Effects of Continuous Positive Airway Pressure Treatment on Fetal Outcomes in Early-to-Mid Gestation Obstructive Sleep Apnea

Abstract Objective: To assess the effects of continuous positive airway pressure (CPAP) on maternal and fetal outcomes in early-to-mid gestation obstructive sleep apnea (OSA) and to examine the association between CPAP use, placental weight, and the placental-to-birth-weight ratio. A secondary objective was to compare CPAP effects across different trimesters. Methods: This retrospective cohort study included 208 pregnant women diagnosed with OSA through sleep monitoring at Peking University People’s Hospital between January 2021 and September 2024. Early-to-mid gestation OSA was defined as OSA diagnosed in the first or second trimester, and late-gestation OSA was defined as OSA diagnosed in the third trimester. Among 87 early-to-mid gestation OSA patients, 24 received CPAP treatment (CPAP group), whereas 63 did not receive CPAP (non-CPAP group). Among 121 late-gestation OSA patients, 24 received CPAP (CPAP group). Clinical and perinatal data were extracted from medical records. Results: In early-to-mid gestation OSA, CPAP use was associated with later gestational age at delivery (38.9 and 37.9 weeks), lower rates of small-for-gestational-age infants (0 vs . 20.6%), and higher birth weights (3387.5 ± 477.3 vs . 3010.0 ± 739.3 g), all statistically significant ( P < 0.05). CPAP users had lower placental weights (546.3 ± 61.6 vs . 604.6 ± 132.9 g) and significantly reduced placental-to-birth-weight ratios (0.16 (0.15–0.17) vs . 0.19 (0.18–0.22), P < 0.001). There was no statistical significance in maternal and fetal outcomes of the early-to-mid gestation and late-gestation OSA groups ( P > 0.05). In late-gestation OSA, conventional maternal and fetal outcomes were similar between the groups ( P > 0.05), although CPAP significantly reduced placental weight and the placental-to-birth-weight ratio ( P < 0.05). Conclusion: CPAP use in early-to-mid gestation OSA was associated with improved fetal growth parameters and more favorable placental metrics. These preliminary findings suggest that CPAP may play a beneficial role in fetal and placental development, though prospective, larger-scale trials are required to confirm causality. Early sleep-respiratory monitoring and timely intervention are crucial for high-risk individuals with OSA.