In the latest edition of Our Bodies, Our Lives by UTMB Drs. Tristi Muir and Catherine Hansen: While we blame pregnancy for a momentary lapse of memory, sleep deprivation may actually be the cause of forgetfulness. During pregnancy, sleep becomes interrupted. Women have to wake up to roll over or their bladder sends them running to the bathroom. In the first year after the baby’s birth, a woman accumulates up to 700 hours of sleep debt.