Sleep apnea is a sleep disorder in which people stop breathing repeatedly during sleep. It is common and can be a serious problem. Sleep apnea can also cause problems during pregnancy, including low birth weight, premature birth, and even miscarriage.
There is some evidence that using a CPAP machine (mouthpiece that supplies air through the nose) can help people with sleep apnea during pregnancy. CPAP is also though to reduce pregnant women's risks of preeclampsia, gestational diabetes, and other pregnancy complications.