September 12th, 2008

fertility patterns in the US

I got a little curious about this whole she's-just-like-me thing that comes up around Sarah Palin. NPR talk shows, newspaper articles and bloggers often compare the number of kids they have to Palin's five and come up pretty similar. This just doesn't match my current experience. I grew up on a street with a lot of Catholic families sending their kids to Catholic school in an area that was very much not predominantly Catholic. Every one of those families had way more than 5 kids. But other than my neighbors, everyone else I knew thought that 4 kids was really quite a lot. And I'll be 40 next year.

As an adult, I have a lot of friends who have 2 kids. I have some friends who have no kids (and who increasingly look like they won't ever have children, since they're my age and older in general). I have a very few friends who have 3 kids. And I don't have any friends near me in age with more than 3 kids (I have significantly older friends who had more than three kids, but those kids are grown now). I'm related to people with more than three kids (duh), and other than those relatives, I do know a few people with more than 3 kids, but not well. Some of this is selection bias. As one of 4 kids, married to someone who was one of 4, and knowing a lot of people who were 1 of 4 or more, I have a theory about 4+ kids that I'm not shy about sharing: if you weren't crazy in _wanting_ 4 kids, you were definitely crazy after you had 4 or more kids. Crazy isn't necessarily bad -- there can be good crazy. But you can see where this would inhibit people with 4+ offspring from wanting to hang out with me. I'm a Bigot on this topic.

I also have friends at the 2 kids point who really want another kid -- at least part of the time. I tell them to Stop Now, because they might get twins. I grew up knowing a family with 3 boys who Really, Really, Really wanted a girl. They got a girl on their fourth try -- along with twin boys. I have never before or since seen such physically attractive, intelligent twin boys so totally ignored. I think their oldest brother mostly raised them. They were terrors, needless to say.

But when I keep seeing people with 5, 6, 7, whatever kids rave about Palin, I gotta wonder: how many of these people are there? Is this normal, and I just don't know about it? I mean, I know the average number of kids per mother these days is below 2 in the US, but that could be a combination of a lot of only children and a few mothers having a half dozen. Where there is google, there is an answer. And the answer is, no, there aren't a lot of mothers out there having a half dozen.

As of June 2006, 17 percent of women 15-44 had one child, 22 percent had two, 11 percent had three, 4 percent had four and 2 percent had five or more.

This doesn't add up to 100% because of things like 15-19 year olds are 93% childless and even women 40-44 are 20% childless (19% in the 35-39 range, which is sort of interesting).

In other words, if there is a demographic that identifies with Palin on the basis of kid-volume, it isn't some mysteriously huge demographic I've somehow avoided running into. The 2 kids phenomena is, indeed, the plurality, and the drop from double digit to single digit occurs at 4 kids.

I didn't read the whole thing, altho I did read large chunks of it. The maps are kind of interesting in a spooky sort of way.

effectiveness of well-baby care

After asking about the doc in a box/retail clinic controversy, I got interested in the question of pediatrician/well-baby visits: what kind of evidence has been collected for the effectiveness of well baby care? I think we know from a wide variety of other studies that physicals, in general, are a massive waste of time, money and other resources (some particular screening tests for specific populations are still considered worthwhile).

Here's my first cut at an answer, from the Canadian Task Force on Preventive Health Care.

I'm struck by a couple things. First, the research on some of the issues is just completely lacking, because other aspects of maternity/newborn care have changed drastically since the last time the studies were done (feeding problems, basically, since time-to-discharge from a normal birth has shortened up so much). Second, I'm a little startled to see the details of well-baby care laid out so clearly, in a way that causes me such consternation.

While well-baby care clearly increases rates of vaccination, the details of which vaccines were given when have changed so much over time that it seems making much of a statement beyond the rates of vaccination (in terms of real health outcomes as opposed to proxies) would be very difficult. I had not realized that asking about sleep, night time waking and crying was considered a measurable component of well-baby care with specific advice associated with a particular parental response: does it bug you? Here's how to implement cry-it-out. Yeesh. (They call it "systematic ignoring". I'm honestly not sure which is worse as a description or mind-set.)

The Canadians note problems with defining eye problems, detecting hearing problems, and whether or not to diagnose hip problems and what to do if you have diagnosed a hip problem. They flat out say that screening for child abuse/advising on child abuse hasn't been shown to help at all. The iron deficiency anemia problem is too complex to get into here. It should be sufficient to note that there's no clear evidence in wee ones that iron deficiency anemia as currently diagnosed and treated is anything other than a poor proxy, at best, for other issues.

The childproofing advice in particular, and the studies that attempt to show benefit, are really interesting.

Given how freaked out everyone gets as a result of height and weight measurements, it's a little shocking that while there is evidence of some benefit, it's not very strong.

Expect to hear more whining from me on this topic. This is at least as shocking as discovering how useless prenatal/antenatal care is.

HEY! YOU! Before you get all over me, I do, in fact, go to prenatal visits and I take them very seriously. I did, for T., more than the schedule of well-baby advised by the Canadians. And I took those really seriously, too.