7 week old baby is often sleeping 4, sometimes 5 hours at night before waking. should i wake him up after 3 hours to make sure he's feeding enough?

No: A normal, happy, growing 7-week-old baby follows the saying, "Never wake a sleeping baby." Normal babies at this age who happen to sleep through the night will just eat more during the daytime. Normal babies at 3 months of age can sleep through the night, meaning a 6-7 hour stretch without needing a feeding.

No: What you are describing is a normal sleep pattern in newborn babies. The periods of sleep will vary but will also be initially fairly consistent around a given hour and then gradually increase. As long as the baby is feeding well, the sleep pattern will adjust itself