Sleep is a truly tricky thing for all new families. It can be a really polarizing topic for many parents as well as professionals who support them.
While I can understand a practitioner's stance to not want to be included due to different approaches being represented, it is of the utmost importance that parents do know their options across the board. This may be a bit long-winded, but take as much or as little of this as you like and I'm happy to elaborate more as well as put you in touch with our Sleep Consultants.
Although the AAP's stance is that an infant should be in the same room with parents for at least 6 months and optimally one year, the policy is very clear that the infant has a separate sleep surface, i.e. not in the parents' bed. Due to this recommendation and the fact that most pediatricians follow these recommendations, it is very difficult to get proper research on co-sleeping and infant safety due to the fact that parents who may be co-sleeping are reluctant to share this information with care providers.
The true research on co-sleeping comes from Dr. James McKenna who is running a sleep lab at Notre Dame University. His research is based in breastfeeding and co-sleeping and supports co-sleeping with breastfed infants as not only safe, but important for development and attachment. That's the academic way to look at this and we could dive into that research as it's fairly new and really interesting, but I'm going to give you the answer we give the families. (Here is a link to more about Dr. McKenna: https://cosleeping.nd.edu/)
At the mama 'hood we base everything we recommend based on what the family wants to do. If a family comes to us looking for sleep training, while we don't do that, we are happy to help them understand different methods and locate a professional who may be able to help with a sleep training program. We try to always remind the mama that the infant is a tiny mammal that lacks cognitive reasoning. The reason an infant left alone will cry for it's mother is not because it's spoiled, it is simply because it is a mammal and it is alerting it's caretaker that it is alone and it needs to be retrieved before the wolves find it. Human infants are born more premature than any other primate. We are underdeveloped at birth due to evolution - when we started walking upright the pelvis narrowed, therefore the birth canal narrowed, therefore human infants heads had to be smaller to come thru the birth canal safely, and human infants were born before reaching a mature gestational age. Babies aren't ready to be left alone, can't take care of anything for themselves, and must use their cries to communicate their needs with their caretakers. Realizing this about our babies is very helpful for parents to realize, a human baby is not equipped to be left alone for a significant amount of time - it is truly not safe. When appropriate I will use the anecdote that if you walk into an orphanage that has babies lined up in cribs, it is eerily silent. The babies aren't crying as a defense mechanism. Because they were crying and no one came to them, in order to defend themselves from predators they stopped crying so the wolves couldn't find them. In essence, they gave up, their mammalian brain took over and knew how to keep itself safe.
Now, are there cases where it may be absolutely necessary to sleep train a baby? Perhaps. If mama is suffering from postpartum depression and anxiety, a lack of sleep can simply exacerbate this and in some cases lead to postpartum psychosis. Therefore making a sleep plan that works which may or may not include sleep "training" makes sense. There is only anecdotal evidence of long term effects of sleep training on infants. However, the parenting style that would seek out rigid sleep training may also lend itself to accept it's outcomes.
As with everything, we ask parents, "What do you want to do?" If they say I want to sleep - we discern what that means for the family. An infant has to eat every few hours, it's just how it works biologically. Expecting a tiny infant to sleep "thru the night" is unrealistic and can be harmful. So we work with the family to define what "thru the night" means. We work on the environment for sleep for the entire family. And if the conversation comes about that what a mama really wants to do is sleep with her baby in bed with her, then we talk about how to do that safely.
From the approach of anthropological parenting we can discern what we could have done "in the cave." However, we don't live in the cave anymore so how can we take what we've learned from how infants and their caretakers have slept for thousands of years and apply it to what we do now. Understanding the infant as a tiny helpless mammal makes a lot of sense to parents once it's broken down for them. Giving parents access to the research, an anthropological perspective, and permission to follow their instincts, generally leads them to an outcome they can feel happy with and empowers them to know they are doing what is best for them and their family in their crazy lives.