Why is sleep so important to getting pregnant? There are actually multiple reasons. Sleeping (or not sleeping) has a powerful effect on your body’s hormonal system. If you don’t get enough sleep, then your cycle as well as ovulation can get thrown off. If you don’t get enough shut-eye, your leptin (appetite hormone) levels typically go down, and this can negatively impact ovulation as well. People who have serious sleep problems, like insomniacs, also tend to have higher levels of stress hormones, which is not encouraging of fertility. (9)