I promise that I will not be one of those bloggers who, upon finding out about impending parenthood, turns their site over entirely to baby stuff. However, this ties in with themes that I have often addressed in the past, so it seems appropriate.
I have long been aware of the ubiquitous presence of sloppy thinking that exists as regards pregnancy and child-raising. It ranges from holier-than-thou attitudes about "eating only organic food from the pygmies of Northern India in order to make it easier to give birth to a clairvoyant baby in a redwood Hot Tub on an ancient Native American holy site" to poorly-thought-out folk wisdom along the lines of "my granny used to dope her babies up on morphine to get them to go to sleep, so it's just fine for babies, good for 'em even, and you can keep your eggheaded book-learnin' science away from me!" What all of this has in common is just good (or, actually, bad) old-fashioned sloppy thinking and a heaping dollop of credulousness and gullibility.
Okay, let's start with the "my granny says that cocaine is fine for a collicky baby!" crowd first. Every now and again, I meet someone who informs me that all manner of things that are frowned upon by the medical community are fine for pregnant women and infants, because some relative (usually, though not always, the parent or grandparent of the person telling me this) continued to smoke/drink/shoot heroine/etc. when they were pregnant or nursing, and that person's kids turned out fine. When you point out to the person that a range of long-term, well-controlled and documented studies show that, actually, these things result in significantly higher odds of problems for the child and/or mother, they quickly respond by referring back to said relative who did this thing and their kid who allegedly turned out "just fine."
The basic problem here is a lack of grasp of statistics. An anecdote, assuming that the person even grasped the example upon which their anecdote is based, is a single data point. There are always anomalous data points. It doesn't matter what data set you are looking at. And when you deal with biological entities, such as humans, where there are a number of weird confounding variables, you should expect the number of anomalous data points to increase. That does not, in any way, change the fact that there will be clear trends within a larger data pool that will point to underlying causal relationships.
So, I don't care that your grandmother had a beer every day while pregnant with your dad and he came out okay. Your dad's one data point. When you look at a larger picture and take into account a large number of pregnancies, the fact still remains that consuming alcohol while pregnant increases the odds of problems. Note the way that I phrased it there: it doesn't guarantee that something will go wrong, but the chances of something going wrong are much higher. Given our growing understand of fetal and early childhood development, this makes perfect sense.
To make matters more confounding, the emerging understanding of the biology of a developing human is demonstrating that problems related to consumption of substances such as alcohol and tobacco during pregnancy or early childhood (which largely comes from parents using doses of alcohol to get their young children to go to sleep) may be subtle and may not be apparent until the child is older. Problems with coordination, brain development, behavior (related to brain development), etc. may become apparent long enough after the use of the alcohol that nobody without an advanced knowledge of developmental neurology is likely to link the two. Nonetheless, such problems have begun to become apparent in the scientific data, which gives further reason to question much of the folk wisdom regarding the use of various substances while pregnant or nursing, or during early childhood.
Now, flip that around to the "my womb is a temple to my child's purity" group, and you see the flipside of this misapprehension of basic mathematical and scientific concepts. Recently, Kaylia was having a hard time eating. She suddenly had a craving for chicken McNuggets, and she indulged. She has, by and large, been eating well (plenty of fruits and vegetables, good protein sources, etc.), but this one day she had a single thing from a fast food place (which she supplemented with a green salad and some milk). When she mentioned this on Facebook, she received a bizarrely negative reaction from a couple of people who insisted that she was somehow "poisoning her baby!" by eating the deep-fried chicken gloop. Every mother or expectant mother that I know has had a similar experience.
Part of this comes from people who fail to grasp reality just as badly as the people who think that drinking while pregnant is a fine idea. There are studies that show problems resulting from poor nutrition during pregnancy. However, what people who think that "Chicken McNuggets are poison!" fail to grasp is that it isn't some magical substance in the food that causes the problem (well, not usually*), but rather the problems result from chronic malnutrition resulting in women relying heavily on fast food or other nutrient-poor diets through a substantial portion of their pregnancy. Having Chicken McNuggets every now and again is not going to do you or your fetus any harm. In fact, much of the alarmist thinking regarding these sorts of things seems to derive from some of our deep-rooted mechanisms for avoiding contagion and pollution (the same mechanisms that, weirdly, also likely form at least part of our tendency towards bigotries), where we have a notion of "one drop pollution" built into our brains (and conversely, the real issue of dose size corresponding to response is counter-intuitive and therefore often ignored, even though it is actually true), which gets applied even when it is plainly, obviously wrong.
Another part of this seems to comes from the fact that people have a difficult time separating what seems gross to them from what is actually bad for them. This is probably related to our weird, and wrong, built-in cognition regarding pollution, but it seems to go wider. If you know the process by which Chicken McNuggets are made, it sounds pretty disgusting. However, the process does not result in anything that is dangerous (provided it is eaten in moderation). Indeed, during the Facebook thread, the majority of the comments attempting to take Kay to task focused not on any actual data regarding the content of the food, but instead on the perceived "grossness" of how it was made. The fact that these people were having such problems distinguishing food safety reality from their culturally-inculcated ideas regarding disgust made their holier-than-thou attitude about the matter even more annoying than they otherwise would have been.
One of the obnoxious issues that we have encountered is that it is very common for people in one of these two groups to not grasp that you are not from the opposing lunatic group when you disagree with them. Suggesting that someone might want to reconsider using whiskey to put their child to sleep (yes, I know people who have done this) is not the same as saying that you should only be feeding your child shaman-blessed dehydrated organic carrots from the Mongolian Plain. Likewise, being willing to feed your kid formula on occasion rather than a diet of all breast milk all of the time** doesn't mean that you are an unfit parent who would willingly let their kid shoot up heroine by the age of one.
Ultimately, we have made it as a species as long as we have because we are resilient, and we do alright in the long run. We don't need to have a moral panic over whether or not a pregnant woman has a hamburger. However, we now have tools, thanks to science, that allow us to find flaws in the folk knowledge that we have long relied upon, and to do better as a result, and those who choose to ignore them for the sake of tradition are being foolish.
*There are, of course, foods that pregnant women should avoid, and an even wider range that pregnant women should only have in moderation. These are well known, though you should check with a real doctor (the kind you'll find at a real hospital) and not the local naturopath, herb seller, etc. The research backing pregnancy diets is fairly good, but most people outside of medicine rely overly-much of "folk wisdom" that should more accurately be referred to as "folk misinformation."
**Oh, and the weird nations that people have about the magical nature of breast milk are pretty obnoxious, too. Yes, I grasp that the data does support the claim that breast feeding is best for an infant. That doesn't mean that breast feeding is the only, or even the primary, factor influencing success in life, and if you want to rant at me otherwise, then save us both the trouble and go stick your head in a pig.