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

Babies who drink breast milk during the night that was expressed in the daytime may take longer to fall asleep, due to changes in the level of the sleep-inducing hormone melatonin in the milk

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 …