Bring up the topic of sleep with a parent of a newborn baby, and you’re likely to receive a deep sigh, a slow shake of the head and a slightly sarcastic comment, such as “Sleep? What’s that?” With newborns waking up for feedings every few hours, parents are understandably sleep-deprived. Big time. Most dream (when they can) of returning to the full nights of uninterrupted, restful slumber they once enjoyed. They also cling to the conventional belief that once their baby starts sleeping for longer stretches through the night — typically at around three or four months — their own sleep will finally return to normal. Unfortunately, that belief may be wishful thinking. A new study has found that the birth of a child not only has a severe, short-term impact on the quantity and quality of the sleep of parents (especially mothers), the effect appears to continue for many years. “While having children is a major source of joy for most parents, it is possible that increased demands and re...