I'm not sure if it will exactly kill the baby but you should not give the baby anything that is not for infants because it could be too big a dose causing an overdose. Or it could make them really sick, I would look up some nice pm remedies online if I were you! Hope this answer helps! :)
Are you pregnant and taking this? Or are you giving this to your child? Either way, here's my take.....if you're pregnant, many other ways to aid sleep naturally, several teas like chamomile or sleepytime tea will work, aroma therapy with lavender, a nice warm bath and a good book. Now if it's baby, don't give baby adult medication yes, it can harm the child....it's nit made for children. Again, a nice warm bath with lavender baby wash then lotion will go a long way in aiding the young one to sleep.