There has recently been much evidence to support the definition of gestational sleep apnea. During pregnancy, many women experience disruptions in their sleep patterns related to the physical and emotional changes in pregnancy. Although these are common in pregnancy, they can be damaging to both the mother and baby.
Now a new, large study gives us better evidence than ever about the significance of these effects. It shows that women with sleep apnea and other sleep disorders experience a much higher rate of preterm births, more than twice the risk of early preterm birth.
Researchers are hopeful, however, because sleep apnea and other sleep disorders are a potentially modifiable risk factor. Treating them could reduce risks.
A Large Study with Detailed Findings
Other studies have been done on the link between sleep apnea and preterm birth (defined as birth at 37 weeks or before), but none with as large a sample size as this one. This study was run out of the University of California San Francisco, with access to data from the entire state. They were able to take 2265 women with a sleep disorder diagnosis (less than 1% of the total sample), and match each one with multiple controls who had similar other risk factors for preterm birth–such as previous preterm birth, smoking, hypertension, etc–but no sleep disorder. This allowed them to separate the effects of other factors so that they could distinguish the sleep effect.
The sample size was so large that they were able to distinguish between the effects of sleep apnea and insomnia. They found that women without a sleep disorder had a 10.9% risk of preterm birth, while those with a sleep disorder had a 14.6% risk. The relative risk was 1.3 times higher for insomnia and 1.5 times higher for sleep apnea. For early preterm birth (34 weeks and before), the relative risk was just under 2.0 for insomnia, and slightly higher for sleep apnea.
Better Diagnosis and Treatment Needed
One thing that surprised researchers is the low diagnosis of sleep disorders among the population. Other studies have estimated that the incidence of obstructive sleep apnea in pregnant women may be as high as 19.7% in the third trimester. This means that more than 95% of pregnant women with sleep apnea are going undiagnosed.
Doubtless, part of the reason for this is that some level of sleep disruption is expected during pregnancy. However, doctors need to be more aware of the symptoms and risks of sleep apnea for pregnant women. Simple screening tools could be used to help identify women who would benefit from additional diagnosis.
And when sleep apnea is detected, women need to be given good treatment options. Although CPAP is a good treatment, it can take up to two months to adapt to, which may make oral appliances a more practical front-line treatment for most women experiencing sleep apnea during pregnancy. More studies are needed to show the effectiveness of the treatment and how it might impact the health effects of sleep apnea.