Sleep during Pregnancy
Women may experience increased sleepiness and fatigue during pregnancy. Changes in sleep patterns can be quite normal during pregnancy and typically start during the first trimester. Such changes include decreased rapid eye movement (REM) sleep secondary to increased estrogen levels and increased non-REM sleep secondary to increased progesterone levels. Decreased lung volumes can become worse during sleep and some pregnant women may be more likely to have central sleep apnea secondary to an increased sensitivity threshold to carbon dioxide levels, with subsequent hyperventilation. Oxytocin levels, noted to increase at night, may cause increased contractions with interruption of sleep. Other factors affecting sleep include gastroesophageal reflux, nocturia, and leg cramps.