The Body, page 33
Even with the best care, the long process of creating life and giving birth was agonizing and dangerous. Pain was considered a more or less necessary correlate of the process because of the biblical injunction “in sorrow thou shalt bring forth children.” Death for mother or baby or both was not uncommon. “Maternity is another word for eternity” was a common saying.
For 250 years, the great fear was puerperal fever, or childbed fever as it was more commonly known. Like so many other diseases, it seemed to leap into ugly existence from out of nowhere. It was first recorded in Leipzig, Germany, in 1652 and then swept through Europe. It came on suddenly, often after a successful delivery when the new mother was feeling quite well, and left the victims fevered and delirious, and all too often dead. In some outbreaks, 90 percent of those infected died. Women often begged not to be taken to the hospital to give birth.
In 1847, a medical instructor in Vienna named Ignaz Semmelweis realized that if doctors washed their hands before conducting intimate examinations, the disease all but vanished. “God knows the number of women whom I have consigned prematurely to the grave,” he wrote despairingly when he realized it was all a matter of hygiene. Unfortunately, no one at all listened to him. Semmelweis, who was not the most stable of persons at the best of times, lost his job and then his mind and ended up stalking through the streets of Vienna, ranting at thin air. Eventually, he was confined to an asylum where he was beaten to death by his guards. Streets and hospitals should be named for him, poor man.
A commitment to hygiene did gradually catch on, though it was an uphill battle. In Britain, the surgeon Joseph Lister (1827–1912) famously introduced the use of carbolic acid, an extract of coal tar, into operating theaters. He also believed that it was necessary to sterilize the air around patients, so he built a device that put out a mist of carbolic acid all around the operating table, which must have been pretty awful, particularly for anyone wearing spectacles. Carbolic acid was actually a terrible antiseptic. It could be absorbed through the skin of patients and medical practitioners alike and could cause kidney damage. In any case, Lister’s practices didn’t spread much beyond operating theaters.
In consequence, puerperal fever went on for far longer than it need have. Into the 1930s, it was responsible for four out of every ten maternal hospital deaths in Europe and America. As late as 1932, one mother in every 238 died in (or from) childbirth. (For purposes of comparison, today in Britain it is one in every 12,200; in the United States, it is one in every 6,000.)
Partly for these reasons, women continued to shun hospitals well into the modern era. Into the 1930s, fewer than half of American women gave birth in hospitals. In Britain, it was closer to one in five. Today the proportion in both countries is 99 percent. It was the rise of penicillin, not improved hygiene, that finally conquered puerperal fever.
Even now, however, there is huge variability in maternal mortality rates among countries of the developed world. In Italy, the number of women who die in childbirth is 3.9 per 100,000. Sweden is 4.6, Australia 5.1, Ireland 5.7, Canada 6.6. Britain comes only twenty-third on the list with 8.2 deaths per 100,000 live births, putting it below Hungary, Poland, and Albania. But also doing surprisingly poorly are Denmark (9.4 per 100,000) and France (10.0). Among developed nations, the United States is in a league of its own, with a maternal death rate of 16.7 per 100,000, putting it thirty-ninth among nations.
The good news is that for most women in the world childbirth has become vastly safer. In the first decade of the twenty-first century, only eight countries in the world saw their rates of childbirth deaths increase. The bad news is that the United States was one of those eight.
“Despite its lavish spending, the United States has one of the highest rates of both infant and maternal death among industrialized nations,” according to The New York Times. The average cost of childbirth in the United States is about $30,000 for a conventional birth and $50,000 for a Cesarean, about three times the cost for either in the Netherlands. Yet American women are 70 percent more likely to die in childbirth than women in Europe and about three times more likely to suffer a pregnancy-related fatality than women in Britain, Germany, Japan, or the Czech Republic. Their infants are no less at risk. One of every 233 newborn babies dies in the United States, compared with just one in 450 in France and one in 909 in Japan. Even countries like Cuba (one in 345) and Lithuania (one in 385) do much better.
The causes in America include higher rates of maternal obesity, greater use of fertility treatments (which produce more failed outcomes), and increased incidence of the rather mysterious disease known as preeclampsia. Formerly known as toxemia, preeclampsia is a condition in pregnancy that leads to high blood pressure in the mother, which can be a danger to both her and her baby. About 3.4 percent of pregnant women get it, so it is not uncommon. It is thought to result from structural deformities in the placenta, but the cause is still largely a mystery. If not headed off, preeclampsia can advance to the more serious condition of eclampsia, when a woman may experience seizures, coma, or death.
If we don’t know as much as we would like to about preeclampsia and eclampsia, it is in large part because we don’t know as much as we ought to about the placenta. The placenta has been called “the least understood organ in the human body.” For years the focus of medical research on childbirth was almost exclusively on the developing baby. The placenta was just a kind of adjunct to the process, useful and necessary but not very interesting. Only belatedly have researchers come to realize that the placenta does much more than just filter wastes and pass on oxygen. It takes an active role in the development of the child: stops toxins from passing from the mother to the fetus, kills parasites and pathogens, distributes hormones, and does everything it can to compensate for maternal deficiencies—if, say, the mother smokes or drinks or stays up too late. It is in a sense a kind of proto-mother for the developing baby. It can’t work miracles if the mother is truly deprived or neglectful, but it can make a difference.
At all events, we now know, most miscarriages and other setbacks in pregnancy are because of problems with the placenta, not the fetus. Much of this is not well understood. The placenta acts as a barrier to pathogens, but only to some. The notorious Zika virus, for instance, can cross the placental barrier and cause terrible birth defects, but the very similar dengue virus cannot cross the barrier. No one knows why the placenta stops one but not the other.
The good news is that with intelligent, targeted prenatal care, outcomes for all kinds of conditions can be greatly improved. California addressed preeclampsia and the other leading causes of maternal death in childbirth through a program called the Maternal Quality Care Collaborative, and in just six years reduced the rate of childbirth deaths from 17 per 100,000 to just 7.3 between 2006 and 2013. During the same period, alas, the national rate rose from 13.3 deaths to 22 deaths per 100,000.
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The moment of birth, the starting of a new life, really is quite a miracle. In the womb, a fetus’s lungs are filled with amniotic fluid, but with exquisite timing at the moment of birth the fluid drains away, the lungs inflate, and blood from the tiny, freshly beating heart is sent on its first circuit around the body. What had until a moment before effectively been a parasite is now on its way to becoming a fully independent, self-maintaining entity.
We don’t know what triggers birth. Something must count down the 280 days of human gestation, but no one has worked out where and what that mechanism is or what makes its alarm go off. All that is known is that the body begins to produce hormones called prostaglandins, which normally are involved in dealing with injuries to tissue but now activate the uterus, which begins a series of increasingly painful contractions to move the baby into position for birth. This first stage will go on for about twelve hours on average during a woman’s first birth but often becomes faster for subsequent births.
The problem with human childbirth is cephalopelvic disproportion. In simple terms, a baby’s head is too big for smooth passage through the birth canal, as any mother will freely attest. The average woman’s birth canal is about an inch narrower than the width of the average newborn’s head, making it the most painful inch in nature. To squeeze through this constricted space, the baby must execute an almost absurdly challenging ninety-degree turn as it proceeds through the pelvis. If ever there was an event that challenges the concept of intelligent design, it is the act of childbirth. No woman, however devout, has ever in childbirth said, “Thank you, Lord, for thinking this through for me.”
The one piece of assistance that nature gives is that the baby’s head is a bit compressible because the skull bones have not yet fused into a single plate. The reason for these contortions is that the pelvis had to undergo a number of design adjustments to make upright walking feasible, and that made human birth a much more trying and protracted business. Some species of primates can give birth in literally a couple of minutes. Human females can only dream of such ease.
We have made surprisingly little progress in making the process more bearable. As the journal Nature noted in 2016, “Women in labour have pretty much the same pain-relief options as their great grandmothers—namely gas and air, an injection of pethidine (an opioid) or an epidural anaesthetic.” According to several studies, women are not terribly good at remembering the severity of the pain of childbirth; almost certainly this is a kind of mental defense mechanism to prepare them for further births.
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You leave the womb sterile, or so it is generally thought, but are liberally swabbed with your mother’s personal complement of microbes as you move through the birth canal. We are only beginning to understand the importance and nature of a woman’s vaginal microbiome. Babies born by Cesarean section are robbed of this initial wash. The consequences for the baby can be profound. Various studies have found that people born by C-section have substantially increased risks for type 1 diabetes, asthma, celiac disease, and even obesity and an eightfold greater risk of developing allergies. Cesarean babies eventually acquire the same mix of microbes as those born vaginally—by a year their microbiota are usually indistinguishable—but there is something about those initial exposures that makes a long-term difference. No one has figured out quite why that should be.
Doctors and their hospitals can charge more for Cesarean births than for vaginal ones, and women understandably often like to know exactly when birth will take place. One-third of women in the United States give birth by Cesarean section now, and more than 60 percent of Cesareans are done for convenience rather than from medical necessity. In Brazil, nearly 60 percent of all births are by C-section; in Britain, it is 23 percent; in the Netherlands, it is 13 percent. If it were done only for medical reasons, the rate would be between 5 and 10 percent.
Other useful microbes are picked up from the mother’s skin. Martin Blaser, a doctor and professor at New York University, suggests that the rush to clean up babies as soon as they are born may actually be depriving them of protective microorganisms.
On top of all that, about four women in every ten are given antibiotics during delivery, which means that doctors are declaring war on babies’ microbes just as they are acquiring them. We’ve no idea what consequences this has for their long-term health, but it’s unlikely to be good. There are concerns already that certain beneficial bacteria are becoming endangered. B. infantis, an important microbe in mother’s milk, is found in up to 90 percent of children in developing countries but as little as 30 percent in the developed world.
Whether born by Cesarean or not, by the age of one the average baby has accumulated about a hundred trillion microbes, or so it has been estimated. But by that time, for reasons unknown, it appears to be too late to reverse the predisposition for acquiring certain diseases.
One of the most extraordinary features of early life is that nursing mothers produce over two hundred kinds of complex sugars—the formal name is oligosaccharides—in their milk that their babies cannot digest because humans lack the necessary enzymes. The oligosaccharides are produced purely for the benefit of the baby’s gut microbes—as bribes, in effect. As well as nurturing symbiotic bacteria, breast milk is full of antibodies. There is some evidence that a nursing mother absorbs a little of her suckling baby’s saliva through her breast ducts and that this is analyzed by her immune system, which adjusts the amount and types of antibodies she supplies to the baby, according to its needs. Isn’t life marvelous?
In 1962, only 20 percent of American women breast-fed their babies. By 1977, this had increased to 40 percent, still clearly a minority. Today almost 80 percent of American women breast-feed just after birth, though that number falls to 49 percent after six months and 27 percent after a year. In Britain, the proportion starts at 81 percent but then plunges to 34 percent after six months and just 0.5 percent after a year, the worst rate in the developed world. In the poorer nations, many women were long encouraged by advertising to believe that infant formula was better for their babies than their own milk and so began switching to formula. But formula was expensive, so often they watered it down to make it go further. Sometimes also the only water available to them was less clean than their own breast milk. The result in some places was an increase in childhood mortality.
Although formulas have greatly improved over the years, no formula can fully replicate the immunological benefits of mother’s milk. In the summer of 2018, the administration of President Donald Trump provoked dismay among many health authorities by opposing an international resolution to encourage breast-feeding and reportedly threatened Ecuador, the sponsor of the initiative, with trade sanctions if it didn’t change its position. Cynics pointed out that the infant formula industry, which is worth $70 billion a year, might have had a hand in determining the U.S. position. A Department of Health and Human Services spokesperson denied that that was the case and said that America was merely “fighting to protect women’s abilities to make the best choices for the nutrition of their babies” and to make sure that they were not denied access to formula—something the resolution wouldn’t have done anyway.
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In 1986, Professor David Barker of the University of Southampton in England proposed what has become known as the Barker hypothesis or, a little less snappily, the theory of fetal origins of adult disease. Barker, an epidemiologist, posited that what happens in the womb can determine health and well-being for the rest of one’s life. “For every organ, there is a critical period, often very brief, when it goes through development,” he said not long before his death in 2013. “It happens for different organs at different times. After birth only the liver and the brain and the immune system remain plastic. Everything else is done.”
Most authorities now extend that period of crucial vulnerability from the moment of your conception to your second birthday—what has become known as the first thousand days. That means that what happens to you in this comparatively brief, formative period of your life can powerfully influence how comfortably alive you are decades later.
A famous example of this tendency was revealed by studies done in the Netherlands of people who lived through a very serious famine in the winter of 1944, when Nazi Germany stopped food from entering the parts of the country that were still in its control. The babies conceived during the famine had miraculously normal birth weights, presumably because their mothers instinctively diverted nutrition to their developing fetuses. And because the famine ended with the fall of Germany the following year, the children grew up eating as healthily and as well as any other children in the world. To the delight of all concerned, they seemed to escape all the effects of the Great Hunger, as it was known, and were indistinguishable from children born elsewhere in less stressful circumstances. But then a disturbing thing happened. As they reached their fifties and sixties, the famine children developed double the rate of heart disease, and increased rates of cancer, diabetes, and other life-compromising maladies, as children born elsewhere at the same time.
These days the legacy newborn babies bring into the world with them isn’t a lack of nutrition but the opposite. So they are not only being born into households where people eat more and exercise less, but have an innate and enhanced vulnerability to succumb to the diseases that poor lifestyles bring.
It has been suggested that children growing up today will be the first in modern history to live shorter, less healthy lives than those of their parents. We aren’t just eating ourselves into early graves, it seems, but breeding children to jump in alongside us.
*1 From a Greek word meaning “to sow,” the term “sperm” is first recorded in English in The Canterbury Tales. In those days, and at least until the time of Shakespeare, it was generally pronounced “sparm.” Spermatozoa, the more formal designation, dates only from 1836, in a British anatomical guide.
*2 Doctors also sometimes use the terms “binovular” for fraternal twins and “uniovular” for a matched set.
19 NERVES AND PAIN
Pain has an element of blank;
It cannot recollect
When it began, or if there were
A day when it was not.
