Cribsheet: A Data-Driven Guide to Better, More Relaxed Parenting, from Birth to Preschool (The ParentData Book 2)

by Emily Oster

These tests are quite good at detecting hearing loss (they catch 85 to 100 percent of cases), but turn up a lot of false positives. By some estimates, 4 percent of infants will fail this test, while only 0.1 to 0.3 percent actually have hearing loss.

The authors of this paper created a website, www.newbornweight.org, where you can enter the time of birth of your child, method of birth, method of feeding, birth weight, and current weight and learn where they are in the distribution.

In high concentrations, bilirubin is neurotoxic (meaning it can poison the brain), so jaundice is potentially very serious in extreme cases. Severe untreated jaundice can lead to a condition called kernicterus, a form of long-term brain damage.

As there is for determining risky infant weight loss, there is also a website that will tell you if jaundice treatment is recommended given bilirubin levels: www.bilitool.org. It’s for doctors, but it’s accessible to anyone who is curious.

On net, the recommendations increasingly favor delaying the cord cutting, if possible.

Two treatments have some known success with colic. One is supplementation with a probiotic, which a number of studies have shown to reduce crying.

The other treatment that has shown some success is managing the baby’s diet, either by changing formula types or, if the baby is breastfed, changing the mother’s diet. Changing formula is relatively straightforward, although the formulas appropriate for colic tend to be a bit more expensive. One recommendation is to switch to a soy-based or hydrolyzed protein formula10 (most of the major formula makers—Similac, Enfamil—have versions of these).

If you’re breastfeeding, changing the baby’s diet is complicated, since it means changing your own. There is some evidence supporting a “low-allergen” diet for Mom: randomized studies have shown reductions in crying and infant distress when mothers adopt this type of diet.11 The standard recommendation is the elimination of all dairy, wheat, eggs, and nuts, so this means a pretty dramatic dietary change.

for example, the two category-killer sleep books: Ferber (Solve Your Child’s Sleep Problems) and Weissbluth (Healthy Sleep Habits, Happy Child). Both provide some guidance on the amount you should expect your child to sleep. The trouble is, they do not agree. Ferber, for instance, says that at six months, a baby should sleep a total of about 13 hours: 9.25 hours at night, and two 1- to 2-hour naps. Weissbluth suggests this same six-month-old should sleep a total of about 14 hours, but with more of those hours falling at night: 12 hours at night, and two 1-hour naps. This is a 3-hour difference in the suggested nighttime sleep.

One academic article on parental approaches to sleep lists forty different books, from Ready, Set, Sleep: 50 Ways to Get Your Child to Sleep to Winning Bedtime Battles.

Weissbluth, Healthy Sleep Habits, Happy Child Ferber, Solve Your Child’s Sleep Problems Ezzo and Bucknam, On Becoming Baby Wise Pantley, The No-Cry Sleep Solution Hogg, Secrets of the Baby Whisperer Waldburger and Spivack, The Sleepeasy Solution Mindell, Sleeping Through the Night Giordano, The Baby Sleep Solution Turgeon and Wright, The Happy Sleeper

One of the things visitors noticed in these places was the eerie quiet of the rooms the children were kept in. Infants and babies didn’t cry, because they knew no one would come. The argument is that “cry it out” is the same thing: Your baby will stop crying because she knows you will not come, just as the children in these orphanages did. And just as in those settings, her ability to attach to you and others will be forever changed.

“Cry it out” works, helps parents and kids sleep better, and improves parental mood and happiness. Is it harmful for your child? There are a number of good randomized trials that speak to this. One representative study from Sweden, published in 2004, took ninety-five families and randomized them into a sleep-training regime involving a form of “cry it out.”8 The authors focused on whether behavior during the day was impacted by the nighttime—basically, they asked whether the infants were less attached to their parents during the day as a result of being left to cry during the night. This particular study found that, in fact, infant security and attachment seemed to increase after the “cry it out” intervention. It also found improvements in daytime behavior and eating as reported by the babies’ parents. Note that this is the opposite of the concerns raised about “cry it out” methods. This study is not alone. A 2006 review of sleep-training studies, which included thirteen different interventions, noted the following: “Adverse secondary effects as the result of participating in behaviorally based sleep programs were not identified in any of the studies. On the contrary, infants who participated in sleep interventions were found to be more secure, predictable, less irritable, and to cry and fuss less following treatment.”9 (Translation: Nothing bad happened in any study, and in most cases, the babies seemed happier after sleep training than before.) More recent studies draw t...

A number of academic articles argue against “cry it out” from a theoretical perspective. One good example comes from an article published in 2011 in a journal called Sleep Medicine Reviews.13 The authors of this article presented a case against “cry it out,” largely based on the idea that infant crying is intended as a signal of distress, and parents should therefore not be encouraged to ignore it. They draw on the attachment theories cited earlier (i.e., the orphanage literature), and argue that parents who engage in this are ignoring their children’s efforts to begin communication with them. The fact that “cry it out” works is not compelling to these researchers and, indeed, is an indication of harm. As one article in the journal Sleep put it, “Is the cessation of crying a ‘cure’ or is it that the child has ‘given up’ and is now depressed and has partially withdrawn from the attachment dyad?”14 The primary argument offered by this and similar papers is that infant crying is a signal of stress (probably true) and that stress, even over a short period of days or weeks, may have long-term consequences for babies (this is speculative).

The goal of the stay in the lab was to sleep train the infants. Nurses in the study collected data on the stress hormone cortisol in both the babies and their mothers, and were also responsible for putting the infants to sleep, and monitoring the sleep training. Before the sleep training each day, the babies’ and moms’ cortisol levels were tested and recorded. This was done again after the infant fell asleep. On the first day, the babies all cried. Their cortisol levels were the same before the training and after they fell asleep. Their mothers’ cortisol levels were also the same before the babies cried and after they were asleep. This was the same on the second day. On the third day, none of the infants cried (see above: sleep training works). However, they showed the same cortisol patterns: equal before bedtime and after they fell asleep. But for the moms, this changed: they had lower cortisol levels in the later period, when the babies weren’t crying. The authors suggested that this presents a problem with sleep training. In particular, they note that after sleep training, the mother’s stress levels do not stay in sync with the infant’s, which they interpret as possible evidence that the attachment between mother and infant is weakening. A number of commentators have argued that this is an overinterpretation of the study. For one thing, there is no baseline level of cortisol given, so we actually have no way to know if the babies were even experiencing elevated stress. ...

A related argument is that although children may look fine at five or six years old, the damage from sleep training may not manifest until they are adults. Again, very hard to study. I think it is fair to say that it would be good to have more data—it’s always good to have more data! And yes, it is possible that if we had more data, we would find some small negative effects. The studies we have are not perfect. However, the idea that this uncertainty should lead us to avoid sleep training is flawed.

You could also argue that the effects of maternal depression on children are long-lasting, and therefore this intervention may have beneficial long-term effects. This seems in many ways more plausible. You’ll have to make a choice about this without perfect data. (This is true of virtually all parenting choices.

Most “cry it out” methods are variants on one of three themes: Extinction—just leave, and do not return; Graduated Extinction—come back at increasingly lengthy intervals; and Extinction with Parental Presence—sit in the room, but do not do anything. Ferber is a proponent of the second, whereas Weissbluth is more in favor of the first. There is evidence that all three methods work—more evidence, perhaps, on the first two than the third—but relatively little evidence on which works best. On the one hand, some reports seem to find that Graduated Extinction is easier for parents and leads to more consistency; other studies have found it prolongs crying.16 The only general principle from these is that consistency is key.

Daytime sleep is more complicated than nighttime sleep. It comes together later (as we talked about in the baby-organization chapter), and it is dropped sooner. Even infants who sleep very well at night have more variable daytime sleeping schedules. All this is to say that sleep training is likely to be more hit-or-miss for naps than at bedtime.

And we did sleep train Penelope, working roughly out of the Healthy Sleep Habits, Happy Child playbook.

Finally, at one pediatrician visit, we explained our system to Dr. Li, who told us, nicely but firmly, that we should probably cut it out with the checks. When we did this, the sleep training finally took, and Penelope became (and remains) a good sleeper.

After some back and forth, we agreed on the following system. PART 1: BEDTIME/START OF NIGHT Finn will go to bed during Penelope’s bedtime, around 6:45. We will put his pj’s on and read him a book as part of the bedtime routine. He will nurse, and then we’ll put him down in bed. We will not return at all before 10:45 p.m. PART 2: OVERNIGHT SCHEDULE Will feed Finn the first time he cries after 10:45 p.m. After the first feeding, do not respond again until at least 2 hours after the end of each feeding. Example: If he eats from midnight to 12:30 a.m., then do not respond for another feeding until, at the earliest, 2:30 a.m. NOTE: THE LONGEST STRETCH OF SLEEP IS EARLY IN THE NIGHT, SO WEISSBLUTH SAYS WE SHOULD RESPOND MORE FREQUENTLY IN THIS PERIOD THAN AT THE START OF THE NIGHT. PART 3: THE MORNING Wake-up is between 6:30 and 7:30 a.m. If he is awake at 6:30 we get him up. If he is not awake he can sleep until as late as 7:30. At that time we wake him up if he is not up already. This plan is roughly in the Weissbluth mode. The goal was to encourage Finn to go to sleep on his own at bedtime, but not to deprive him of food. We started this around ten weeks, at which point he was still eating two or three times a night, but we thought he was ready to fall asleep alone at the start of the night. I did get a successful do-over on this one. Finn was much easier than Penelope—he cried for perhaps twenty-five minutes the first night, a few minutes on the second, and then very little...

The results—I put them in a graph on this page—are striking. Children who were exposed to peanuts were far less likely to be allergic to them at the age of five than children who were not. In the group that didn’t get peanuts, 17 percent of children were allergic to peanuts at age five. (Remember, this figure is higher than it would be in the general population because of the way the researchers selected their sample.) However, only 3 percent of the children who were given peanuts were allergic. Since the study was randomized, there was no reason other than the peanut exposure that allergy rates would be different. And these differences showed up in both the high- and low-allergy-risk groups.

Early exposure to peanuts is now the normal recommendation, especially for children at risk for an allergy. The hope is that with wider dissemination and use of these updated recommendations, there will be fewer life-threatening peanut allergies.

The AAP recommendations echo the traditional Western way to introduce your children to food. This begins, between four and six months, with either rice cereal or oatmeal. You feed your child with a spoon.

Then, a few days or a week later, you introduce fruits and vegetables, one variety at a time, every three days. The standard advice is to do veggies first so kids do not learn fruit tastes better. A month or so after that, you introduce meat. All of this is in a pureed form and fed to your baby with a spoon.

Eventually, you introduce foods the kid can pick up with their hands. This would include, say, Cheerios and rice puffs. Gradually, around a year or so, you phase out the

You start with rice cereal because it is flavorless, and you can therefore mix it with breast milk or formula so your kid is more likely to eat it. These cereals are also iron fortified, which is helpful if you’re nursing, since this is an age at which breast milk may no longer provide enough iron.

The delay between food introductions is to see if any food causes an allergy. If you feed your kid strawberries and eggs and tomatoes and wheat all in a single day and they have an allergic reaction, it will be hard to know what the source is.

Nearly all allergies are caused by one of a few foods—milk, eggs, peanuts, and tree nuts—and it’s sensible not to introduce these foods all at the same time.

As a review article from 2012 notes, “The majority of children between one and five years of age who are brought in by their parents for refusing to eat are healthy and have an appetite that is appropriate for their age and growth rate.”

Other studies show that parental pressure to try new foods or to eat in general is associated with more food refusal, not less.13 These studies also show that food refusals are more common in families where parents offer an alternative. That is, if your kid doesn’t eat broccoli and then you offer him chicken nuggets instead, he may learn that this is always the reward for not eating new foods.

If they won’t eat the new foods, don’t replace the foods with something else that they do like or will eat. And don’t use threats or rewards to coerce them to eat.

The vast majority of allergies result from eight food types: milk, peanuts, eggs, soy, wheat, tree nuts, fish, and shellfish. The incidence of these allergies has grown over time, perhaps as a result of better hygiene (so less allergen exposure early on), and clearly due in part to a lack of early introduction.

All this points to the possible importance of introducing all these allergens early—probably as early as four months. (Milk can be introduced in the form of yogurt or cheese.)

Which leads to the question: How? This is a setting in which going slowly is a good idea. Try a little bit at first—only one allergenic food in a given day—and see how they react. If nothing, give them a little bit more. And so on until you get up to a normal amount. And then keep these foods in the rotation.

Finally, honey. The concern with honey is that it could lead to infant botulism. Infant botulism is a serious disease—basically, a toxin interferes with neurological functions, including affecting the infant’s ability to breathe. It is most common under the age of six months and it is treatable, with a very high success rate. Still, the treatment is not easy: the baby typically needs to be hooked up to a breathing machine for a few days until they are able to breathe on their own again.

infants who developed botulism had consumed honey, led to the recommendation against honey through the first year of life (sometimes even two or three).

Vitamin D deficiency causes rickets. Vitamin C deficiency famously causes scurvy, as was first recognized in sailors who went months without eating any fresh vegetables or fruit. However, if you eat a typical varied diet—even one that’s pretty unhealthy by many standards—you are very unlikely to be seriously deficient in any of these vitamins.

In addition, doctors will look for some basic developmental milestones at each visit. Here are some examples from the 9-, 18-, and 30- or 36-month visits. Visit Milestones 9 months Rolling both sides, sitting with support, motor symmetry, grasping and transferring objects between hands. 18 months Sitting, standing, and walking independently; grasping and manipulating small objects. 30 months Subtle gross motor errors, looking for loss of previous skills (marker of progressive disease).

Milestone Range Sitting without support 3.8 months to 9.2 months Standing with assistance 4.8 months to 11.4 months Crawling (5% of kids never do) 5.2 months to 13.5 months Walking with help 5.9 months to 13.7 months Standing alone 6.9 months to 16.9 months Walking alone 8.2 months to 17.6 months

On the other hand, there is a tremendous amount of evidence suggesting that exposure to TV—and, more generally, to any screens—is associated with lower cognitive development. Researchers have shown that kids who watch more TV are less healthy and have lower test scores.

The American Academy of Pediatrics falls squarely in agreement with the second answer. They recommend no TV or screen time at all for children under eighteen months, and no more than an hour a day, ideally consumed with a parent, for older children. In addition, they recommend choosing “high-quality” programming, such as that featured on PBS. That would include Sesame Street, although it would also include less learning-focused shows, such as the parent-despised Canadian-export Caillou.

In one example, children twelve, fifteen, and eighteen months old were shown either a live person or a person on TV demonstrating some actions with puppets.1 The researchers evaluated whether the children could repeat the action either in the moment or twenty-four hours later. In all three age groups, when kids watched an actual person doing the action, some of them were able to replicate it a day later. The video demonstration was much less successful—the twelve-month-olds learned nothing, and the older kids learned much less than from seeing a live person do it.

Does TV rot your child’s brain? Many studies say yes. For example, a 2014 study shows that preschoolers who watch more TV have lower “executive function”—meaning less self-control, focus, etc.9 An earlier study, from 2001, shows obesity is higher among girls who watch more TV.

Based on what is available, I’d say we can learn a few things: Children under two years old cannot learn much from TV. Children ages three to five can learn from TV, including vocabulary and so on from programs like Sesame Street. The best evidence suggests that TV watching in particular, even exposure at very young ages, does not affect test scores.