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Motherhood After 30 Is Historical Norm Rather Than New Trend

December 29, 2014

There is much ado in the media about how women age, and how we can’t reproduce over 40, for reasons based on rather shaky science. For instance, the New York Times published an article detailing the rather prevalent belief that a woman is born with all the eggs she will have in a lifetime, and the moment of birth signals the start of her biological clock, doomed to just die as a woman ages rather than renew:

Even with the Great Egg Disappearance, girls enter puberty with many more than they will use, 300,000 or more. Each month, the body produces a hormone, FSH, which stimulates the follicles to prepare an egg for maturation and release.

With eggs backed up like bowling balls on a busy Saturday night at the lanes, the ovaries can afford to be a little wasteful, and as many as several dozen follicles are called into action. Then a single mature egg — usually, anyway — gets the tap on the shoulder and begins its travels to the uterus.

As for the maturing eggs that didn’t make the grade, there is no second chance. But they do not go out on their own. “Each month you probably lose a thousand or so,” said Dr. James T. Breeden, president of the American Congress of Obstetrics and Gynecology. “There’s just a natural death of them.”

For all the eggs a woman begins with, in the end only about 400 will go through ovulation. While men produce sperm throughout their lives, over time the number of eggs declines, and they disappear with increasing frequency the decade or so before menopause. Those that remain may decline in quality. “When you have a thousand or less within the ovaries, you’re thought to have undergone menopause,” said Dr. Mitchell Rosen, the director of the Fertility Preservation Center at the University of California, San Francisco.

This commonly held belief puts dire pressure on women to reproduce young, lest they grow too old to have children, and headlines trumpet the fearmongering of growing older and declining fertility. We will call this Theory #1-Biological Clock/Death At Birth.

Theory #2 is a bit more convoluted, having been tested on mice stem cells, but seems to shake Theory #1-Biological Clock/Death At Birth. National Geographic published an article about how women may, gasp, shudder, make egg cells throughout their lives, an eminently more logical solution than eggs just withering away and dying all a woman’s life. Scientists concur that this is more reasonable:

From a purely biological perspective, the concept that a woman would continually generate new eggs during her reproductive years makes sense—since men constantly replenish their sperm, Tilly added. (Read how men produce 1,500 sperm a second.)

There’s no fathomable reason,” he said, why a woman would have evolved to carry stale eggs around for decades before attempting to get pregnant while men evolved to have fresh sperm always available.

Theory #2-Women Make Egg Cells All Their Lives, is gaining traction and supported by the mouse stem cell study:

Previous research had suggested that a woman is born with all the egg cells she will ever have in her lifetime.

But in recent experiments, scientists discovered a new type of stem cell in the ovaries that—when grown in the lab—generates immature egg cells. The same immature cells isolated from adult mouse ovaries can turn into fertile eggs. …

The finding reinforces the team’s previous experiments in mice, which had identified a new type of ovarian stem cell that renews a female mouse’s source of eggs throughout its fertile years.

That study, published in the journal Nature in 2004, was the “first to reach the conclusion that this long-held belief in our field—that young girls are given a bank account at birth that you can no longer deposit eggs to, just withdraw from—was no longer true,” said study leader Jonathan Tilly.

In purely rational terms it makes sense that a woman’s fertility could be adaptive, because being human can be taxing. Reproduction takes a lot out of a mother’s body, and that level of growth and nurturing required to raise a child consumes additional resources. Turns out history supports this concept of the flexibility of human reproduction inTheory #2-Women Make Egg Cells All Their Lives rather that the pseudo-science of Theory#1-Biological Clock/Death At Birth.

Slate published an article about the history of the ages at which women reproduce, and it turns out that the economic climate, or most basically, the availability of resources determines a woman’s reproduction more definitively than her supposed biological clock: “History shows us that the “best age” to have a child is very much a product of the cultural and economic moment, not a just dictate of biology that we need to escape.”

The article in Slate, Long Before The Pill, American Women Put Off Motherhood Until Their 30’seasily supports the rationale that women have flexible fertility by looking at historical birth rates. Turns out, childbearing rates aren’t so cut and dried.

The shift towards late motherhood—commonly defined as motherhood after 35—is often presented as a story of progress and technological liberation from the biological clock.

 The narrative goes something like this: Before the widespread availability of the Pill women had no choice but to have children in their teens and early twenties. But the introduction of effective contraception meant that women could trade babies for briefcases. And technologies such as IVF, egg donation and egg freezing allow women to beat the biological clock, freeing them from the tyranny of their own biology. A recent Newsweek headline, for example, announced that women can now “freeze” their biological clocks, while the cover of Businessweek urged women to “Freeze Your Eggs, Free Your Career.”
While this triumphal narrative contains a few grains of truth, it is as simplistic as it is satisfying. History shows us that the “best age” to have a child is very much a product of the cultural and economic moment, not a just dictate of biology that we need to escape.
I can’t help but notice the patriarchal bent of lecturing women to reproduce young, sacrificing their careers in the process, coinciding with a financial imperative for women to work to support their families. Lo and behold, then “science,” coincidentally dominated by men, suddenly trumpets fears about women aging, not reproducing, and the danger involved in “choosing a career over a family.” As if women have a choice in most of these things. Women don’t choose to be financially insecure if they don’t work twice as hard as men for less pay (earning 77 cents for every dollar men earn). Women don’t have a choice in their biology of their egg structure. Women don’t have a choice in how their ovaries behave.
This is not a myth that women work twice as hard as men; it’s been proven by a United Nations Study that examines women’s work worldwide:

According to the UN Food and Agriculture Organisation in Rome, women are responsible for ‘at least 50 per cent of all food production’. A study by the Economic Commission for Africa, for example, has shown that women do 60 per cent to 80 per cent of all the agricultural work on the continent plus 50 per cent of all animal ‘husbandry’ and 100 per cent of the food processing.

In one region studied – Bukaba in Tanzania – the men work an average of 1800 hours a year in agriculture and then their work is largely done. The women, on the other hand, work an average of 2600 hours a year in the field . . . and their work has only just begun. In the local Haya language, the word ‘to marry’ literally means ‘the man gets a hoe’.

Women have no choice in the fact that they are paid less. They “pay” a penalty for having children. That is not a choice. No woman chooses to be paid less for doing more work.

In 2010 in only six of 24 fields were salaries of males significantly greater than those of females: assistant and full professors in economics, life science assistant professors, associate and full professors in engineering and the physical sciences, and full professors in geoscience.

Economists have many competing explanations for sex differences in salaries. Women’s decision to spend time in child care may be directly related to their salaries. Hundreds of studies have identified a “child salary penalty” for women in the labor market as a whole, at the same time identifying a marriage and child premium for men.

This idea of choosing our fertility is bizarre. The idea of dying from the moment we are born is equally bizarre. What makes more sense is that women are rational, and since we are the means by which species reproduces, infinitely flexible humans. The trend of supposed “later” motherhood is a bullshit. Motherhood is often determined by resources, just as much as by cultural pressure, according to the Slate article:

In motherhood manuals published in the early 20th century, eugenicists warned women to wait until they were at least 24 to have children, lest their offspring suffer from both their biological and emotional immaturity. …
In the late 1920s, one sociologist recalled that couples who had children soon after marriage were the targets of gossip and severe judgment. The Great Depression also added to the popularity of postponing pregnancy, as economic anxiety dampened the desire to procreate and American birthrates dropped. …
In fact, it was only after second world war that early parenthood became a cultural norm. A strong economy and widespread embrace of domesticity encouraged both early marriage and childbearing, resulting in a “baby boom” that lasted almost two decades. In 1957, birthrates among American teenagers hit an all-time high, at 96.3 births per 1,000 adolescents aged 15-19. To compare, the current birth rate for teenage girls aged 15-19 sits at 26.6 births per 1,000 women. The postwar tendency toward early childbearing, which we now imagine to be the product of some kind of biological inevitability, was actually a cultural aberration.
Notice that the panic over early or supposed delayed childbearing a.k.a. planned pregnancies, surfaced at a time when feminism was coming to the forefront of American culture, again:

This shift towards midlife pregnancy that started in the 1970s was, of course, connected to both the widespread availability of new contraceptive technologies, as well the successes of second-wave feminism. But there is a third, often overlooked, catalyst in this story: the flagging economy.The 1970s saw the combination of runaway inflation with stagnating growth. The real value of wages fell dramatically. In this environment, the movement of middle-class women into the workplace was not just liberating—it was an economic necessity. Two working parents were now required to achieve the middle-class status that a single income used to support.

The return to delayed childbearing was not a dramatic break with the past, but a continuation of a trend that began before the second world war. Delaying parenthood to invest more time in education and career development became a favored strategy for surviving in an increasingly competitive marketplace.

According to history, women have babies when they can afford them, not just when they are told they are most fertile.  From a very male-based perspective, fertility is an essence that needs to be controlled, kind of like trying to chain Pan and tell him when to bring in spring, and “progress” is defined if spring comes during winter, or pretty much whenever the hell we want. Fertility, birth, reproduction, is a wild goddess, and one that certainly should hew to the male counting mechanisms designed to regulate it. Take a look at “fertility treatments” that want to “regulate” the menstrual cycle first, stop it, and then chemically induce it, to “treat” infertility. “Progress” in a field dominated by men equates to control over something that has supposedly been under female purview for eons. The Slate article recognizes that “progress” equates to women relying on technology to reproduce, and in my own note,  much as the birth process is mechanized or relies on hospitals, obstetricians, surgical interventions, and insurance quotas.

Reproductive technologies are often cast as the heroes of this story. Women who waited too long to have children were “saved” by the ingenuity of these technologies, tricking their own biology to have children later and later in life.

This narrative has two problems. First, it implies that women who have children in their 30s or even their 40s always need reproductive technologies to conceive—they don’t. Fertility is highly individual, influenced by both members of the couple hoping to conceive. Surprisingly little is known about the exact decline of fertility with age. There is no magic age limit for pregnancy that applies to all women.

Second, it implies that using fertility technologies to delay pregnancy is a story of progress, of technology trumping biological limitation. Carl Djressai, father of the birth control pill, recently predicted that by 2050 all women would use egg freezing and IVF to reproduce. The resulting “Manana” generation will be able to delay pregnancy indefinitely and without consequence. This is not inevitable. In fact, this vision of the future may be less about triumphing over biology, and more a statement of how our society and corporate culture treats working mothers.

 Djressai just assumes that all women will resort to male techniques for reproducing, that women will give up their unique ability to choose when to reproduce, even if it is outside of the medical model, and embrace invasive techniques to conceive. Chain Pan and spring will blossom under the male medical model. Or, not.

The study that says that women between the ages of 35 to 39 will have problems conceiving was based on the 1600’s, for real:

The widely cited statistic that one in three women ages 35 to 39 will not be pregnant after a year of trying, for instance, is based on an article published in 2004 in the journal Human Reproduction. Rarely mentioned is the source of the data: French birth records from 1670 to 1830.

It might just be that the “science” behind the hype is just hype, not science. According to a science writer who found herself investigating the myth of Theory #1-Death bit, there is no true science behind fertility statistics trumpeted by the media.

In other words, millions of women are being told when to get pregnant based on statistics from a time before electricity, antibiotics, or fertility treatment. Most people assume these numbers are based on large, well-conducted studies of modern women, but they are not. When I mention this to friends and associates, by far the most common reaction is: “No … No way. Really?

Surprisingly few well-designed studies of female age and natural fertility include women born in the 20th century—but those that do tend to paint a more optimistic picture. One study, published in Obstetrics & Gynecology in 2004 and headed by David Dunson (now of Duke University), examined the chances of pregnancy among 770 European women. It found that with sex at least twice a week, 82 percent of 35-to-39-year-old women conceive within a year, compared with 86 percent of 27-to-34-year-olds. (The fertility of women in their late 20s and early 30s was almost identical—news in and of itself.) Another study, released this March in Fertility and Sterility and led by Kenneth Rothman of Boston University, followed 2,820 Danish women as they tried to get pregnant. Among women having sex during their fertile times, 78 percent of 35-to-40-year-olds got pregnant within a year, compared with 84 percent of 20-to-34-year-olds. A study headed by Anne Steiner, an associate professor at the University of North Carolina School of Medicine, the results of which were presented in June, found that among 38- and 39-year-olds who had been pregnant before, 80 percent of white women of normal weight got pregnant naturally within six months (although that percentage was lower among other races and among the overweight). “In our data, we’re not seeing huge drops until age 40,” she told me.

Even some studies based on historical birth records are more optimistic than what the press normally reports: One found that, in the days before birth control, 89 percent of 38-year-old women were still fertile. Another concluded that the typical woman was able to get pregnant until somewhere between ages 40 and 45.

So, the big question is: why has this not been reported? Why are women still chained to the belief that their eggs are dying AS WE SPEAK, and we must immediately fuck and get pregnant if we ever, ever, ever, want children??? It is too much coincidence to believe that this misreporting is purely happenstance.

For the author of the above article, fertility was not denied. She did not need advancing so-called science to conceive:

In Dunson’s study of modern women, the difference in pregnancy rates at age 28 versus 37 is only about 4 percentage points. Fertility does decrease with age, but the decline is not steep enough to keep the vast majority of women in their late 30s from having a child. And that, after all, is the whole point.

I am now the mother of three children, all born after I turned 35. My oldest started kindergarten on my 40th birthday; my youngest was born five months later. All were conceived naturally within a few months. The toddler in my lap at the airport is now mine.

From a generous perspective, one might simply say that only fertility doctors are qualified to report on these statistics and therefore are the largest voice in the room. That is what the author above hypothesizes:

One possibility is the “availability heuristic”: when making judgments, people rely on what’s right in front of them. Fertility doctors see the effects of age on the success rate of fertility treatment every day. That’s particularly true for in vitro fertilization, which relies on the extraction of a large number of eggs from the ovaries, because some eggs are lost at every stage of the difficult process. Younger women’s ovaries respond better to the drugs used to extract the eggs, and younger women’s eggs are more likely to be chromosomally normal. As a result, younger women’s IVF success rates are indeed much higher—about 42 percent of those younger than 35 will give birth to a live baby after one IVF cycle, versus 27 percent for those ages 35 to 40, and just 12 percent for those ages 41 to 42. Many studies have examined how IVF success declines with age, and these statistics are cited in many research articles and online forums.

Yet only about 1 percent of babies born each year in the U.S. are a result of IVF, and most of their mothers used the technique not because of their age, but to overcome blocked fallopian tubes, male infertility, or other issues: about 80 percent of IVF patients are 40 or younger. …

Studies of natural conception are surprisingly difficult to conduct—that’s one reason both IVF statistics and historical records play an outsize role in fertility reporting. Modern birth records are uninformative, because most women have their children in their 20s and then use birth control or sterilization surgery to prevent pregnancy during their 30s and 40s. Studies asking couples how long it took them to conceive or how long they have been trying to get pregnant are as unreliable as human memory.

Another problem looms even larger: women who are actively trying to get pregnant at age 35 or later might be less fertile than the average over-35 woman. Some highly fertile women will get pregnant accidentally when they are younger, and others will get pregnant quickly whenever they try, completing their families at a younger age. Those who are left are, disproportionately, the less fertile. Thus, “the observed lower fertility rates among older women presumably overestimate the effect of biological aging,” says Dr. Allen Wilcox, who leads the Reproductive Epidemiology Group at the National Institute of Environmental Health Sciences. “If we’re overestimating the biological decline of fertility with age, this will only be good news to women who have been most fastidious in their birth-control use, and may be more fertile at older ages, on average, than our data would lead them to expect.”

The business of timing babies is tricky, and small reporting differences may account for the panic over female fertility. Consider the study discussed below, that initially indicates that women in their thirties are less fertile, only to demonstrate that they are less fertile for a day, and at the same rate of fertility as 20-year olds on the other day. We are talking a day’s difference here, literally, and a significant day in the reporting of  human fertility:

David Dunson’s analysis revealed that intercourse two days before ovulation resulted in pregnancy 29 percent of the time for 35-to-39-year-old women, compared with about 42 percent for 27-to-29-year-olds. So, by this measure, fertility falls by about a third from a woman’s late 20s to her late 30s. However, a 35-to-39-year-old’s fertility two days before ovulation was the same as a 19-to-26-year-old’s fertility three days before ovulation: according to Dunson’s data, older couples who time sex just one day better than younger ones will effectively eliminate the age difference.

Huh, one day is all it takes. Funny, that is usually not mentioned. Why? Because the so-called science has apparently been dumbed down to make it easier for we women to understand, a problem that reproductive groups seem disinclined to detail, according to the reporter who questioned the group:

The American Society for Reproductive Medicine’s guide provides no citation for these statistics; when I contacted the association’s press office asking where they came from, a representative said they were simplified for a popular audience, and did not provide a specific citation.

 

Simplified for a popular audience of women? They did just say that? Oh yes.

Data from another study demonstrate that women’s fertility at 40 may also be the same as at 20: “the data from women who already have a child may give a more accurate picture of the fertility decline due to “ovarian aging.” In Kenneth Rothman’s study of the Danish women, among those who’d given birth at least once previously, the chance of getting pregnant at age 40 was similar to that at age 20.”

Yet another study proving women have flexible fertility? Perhaps it’s time to actually calling out what is “science” and what is patriarchal science, with a bent on telling women what to do. Fertility still doesn’t belong to science but Mother Nature, and perhaps our economy.

 

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