4,874
Views
2
CrossRef citations to date
0
Altmetric
Review Article

Prevention of spontaneous preterm delivery – an update on where we are today

, &
Article: 2183756 | Received 18 May 2022, Accepted 18 Feb 2023, Published online: 26 Mar 2023

References

  • Kinney V, Rhoda NR. Understanding the causes of preterm birth: solutions depend on context. Lancet Glob Health. 2019;7:e1000–e1001.
  • Chawanpaiboon S, Vogel JP, Moller AB, et al. Global, regional, and national estimates of levels of preterm birth in 2014: a systematic review and modelling analysis. Lancet Glob Health. 2019;7(1):e37–46–e46.
  • Blencowe H, Cousens S, Chou D, et al. LawnJ on behalf of the born too soon preterm birth action group born too soon: the global epidemiology of 15 million preterm births. Reprod Health. 2013;10(S1):S2.
  • Chawanpaiboon S, Vogel JP, Moller A-B, et al. Global, regional, and national estimates of levels of preterm birth in 2014: a systematic review and modelling analysis. Lancet Glob Health. 2019;7(1):e37–e46.
  • Born Too Soon: The Global Action Report on Preterm Birth. https://www.efcni.org/wp-content/uploads/2018/03/BornTooSoonExecSummary_v05.pdf.
  • Blencowe H, Cousens S, Oestergaard MZ, et al. National, regional, and worldwide estimates of preterm birth rates in the year 2010 with time trends since 1990 for selected countries: a systematic analysis and implications. Lancet. 2012;379(9832):2162–2172.
  • National Center for Health Statistics. Final Mortality data and Marchof Dimes 2021 Premature Birth Report Card. https://www.marchofdimes.org/peristats/tools/reportcard.aspx. Accessed 12 August 2022
  • Petrou S, Yiu HH, Kwon J. Economic consequences of preterm birth: a systematic review of the recent literature (2009–2017). Arch Dis Childh. 2018;0:1–10.
  • Barros FC, Papageorghiou AT, Victora CG, et al. The distribution of clinical phenotypes of preterm birth syndrome: implications for prevention. JAMA Pediatr. 2015;169(3):220. Published on line January 5th 2015
  • Muglia LJ, Katz M. The enigma of spontaneous preterm birth. N Engl J Med. 2010;362(6):529–535.
  • Villar J, Papageorghiou AT, Knight HE, et al. The preterm birth syndrome: a prototype phenotypic classification. Am J Obstet Gynecol. 2012;206(2):119–123.
  • Manuck TA, Esplin MS, Biggio J, et al. The phenotype of spontaneous preterm birth: application of a clinical phenotyping tool. Am J Obstet Gynecol. 2015;212(4):487.e1–487.e11.
  • ACOG Bulletin Summary Number 234. Prediction and prevention of spontaneous preterm birth. Obstetrics and Gynecology. 2021;138:320–233.
  • Goldenberg RL, Culhane JF, Iams JD, et al. Epidemiology and causes of preterm birth. The Lancet. 2008;371(9606):75–84.
  • Bhutta Z, Yakoob M, Salam R, et al. 2011. Global review of interventions related to maternal, newborn and child health (MNCH): what works and can be scaled up?. Pakistan: Aga Khan University.
  • Barros AJ, Ronsmans C, Axelson H, et al. Equity in maternal, newborn, and child health interventions in countdown to 2015: a retrospective review of survey data from 54 countries. Lancet. 2012;379(9822):1225–1233.
  • Tessema GA, Marinovich ML, Håberg SE, et al. Interpregnancy intervals and adverse birth outcomes in high-income countries: an international cohort study. PLOS One. 2021;16(7):e0255000.
  • Rahmati S, Azami M, Badfar G, et al. The relationship between maternal anemia during pregnancy with preterm birth: a systematic review and meta-analysis. J Matern Fetal Neonatal Med. 2020;33(15):2679–2689.
  • Mazaki-Tovi S, Kusanovic JP, Erez O, et al. Recurrent preterm birth. Semin Perinatol. 2007;31(3):142–158.
  • Yang J, Baer RJ, Berghella V, et al. Recurrence of preterm birth and early term birth. Obstet Gynecol. 2016;128(2):364–372.
  • Shennan AH, Story L. on behalf of the royal college of obstetricians and gynaecologists. Cervical Cerclage. RCOG Green-Top Guideline. 2022;129:1178–1210.
  • Preterm labour and birth NICE guideline [NG25] Published: 20 November 2015 Last updated: 02 August 2019. National Institute for Health and Care Excellence. Preterm Labour and Birth. NICE Guideline 25. London: NICE; 2015.
  • Gream GT. Dilatation or division of the cervix uteri. The Lancet. 1865;85(2171):381.
  • Shirodkar VN. A new method of operative treatment for habitual abortions in the second trimester of pregnancy. Antiseptic. 1955;52:299–300.
  • McDonald IA. Suture of the cervix for inevitable miscarriage. BJOG: Int J Obstet Gynaecol. 1957;64(3):346–350.
  • Final report of the Medical Research Council/Royal College of Obstetricians and Gynaecologists multicentre randomised trial of cervical cerclage. MRC/RCOG Working Party on CervicalCerclage. BJOG 1993;100:516–23.
  • Care A, Nevitt S, Medley N, et al. Interventions to prevent spontaneous preterm birth in women with singleton pregnancy who are at high risk: systematic review and network meta-analysis. BMJ. 2022;376:e064547.
  • Althuisius SM, Dekker GA, van Geijn HP, et al. Cervical incompetence prevention randomized cerclage trial(CIPRACT): study design and preliminary results. Am J ObstetGynecol. 2000;183(4):823–829.
  • Berghella V, Haas S, Chervoneva I, et al. Patients with prior second-trimester loss: prophylactic cerclage or serial transvaginal sonograms? Am J Obstet Gynecol. 2002;187(3):747–751.
  • Berghella V, Mackeen AD. Cervical length screening with ultrasound-indicated cerclage compared with history-indicated cerclage for prevention of preterm birth: a meta-analysis. Obstet Gynecol. 2011;118(1):148–155.
  • Berghella V, Timothy R, Jeff S, et al. Cerclage for short cervix on ultrasonography in women with singleton gestations and previous preterm birth. Obstet Gynecol. 2011;117(3):663–671.
  • Phung J, Williams KP, McAullife L, et al. Vaginal progesterone for prevention of preterm birth in asymptomatic high-risk women with a normal cervical length: a systematic review and meta-analysis. J Matern Fetal Neonatal Med. 2022;35:7093–7101.
  • Conde-Agudelo A, Romero R, Da Fonseca E, et al. Vaginal progesterone is as effective as cervical cerclage to prevent preterm birth in women with a singleton gestation, previous spontaneous preterm birth, and a short cervix: updated in direct comparison meta-analysis. Am J Obstet Gynecol. 2018;219(1):10–25.
  • Jarde A, Lutsiv O, Beyene J, et al. Vaginal progesterone, 17-OHPC, cerclage and pessary for preventing preterm birth in at risk singleton pregnancies: an updated systematic review and network meta-analysis. BJOG. 2019;126(5):556–567.
  • Saccone G, Khalifeh A, Elimian A, et al. Vaginal progesterone vs intramuscular 17α-hydroxyprogesterone caproate for prevention of recurrent spontaneous preterm birth in singleton gestations: systematic review and meta-analysis of randomized controlled trials. Ultrasound Obstet Gynecol. 2017;49(3):315–321.
  • Romero R, Nicolaides KH, Conde-Agudelo A, et al. Vaginal progesterone decrerases preterm birth < =34 weeks of gestation in women with a singleton pregnancy and a short cervix: an updated meta-analysis including data from the OPTIMUM study. Ultrasound Obstet Gynecol. 2016;48:308–317.
  • Cervical cerclage for the woman with prior adverse pregnancy. https://www.smfm.org/publications/98-cervical-cerclage-for-the-woman-with-prior-adverse-pregnancy-outcome. Accessed 13th April 2022.
  • McIntosh J, Feltovich H, Berghella V, et al. The role of routine cervical length screening in selected high- and low-risk women for preterm birth prevention. Am J Obstet Gynecol. 2016;215(3):B2–B7.
  • Shennan AH, Chandiramani M, Bennett P, et al. MAVRIC: a multicenter randomized controlled trial of transabdominal vs transvaginal cervical cerclage. Am J Obstet Gynecol. 2020; 222(3):261.e1–261.e9.
  • Mastantuoni E, Saccone G, Gragnano E, et al. Cervical pessary in singleton gestations with arrested preterm labor: a randomized clinical trial. Am J Obstet Gynecol Maternal Fetal Medicine. 2021;3(2):100307.
  • Jin XH, Li D, Huang LL. Cervical pessary for prevention of preterm birth: a meta-analysis. Sci Rep. 2017;7(1):42560.
  • RANZCOG Best Practice Statement: measurement of cervical length for prediction of preterm birth. First endorsed by RANZCOG: November 2008. Current: November 2021.
  • Berghella V, Ciardulli A, Rust OA, et al. Cerclage for sonographic short cervix in singleton gestations without prior spontaneous preterm birth: systematic review and meta-analysis of randomized controlled trials using individual patient-level data. Ultrasound Obstet Gynecol. 2017; Nov50(5):569–577.
  • Gulersen M, Bornstein E, Domney A, et al. Cerclage in singleton gestations with an extremely short cervix (≤10 mm) and no history of spontaneous preterm birth. Am J Obstet Gynecol MFM. 2021;3(5):100430.
  • Gulersen M, Divon MY, Krantz D, et al. The risk of spontaneous preterm birth in symptomatic women with a short cervix (< =25mmm) at 23-28 weeks’ gestation. Am J Obstet Gynecol. 2020;2:100059.
  • Ho N, Liu C, Nguyen A, et al. Prediction of time of delivery using cervical length measurement in women with threatened preterm labour. J Matern Fetal Neonatal Med. 2019;34(16):2649–2654.
  • Wong TTC, Yong X, Tung JSZ, et al. Prediction of labour onset in women who present with symptoms of preterm labour using cervical length. BMC Pregnancy Childbirth. 2021;21(1):359.
  • Kalikkot Thekkeveedu R, Dankhara N, Desai J, et al. Outcomes of multiple gestation births compared to singleton: analysis of multicenter KID database. Matern Health, Neonatol Perinatol. 2021;7(1):15.
  • Thekkeveedu K, et al. Outcomes of multiple gestation births compared to singleton: analysis of multicentre KID database. Maternal Health, Neonatal Perinatol. 2021;7:15.
  • Conde-Agudelo A, Romero R, Hassan SS, et al. Transvaginal sonographic cervical length for the prediction of spontaneous preterm birth in twin pregnancies: a systematic review and metaanalysis. Am J Obstet Gynecol. 2010;203(2):128.e1–128.e12.
  • Lim AC, Hegeman MA, Huis I, et al. Cervical length measurement for the prediction of preterm birth in multiple pregnancies: a systematic review and bivariate meta-analysis. Ultrasound Obstet Gynecol. 2011;38(1):10–17.
  • Conde-Agudelo A, Romero R. Predictive accuracy of changes in transvaginal sonographic cervical length over time for preterm birth: a systematic review and meta-analysis. Am J Obstet Gynecol. 2015;213(6):789–801.
  • Meller C, Izbizky G, Aiello H, et al. Cervical length as a screening for spontantous preterm birth in uncomplicated twins: one vs serial measurements. J Maternal Fetal Neonatal Med. 2022;35(21):4097–4103.
  • Khalil A, Rodgers M, Baschat A, et al. ISUOG Practice Guidelines: role of ultrasound in twin pregnancy. Ultrasound Obstet Gynecol. 2016;47:247–263.
  • Romero R, Conde-Agudelo A, El-Refaie W, et al. Vaginal progesterone decreases preterm birth and neonatal morbidity and mortality in women with a twin gestation and a short cervix: an updated meta-analysis of individual patient data. Ultrasound Obstet Gynecol. 2017;49(3):303–314.
  • Caritis SN, Rouse DJ, Peaceman AM, et al. Prevention of preterm birth in triplets using 17 alpha-hydroxyprogesterone caproate: a randomized controlled trial. Obstet Gynecol. 2009;113(2 Pt 1):285–292.
  • Almutairi A, Aljohani HI, Al-Fadel NS. 17-Alpha-Hydroxyprogesterone vs. Placebo for Preventing of Recurrent Preterm Birth: a systematic review and meta-analysis of randomized trials. Front Med. 2021. published: 01 December
  • Rehal A, Benkő Z, De Paco Matallana C, et al. Early vaginal progesterone versus placebo in twin pregnancies for the prevention of spontaneous preterm birth: a randomized, double-blind trial. Am J Obstet Gynecol. 2021; 224(1):86.e1–86.e19.
  • Roeckner JT, Sanchez-Ramos L. The comparative efficacy of cervical pessary, cerclage, vaginal and parenteral progesterone for the prevention of preterm birth in women with a sonographic short cervix and a singleton gestation: a systematic review and network meta-analysis. Am J Obstet Gynecol. 2017;216(1):S382.
  • Roeckner JT, Mitta M, Sanchez-Ramos L, et al. Twin pregnancies with short cervix: vaginal progesterone is agent of choice for preterm prevention. Am J Obstet Gynecol. 2019;220(1):S368–S369.
  • Norman JE, Norrie J, MacLennan G, et al. The Arabin pessary to prevent preterm birth in women with a twin pregnancy and a short cervix (STOPPIT-2): an open-label randomised trial and updated meta-analysis. PLOS Med. 2021; 18(3):e1003506.
  • Norman JE, Mackenzie F, Owen P, et al. Progesterone for the prevention of preterm birth in twin pregnancy (STOPPIT): a randomised, double-blind, placebo-controlled study and meta-analysis. Lancet. 2009;373(9680):2034–2040.
  • ClinicalTrials.gov Identifier: NCT03540225. Completion date Dec 2022. Chiu lee Liona Poon - Chinese University Hongkong; 2018.
  • Zhang J, Zhan W, Lin Y, et al. Development and external validation of a normogram for predicting preterm birth at <32 weeks in twin pregnancy. Sci Reproduction. 2021;11:12430.
  • Romero R, Gonzalez R, Sepulveda W, et al. VIII. Microbial invasion of the amniotic cavity in patients with suspected cervical incompetence: prevalence and clinical significance. Am J Obstet Gynecol. 1992; Oct167(4 Pt 1):1086–1091.
  • Jung E, Romero R, Yoon BH, et al. Bacteria in the amniotic fluid without inflammation: early colonization vs. contamination. J Perinat Med. 2021;49(9):1103–1121.
  • Oh KJ, Romero R, Park JY, et al. Evidence that antibiotic administration is effective in the treatment of a subset of patients with intra-amniotic infection/inflammation presenting with cervical insufficiency. Am J Obstet Gynecol. 2019;221(2):140.e1–140.e18.
  • Romero R, Kusanovic JP, Espinoza J, et al. What is amniotic fluid sludge? Ultrasound Obstet Gynecol. 2007;30(5):793–798.
  • Kusanovic JP, Espinoza J, Romero R, et al. Clinical significance of the presence of amniotic fluid sludge in asymptomatic patients at high risk of spontaneous preterm delivery. Ultrasound Obstet Gynecol. 2007;30(5):706–714.
  • Hatanaka AL, Fraca MA, Nishimoto TE, et al. Antibiotic treatment for patients with amniotic fluid “sludge. To prevent spontaneous preterm birth: a historically controlled observational study. Acta Obstet Gynecol Scand. 2019;98:1157–1163.
  • Himaya E, Rhalmi N, Girard M, et al. Midtrimester intra-amniotic sludge and the risk of spontaneous preterm birth. Amer J Perinatol. 2011;28(10):815–820.
  • Pérez-Pedregosa J, Ruiz MC, Medina TB, et al. Amniotic sludge and short cervix as inflammation and intraamniotic infection markers. OGIJ. 2017;7(2):00239.
  • Yeo L, Romero R, Chaiworapongsa T, et al. Resolution of acute cervical insufficiency after antibiotics in a case with amniotic fluid sludge. J Matern-Fetal Neonatal Med. 2022;35(25):5416–5426.
  • Cuff RD, Carter E, Taam R, et al. Effect of antibiotic treatment of amniotic fluid sludge. Am J Obstet Gynecol MFM. 2020;2(1):100073.
  • Althuisius SM, Dekker GA, Hummel P, et al. Cervical incompetence prevention randomized cerclage trial: emergency cerclage with bed rest versus bed rest alone. Am J Obstet Gynecol. 2003;189(4):907–910.
  • Ehsanipoor RM, Seligman NS, Saccone G, et al. Physical examination indicated cerclage. A systematic review and meta-analysis. Obstet Gynecol. 2015;126(1):125–135.
  • Chatzakis C, Efthymiou A, Sotiriadis A, et al. Emergency cerclage in singleton pregnancies with painless cervical dilatation: a meta-analysis. Acta Obstet Gynecol Scand. 2020;99(11):1444–1457.
  • Kilani Z, Hamarsheh M, Kilani S, et al. A Novel Technique of Emergency Cerclage for Mid Trimester Cervical Dilatation Annals of Infertility & Reproductive Endocrinology Published: 10 May2018.
  • Locatelli A, Vergani P, Bellini P, et al. Amnioreduction in emergency cerclage with prolapsed membranes: comparison of two methods for reducing the membranes. Am J Perinatol. 1999;16(2):73–77.
  • Makino Y, Makino I, Tsujioka H, et al. Amnioreduction in patients with bulging prolapsed membranes out of the cervix and vaginal orifice in cervical cerclage. J Perinat Med. 2004;32(2):140–148.
  • Ogawa M, Sanada H, Tsuda A, et al. Modified cervical cerclage in pregnant women with advanced bulging membranes: knee- chest positioning. Acta Obstet Gynecol Scand. 1999;78(9):779–782.
  • Ochi M, Ishikawa K, Itoh H, et al. Aggressive management of prolapsed fetal membranes earlier than 26 weeks’ gestation by emergent McDonald cerclage combined with amniocentesis and bladder overfilling][article in Japanese]. Nihon Sanka Fujinka Gakkai Zasshi. 1994; 46(4):301–307.
  • Wong GP, Farquharson DF, Dansereau J. Emergency cervical cerclage: a retrospective review of 51 cases. Amer J Perinatol. 1993;10(05):341–347.
  • Debby A, Sadan O, Glezerman M, et al. Favorable outcome following emergency second trimester cerclage. Int J Gynaecol Obstet. 2007;96(1):16–19.
  • Levin I, Salzer L, Maslovitz S, et al. Outcomes of mid-trimester emergency cerclage in twin pregnancies. Fetal Diagn Ther. 2012;32(4):246–250.
  • Tsapanos VS, Decavalas GO, Adonakis GL, et al. Late or emergency (salvage) cerclage of a dilated cervix after tissue support with pelvicol implant: a case. J Biomed Mater Res B Appl Biomater. 2005;72(2):368–372.
  • Lv M, Zhao B, Chen Y, et al. Balloon tamponade for successful emergency cervical cerclage. J Obstet Gynaecol Res. 2020;46(3):418–424.
  • Linehan LA, Walsh J, Morris A, et al. Neonatal and maternal outcomes following midtrimester preterm premature rupture of the membranes: a retrospective cohort study. BMC Pregnancy Childbirth. 2016;16(1):25.
  • Bond DM, Middleton P, Levett KM, et al. Planned early birth versus expectant management for women with preterm prelabour rupture of membranes prior to 37 weeks’ gestation for improving pregnancy outcome. Cochrane Database Syst Rev. 2017;3(3):CD004735.
  • Regan JA, Chao S, James LS. Premature rupture of membranes, preterm delviery and group β streptococcal colonization of mothers. Am J Obstet Gynecol. 1981;141(2):184–186.
  • Thomson AJ,. Care of women presenting with suspected preterm prelabour rupture of membranes from 24 + 0Weeks of gestation. BJOG. 2019;126:e152–166.
  • ACOG. Practice bulletin no 217. Prelabor Rupture of Membranes. Obstet Gynecol. 2020;135:739–743.
  • Miyazaki C, Moreno Garcia R, Ota E, et al. Tocolysis for inhibiting preterm birth in extremely preterm birth, multiple gestations and in growth-restricted fetuses: a systematic review and meta-analysis. Reprod Health. 2016;13:4.
  • van Boeckel SR, Davidson DJ, Norman JE, et al. Stock SJ cell-free fetal DNA and spontaneous preterm birth. Reproduction. 2018;155(3):R137–R145.
  • Leung TN, Zhang J, Lau TK, et al. Maternal plasma fetal DNA as a marker for preterm labour. The Lancet. 1998;352(9144):1904–1905.
  • Darghahi R, Mobaraki‐Asl N, Ghavami Z, et al. Jalilvand FEffect of cell‐free fetal DNA on spontaneous preterm labor. J Adv Pharm Technol Res. 2019;10(3):117–120.
  • Poon LCY, Musci T, Song K, et al. Maternal plasma cell-free fetal and maternal DNA at 11-13 weeks’ gestation: relation to fetal and maternal characteristics and pregnancy outcomes. Fetal Diagn Ther. 2013;33(4):215–223.
  • Quezada MS, Francisco C, Dumitrascu-Biris D, et al. Fetal fraction of cell-free DNA in maternal plasma in the prediction of spontaneous preterm delivery. Ultrasound Obstet Gynecol. 2015;45(1):101–105.
  • Dugoff L, Barberio A, Whittaker PG, et al. l Cell-free DNA fetal fraction and preterm birth. Am J Obstet Gynecol. 2016;215(2):231.e1–231.e7.
  • Bezold KY, Karjalainen MK, Hallman M, et al. The genomics of preterm birth: from animal models to hu- man studies. Genome Med. 2013;5(4):34.
  • Plunkett J, Feitosa MF, Trusgnich M, et al. Mother’s genome or maternally-in- herited genes acting in the fetus influence gestational age in familial preterm birth. Hum Hered. 2009;68(3):209–219.
  • Kistka ZA, DeFranco EA, Ligthart L, et al. Heritability of parturition timing: an extended twin design analysis. Am J Obstet Gynecol. 2008;199(1):43.e1–5.
  • Boyd HA, Poulsen G, Wohlfahrt J, et al. Maternal contributions to preterm delivery. Am J Epidemiol. 2009;170(11):1358–1364.
  • Clausson B, Lichtenstein P, Cnattin- Gius S. Genetic influence on birthweight and gestational length determined by studies in offspring of twins. BJOG: Int J Obstet Gynaecol. 2000;107(3):375–381.
  • York TP, Eaves LJ, Lichtenstein P, et al. Fetal and maternal genes’ influence on gestational age in a quantitative genetic analysis of 244,000 swedish births. Am J Epidemiol. 2013;178(4):543–550.
  • Kistka ZA-F, Palomar L, Boslaugh SE, et al. Risk for post-term delivery after previous post-term delivery. Am J Obstet Gynecol. 2007;196(3):241.e1–241.e6.
  • Plunkett J, Muglia LJ. Genetic contributions to preterm birth: implications from epidemiological and genetic association studies. Ann Med. 2008;40(3):167–195.
  • Zhang G, Feenstra B, Bacelis J, et al. Genetic associations with gestational duration and spontaneous preterm birth. N Engl J Med. 2017;377(12):1156–1167.
  • Ehn NL, Cooper ME, Orr K, et al. Evaluation of fetal and maternal genetic variation in the progesterone receptor gene for contributions to preterm birth. Pediatr Res. 2007;62(5):630–635.
  • Diaz-Cueto L, Dominguez-Lopez P, Cantillo-Cabarcas J, et al. Progesterone receptor gene polymorphisms are not associated with preterm birth in a hispanic population. Int J Gynaecol Obstet. 2008;103(2):153–157.
  • Guoyang L, Morgan T, Bahtiyar MO, et al. Single nucleotide polymorphisms in the human progesterone receptor gene and spontaneous preterm birth. Reprod Sci. 2008;15:147–155.
  • Roberts D, Brown J, Medley N, et al. Antenatal corticosteroids for accelerating fetal lung maturation for women at risk of preterm birth. Cochrane Database Syst Rev. 2017;3(3):CD004454.
  • Nazzaro G, Saccone G, Miranda M, et al. Cervical elastography using E-cervix for prediction of preterm birth in singleton pregnancies with threatened preterm labor. J Matern-Fetal Neonatal Med. 2022;35(2):330–335.
  • Ninan K, Liyanage SK, Murphy KE, et al. Evaluation of long-term outcomes associated with preterm exposure to antenatal CorticosteroidsA systematic review and meta-analysis. JAMA Pediatr. 2022;176(6):e220483.
  • Stock SJ, Horne M, Bruijn M, et al. Development and validation of a risk prediction model for preterm birth for women with preterm labour symptoms (the QUIDS study): a prospective cohort study and individual participant data meta-analysis. PLOS Med. 2021; 18(7):e1003686.
  • Bachkangi P, Taylor AH, Bari M, et al. Prediction of preterm labour from a single blood test: the role of the endocannabinoid system in predicting preterm birth in high-risk women. Eur J Obstet Gynecol Reprod Biol. 2019;243:1–6.