In healthy pregnant women, eating over a longer period of time during the day is linked to lower levels of melatonin at night, but only in the third trimester, suggesting that how meals affect sleep hormones changes as pregnancy advances.

In pregnant women during the later stages of pregnancy, eating over a period longer than 12 hours per day is linked to lower levels of melatonin, a hormone that regulates sleep-wake cycles, across multiple measures of its daily production.

Pregnant women who do not eat breakfast tend to have lower levels of cortisol in the morning during the second and third trimesters of pregnancy, suggesting a link between skipping this meal and a reduced stress hormone response upon waking.