Babies are more prone to infections and are best kept at home for the first two years of their lives rather than being with too many different people day in day out.And the way I see it having a trustworthy,loving nanny will be better for an infant since he will also have more invidual attention and care. And I feel as a working mother who will constantly be needing to moniter your childs caretaker dealing with one fixed person will always be easier and it will be in the comfort of your own home.