Publication date: Available online 2 February 2018 Source: American Journal of Obstetrics and Gynecology Author(s): Judette M. Louis, Matthew A. Koch, Uma M. Reddy, Robert M. Silver, Corette B. Parker, Francesca L. Facco, Susan Redline, Chia-Ling Nhan-Chang, Judith H. Chung, Grace W. Pien, Robert C. Basner, William A. Grobman, Deborah A. Wing, Hyagriv N. Simhan, David M. Haas, Brian M. Mercer, Samuel Parry, Daniel Mobley, Benjamin Carper, George R. Saade, Frank P. Schubert, Phyllis C. Zee Background Sleep disordered breathing (SDB) is common in pregnancy, but there are limited data on predictors. Objectives The objective of this study was to develop predictive models of SDB during pregnancy. Study Design Nulliparous women completed validated questionnaires to assess for symptoms related to snoring, fatigue, excessive daytime sleepiness insomnia and restless leg syndrome. These included questions regarding the timing of sleep and sleep duration, work schedules (e.g., shift work, night work), sleep positions, and previously diagnosed sleep disorders. Frequent snoring was defined as self-reported snoring ≥3 days per week. Participants underwent in-home portable sleep studies for SDB assessment in early (6-15 weeks’) and mid-pregnancy (22-31 weeks’). SDB was characterized using an apnea hypopnea index (AHI) that included all apneas, plus hypopneas with ≥3% oxygen desaturation. For primary analyses, an AHI ≥5 events/hour was used to define SDB. Odds ratios and 95% confidence intervals (CIs) were calculated for predictor variables. Predictive ability of the logistic models was estimated using area under the receiver-operating-characteristic curves, along with sensitivities, specificities, and positive and negative predictive values and likelihood ratios. Results Among 3705 women who were enrolled, data were available for 3,264 and 2,512 women in early and mid-pregnancy, respectively. The corresponding prevalence of SDB was 3.6% and 8.3%. At each time point in gestation, frequent snoring, chronic hypertension, greater maternal age, BMI, neck circumference, and systolic blood pressure were most strongly associated with an increased risk of SDB. Logistic regression models that included current age, BMI, and frequent snoring predicted SDB in early pregnancy, SDB in mid-pregnancy, and new onset SDB in mid-pregnancy with 10-fold cross-validated AUCs of 0.870, 0.838, and 0.809. We provide a supplement with expanded tables, integrated predictiveness and classification curves, and an Excel predicted probability calculator. Conclusion(s) Among nulliparous pregnant women, logistic regression models with just three variables (i.e., age, BMI, and frequent snoring) achieved good prediction of prevalent and incident SDB. These results can help with screening for SDB in the clinical setting and for future clinical treatment trials.