While women of childbearing age are generally at low risk for sleep disorder such as obstructive sleep apnea (OSA), the changes of pregnancy can suddenly make them high risk. OSA is an inherited condition in which a person has a decreased ability to keep the airway open during deep sleep.
Anything which tends to close the airway or get in the way of the flow of air makes it more likely that the airway will close during normal sleep. As the abdomen swells, it takes more work to breathe. Also, pregnancy tends to cause generalized swelling everywhere. That makes airways more narrow. And pregnancy can cause heartburn.
All pregnant women are screened for diabetes. I believe that all pregnant women should be screened for sleep apnea in their third trimester, too.
Which means that the OSA sufferer experiences a combination of low oxygen spells and sleep interruptions as she moves from deep to light sleep in order to open the airway again (by shifting position, coughing etc. things that most people can do automatically in deep sleep).
The sleep deprivation makes her tired, irritable, forgetful. The low oxygen spells raise her blood pressure—and can be dangerous for her developing fetus. As she gets more and more fatigued, she begins to sleep through more of the low oxygen spells—which is really bad for the fetus and its placental blood flow. The result can be a low birth weight or premature baby.
A useful screening tool could combine cheap measures and history. For instance, a woman with a personal history of controlled OSA needs a sleep study when she enters the third trimester. A family history of OSA, a history of unexplained low birth weight or premature delivery or fetal demise, age over 40, witnessed snoring and apnea in the third trimester, admission to the hospital for early labor that is controlled, first morning blood pressure that is higher than afternoon blood pressure should warrant at least a simple test in which you wear an oxygen probe on your finger when you sleep. If your oxygen goes down when you sleep, then your baby’s oxygen is going down, too.
Treatment for OSA in pregnancy would be relatively cheap and while OSA sufferers tend to be non-compliant with CPAP in the long run, I believe that pregnant women are likely to be highly compliant for one to two months if it means that their babies will be healthier. And the program would more than pay for itself if even a few extremely premature infant deliveries could be delayed.
Low birth weight due to preterm delivery is a major epidemic in many of our communities. Sleep apnea incidence is rising in part due to our obesity epidemic and our poor air quality. Sleep apnea is the most common commonly missed diagnosis in the country. Maybe if we did not miss it so often—in 80% of cases—our NICUs (neonatal intensive care units) would not be so full.