P062 Validation of Unattended Polysomnography using Somte for Diagnosis of OSA in Pregnant Women during Early Gestation.

Introduction The detection of obstructive sleep apnoea (OSA) in pregnant women in early gestation using polysomnography (PSG) was logistically difficult during covid-19 lockdowns. Reliable alternates to PSG haven’t been well validated in early pregnancy. We compared the agreement between self-applied, unattended Somte and attended PSG, in pregnant women by 24 weeks gestation. Methods Women were recruited to undergo self-applied, unattended Somte and attended Grael PSG, by 24 weeks gestation. Tests were scored by a single experienced scorer (blinded to PSG result). An apnoea-hypopnea index (AHI) 5 or above at PSG was considered diagnostic of OSA. Diagnostic test analysis was undertaken (sensitivity, specificity, positive and negative predictive value (PPV/NPV)), by creating receiver operating characteristic (ROC) curves. The calculated AHI was compared and Bland-Altman plot used to plot agreement. Results Twenty-Four participants were included for analysis, median age 33.5(29.0, 37.0) years, gestation at PSG 14.1(13.4, 15.7) weeks and median BMI 31.2(26.3, 36.5). Five (20.8%) women had OSA. Median AHI were similar, 1.75 (0.50, 4.53) and 1.6 (0.58, 4.25) for Somte and PSG respectively. Somte demonstrated reasonable diagnostic test accuracy (area under the ROC curve 0.94 (95%CI 0.81-1.0)), sensitivity 80% (cut off AHI 5) and specificity 89.5%. The PPV and NPV were 80.0% and 94.7% respectively. Bland-Altman plot upper and lower confidence intervals of 6.37, -8.89, demonstrated lower and higher AHI scores slightly underestimated and overestimated, respectively. Discussion Somte provided reasonable accuracy compared to PSG in identifying OSA in early gestation in this sample. Larger studies will be helpful to confirm this finding.