, BBC OPEN University England, SVT1 Sweden, NRK Kingdom of norway, DR TV Kingdom of denmark, YLE1 Finland, RUV Iceland