Generations of parents have slogged through sleepless nights, seeking advice from their pediatricians. But many modern moms and dads, overwhelmed by well-meaning but contradictory advice from friends, social media and books, have turned to sleep consultants. The consultants talk with parents to understand their unique challenges and offer tips for improving babies’ sleep environments. They also come up with step-by-step plans for parents that address questions such as when to put babies to bed, how long to let them cry at night and how to respond to that crying