More and more studies are showing conclusive data that obstruction sleep apnea (OSA) is directly associated with an increase in maternal and fetal complications. In fact, OSA is associated with more frequent cesarean delivery, but the correlations do not end there. Mahesh Nagappa, MD, assistant professor of anesthesia and perioperative medicine at Western University in London, Ontario conducted a literature review to find out just how many adverse outcomes were associated with OSA and how screening might be improved. His findings shed light on the underserved, pregnant OSA population and all the risks they and their babies suffer as a result.
Literature Review Findings
As Dr. Nagappa reported at the 2016 annual meeting of the International Research Society, there were several adverse events which occurred as a result of undiagnosed OSA in pregnant women including low birth weight, gestational diabetes and hypertension, pulmonary embolism, greater risk of preeclampsia and fetal heart rate deceleration in his review of 33 individual studies on OSA and pregnant women. He also noted that many of those expectant mothers with severe OSA did not carry their babies to term and delivered early mostly via unplanned caesarean delivery. He pointed out that current screening methods were inadequate for diagnosing OSA in pregnant women saying, "…most OSA screening tools had a sensitivity between 70 – 80%, with very low specificity…and none of them worked very well in pregnant women." As a high-risk population undergoing dynamic bodily changes, pregnant women have unique circumstances which make diagnosis difficult.
Why are pregnant women prone to OSA when they were previously undiagnosed?
While pregnancy is a miraculous time in the expectant mother's life and the female body, it is also the home to many physiologic and hormonal changes. Along with changes in sleep architecture (sleeping position), pregnant women are at risk for the development of sleep-disordered breathing or worsening of preexisting sleep apnea. Weight gain, upper displacement of the diaphragm, hormonal-induced hyperemia, or increase in blood flow to the nasopharyngeal muscles causing compression of the airway passages leading to sleep disordered breathing (SBD) are the most common causes of OSA in pregnant women. It is further estimated that approximately 15.4% of obese expectant mothers suffer from OSA. What's more, completely aside from pregnancy, OSA is an especially dangerous condition as over half of the population it affects goes undiagnosed. Many expectant mothers could have had OSA prior to pregnancy without knowing.
Current Screening Tools and New Developments
Excessive daytime sleepiness, loud snoring, and witnessed (by a partner) apneas are all symptoms of OSA. When pregnant patients experience these symptoms and go in for screening, for an undetermined reason, the screening tools seem to work less efficiently for pregnant women versus their non-pregnant counterparts. Most commonly used are The Berlin Questionnaire and Epworth Sleepiness Scale (ESS) to screen possible OSA patients. In a study conducted by Drs. Facco, Ouyang, Zee, and Grobman, they find that both are not adequate for the screening of pregnant women. They are now in the process of creating a pregnancy-specific screening tool that includes the measure of four variables: self-reported frequency of snoring, chronic hypertension, BMI, and age based on the findings of their study.
Treatment for pregnant women diagnosed with OSA might come best in the form of an easy to use, mandibular advancement device (MAD). MADs have been shown to be an effective and comfortable option for pregnant mothers who might feel restrained by Continuous Positive Airway Pressure (CPAP) machines. In fact, studies have shown that MADs have a higher rate of consistent use than CPAP machines leading to better health outcomes and reduced risks for expectant mothers and their babies.