, World Health Organization International Classification of Diseases: Manual of the International Statistical Classification of Diseases, Injuries, and Causes of Death, Ninth Revision World Health Organization, pp.763-764

M. Mccormick, The Contribution of Low Birth Weight to Infant Mortality and Childhood Morbidity, New England Journal of Medicine, vol.312, issue.2, pp.82-90, 1985.
DOI : 10.1056/NEJM198501103120204

, World Health Organization Neonatal and Perinatal Mortality: Country, Regional and Global Estimates, pp.2-4, 2006.

K. Haram, J. Mortensen, and A. Wollen, Preterm delivery: an overview, Acta Obstetricia et Gynecologica Scandinavica, vol.175, issue.8, pp.687-704, 2003.
DOI : 10.1006/enrs.2000.4094

S. Inglis, Biochemical markers predictive of preterm delivery, Infectious Diseases in Obstetrics and Gynecology, vol.5, issue.2, pp.158-164, 1997.
DOI : 10.1002/(SICI)1098-0997(1997)5:2<158::AID-IDOG11>3.0.CO;2-N

M. Gürsoy, E. Könönen, U. Gürsoy, T. Tervahartiala, R. Pajukanta et al., Periodontal Status and Neutrophilic Enzyme Levels in Gingival Crevicular Fluid During Pregnancy and Postpartum, Journal of Periodontology, vol.105, issue.12, pp.1790-1796, 2010.
DOI : 10.1111/j.1601-0825.1996.tb00236.x

J. Challis, Understanding pre-term birth, Clin Invest Med, vol.24, pp.60-67, 2001.

A. Heimonen, S. Janket, R. Kaaja, L. Ackerson, P. Muthukrishnan et al., Oral Inflammatory Burden and Preterm Birth, Journal of Periodontology, vol.75, issue.6, pp.884-891, 2009.
DOI : 10.1902/jop.2004.75.3.495

I. Ishikawa, K. Nakashima, and T. Koseki, Induction of the immune response to periodontopathic bacteria and its role in the pathogenesis of periodontitis, Periodontology 2000, vol.154, issue.1, pp.79-111, 20001997.
DOI : 10.1111/j.1600-051X.1985.tb01348.x

D. Cochran, Inflammation and Bone Loss in Periodontal Disease, Journal of Periodontology, vol.86, issue.8s, pp.1569-1576, 2008.
DOI : 10.1902/jop.2007.060480

S. Theoleyre, Y. Wittrant, S. Tat, Y. Fortun, F. Redini et al., The molecular triad OPG/RANK/RANKL: involvement in the orchestration of pathophysiological bone remodeling, Cytokine & Growth Factor Reviews, vol.15, issue.6, pp.457-475, 2004.
DOI : 10.1016/j.cytogfr.2004.06.004

B. Choi, S. Moon, J. Cha, K. Kim, and Y. Yoo, Journal of Periodontology, vol.11, issue.5, pp.813-820, 2005.
DOI : 10.1034/j.1600-0765.2003.00615.x

, J Periodontol ?, 2016.

C. Africa, Oral colonization of Gram-negative anaerobes as a risk factor for preterm delivery, Virulence, vol.2, issue.6, pp.498-508, 2011.
DOI : 10.4161/viru.2.6.17719

E. Ercan, K. Eratalay, and O. Deren, Acta Odontologica Scandinavica, vol.84, issue.3-4, pp.553-559, 2013.
DOI : 10.1016/j.jri.2009.11.003

T. Nakashima, Y. Kobayashi, and S. Yamasaki, Protein Expression and Functional Difference of Membrane-Bound and Soluble Receptor Activator of NF-??B Ligand: Modulation of the Expression by Osteotropic Factors and Cytokines, Biochemical and Biophysical Research Communications, vol.275, issue.3, pp.768-775, 2000.
DOI : 10.1006/bbrc.2000.3379

T. Nagasawa, M. Kiji, and R. Yashiro, Roles of receptor activator of nuclear factor-?B ligand (RANKL) and osteoprotegerin in periodontal health and disease, Periodontology 2000, vol.18, issue.1, pp.65-84, 2000.
DOI : 10.1074/jbc.M212473200

D. Graves, Cytokines That Promote Periodontal Tissue Destruction, Journal of Periodontology, vol.22, issue.8s, pp.1585-1591, 2008.
DOI : 10.1359/jbmr.070518

J. Beck, R. Garcia, G. Heiss, P. Vokonas, and S. Offenbacher, Periodontal Disease and Cardiovascular Disease, Journal of Periodontology, vol.90, issue.10s, pp.1123-1137, 1996.
DOI : 10.1111/j.1752-7325.1992.tb02260.x

S. Grossi and R. Genco, Periodontal Disease and Diabetes Mellitus: A Two-Way Relationship, Annals of Periodontology, vol.74, issue.1, pp.51-61, 1998.
DOI : 10.1902/jop.1993.64.8s.819

T. Van-dyke and A. Van-winkelhoff, Infection and inflammatory mechanisms, Journal of Clinical Periodontology, vol.12, issue.Suppl 1, pp.1-7, 2013.
DOI : 10.1016/S1074-7613(00)80165-X

M. Sanz and K. Kornman, Periodontitis and adverse pregnancy outcomes: consensus report of the Joint EFP/AAP Workshop on Periodontitis and Systemic Diseases, Journal of Clinical Periodontology, vol.40, pp.164-169, 2013.
DOI : 10.1111/jcpe.12081
URL : http://onlinelibrary.wiley.com/doi/10.1111/jcpe.12083/pdf

P. Madianos, Y. Bobetsis, and S. Offenbacher, Adverse pregnancy outcomes (APOs) and periodontal disease: pathogenic mechanisms, Journal of Periodontology, vol.73, issue.4-s, pp.170-180, 2013.
DOI : 10.1016/0952-3278(88)90137-8
URL : http://www.joponline.org/doi/pdf/10.1902/jop.2013.1340015

A. Bosnjak, T. Relja, V. Vuci-cevi-c-boras, H. Plasaj, and D. Plancak, Pre-term delivery and periodontal disease: a case?control study from Croatia, Journal of Clinical Periodontology, vol.313, issue.10, pp.710-716, 2006.
DOI : 10.1016/S0002-9378(88)80030-9

S. Santos-pereira, P. Giraldo, and E. Saba-chujfi, Chronic periodontitis and pre-term labour in Brazilian pregnant women: an association to be analysed, Journal of Clinical Periodontology, vol.70, issue.20, pp.208-213, 2007.
DOI : 10.1111/j.1600-051X.2004.00564.x

, The PLOS Medicine Editors Observational studies: Getting clear about transparency, PloS Med, vol.11, p.10011711, 2014.

G. Armitage, Periodontal diagnoses and classification of periodontal diseases, Periodontology 2000, vol.63, issue.1, pp.9-21, 2000.
DOI : 10.1902/jop.1992.63.10.854

A. Petkovic, S. Matic, and N. Stamatovic, Proinflammatory cytokines (IL-1?? and TNF-??) and chemokines (IL-8 and MIP-1??) as markers of peri-implant tissue condition, International Journal of Oral and Maxillofacial Surgery, vol.39, issue.5, pp.478-485, 2010.
DOI : 10.1016/j.ijom.2010.01.014

I. Chapple, I. Cross, H. Glenwright, and J. Matthews, Calibration and reliability of the Periotron 6000 for individual gingival crevicular fluid samples, Journal of Periodontal Research, vol.28, issue.1, pp.73-79, 1995.
DOI : 10.1111/j.1600-051X.1988.tb02263.x

V. Canakci, C. Canakci, A. Yildirim, M. Ingec, A. Eltas et al., Periodontal disease increases the risk of severe pre-eclampsia among pregnant women, Journal of Clinical Periodontology, vol.113, issue.164, pp.639-645, 2007.
DOI : 10.1111/j.1471-0528.2005.00827.x

S. Offenbacher, H. Jared, O. Reilly, and P. , Potential Pathogenic Mechanisms of Periodontitis-Associated Pregnancy Complications, Annals of Periodontology, vol.75, issue.1, pp.233-250, 1998.
DOI : 10.1016/S1079-2104(96)80042-4

T. Konopka, M. Rutkowska, L. Hirnle, W. Kopec, and E. Karolewska, The secretion of prostaglandin E2 and interleukin 1-beta in women with periodontal diseases and preterm lowbirth-weight, Bull Group Int Rech Sci Stomatol Odontol, vol.45, pp.18-28, 2003.

G. Carta, G. Persia, K. Falciglia, and P. Iovenitti, Periodontal disease and poor obstetrical outcome, Clin Exp Obstet Gynecol, vol.31, pp.47-49, 2004.

B. Noack, J. Klingenberg, J. Weigelt, and T. Hoffmann, Periodontal status and preterm low birth weight: a case control study, Journal of Periodontal Research, vol.18, issue.4, pp.339-345, 2005.
DOI : 10.1902/jop.1991.62.5.330

F. Tarannum, M. Faizuddin, and H. Madaiah, Gingival crevicular fluid prostaglandin E2 level as a predictor of preterm low birth weight: a pilot investigation, Journal of Oral Science, vol.53, issue.3, pp.293-300, 2011.
DOI : 10.2334/josnusd.53.293

P. Stadelmann, S. Eick, and G. Salvi, Increased periodontal inflammation in women with preterm premature rupture of membranes, Clinical Oral Investigations, vol.119, issue.7, pp.1537-1546, 2014.
DOI : 10.1111/j.1471-0528.2012.03328.x

P. Stadelmann, R. Alessandri, S. Eick, G. Salvi, D. Surbek et al., The potential association between gingival crevicular fluid inflammatory mediators and adverse pregnancy outcomes: a systematic review, Clinical Oral Investigations, vol.114, issue.3, pp.1453-1463, 2013.
DOI : 10.1097/AOG.0b013e3181b1341f

N. Kassebaum, E. Bernabé, M. Dahiya, B. Bhandari, C. Murray et al., Global Burden of Severe Periodontitis in 1990-2010, Journal of Dental Research, vol.2000, issue.11, pp.1045-1053, 2014.
DOI : 10.1016/S0140-6736(12)61719-X

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