Abstract: Objective：To explore whether sleep-disorder breathing is a risk factor of spontaneous preterm birth in late pregnancy. Methods：This is a nested case control study, from October 2018 to May 2019, pregnant women in the late pregnancy in People′s Hospital of Beijing Daxing District were collected as subjects. Relevant data of pregnant women were collected, including demographic information, medical history information, Berlin Questionnaire (BQ), Pittsburgh Sleep Quality Index (PSQI), and Epworth Sleepiness Scale (ESS). Spontaneous preterm birth was diagnosed according to the clinical diagnosis and treatment guidelines for preterm birth in China (2014). The spontaneous preterm birth group (46 cases) and the term birth group (407 cases) without complications at the same time were determined. The general situation of pregnant women, sleep disorders of breathing questionnaire scores were compared between the two groups. The independent risk factors of spontaneous premature birth were analyzed. Results：The age, body mass index before pregnancy, previous abortions frequent, and the history of preterm birth of the pregnant women in the spontaneous preterm birth group were higher than those in the term birth group, and the education level was lower than that in the term birth group, the differences were statistically significant (P＜0.05). The PSQI score and the high risk of obstructive sleep apnea (BQ-positive) in spontaneous preterm birth group were higher than those in the term birth group (P＜0.05). Logistic regression analysis showed that the risk of spontaneous preterm birth in BQ-positive pregnant women was 2.61 times higher than that in BQ-negative pregnant women (OR=2.61, 95%CI: 1.21-5.64, P=0.015). Conclusions：Pregnant women with high risk of obstructive sleep apnea are more likely to have spontaneous preterm birth.

Key words: Sleep apnea syndromes, Sleep apnea, obstructive, Sleep disorders, Pregnancy, Premature Birth