Diagnostic Performance of a Type III Portable Monitoring Device for Obstructive Sleep Apnea in Pregnant Women: A Prospective Validation Study

<b><i>Rationale:</i></b> Obstructive sleep apnea (OSA) during pregnancy is linked to negative maternal and neonatal outcomes. Diagnosing OSA in this population is particularly challenging. Portable monitoring devices (PMD) present a potential alternative to polysomnography (PSG), but their effectiveness in pregnant women is uncertain. <b><i>Objective:</i></b> To evaluate diagnostic accuracy of a PMD to detect OSA in pregnant women. <b><i>Methods:</i></b> A prospective study of 136 middle-aged pregnant women (34 ± 4 years) in their third trimester of pregnancy (34 ± 3 weeks) who underwent laboratory type III PMD and PSG simultaneously. <b><i>Results:</i></b> Using an apnea-hypopnea index (AHI) ≥5 event/h by PSG, OSA was diagnosed in 10.3% of women (mild OSA: 86%; moderate OSA: 14%). An acceptable positive correlation was found between both tests in the AHI (<i>r</i> = 0.787; <i>p</i> < 0.001) and oxygen desaturation index (ODI) (<i>r</i> = 0.806; <i>p</i> < 0.001). The agreement limits between PSG and type III PMD were -4.1 to 5.4 for AHI and -6.0 to 4.5 for ODI. The sensitivity and specificity of type III PMD for an AHI ≥5 events/h were 57.1% and 99.2%, respectively, with a positive predictive value (PPV) of 88.9% and a negative predictive value (NPV) of 95.3%. On a receiver operating characteristic curve, the best cutoff point of AHI by type III PMD to identify OSA according to PSG criteria was 2.25 events/h. The sensibility and specificity for this point were 85.7% and 88.5%, respectively, with a PPV of 46.2% and NPV of 98.2%. <b><i>Conclusions:</i></b> A type III PMD with an AHI cutoff of 5 events/h could be a good alternative for OSA diagnosis in pregnant women. Additionally, an AHI ≥2.25 event/h demonstrates good diagnostic performance, but its low positive predictive value suggests that it is more appropriate as a screening tool. Further studies are needed to validate this sleep study tool in pregnant women, particularly in home settings.