A reader wrote asking for advice about how to sleep-train her child. Dear Dr. Rosen: I found your blog, Sleeping Angels, through a Google search. My 7-month-old son is not sleeping normally.

may sleep less. 1-4 months old: 14-15 hours per day As early as 6 weeks of age, you may start to notice more regular sleep patterns. Your baby may now sleep as long as 4 to 6 hours, usually during ...