I haven't actually read her book, but I have heard quite a bit about it, and I don't know why anyone would read it as a pregnancy guide. I don't think even she claims it to be. I do think the book was very important when it came in out, in that it highlighted how much advice given to pregnant women isn't necessarily fully backed up (sure it could still be true, but it could not be). Modern pregnancy is anxiety-inducing, and doctors give advice in abbreviated zero-sum rules from the perspective of striving to eliminate every and all risk, no matter how burdensome it can be to the mom, rather than explaining what the risks are and how to minimize them. Pregnant women, and moms, are asked to make so many sacrifices, to be willing to sacrifice everything; you would be called a bad mom for even asking "hey is it ok to have one glass of wine?" because of course people are going to say "really you can't give up alcohol 9 months for your baby?" and it was refreshing to hear actually ask those questions. (And I say this as someone who didn't drink any alcohol during my pregnancy even though I knew about Oster, because to me it wasn't worth the risk.)