Liu L, Oza S, Hogan D, Perin J, Rudan I, Lawn JE, et al. Global, regional, and national causes of child mortality in 2000-13, with projections to inform post-2015 priorities: an updated systematic analysis. Lancet (London, England). 2015;385:430-40.
 Born Too Soon：The Global Action Report on Preterm Birth. World Health Organization.
 Khashu M, Narayanan M, Bhargava S, Osiovich H. Perinatal Outcomes Associated With Preterm Birth at 33 to 36 Weeks' Gestation: A Population-Based Cohort Study. Pediatrics. 2009;123:109-13.
 Allen MC. Neurodevelopmental outcomes of preterm infants. Curr Opin Neurol. 2008;21:123-8.
 Children：Reducing Mortality. http://www.who.int/mediacentre/factsheets/fs178/en/: World Health Organization.
 Vogel JP, Chawanpaiboon S, Moller AB, Watananirun K, Bonet M, Lumbiganon P. The global epidemiology of preterm birth. Best Pract Res Clin Obstet Gynaecol. 2018;52:3-12.
 Baer RJ, McLemore MR, Adler N, Oltman SP, Chambers BD, Kuppermann M, et al. Pre-pregnancy or first-trimester risk scoring to identify women at high risk of preterm birth. European journal of obstetrics, gynecology, and reproductive biology. 2018;231:235-40.
 Reid KJ, Facco FL, Grobman WA, Parker CB, Herbas M, Hunter S, et al. Sleep During Pregnancy: The nuMoM2b Pregnancy and Sleep Duration and Continuity Study. Sleep. 2017;40.
 Dunietz GL, Shedden K, Schisterman EF, Lisabeth LD, Treadwell MC, O'Brien LM. Associations of snoring frequency and intensity in pregnancy with time-to-delivery. Paediatric and perinatal epidemiology. 2018.
 Na-Rungsri K, Lertmaharit S, Lohsoonthorn V, Totienchai S, Jaimchariyatam N. Obstructive sleep apnea and the risk of preterm delivery. Sleep & breathing = Schlaf & Atmung. 2016;20:1111-7.
 Facco FL, Liu CS, Cabello AA, Kick A, Grobman WA, Zee PC. Sleep-disordered breathing: a risk factor for adverse pregnancy outcomes? American journal of perinatology. 2012;29:277-82.
 Maxmen A. Insomnia linked to premature birth in study of 3 million mothers. Nature. 2017;548:145.
 Meharaban Z, Yahya S, Sadegniiat K. Restless Legs Syndrome During Pregnancy and Preterm Birth in Women Referred to Health Centers of Ardabil. Iranian Red Crescent Medical Journal. 2015;17.
 Suzuki K, Ohida T, Sone T, Takemura S, Yokoyama E, Miyake T, et al. [An epidemiological study of sleep problems among the Japanese pregnant women]. Nihon Koshu Eisei Zasshi. 2003;50:526-39.
 Guendelman S, Pearl M, Kosa JL, Graham S, Abrams B, Kharrazi M. Association between preterm delivery and pre-pregnancy body mass (BMI), exercise and sleep during pregnancy among working women in Southern California. Maternal and child health journal. 2013;17:723-31.
 Micheli K, Komninos I, Bagkeris E, Roumeliotaki T, Koutis A, Kogevinas M, et al. Sleep patterns in late pregnancy and risk of preterm birth and fetal growth restriction. Epidemiology (Cambridge, Mass). 2011;22:738-44.
 Okun ML, Schetter CD, Glynn LM. Poor sleep quality is associated with preterm birth. Sleep. 2011;34:1493-8.
 Li R, Zhang J, Zhou R, Liu J, Dai Z, Liu D, et al. Sleep disturbances during pregnancy are associated with cesarean delivery and preterm birth. The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstet. 2017;30:733-8.
 Warland J, Dorrian J, Morrison JL, O'Brien LM. Maternal sleep during pregnancy and poor fetal outcomes: A scoping review of the literature with meta-analysis. Sleep medicine reviews. 2018;41:197-219.
 Knobloch K, Yoon U, Vogt PM. Preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement and publication bias. Journal of cranio-maxillo-facial surgery : official publication of the European Association for Cranio-Maxillo-Facial Surgery. 2011;39:91-2.
 Hashmi AM, Bhatia SK, Bhatia SK, Khawaja IS. Insomnia during Pregnancy: Diagnosis and Rational Interventions. Pakistan journal of medical sciences. 2016;32:1030-7.
 Wells GA SB, O'Connell D. The Newcastle-Ottawa Scale (NOS) for assessing the quality of nonrandomised studies in meta-analyses.
 Gao SY, Wu QJ, Sun C, Zhang TN, Shen ZQ, Liu CX, et al. Selective serotonin reuptake inhibitor use during early pregnancy and congenital malformations: a systematic review and meta-analysis of cohort studies of more than 9 million births. BMC medicine. 2018;16:205.
 Odutayo A, Wong CX, Hsiao AJ, Hopewell S, Altman DG, Emdin CA. Atrial fibrillation and risks of cardiovascular disease, renal disease, and death: systematic review and meta-analysis. BMJ (Clinical research ed). 2016;354:i4482.
 Hamling J, Lee P, Weitkunat R, Ambuhl M. Facilitating meta-analyses by deriving relative effect and precision estimates for alternative comparisons from a set of estimates presented by exposure level or disease category. Statistics in medicine. 2008;27:954-70.
 Chen LH, Wang YF, Xu QH, Chen SS. Omega-3 fatty acids as a treatment for non-alcoholic fatty liver disease in children: A systematic review and meta-analysis of randomized controlled trials. Clinical nutrition (Edinburgh, Scotland). 2018;37:516-21.
 Patsopoulos NA, Evangelou E, Ioannidis JP. Sensitivity of between-study heterogeneity in meta-analysis: proposed metrics and empirical evaluation. Int J Epidemiol. 2008;37:1148-57.
 Trivedi P, Saxena D, Puwar T, Savaliya S, Ganguly P. A cohort study on risk factors for preterm births in rural Gujarat. Indian journal of public health. 2018;62:111-6.
 Reutrakul S, Zaidi N, Wroblewski K, Kay HH, Ismail M, Ehrmann DA, et al. Sleep disturbances and their relationship to glucose tolerance in pregnancy. Diabetes care. 2011;34:2454-7.
 Kajeepeta S, Sanchez SE, Gelaye B, Qiu C, Barrios YV, Enquobahrie DA, et al. Sleep duration, vital exhaustion, and odds of spontaneous preterm birth: a case-control study. BMC pregnancy and childbirth. 2014;14:337.
 Okun ML, Luther JF, Wisniewski SR, Sit D, Prairie BA, Wisner KL. Disturbed sleep, a novel risk factor for preterm birth? Journal of women's health (2002). 2012;21:54-60.
 Ota H, Hasegawa J, Sekizawa A. Effect of sleep disorders on threatened premature delivery. Journal of perinatal medicine. 2017;45:57-61.
 Blair LM, Porter K, Leblebicioglu B, Christian LM. Poor Sleep Quality and Associated Inflammation Predict Preterm Birth: Heightened Risk among African Americans. Sleep. 2015;38:1259-67.
 Begum F, Buckshe K, Pande JN. Risk factors associated with preterm labour. Bangladesh Medical Research Council bulletin. 2003;29:59-66.
 Rao CR, de Ruiter LE, Bhat P, Kamath V, Kamath A, Bhat V. A case-control study on risk factors for preterm deliveries in a secondary care hospital, southern India. ISRN obstetrics and gynecology. 2014;2014:935982.
 Irwin MR, Wang M, Campomayor CO, Collado-Hidalgo A, Cole S. Sleep deprivation and activation of morning levels of cellular and genomic markers of inflammation. Archives of internal medicine. 2006;166:1756-62.
 Okun ML, Coussons-Read ME. Sleep disruption during pregnancy: how does it influence serum cytokines? Journal of reproductive immunology. 2007;73:158-65.
 Holingue C, Owusu JT, Feder KA, Spira AP. Sleep duration and C-reactive protein: Associations among pregnant and non-pregnant women. Journal of reproductive immunology. 2018;128:9-15.
 Irwin M. Effects of sleep and sleep loss on immunity and cytokines. Brain, behavior, and immunity. 2002;16:503-12.
 Ibarra-Coronado EG, Pantaleon-Martinez AM, Velazquez-Moctezuma J, Prospero-Garcia O, Mendez-Diaz M, Perez-Tapia M, et al. The Bidirectional Relationship between Sleep and Immunity against Infections. Journal of immunology research. 2015;2015:678164.
 Cappelletti M, Della Bella S, Ferrazzi E, Mavilio D, Divanovic S. Inflammation and preterm birth. J Leukoc Biol. 2016;99:67-78.
 Wei SQ, Fraser W, Luo ZC. Inflammatory cytokines and spontaneous preterm birth in asymptomatic women: a systematic review. Obstetrics and gynecology. 2010;116:393-401.
 Palagini L, Gemignani A, Banti S, Manconi M, Mauri M, Riemann D. Chronic sleep loss during pregnancy as a determinant of stress: impact on pregnancy outcome. Sleep medicine. 2014;15:853-9.
 Miller EH. Women and insomnia. Clinical cornerstone. 2004;6 Suppl 1B:S8-18.
 Teran-Perez G, Arana-Lechuga Y, Esqueda-Leon E, Santana-Miranda R, Rojas-Zamorano JA, Velazquez Moctezuma J. Steroid hormones and sleep regulation. Mini reviews in medicinal chemistry. 2012;12:1040-8.
 Izci-Balserak B, Pien GW. Sleep-disordered breathing and pregnancy: potential mechanisms and evidence for maternal and fetal morbidity. Current opinion in pulmonary medicine. 2010;16:574-82.
 Okun ML, Roberts JM, Marsland AL, Hall M. How disturbed sleep may be a risk factor for adverse pregnancy outcomes. Obstetrical & gynecological survey. 2009;64:273-80.
 Sedov ID, Cameron EE, Madigan S, Tomfohr-Madsen LM. Sleep quality during pregnancy: A meta-analysis. Sleep medicine reviews. 2018;38:168-76.
 Gangwisch JE, Heymsfield SB, Boden-Albala B, Buijs RM, Kreier F, Pickering TG, et al. Sleep duration as a risk factor for diabetes incidence in a large U.S. sample. Sleep. 2007;30:1667-73.
 Vgontzas AN, Liao D, Bixler EO, Chrousos GP, Vela-Bueno A. Insomnia with objective short sleep duration is associated with a high risk for hypertension. Sleep. 2009;32:491-7.
 Williams MA, Miller RS, Qiu C, Cripe SM, Gelaye B, Enquobahrie D. Associations of early pregnancy sleep duration with trimester-specific blood pressures and hypertensive disorders in pregnancy. Sleep. 2010;33:1363-71.
 Kohatsu ND, Tsai R, Young T, Vangilder R, Burmeister LF, Stromquist AM, et al. Sleep duration and body mass index in a rural population. Archives of internal medicine. 2006;166:1701-5.
 Perlis ML, Giles DE, Buysse DJ, Tu X, Kupfer DJ. Self-reported sleep disturbance as a prodromal symptom in recurrent depression. Journal of affective disorders. 1997;42:209-12.
 Roberts RE, Duong HT. The prospective association between sleep deprivation and depression among adolescents. Sleep. 2014;37:239-44.
 Li D, Liu L, Odouli R. Presence of depressive symptoms during early pregnancy and the risk of preterm delivery: a prospective cohort study. Human reproduction (Oxford, England). 2009;24:146-53.
 Wang W, Zhong C, Zhang Y, Huang L, Chen X, Zhou X, et al. Shorter sleep duration in early pregnancy is associated with birth length: a prospective cohort study in Wuhan, China. Sleep medicine. 2017;34:99-104.
 Owusu JT, Anderson FJ, Coleman J, Oppong S, Seffah JD, Aikins A, et al. Association of maternal sleep practices with pre-eclampsia, low birth weight, and stillbirth among Ghanaian women. International journal of gynaecology and obstetrics: the official organ of the International Federation of Gynaecology and Obstetrics. 2013;121:261-5.
 Strange LB, Parker KP, Moore ML, Strickland OL, Bliwise DL. Disturbed sleep and preterm birth: a potential relationship? Clinical and experimental obstetrics & gynecology. 2009;36:166-8.