Parents of newborns often complain about being chronically tired because their infants' crying, feeding, and diaper changing interrupt their sleep nightly. After many nights, they develop what is known as:

I believe the answer is: sleep debt

Sleep debt refers to accumulative effect that keep increasing as people keep not getting enough time for proper sleep. Studies show that in the long run, sleep debt would resulted in decreasing overall productivity and the actual effect of repaying sleep debt could only be felt if the debt is paid within one week period.