Births to mothers in their forties are less common now than in the old days

In my post the other day I suggested that, when it comes to children’s health, mothers’ health is a bigger issue than mothers’ (advancing) age when they give birth. I was motivated to post it by the widespread discussion of Judith Shulevitz’s essay in the New Republic, “How Older Parenthood Will Upend American Society” — discussion that has continued with today’s On Point (which I haven’t heard yet), including the author Elizabeth Gregory, who has written Ready: Why Women Are Embracing the New Later Motherhood (which I haven’t read yet).

In the comments, several people (Reeve Vannamen and relfal) brought up the issue of later births in the olden days (before 1970). We need to think about two different issues: having first children at a later age, and having any (or many) children at a later age. For some questions of children’s health – especially the sperm-mutation issue with autism – I don’t think it matters: an older-age birth is an older age birth. The same goes for the angst over whether children will know their grandparents, whether parents will be too old to take them to soccer practice, and so on.

On the other hand, “starting a family” at an older age (because, remember, it’s not a “family” until you have kids), is a different issue, with its own implications for total fertility rates, the age composition of the population, etc.

Both having any children and having first children at older ages have been increasing in recent decades, but having any children at older ages is not historically unprecedented. Here are the birth rates for women ages 40-44, from 1940 to 2011, along with the percentage of all children born to those women from 1960-2010:


Sources: Birth rates 1940-1969, 1970-2010, 2011; Percent of births 1960-1980, 1980-2008.

Birth rates to women ages 40-44 are still substantially lower than they were in the olden days. So the number of kids whose parents will be over 60 when the kids come back to live with them after college is lower now despite an increase for 30 years.

On the other hand, the percentage of kids born to older mothers has surpassed those rates, because these are more often first or second, rather than third or fourth or fifth children. Put another way, the chance that women will have their first, and possibly only, baby at an older age has increased since 1960. While the overall birth rate for older women is still lower than it was in 1960, the first-birth rate is much higher. Here is the birth rate among women with no previous births, for those aged 35, 40 and 45, from 1960 to 2005:

first birth rates 60-05

Source: Table 4 on this page.

In 1960, only 4% of women who reached age 35 without having a baby had one that year. They probably weren’t just delaying their childbearing intentionally or putting off finding a mate while they pursued their careers. On the other hand, by 2005 almost 9% of those who reached age 35 without having a baby had one that year. The late first birth has become much more common.

Now if you go back to the promo blurb for On Point, you see how the issues are jumbled together:

American parents are having kids old and older. Look around. Are those two that child’s parents? Or its grandparents? It is very often hard to know these days. In many ways, this has been liberating. Twenty-somethings with a child-free, diaper-free decade of youth. People with time and space to start careers. But there is a price, and it’s becoming clearer. Older parents juggling kid’s soccer and their own aches and pains. Kids who won’t know their grandparents. Parents who won’t know their grandkids. And a baby bust.

The hardships faced by older parents are nothing new, but parents used to have more kids around when they went through them. It’s good to keep an eye on the issues separately.

Note: there is some more background and analysis in my working paper: here.


Study shows home births are not as safe. So?

There’s an interesting example of how to interpret scientific results — and draw policy implications from them — from the world of birth practices and safety.

The subject of the debate is a major new study from the British Medical Journal. The study followed more than 60,000 women in England with uncomplicated pregnancies, excluding those who had planned caesarean sections and caesarean sections before the start of labor. They compared the number of bad outcomes — from death to broken clavicles — for women depending on where they had their births.

One comparison stands out in the results. From the abstract: “For nulliparous women [those having their first birth], the odds of the primary outcome [that is, any of the negative events] were higher for planned home births” than among those planned for delivery in obstetric units. That is, the home births had higher rates of negative events. The difference is large. Here’s a figure to illustrate:

The error bars show 95% confidence intervals, so you can see the difference between home births and obstetric-unit births is statistically significant at that level. These are the raw comparisons, but the home-versus-obstetric comparison was unchanged when the analysts controlled for age, ethnicity, understanding of English, marital or partner status, body mass index, “deprivation score,” previous pregnancies, and weeks of gestation. Further, by restricting the comparison to uncomplicated pregnancies and excluded all but last-minute c-sections, it seems to be a very strong result.

But what to make of it?

In their conclusion, the authors write:

Our results support a policy of offering healthy nulliparous and multiparous women with low risk pregnancies a choice of birth setting. Adverse perinatal outcomes are uncommon in all settings, while interventions during labour and birth are much less common for births planned in non-obstetric unit settings. For nulliparous women, there is some evidence that planning birth at home is associated with a higher risk of an adverse perinatal outcome.

But in what way do the results “support a policy”? The “higher risks” they found for planned home births are still “uncommon,” by comparison, with those in poor countries, for example. But the home birth risk is 2.7-times greater.

The Skeptical OB, who is a reliable proponent of modern medical births, titled her post, “It’s official: homebirth increases the risk of death.” She added some tables from the supplemental material, showing the type of negative events and conditions that occurred. Her conclusion:

“In other words, any way you choose to look at it, no matter how carefully you slice and dice the data, there is simply no getting around the fact that homebirth increases the risk of perinatal death and brain damage.”

I guess the policy options might include include whether home births should be encouraged, more regulated, covered by public and/or private health insurance, banned, penalized or (further) stigmatized.

Home birth seems safer than letting children ride around unrestrained in the back of pickup trucks, which is legal in North Carolina — as long as they’re engaged in agricultural labor. On the other hand, we have helmet laws for kids on bicycles in many places. And if a child is injured in either situation, hopefully an ambulance would take them to the hospital even if the accident were preventable.

In other words, I don’t think policy questions can be resolved by a comparison of risks, however rigorous.

Fertile decline

The numbers are starting to add up.

U.S. Senator Rick Santorum blamed abortion for the lack of young workers to pay for Social Security: “Well, a third of of all the young people in America are not in America today because of abortion — because one-in-three pregnancies end in abortion.” If he was right about that, he should consider blaming someone for the recession.

The latest data brief from the National Center for Health Statistics offers the strongest evidence yet that the recession has driven birth rates down.

Here are three ways the evidence points toward the recession decreasing Americans’ production of children. First, the timing: 2009 saw the largest single-year drop in fertility rates since the early 1970s. Here is my graph of annual change in the number of live births per 1,000 women ages 15-44 (sometimes called the “general fertility rate”):

The decline is very broad — affecting all race-ethnic groups, almost all states, and all ages of women (except the oldest). However, I’m taken by a second pattern, which shows the declines steepest at the higher birth orders — so the people who are most affected are those who already have kids, which fits the idea of families embracing the new austerity in place of the old three-is-the-new-two gestalt that seems so mid-2000s now:

I wrote a longer post on this last fall, in which I summarized the argument that this recession was serious business for birth rates:

If you put together busted real estate values and increasing education costs, collapsing state services increasing insecurity, and tightened access to credit, then the resulting “era of thrift” in the culture of consumption might include fewer children among both rich and poor. There is room for such a change, as a very serious “correction” would still only take the U.S. down to the level of its economic peers.

At the time I quoted this 2010 Pew report, which concluded: “Birth rates in the United States began to decline in 2008 after rising to their highest level in two decades, and the decrease appears to be linked to the recession”. In it, the analysts compared home prices and per capita income changes in states with changes in fertility, which showed a consistent pattern of greater birth declines in harder-hit states.

With the new data new birth data by state, and state unemployment rates from the Bureau of Labor Statistics, I can extend that now, and I think it’s a pretty strong third point: fertility fell more where the recession hit harder. The state-level correlation between changing fertility rates in 2007-2009 and changing unemployment rates in 2006-2008 is .48 on a scale of 0 to 1. (I figured it made sense to take unemployment rates from the year previous.) Here is the pattern:

It remains to be seen whether this is a small correction, or even just a delay, in birth rates on account of the economic crisis. Compared with the other rich countries, the U.S. still has high fertility rates. And in the long run that might be a more important issue than the recent fluctuations.

Health inequality compendium

The CDC releases a slew of inequality trends.

Many people will find the new report from the Centers from Disease Control very helpful. It’s called CDC Health Disparities and Inequalities Report — United States, 2011, and it covers everything from inadequate and unhealthy housing to preterm birth by race/ethnicity:

I previously reported national comparisons showing the U.S. bringing up the rear on this health indicator, and discussed the evidence for the role of obesity. This table was nice because it broke out the Latino groups, which we often don’t get (next step, Asians).

Anyway, very nice to see CDC putting resources into the collection and dissemination of inequality indicators. This report should be especially useful to teachers who want to include health in their discussion of inequality, but aren’t specialists in health outcomes (like me).

Receding birth rates: milestone or tipping point?

Seems like only 2009 that everyone was wondering why birth rates were rising.

“Forget the Dow and the GDP. Here’s the latest economic indicator: The U.S. birth rate has fallen to its lowest level in at least a century as many people apparently decided they couldn’t afford more mouths to feed.” In this opening, AP’s Marilynn Marchione is going too far.

Still, birth rates have fallen for two straight years. And the number of children born, per 1,000 people in the population, reached its lowest level ever recorded in the U.S. in 2009:

Source: My graph from various sources, including most recently this from NCHS.

So how could it be that less than two years ago I was asking, “Why Are American Women Having More Children?”

For one thing, that “birth rate” — births per 1,000 population — is strongly affected by what’s going on among non-childbearing people, especially their recent practice of living longer, which weighs down the denominator of that rate, so to speak.

If you are interested in the childbearing decisions people make, and how those decisions are affected by the recession, it’s better to look at what is often called the “general fertility rate,” which is the number of births for every 1,000 women in the ages 15-44. By that measure, we’ve still had two straight years of decline — which could be due to the recession — but the rate remains higher than it was through most of the 1990s.

So my question about America’s high fertility is still germane. In fact, by an even more exact measure — the “total fertility rate,” which estimates how many children each woman will bear in her lifetime — the U.S. has just about the highest fertility in the rich world, at 2.1.

Source: My chart from Population Reference Bureau data.

The explanations I preferred in 2009 may still apply: (a) immigration of healthy young go-getters from higher-fertility places; (b) the new math for some middle-class parents, by which three is the new two; (c) a rebound in teen birth rates; (d) rising birth rates among single women, and; (e) neo-traditionalist pro-natalism, which is part of the stalled progress toward gender equality.


So, is it true that the recession has changed the birth calculus, raising the specter of “more mouths to feed“? That AP article cited evidence that economics were crimping family expansion plans, especially among those who are economically insecure, and quoted the highly expert Andrew Cherlin, pursuing that logic:

When the economy is bad and people are uncomfortable about their financial future, they tend to postpone having children. We saw that in the Great Depression the 1930s and we’re seeing that in the Great Recession today.

As early as January 2009, Carl Haub at the Population Reference Bureau raised the possibility that fertility would fall in a serious recession. And Heather Hopkins at Hitwise tracked baby term searches on the Internet through early 2009, finding evidence of declining interest in “baby names,” “pregnancy,” and “maternity clothes.”

Then in April, Gretchen Livingston and D’Vera Cohn at the Pew Research Center reported: “U.S. Birth Rate Decline Linked to Recession.” Based on early data from 25 states, they wrote:

Strong associations were found between the magnitude of state-level birth rate change from 2007 to 2008 and the magnitude the previous year of per capita income change and housing price change. Strong associations also were found between the magnitude of state-level birth rate change from 2007 to 2008, and the previous year’s change in gross domestic product by state, as well as in first claims for unemployment benefits. Analysis also found a strong association between the magnitude of birth rate change from 2007-2008 and a state’s housing foreclosure rate in 2007. No correlation was found with change in state-level employment or unemployment rates.

At the time, I plotted the change in birth rates against change in per capita income for those states, and it looked pretty good for the economy’s role:

Now the fertility data runs through 2009. I haven’t looked at it by state, but a closer look at the monthly trends (made possible for me by my colleague Yong Cai) — here smoothed with a 12-month moving average — shows a drop starting in mid-2008, as well as a drop in late-2000 or so, at the start of the last recession. Oddly, in both of those cases the drop appears a little too early, especially when one considers that births usually occur at least 6 months after someone decides to feed another mouth.

To look at that timing more closely, here is the same data, but charted as 12-month change (e.g., the difference between January 2009 and January 2008). This looks like strong evidence that birth rates are lower during the last two recessions, but still a little early — before the rapid rise in unemployment, for example.

To look for evidence that people are doing less baby planning, I did an updated Google search trend. Averaging the relative frequency of searches for “baby names,” “maternity clothes,” and “baby shower,” — and again taking the 12-month change — it looks like a drop occurs in early- to mid-2007, and continues to the present (those few positive months in 2009 are 12-month changes from months that were negative, so the whole trend is downward after 2007).

Source: My analysis of Google search trends. You can do your own, and read about the data, here.

Since births take a while from decision to mouth-feeding, and then even longer for the data to come out, it’s hard to use them as a leading economic indicator. But this Google thing has potential. Anyways…

Milestone, or tipping point?

Reaching a data point such as the lowest-birth-rate-ever is a milestone. It’s not a tipping point unless it leads to accelerating change in the same direction. Sure, a recession might produce delayed fertility, and some births foregone as a result (as well as more divorces and child abuse). But invoking the Great Depression is serious — just look at the chunk taken out of the fertility trend above.

Could this be sewius? I could see an argument to make that prediction. If you put together busted real estate values and increasing education costs, collapsing state services increasing insecurity, and tightened access to credit, then the resulting “era of thrift” in the culture of consumption might include fewer children among both rich and poor. There is room for such a change, as a very serious “correction” would still only take the U.S. down to the level of its economic peers.

Obesity, birth and health

The NYTimes reports that obesity is increasingly complicating pregnancy and delivery for U.S. women, and hospitals are slowly adjusting. One obvious correlation is between obesity and the odds of Cesarean-section deliveries:.

Obesity rates are likely to be one of the factors behind the U.S.’s anomalous upward trend in maternal mortality in recent decades, and its abysmal ranking in preterm births and infant mortality. Obesity, along with other health problems, increases the odds of preterm delivery, much of which is by C-section — the subject of a recent Congressional hearing. However, although obesity rates are higher for Blacks than for Whites, preterm delivery rates have risen in the last 20 years for all groups except Blacks (despite tapering downward in the last several years):

Although obesity is a proximate cause of some health problems, it is also a consequence of other health conditions, poor diet, poverty, and so on. Obesity does not cause all the problems with which it is correlated, even when the association is strong, as with C-sections.

Recession stalls birth rates

More evidence that the recession is having large-scale effects on family life.

The birth rate dropped in the U.S. from 2007 to 2008, for all age groups of women except those 40-44. So why is the Centers for Disease Control press release headlined, “Teen Birth Rates Drop in 2008 Following a Two-Year Increase”?

In case the significance of the news was not clear, Stephanie Ventura of the National Center for Health Statistics told the Washington Post, “This is good news.” Really?

The longer term trends — which never seem to figure in the breathless reporting of each new data release — are still clear: overall, U.S. women are having more children than they did in the 1970s, teenagers are having a smaller portion of them, and single women are having a rising proportion of them. Nothing in the last few years has changed this story.

However, there is something interesting in the latest data, and it’s not necessarily good news. According to a nice analysis by the Pew Research Center, including my old friend Gretchen Livingston, this most recent birth rate decline seems to be driven by the recession.

I took the liberty of adapting one of their tables into the following chart, which shows the relationship between the 2007-2008 change in per-capita income and concomitant change in the birth rate (births per 1,000 women 15-44). The larger states are shown with bigger dots, and the trend line is plotted, showing a strong association:

Chances are this will not lead to a large decline in lifetime fertility for today’s families — more likely a stall that most women will make up for down the road (which could be why 40-44s are the one group that doesn’t show a decline — less time for timing). For the same reasons, ironically, divorces may be taking a breather as well.

Like fertility and divorce, the increase in family violence during the recession might not be enough to overcome long term trends. But as we start to wrap our heads around the long term consequences of this crisis, which outstrip those of recent business cycles, family changes are an important part of the story.