Cribsheet

by Emily Oster

  There is one benefit that does have a larger and more robust evidence base: the link between breastfeeding and cancers, in particular breast cancer. Across a wide variety of studies and locations, there seems to be a relationship here, and a sizable one—perhaps a 20 to 30 percent reduction in the risk of breast cancer. Breast cancer is a common cancer—almost 1 in 8 women will have a form of it at some point in their lives—so this reduction is big in absolute terms.

  This data isn’t perfect—for one thing, the controls for maternal socioeconomic status are almost always missing—but the case for causality is bolstered by a concrete set of mechanisms. Breastfeeding changes some aspects of the cells of the breast, which makes them less susceptible to carcinogens. In addition, breastfeeding lowers estrogen production, which in turn can lower the risk of breast cancer.

  After all that focus on the benefits of breastfeeding for kids, it may be that the most important long-term impact is actually on Mom’s health.

  THE VERDICT

  We can now return, at long last, to our table of significant benefits, and try to weed out those for which we did not find compelling evidence.

  In some cases, things drop out of the table because there is simply no data on them—better friendships, for example. It’s not that we have compelling evidence to reject this, it’s just that no one has actually run any studies about it. In other cases—obesity, say—the facts show that people have studied this, and the best data doesn’t support a link.

  For the relationships that were dropped from the table, nothing in the data suggests they are really linked. Put differently, you might equally plausibly link breastfeeding to a wide variety of other outcomes—being a fast runner or good at playing the violin. This doesn’t mean it can’t be true, just that there is nothing in the data to suggest it is. You can take the relationship on faith, but you shouldn’t take it as evidence.

  Short-Term Baby Benefits

  Fewer allergic rashes

  Fewer gastrointestinal disorders

  Lower risk of NEC

  Fewer ear infections (maybe)

  Long-Term Child Benefits: Health

  Long-Term Child Benefits: Cognitive

  Benefits for Mom

  Lower risk of breast cancer

  Benefits for World

  Lower methane production from cows

  Our list of benefits supported by evidence is now more limited, although not entirely empty. There do seem to be some short-term benefits for your baby, and maybe some longer-term benefits for you. And don’t forget the methane! But relative to the initial list, this one is a lot shorter.

  The pressure on moms to breastfeed can be immense. The rhetoric makes it seem like this is the most important thing you can—and need—to do to set your child up for success. Breastfeeding is magic! Milk is liquid gold!

  This just isn’t right. Yes, if you want to breastfeed, great! But while there are some short-term benefits for your baby, if you don’t want to nurse, or if it doesn’t work out, it’s not a tragedy for your baby, or for you. It is almost certainly worse if you spend a year sitting around feeling bad about not nursing.

  When I was writing this book, I looked back at the books my mother and grandmother used when they had children. My mother was a fan of Dr. Spock’s Baby and Child Care, a book written in the 1940s and updated periodically; I have her version from the mid-1980s.

  Dr. Spock addresses the issue of breastfeeding by suggesting that moms try it to see if they like it. He says something brief about possible protection from infection for babies, and then says, “The most convincing evidence on the value of breastfeeding comes from mothers who have done it. They tell of the tremendous satisfaction they experience from knowing that they are providing their babies with something no one else can give them . . . from feeling their closeness.”

  At least for me, this resonated very strongly. I am happy I nursed my children because—aside from some of the early hot-closet incidents—I enjoyed it. It made for many nice moments with them, doing something we could only do together, watching them fall asleep. This is a great reason to do it, and a good reason to try. It’s also a good reason to support women who want to try, and to not shame women who breastfeed in public. But this is not a good reason to judge yourself if you decide breastfeeding isn’t for you.

  The Bottom Line

  There are some health benefits to breastfeeding early on, although the evidence supporting them is more limited than is commonly stated.

  There are likely some long-term health benefits, related to breast cancer, for Mom.

  The data does not provide strong evidence for long-term health or cognitive benefits of breastfeeding for your child.

  5

  Breastfeeding: A How-To Guide

  When I think back on my first weeks of breastfeeding Penelope, they are mostly a haze of frustration.

  At the time, I felt like I had all the breastfeeding problems. The latching problem. The supply problem. I would nurse and nurse and then every night we’d have to feed Penelope a huge bottle, which she sucked down, seemingly judging me for not having enough milk (I might have been imagining that). Then there was the pump: When to pump? How often, early on? Once I was back at work, how was I supposed to relax enough to pump? Can you pump on a conference call? Only if you mute it?

  It can feel like you are the only person with these problems. This is especially true at the beginning, when it’s hard to make breastfeeding work. The hours of sitting alone in a room with a newborn, trying to get them to eat—it’s isolating. This is exacerbated by the fact that all the breastfeeding moms you see—the ones walking around the farmers’ market nursing their infants—seem to be having no problem carrying a bag of corn, herding their three-year-old past the cookie display, and feeding their baby. Maybe you are the only one with problems.

  You are not. In writing this chapter, I appealed to Twitter: Fellow moms, tell me your breastfeeding woes.

  They had a lot to say.

  People told me about trying and trying to get their babies to latch, without success. They told me about their “stupid tiny nipples” and the time they bought a “booby tube” (Google it). About painful nipples—bleeding, cracked, and, in one especially gory case, actually partially coming off.

  People told me about supply issues. Undersupply—the time one woman sent her husband on a thirty-minute bus ride to get her nettle tea right now, or the constant attempts to increase supply by nursing and then pumping twelve times a day, after every feeding. Oversupply—leaky breasts getting milk on everything; mattresses smelling of Parmesan and clothes stiff with dried milk. One woman told me she had an undersupply of milk, yet started spurting milk on the bus every time a baby cried.

  And then there was the pump. “Pumping is the worst” filled my email inbox. One woman said she lost her fingerprints from transferring sterilized pump parts to a drying rack. People wrote of feeling isolated and falling behind at their jobs because of the hours they spent shut in their offices pumping, of the embarrassment of asking for pumping time on business trips, or pumping in the bathroom since there was no other place to do it. And they told of the frustration of not getting enough milk, even with all their effort.

  I can perhaps be accused of armchair psychology here, but these struggles seem particularly acute because trying harder—something that usually breeds success—doesn’t always work with breastfeeding. You worked hard to get a job, or to get into college—even to get pregnant—and you were successful! But introduce a new person, and some further constraints of biology, and all bets are off. You may have to accept, as I did, that no matter how hard you try, you will not make quite enough milk.

 
It is not helpful that this is a surprise for many women, who thought, Hey, billions of people do this, how hard can it be? When I asked, many women expressed the wish that they had known it could be so hard and had not felt such shame and pressure to continue. For that, I refer you to the previous chapter. Here, let’s leave it at this: Breastfeeding is hard for many women, and many women struggle with it, especially with their first child. If you are one of them, you are not alone. There is some evidence that might help in the pages that follow—and giving yourself a break will help, too.

  GENERAL INTERVENTIONS

  If, like many breastfeeding women, you have faced these challenges, you have likely heard about many different strategies to overcome them. Some of these strategies seem reasonable, some not so much. What does the data say?

  Evidence on causes of breastfeeding success can really be divided into two categories. There are some specific questions: Do nipple shields work? Will fenugreek increase your milk supply? And there are more general questions: Is there anything you can plan on before birth that might increase your likelihood of breastfeeding success?

  The broad answer to this second question is yes, there are two evidence-supported things you can do. We’ll start with these.

  First, there is some randomized evidence on the success of skin-to-skin contact at improving breastfeeding success rates. Skin-to-skin contact is the practice of having women hold their naked (or diapered) baby against their naked chest, typically right after birth. The idea is that the smells and the proximity will encourage the baby to start feeding immediately. Much of this evidence comes from developing countries, where the overall breastfeeding rates are different and technologies around birth may also be different. Nevertheless, breastfeeding is a universal human experience, so there is no reason we cannot learn from the experiences of women in these countries. One study of two hundred women in India randomized the mothers into either holding their infant skin to skin for forty-five minutes after birth or having them in an infant warmer.1 The moms who had their infants skin to skin were more likely (72 percent versus 57 percent) to be breastfeeding at six weeks; they also reported less pain while being stitched up after birth.

  These results are confirmed by a review of a large number of small studies.2 Putting them together, breastfeeding initiation and success seem to be higher with skin-to-skin contact, including after a caesarean section.

  Second, there is some (more limited) evidence that breastfeeding support—by a doctor, or by a nurse or lactation consultant—can increase likelihood of breastfeeding initiation and continuation.3 This evidence comes from a wide variety of studies of different types of interventions. Because not all the interventions are the same, it is hard to pinpoint precisely what is useful. The basic principle is that it can take time to learn to nurse, and having assistance from someone who has seen it before may help you work past some of the obvious problems. It may simply be helpful to have someone to strategize with, ideally someone who has slept in the past few days and can provide some perspective. (This can, by the way, help with a lot of decisions about your newborn.)

  A couple of small studies focus on hospital versus in-home education, and find some additional benefits from getting help once you’re home from the hospital.4 The hospital environment is not your own, and having someone come to your home to help you figure out what you are doing can be hugely useful.

  Anecdotally, breastfeeding support at the hospital can be hit or miss. Some women described their lactation consultants as judgmental and mean. Others thought they were great. If you are not getting the help you need, keep asking to see if you can find the right person. If you can manage it, getting this help from someone you know and trust—a doula, or perhaps a lactation consultant you’ve talked to before the birth about what you want—may be the most helpful.

  A final general intervention that deserves mention is rooming in at the hospital. As discussed in an earlier chapter (see this page), there is no evidence that this enhances the likelihood of breastfeeding success.5

  LATCHING ON

  If you are planning to breastfeed, the first challenge is the latch. In order to efficiently get milk from the breast, your baby needs to open their mouth pretty wide and get your whole nipple in their mouth; they then use their tongue and lips to suck. Contrary to what I had envisioned, it is not like they are delicately sipping the end of the nipple. In the words of my friend Jane, “You really have to jam the kid on there.”

  There is a picture below that captures the fact that the baby needs to get a whole mouthful of boob, although not that you have to jam them on. I will say that until you see it for yourself with an actual baby, it’s tough to visualize.

  Many infants struggle to latch on correctly. Without a good latch, the baby will not get enough milk, and it can be extremely painful for Mom. How do you know you have a good latch? Once you have done it for a while, you’ll just know. You’ll also learn to recognize a kind of weird sigh that many babies have when they get it right. Before that . . . it is useful to have someone else look and tell you. The internet will tell you that if you have a good latch, nursing will not hurt. More on this later, but for now, know that early on, this is often not true. For many women, breastfeeding will hurt for the first couple of weeks whether the baby is latched well or not, so you cannot reliably use pain as a signal.

  Why might infants have trouble latching? Prematurity, illness, or birth injury could be the cause. It could also have to do with their mother’s nipples—some women have inverted nipples that can make latching difficult. Finally, some infants have structural issues in their mouths—in particular, conditions called tongue tie or lip tie—that make it difficult to latch.

  Or maybe your baby hates you! Ha, I’m kidding. It will only feel like that.

  One solution to this problem—at least to some extent—is to keep trying with someone around to help you. Here is where a doula or other support person might come in. Most people do get the hang of this, but being patient with yourself is likely to make it go better.

  If you have prolonged problems with latching, there are two common interventions: nipple shields and a (quick) surgical procedure to address tongue tie.

  Many women swear by nipple shields, at least early on. The name is pretty descriptive: they are shaped like a nipple, typically made of silicone, with little holes in them. You put the shield over the nipple, and the infant sucks on that. These shields can make it easier for infants to latch, in principle, and make nursing less painful for Mom.

  The main downside of the nipple shield, other than that it is annoying to wash, is that it affects milk transfer. The shield reduces stimulation, so your body produces less milk.6 There is a clear physiological basis for this, and it has been shown in randomized trials.

  This doesn’t answer the question of whether nipple shields are effective, though, since the point isn’t to increase milk transfer but to get the baby on the breast in the first place. Unfortunately, there is no very good evidence on whether they work. The best study we have is of thirty-four premature infants, in which researchers had access to information on how much milk they got with and without the shield. This study found that infants got way more milk with the shield than without—more than four times as much—which is encouraging. But, again, this study wasn’t randomized, the sample was tiny, and it focused on a particular population.7

  What we do have as evidence is a lot of qualitative work in which women are interviewed about their experiences with using nipple shields, and they do credit the shields with allowing them to continue breastfeeding and working through issues like pain and latching problems.8 There is an implicit counterfactual here—that they would have quit without the shield—although it is hard to know if this is right.

  The downside of trying nipple shields is that it can be difficult to quit using them—if you and your baby get used to them, it might be hard to transition off. This is okay if you a
re happy using them and your baby is getting enough milk, but it does add another step to the feeding process. So it is probably not a first-line defense—as in, not everyone should start with these. On the other hand, if things are not working, they’re a good option to try.

  A more involved intervention is a surgical procedure to address tongue tie or lip tie in infants. This suggestion will come up only if your infant actually has a tongue or lip tie. The tongue attaches to the floor of the mouth with a cord called the frenulum. In some people, this cord is very short, which can limit tongue mobility. For infants, this can affect the ability to breastfeed, since the mechanics rely on the tongue. Tongue tie is thought to be reasonably common, and in serious cases can affect speech later in a child’s life. Lip tie refers to a similar (but less common) condition in which the cord that attaches the upper lip to the gums is short, or placed very low, limiting lip mobility.

  There is a simple surgical solution to either condition, which is to snip the cord, releasing the tongue or lip and allowing it to move more freely. The surgery is common and safe, and mechanically it does seem like it could be effective.9

  The evidence in favor of realized success, though, is fairly limited. There are four randomized trials of this procedure, all of them very small, and only three of which evaluate its impact on feeding success.10 Among these, two showed no difference in feeding success, and one showed improvements. All four studies did show improvements in maternal pain during nursing, although this was self-reported. The limited evidence suggests that this procedure, even more so than nipple shields, shouldn’t be a first-line defense, even in cases where some tongue tie is present.