If I could sum up my breast-feeding ordeal in one image, it would be me sitting in a hospital bed with one of my newborn sons cradled in my arms.

Above me hovers the lactation consultant, her complexion dewy, her curls buoyant. She clearly hasn’t endured a 38-week twin pregnancy – that’s 14 pounds of baby, baby – followed by a cesarean and 48 hours of unsuccessful breast-feeding, and if she’s trying to hide her impatience with my mental and physical state, she’s not succeeding.

I was supposed to leave the hospital an hour ago, but I can’t go, in the opinion of the lactation consultant, because, up to this point, I’ve done just about everything wrong.

I now realize my not leaving was a little extreme – not to mention spineless. But I was acting on my absolute conviction, inspired and repeatedly reinforced by pediatricians, authors and the U.S. government, that breast is best by a wide and indisputable margin.

Now it’s starting to look as if I, and millions of other women who made significant sacrifices based on that assumption, may have been wrong.

Scientific research

No one is saying that breast-feeding isn’t perhaps, by some measures, a little bit better for your baby’s health, but the argument coming from critics such as Joan Wolf, an associate professor of women’s studies at Texas A&M University, is that the actual scientific research doesn’t say much beyond that.

In her 2011 book, “Is Breast Best?” Wolf cites studies with conflicting outcomes, important methodological problems, and (in the case of positive breast-feeding outcomes) results far less dramatic than we’ve been led to believe.

“My biggest concern is that we have blown infant feeding completely out proportion to its actual importance in babies’ lives,” Wolf says.

“I’m certainly not against breast-feeding in any way, and I think it’s a perfectly viable choice for women who want to do it. But I think it’s very hard right now for a woman to decide whether to breast-feed – there are so many external pressures telling them that it’s the only thing to do, the only reasonable thing to do if you care about your baby. And that concerns me – that we have skewed the alternatives here in ways that are completely inaccurate.”

Causation isn’t clear

Breast-feeding advocates acknowledge that the data aren’t perfect. Because scientists can’t ethically perform experiments in which women are randomly assigned to breast-feed or bottle-feed their babies, they can’t be completely sure that better health outcomes are actually caused by breast-feeding, as opposed to the type of mothering associated with breast-feeding, according to Dr. Richard Schanler, chairman of the American Academy of Pediatrics’ section on breast-feeding.

But Schanler points to an analysis of existing studies in an AAP policy statement that he co-authored. In the analysis, more breast-feeding was associated with better health outcomes.

“When you can’t do a randomized trial, one of the next things you’d like to do is a dose response: Do you get more effect with more breast-feeding? And you see that with a lot of the outcomes that we’ve measured,” he says. “To me, that’s very telling. But can I swear that this is causation, or just association? I can’t, but I have a feeling a lot of this is causation.”

I’ve compiled some of the weakest claims about breast-feeding.

1. It’s not free.

In an article published in the American Sociological Review this year, Phyllis Rippeyoung, an associate professor of sociology at the University of Ottawa, and her co-author, Mary Noonan, an associate professor of sociology at the University of Iowa, looked at the claim that breast-feeding is free. They examined earnings of 1,300 women and found women who breast-fed for six months or more initially made more money than formula feeders. But after childbirth, the long-term breast-feeders’ earnings dipped more, largely due to a reduction in hours worked.

And five years after giving birth, the moms who had breast-fed were, on average, earning less than they did before giving birth ($15,717 a year, compared with $20,957 in the year before childbirth), while the formula feeders group had recouped most of its earnings losses ($16,340 at five years post-childbirth, compared with $16,790 before childbirth).

2. Breast-feeding and IQ.

Among Wolf’s more surprising findings: The evidence for breast-feeding increasing IQ, a big issue in the Baby Einstein era, is quite weak. And don’t just take her word for it: “There was no relationship between breast-feeding in term infants and cognitive performance,” according to a 2007 review of key studies performed for the U.S. Agency for Healthcare Research and Quality.

“But, on balance, you do have this slight correlation – a couple of IQ points, slightly better scores on intelligence tests, and the claim I make, and in fact that a lot of breast-feeding researchers themselves would concede, is that mothers who breast-feed are probably encouraging the intellectual development of their children in many ways. Women who decide that they are going to go through what it takes to breast-feed, particularly if they’re breast-feeding exclusively, if they’re breast-feeding for six months, are more likely to be going the extra mile in ways that might advantage their kids a couple of extra IQ points anyway.”

3. Breast-feeding and weight loss.

In the Agency for Healthcare Research and Quality report, the authors found “the effect of breast-feeding in mothers on return to pre-pregnancy weight was negligible, and the effect of breast-feeding on postpartum weight loss was unclear.”

Of the seven studies they considered, they found that in three, the effect of breast-feeding on return to pre-pregnancy weight was “negligible” (or less than 2.2 pounds) and in four studies, the “effects of breast-feeding on postpartum weight loss were unclear.”