Timing of expressing breast milk and a baby drinking it affects infant sleep

By Alice Klein

Babies who drink expressed breast milk can have disrupted sleep patterns if they consume the milk at a different time to when it was pumped. This may be due to them receiving a mistimed dose of hormones that influence sleep-wake cycles.

Infants are born without circadian rhythms. They rely on external cues, such as routines and changes in light levels, to help them develop a sense of night and day.

A group of German researchers previously found human breast milk contains five times as much of the sleep-inducing hormone melatonin at night, defined as 10pm to 10am, compared …