Preterm birth remains an important global problem, and an important contributor to under-5 mortality. Reducing spontaneous preterm birth rates at the global level will require the early identification of patients at risk of preterm delivery in order to allow the initiation of appropriate prophylactic management strategies. Ideally these strategies target the underlying pathophysiologic causes of preterm labor. Prevention, however, becomes problematic as the causes of preterm birth are multifactorial and vary by gestational age, ethnicity, and social context. Unfortunately, current screening and diagnostic tests are non-specific, with only moderate clinical risk prediction, relying on the detection of downstream markers of the common end-stage pathway rather than identifying upstream pathway-specific pathophysiology that would help the provider initiate targeted interventions. As a result, the available management options (including cervical cerclage and vaginal progesterone) are used empirically with, at best, ambiguous results in clinical trials. Furthermore, the available screening tests have only modest clinical risk prediction, and fail to identify most patients who will have a preterm birth. Clearly defining preterm birth phenotypes and the biologic pathways leading to preterm birth is key to providing targeted, biomolecular pathway-specific interventions, ideally initiated in early pregnancy Pathway specific biomarker discovery, together with management strategies based on early, mid-, and-late trimester specific markers is integral to this process, which must be addressed in a systematic way through rigorously planned biomarker trials.

Biomedical Research Center University Hospital Hradec Kralove Hradec Kralove Czechia

Department of Genetics and Bioinformatics Domain of Health Data and Digitalization Norwegian Institute of Public Health Oslo Norway

Department of Obstetrics and Gynaecology The University of Pretoria School of Medicine Pretoria South Africa

Department of Obstetrics and Gynecology and of Global Health University of Washington Seattle WA United States

Department of Obstetrics and Gynecology Brigham and Women's Hospital and Harvard Medical School Boston MA United States

Department of Obstetrics and Gynecology Faculty of Medicine Hradec Kralove Charles University Prague Hradec Kralove Czechia

Department of Obstetrics and Gynecology Sahlgrenska Academy Gothenburg University Gothenburg Sweden

Department of Obstetrics and Gynecology The University of Texas Medical Branch at Galveston Galveston TX United States

Department of Women and Children's Health Faculty of Life Sciences and Medicine School of Life Course Sciences King's College London London United Kingdom

Department of Women and Children's Health Faculty of Life Sciences and Medicine School of Life Course Sciences St Thomas' Hospital Campus King's College London London United Kingdom

Zobrazit více v PubMed

Stratified, personalised or P4 medicine: a new direction for placing the patient at the Centre of healthcare and health education (technical report). Academy of Medical Sciences (2015). https://acmedsci.ac.uk/more/events/stratified-personalised-or-p4-medicine-a-new-direction

Romero R, Dey SK, Fisher SJ. Preterm labor: one syndrome, many causes. Science. (2014) 345:760–5. doi: 10.1126/science.1251816, PMID: PubMed DOI PMC

Rubens CE, Sadovsky Y, Muglia L, Gravett MG, Lackritz E, Gravett C. Prevention of preterm birth: harnessing science to address the global epidemic. Sci Transl Med. (2014) 6:262sr5. doi: 10.1126/scitranslmed.3009871, PMID: PubMed DOI

Kramer MS, Papageorghiou A, Culhane J, Bhutta Z, Goldenberg RL, Gravett M, et al. . Challenges in defining and classifying the preterm birth syndrome. Am J Obstet Gynecol. (2012) 206:108–12. doi: 10.1016/j.ajog.2011.10.864, PMID: PubMed DOI

Chien PF, Khan KS, Ogston S, Owen P. The diagnostic accuracy of cervico-vaginal fetal fibronectin in predicting preterm delivery: an overview. Br J Obstet Gynaecol. (1997) 104:436–44. doi: 10.1111/j.1471-0528.1997.tb11495.x, PMID: PubMed DOI

Berghella V, Saccone G. Cervical assessment by ultrasound for preventing preterm delivery. Cochrane Database Syst Rev. (2019) 2019:CD007235. doi: 10.1002/14651858.CD007235.pub4, PMID: PubMed DOI PMC

Kuusela P, Jacobsson B, Hagberg H, Fadl H, Lindgren P, Wesström J, et al. . Second-trimester transvaginal ultrasound measurement of cervical length for prediction of preterm birth: a blinded prospective multicentre diagnostic accuracy study. BJOG. (2021) 128:195–206. doi: 10.1111/1471-0528.16519, PMID: PubMed DOI PMC

Ferrero DM, Larson J, Jacobsson B, di Renzo GC, Norman JE, Martin JN, et al. . Cross-country individual participant analysis of 4.1 million singleton births in 5 countries with very high human development index confirms known associations but provides no biologic explanation for 2/3 of all preterm births. PLoS One. (2016) 11:e0162506. doi: 10.1371/journal.pone.0162506, PMID: PubMed DOI PMC

Esplin MS, O’Brien E, Fraser A, Kerber RA, Clark E, Simonsen SE, et al. . Estimating recurrence of spontaneous preterm delivery. Obstet Gynecol. (2008) 112:516–23. doi: 10.1097/AOG.0b013e318184181a PubMed DOI

Mercer BM, Goldenberg RL, Moawad AH, Meis PJ, Iams JD, das AF, et al. . The preterm prediction study: effect of gestational age and cause of preterm birth on subsequent obstetric outcome. National Institute of Child Health and Human Development maternal-fetal medicine units network. Am J Obstet Gynecol. (1999) 181:1216–21. doi: 10.1016/s0002-9378(99)70111-0, PMID: PubMed DOI

Lykke JA, Paidas MJ, Langhoff-Roos J. Recurring complications in second pregnancy. Obstet Gynecol. (2009) 113:1217–24. doi: 10.1097/AOG.0b013e3181a66f2d PubMed DOI

Deng X, Pan B, Lai H, Sun Q, Lin X, Yang J, et al. . Association of previous stillbirth with subsequent perinatal outcomes: a systematic review and meta-analysis of cohort studies. Am J Obstet Gynecol. (2024). doi: 10.1016/j.ajog.2024.02.304, PMID: PubMed DOI

Robinson JN. In: Lockwood CJ, editor. Spontanious preterm birth: overview of risk factors and prognosos. Boston: Wolters Kluwer; (2024)

Donovan BM, Spracklen CN, Schweizer ML, Ryckman KK, Saftlas AF. Intimate partner violence during pregnancy and the risk for adverse infant outcomes: a systematic review and meta-analysis. BJOG. (2016) 123:1289–99. doi: 10.1111/1471-0528.13928, PMID: PubMed DOI

Lin CH, Lin WS, Chang HY, Wu SI. Domestic violence against pregnant women is a potential risk factor for low birthweight in full-term neonates: a population-based retrospective cohort study. PLoS One. (2022) 17:e0279469. doi: 10.1371/journal.pone.0279469, PMID: PubMed DOI PMC

He W, Sparen P, Fang F, Sengpiel V, Strander B, Czene K. Pregnancy outcomes in women with a prior cervical intraepithelial neoplasia grade 3 diagnosis: a Nationwide population-based cohort study with sibling comparison design. Ann Intern Med. (2022) 175:210–8. doi: 10.7326/M21-2793, PMID: PubMed DOI

Iams JD, Goldenberg RL, Meis PJ, Mercer BM, Moawad A, das A, et al. . The length of the cervix and the risk of spontaneous premature delivery. National Institute of Child Health and Human Development maternal fetal medicine unit network. N Engl J Med. (1996) 334:567–73. doi: 10.1056/NEJM199602293340904 PubMed DOI

Berghella V, Palacio M, Ness A, Alfirevic Z, Nicolaides KH, Saccone G. Cervical length screening for prevention of preterm birth in singleton pregnancy with threatened preterm labor: systematic review and meta-analysis of randomized controlled trials using individual patient-level data. Ultrasound Obstet Gynecol. (2017) 49:322–9. doi: 10.1002/uog.17388 PubMed DOI

Celik E, To M. Gajewska K, Smith GC, Nicolaides KH, Fetal Medicine Foundation Second Trimester Screening Group . Cervical length and obstetric history predict spontaneous preterm birth: development and validation of a model to provide individualized risk assessment. Ultrasound Obstet Gynecol. (2008) 31:549–54. doi: 10.1002/uog.5333, PMID: PubMed DOI

Pizzella S, el Helou N, Chubiz J, Wang LV, Tuuli MG, England SK, et al. . Evolving cervical imaging technologies to predict preterm birth. Semin Immunopathol. (2020) 42:385–96. doi: 10.1007/s00281-020-00800-5, PMID: PubMed DOI

Grabner M, Burchard J, Nguyen C, Chung H, Gangan N, Boniface JJ, et al. . Cost-effectiveness of a proteomic test for preterm birth prediction. Clinicoecon Outcomes Res. (2021) 13:809–20. doi: 10.2147/CEOR.S325094 PubMed DOI PMC

Esplin MS, Elovitz MA, Iams JD, Parker CB, Wapner RJ, Grobman WA, et al. . Predictive accuracy of serial transvaginal cervical lengths and quantitative vaginal fetal fibronectin levels for spontaneous preterm birth among nulliparous women. JAMA. (2017) 317:1047–56. doi: 10.1001/jama.2017.1373, PMID: PubMed DOI PMC

Pirjani R, Moini A, Almasi-Hashiani A, Farid Mojtahedi M, Vesali S, Hosseini L, et al. . Placental alpha microglobulin-1 (PartoSure) test for the prediction of preterm birth: a systematic review and meta-analysis. J Matern Fetal Neonatal Med. (2021) 34:3445–57. doi: 10.1080/14767058.2019.1685962, PMID: PubMed DOI

Bruijn MM, Vis JY, Wilms FF, Oudijk MA, Kwee A, Porath MM, et al. . Comparison of the Actim Partus test and the fetal fibronectin test in the prediction of spontaneous preterm birth in symptomatic women undergoing cervical length measurement. Eur J Obstet Gynecol Reprod Biol. (2016) 206:220–4. doi: 10.1016/j.ejogrb.2016.09.018, PMID: PubMed DOI

Saade GR, Boggess KA, Sullivan SA, Markenson GR, Iams JD, Coonrod DV, et al. . Development and validation of a spontaneous preterm delivery predictor in asymptomatic women. Am J Obstet Gynecol. (2016) 214:633.e1–633.e24. doi: 10.1016/j.ajog.2016.02.001, PMID: PubMed DOI

Branch DW, VanBuren JM, Porter TF, Holmgren C, Holubkov R, Page K, et al. . Prediction and prevention of preterm birth: a prospective, randomized intervention trial. Am J Perinatol. (2023) 40:1071–80. doi: 10.1055/s-0041-1732339, PMID: PubMed DOI PMC

Hezelgrave NL, Abbott DS, Radford SK, Seed PT, Girling JC, Filmer J, et al. . Quantitative fetal fibronectin at 18 weeks of gestation to predict preterm birth in asymptomatic high-risk women. Obstet Gynecol. (2016) 127:255–63. doi: 10.1097/AOG.0000000000001240, PMID: PubMed DOI

Abbott DS, Hezelgrave NL, Seed PT, Norman JE, David AL, Bennett PR, et al. . Quantitative fetal fibronectin to predict preterm birth in asymptomatic women at high risk. Obstet Gynecol. (2015) 125:1168–76. doi: 10.1097/AOG.0000000000000754, PMID: PubMed DOI

Centra M, Coata G, Picchiassi E, Alfonsi L, Meniconi S, Bini V, et al. . Evaluation of quantitative fFn test in predicting the risk of preterm birth. J Perinat Med. (2017) 45:91–8. doi: 10.1515/jpm-2015-0414 PubMed DOI

Khambay H, Bolt LA, Chandiramani M, De Greeff A, Filmer JE, Shennan AH. The Actim Partus test to predict pre-term birth in asymptomatic high-risk women. J Obstet Gynaecol. (2012) 32:132–4. doi: 10.3109/01443615.2011.637649, PMID: PubMed DOI

Conde-Agudelo A, Romero R. Cervical phosphorylated insulin-like growth factor binding protein-1 test for the prediction of preterm birth: a systematic review and metaanalysis. Am J Obstet Gynecol. (2016) 214:57–73. doi: 10.1016/j.ajog.2015.06.060, PMID: PubMed DOI PMC

Kuhrt K, Hezelgrave N, Foster C, Seed PT, Shennan AH. Development and validation of a tool incorporating quantitative fetal fibronectin to predict spontaneous preterm birth in symptomatic women. Ultrasound Obstet Gynecol. (2016) 47:210–6. doi: 10.1002/uog.14894 PubMed DOI

Watson HA, Seed PT, Carter J, Hezelgrave NL, Kuhrt K, Tribe RM, et al. . Development and validation of predictive models for QUiPP app v.2: tool for predicting preterm birth in asymptomatic high-risk women. Ultrasound Obstet Gynecol. (2020) 55:348–56. doi: 10.1002/uog.20401, PMID: PubMed DOI

Liza V, Ravikumar G. Placental correlates in categories of preterm births based on gestational age. Placenta. (2024) 152:9–16. doi: 10.1016/j.placenta.2024.05.124 PubMed DOI

Nijman TA, van Vliet EO, Benders MJ, Mol BWJ, Franx A, Nikkels PGJ, et al. . Placental histology in spontaneous and indicated preterm birth: a case control study. Placenta. (2016) 48:56–62. doi: 10.1016/j.placenta.2016.10.006, PMID: PubMed DOI

Stanek J. Comparison of placental pathology in preterm, late-preterm, near-term, and term births. Am J Obstet Gynecol. (2014) 210:234.e1–6. doi: 10.1016/j.ajog.2013.10.015, PMID: PubMed DOI

Jaiman S, Romero R, Pacora P, Erez O, Jung E, Tarca AL, et al. . Disorders of placental villous maturation are present in one-third of cases with spontaneous preterm labor. J Perinat Med. (2021) 49:412–30. doi: 10.1515/jpm-2020-0138, PMID: PubMed DOI PMC

Fettweis JM, Serrano MG, Brooks JP, Edwards DJ, Girerd PH, Parikh HI, et al. . The vaginal microbiome and preterm birth. Nat Med. (2019) 25:1012–21. doi: 10.1038/s41591-019-0450-2, PMID: PubMed DOI PMC

Leow SM, di Quinzio MKW, Ng ZL, Grant C, Amitay T, Wei Y, et al. . Preterm birth prediction in asymptomatic women at mid-gestation using a panel of novel protein biomarkers: the prediction of PreTerm labor (PPeTaL) study. Am J Obstet Gynecol MFM. (2020) 2:100084. doi: 10.1016/j.ajogmf.2019.100084, PMID: PubMed DOI

Cantonwine DE, Zhang Z, Rosenblatt K, Goudy KS, Doss RC, Ezrin AM, et al. . Evaluation of proteomic biomarkers associated with circulating microparticles as an effective means to stratify the risk of spontaneous preterm birth. Am J Obstet Gynecol. (2016) 214:631.e1. doi: 10.1016/j.ajog.2016.02.005, PMID: PubMed DOI PMC

McElrath TF, Cantonwine DE, Jeyabalan A, Doss RC, Page G, Roberts JM, et al. . Circulating microparticle proteins obtained in the late first trimester predict spontaneous preterm birth at less than 35 weeks' gestation: a panel validation with specific characterization by parity. Am J Obstet Gynecol. (2019) 220:488.e1. doi: 10.1016/j.ajog.2019.01.220, PMID: PubMed DOI

Menon R, Debnath C, Lai A, Guanzon D, Bhatnagar S, Kshetrapal P, et al. . Protein profile changes in circulating placental extracellular vesicles in term and preterm births: a longitudinal study. Endocrinology. (2020) 161:bqaa009. doi: 10.1210/endocr/bqaa009 PubMed DOI PMC

Menon R, Debnath C, Lai A, Guanzon D, Bhatnagar S, Kshetrapal PK, et al. . Circulating Exosomal miRNA profile during term and preterm birth pregnancies: a longitudinal study. Endocrinology. (2019) 160:249–75. doi: 10.1210/en.2018-00836, PMID: PubMed DOI PMC

Flaviani F, Hezelgrave NL, Kanno T, Prosdocimi EM, Chin-Smith E, Ridout AE, et al. . Cervicovaginal microbiota and metabolome predict preterm birth risk in an ethnically diverse cohort. JCI Insight. (2021) 6:e149257. doi: 10.1172/jci.insight.149257, PMID: PubMed DOI PMC

Gunko VO, Pogorelova TN, Linde VA. Proteomic profiling of the blood serum for prediction of premature delivery. Bull Exp Biol Med. (2016) 161:829–32. doi: 10.1007/s10517-016-3522-z, PMID: PubMed DOI

Ngo TTM, Moufarrej MN, Rasmussen MH, et al. . Noninvasive blood tests for fetal development predict gestational age and preterm delivery. Science. (2018) 360:1133–6. doi: 10.1126/science.aar3819, PMID: PubMed DOI PMC

Camunas-Soler J, Gee EPS, Reddy M, Mi JD, Thao M, Brundage T, et al. . Predictive RNA profiles for early and very early spontaneous preterm birth. Am J Obstet Gynecol. (2022) 227:72.e1. doi: 10.1016/j.ajog.2022.04.002, PMID: PubMed DOI

Liu L, Oza S, Hogan D, Chu Y, Perin J, Zhu J, et al. . Global, regional, and national causes of under-5 mortality in 2000-15: an updated systematic analysis with implications for the sustainable development goals. Lancet. (2016) 388:3027–35. doi: 10.1016/S0140-6736(16)31593-8, PMID: PubMed DOI PMC

Peeling RW, Holmes KK, Mabey D, Ronald A. Rapid tests for sexually transmitted infections (STIs): the way forward. Sex Transm Infect. (2006) 82:v1–6. doi: 10.1136/sti.2006.024265, PMID: PubMed DOI PMC

Mabey D, Peeling RW, Ustianowski A, Perkins MD. Diagnostics for the developing world. Nat Rev Microbiol. (2004) 2:231–40. doi: 10.1038/nrmicro841 PubMed DOI

Land KJ, Boeras DI, Chen XS, Ramsay AR, Peeling RW. REASSURED diagnostics to inform disease control strategies, strengthen health systems and improve patient outcomes. Nat Microbiol. (2019) 4:46–54. doi: 10.1038/s41564-018-0295-3, PMID: PubMed DOI PMC

Grimes DA, Schulz KF. Refining clinical diagnosis with likelihood ratios. Lancet. (2005) 365:1500–5. doi: 10.1016/S0140-6736(05)66422-7 PubMed DOI

McGee S. Simplifying likelihood ratios. J Gen Intern Med. (2002) 17:647–50. doi: 10.1046/j.1525-1497.2002.10750.x, PMID: PubMed DOI PMC

Fransen M, Meertens R, Schrander-Stumpel C. Communication and risk presentation in genetic counseling. Development of a checklist. Patient Educ Couns. (2006) 61:126–33. doi: 10.1016/j.pec.2005.02.018 PubMed DOI

Ferguson M, Shapiro GD, McDonald SD. Understanding and preferences regarding risk communication during pregnancy: a survey to facilitate provider communication with patients. Am J Obstet Gynecol MFM. (2023) 5:100929. doi: 10.1016/j.ajogmf.2023.100929, PMID: PubMed DOI

Conover EA, Polifka JE. The art and science of teratogen risk communication. Am J Med Genet C Semin Med Genet. (2011) 157:227–33. doi: 10.1002/ajmg.c.30308, PMID: PubMed DOI

Iams JD, Romero R, Culhane JF, Goldenberg RL. Primary, secondary, and tertiary interventions to reduce the morbidity and mortality of preterm birth. Lancet. (2008) 371:164–75. doi: 10.1016/S0140-6736(08)60108-7, PMID: PubMed DOI

Newman RB, Sullivan SA, Menard MK, Rittenberg CS, Rowland AK, Korte JE, et al. . South Carolina Partners for Preterm Birth Prevention: a regional perinatal initiative for the reduction of premature birth in a Medicaid population. Am J Obstet Gynecol. (2008) 199:393.e1–8. doi: 10.1016/j.ajog.2008.07.047 PubMed DOI

Newnham JP, White SW, Meharry S, Lee HS, Pedretti MK, Arrese CA, et al. . Reducing preterm birth by a statewide multifaceted program: an implementation study. Am J Obstet Gynecol. (2017) 216:434–42. doi: 10.1016/j.ajog.2016.11.1037, PMID: PubMed DOI

Iams JD, Applegate MS, Marcotte MP, Rome M, Krew MA, Bailit JL, et al. . A statewide progestogen promotion program in Ohio. Obstet Gynecol. (2017) 129:337–46. doi: 10.1097/AOG.0000000000001841, PMID: PubMed DOI

Wennerholm UB, Bergman L, Kuusela P, Ljungström E, Möller AC, Hongslo Vala C, et al. . Progesterone, cerclage, pessary, or acetylsalicylic acid for prevention of preterm birth in singleton and multifetal pregnancies - a systematic review and meta-analyses. Front Med. (2023) 10:1111315. doi: 10.3389/fmed.2023.1111315, PMID: PubMed DOI PMC

Group E . Evaluating progestogens for preventing preterm birth international collaborative (EPPPIC): meta-analysis of individual participant data from randomised controlled trials. Lancet. (2021) 397:1183–94. doi: 10.1016/S0140-6736(21)00217-8, PMID: PubMed DOI

Conde-Agudelo A, Romero R. Does vaginal progesterone prevent recurrent preterm birth in women with a singleton gestation and a history of spontaneous preterm birth? Evidence from a systematic review and meta-analysis. Am J Obstet Gynecol. (2022) 227:440–461.e2. doi: 10.1016/j.ajog.2022.04.023, PMID: PubMed DOI PMC

Berghella V, Odibo AO, To MS. Rust OA, Althuisius SM. Cerclage for short cervix on ultrasonography: meta-analysis of trials using individual patient-level data. Obstet Gynecol. (2005) 106:181–9. doi: 10.1097/01.AOG.0000168435.17200.53 PubMed DOI

Goya M, Pratcorona L, Merced C, Rodó C, Valle L, Romero A, et al. . Cervical pessary in pregnant women with a short cervix (PECEP): an open-label randomised controlled trial. Lancet. (2012) 379:1800–6. doi: 10.1016/S0140-6736(12)60030-0 PubMed DOI

Conde-Agudelo A, Romero R, Nicolaides KH. Cervical pessary to prevent preterm birth in asymptomatic high-risk women: a systematic review and meta-analysis. Am J Obstet Gynecol. (2020) 223:42–65.e2. doi: 10.1016/j.ajog.2019.12.266, PMID: PubMed DOI PMC

Abdel-Aleem H, Shaaban OM, Abdel-Aleem MA, Aboelfadle MA. Cervical pessary for preventing preterm birth in singleton pregnancies. Cochrane Database Syst Rev. (2022) 2022:CD014508. doi: 10.1002/14651858.CD014508, PMID: PubMed DOI PMC

Aubin AM, McAuliffe L, Williams K, Issah A, Diacci R, McAuliffe JE, et al. . Combined vaginal progesterone and cervical cerclage in the prevention of preterm birth: a systematic review and meta-analysis. Am J Obstet Gynecol MFM. (2023) 5:101024. doi: 10.1016/j.ajogmf.2023.101024, PMID: PubMed DOI

Zhuang Y, Li H, Na Q, Yin S, Li N. Prevention of preterm birth by cervical pessary combined with vaginal progesterone: a systematic review and meta-analysis with trial sequential analysis. Reprod Sci. (2023) 30:93–110. doi: 10.1007/s43032-022-00926-x, PMID: PubMed DOI PMC

Hoffman MK, Goudar SS, Kodkany BS, Metgud M, Somannavar M, Okitawutshu J, et al. . Low-dose aspirin for the prevention of preterm delivery in nulliparous women with a singleton pregnancy (ASPIRIN): a randomised, double-blind, placebo-controlled trial. Lancet. (2020) 395:285–93. doi: 10.1016/S0140-6736(19)32973-3, PMID: PubMed DOI PMC

Landman A, de Boer MA, Visser L, Nijman TAJ, Hemels MAC, Naaktgeboren CN, et al. . Evaluation of low-dose aspirin in the prevention of recurrent spontaneous preterm labour (the APRIL study): a multicentre, randomised, double-blinded, placebo-controlled trial. PLoS Med. (2022) 19:e1003892. doi: 10.1371/journal.pmed.1003892, PMID: PubMed DOI PMC

Osterman M, Hamilton B, Martin JA, Driscoll AK, Valenzuela CP. Births: final data for 2020. Natl Vital Stat Rep. (2021) 70:1–50. PMID: PubMed

Roman A, Ramirez A, Fox NS. Prevention of preterm birth in twin pregnancies. Am J Obstet Gynecol MFM. Orlando, FL, USA. (2022) 4:100551. doi: 10.1016/j.ajogmf.2021.100551 PubMed DOI

Aagaard K VG, Antony K, Sangi-Haghpeykar H, Chirwa R, Dumba M, Petro S, et al. . LB 1: PPaX: cluster randomized trial of xylitol chewing gum on prevention of preterm birth in Malawi. Presented at SMFM 42nd Annual Meeting. Orlando, FL USA: The Pregnancy Meeting (2022).

Brown JE, Partlow BP, Berman AM, House MD, Kaplan DL. Injectable silk-based biomaterials for cervical tissue augmentation: an in vitro study. Am J Obstet Gynecol. (2016) 214:118.e1–9. doi: 10.1016/j.ajog.2015.08.046, PMID: PubMed DOI PMC