Prevention and Therapy of Preterm Birth. Guideline of the DGGG, OEGGG and SGGG (S2k-Level, AWMF Registry Number 015/025, September 2022) – Part 1 with Recommendations
          on the Epidemiology, Etiology, Prediction, Primary and Secondary Prevention of Preterm Birth

Richard Berger; Harald Abele; Franz Bahlmann; Klaus Doubek; Ursula Felderhoff-Müser; Herbert Fluhr; Yves Garnier; Susanne Grylka-Baeschlin; Aurelia Hayward; Hanns Helmer; Egbert Herting; Markus Hoopmann; Irene Hösli; Udo Hoyme; Mirjam Kunze; Ruben-J. Kuon; Ioannis Kyvernitakis; Wolf Lütje; Silke Mader; Holger Maul; Werner Mendling; Barbara Mitschdörfer; Monika Nothacker; Dirk Olbertz; Andrea Ramsell; Werner Rath; Claudia Roll; Dietmar Schlembach; Ekkehard Schleußner; Florian Schütz; Vanadin Seifert-Klauss; Johannes Stubert; Daniel Surbek

doi:10.1055/a-2044-0203

Geburtshilfe und Frauenheilkunde, Table of Contents

Geburtshilfe Frauenheilkd 2023; 83(05): 547-568
DOI: 10.1055/a-2044-0203

GebFra Science

Guideline/Leitlinie

Prevention and Therapy of Preterm Birth. Guideline of the DGGG, OEGGG and SGGG (S2k-Level, AWMF Registry Number 015/025, September 2022) – Part 1 with Recommendations on the Epidemiology, Etiology, Prediction, Primary and Secondary Prevention of Preterm Birth

Article in several languages: English | deutsch

Authors

Richard Berger

¹Frauenklinik, Marienhaus Klinikum Neuwied, Neuwied, Germany
Harald Abele

²Frauenklinik, Universitätsklinikum Tübingen, Tübingen, Germany
Franz Bahlmann

³Frauenklinik, Bürgerhospital Frankfurt, Frankfurt am Main, Germany
Klaus Doubek

⁴Frauenarztpraxis, Wiesbaden, Germany
Ursula Felderhoff-Müser

⁵Klinik für Kinderheilkunde I/Perinatalzentrum, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany
Herbert Fluhr

⁶Frauenklinik, Universitätsklinikum Graz, Graz, Austria
Yves Garnier

⁷Frauenklinik, Klinikum Osnabrück, Osnabrück, Germany
Susanne Grylka-Baeschlin

⁸Zürcher Hochschule für angewandte Wissenschaften, Institut für Hebammenwissenschaft und reproduktive Gesundheit, Zürich, Switzerland
Aurelia Hayward

⁹Deutscher Hebammenverband, Karlsruhe, Germany
Hanns Helmer

¹⁰Universitätsklinik für Frauenheilkunde, Medizinische Universität Wien, Wien, Austria
Egbert Herting

¹¹Klinik für Kinder- und Jugendmedizin, Universitätsklinikum Schleswig-Holstein, Campus Lübeck, Lübeck, Germany
Markus Hoopmann

²Frauenklinik, Universitätsklinikum Tübingen, Tübingen, Germany
Irene Hösli

¹²Frauenklinik, Universitätsspital Basel, Basel, Switzerland
Udo Hoyme

¹³Frauenklinik, Ilm-Kreis-Kliniken, Arnstadt, Germany
Mirjam Kunze

¹⁴Frauenklinik, Universitätsklinikum Freiburg, Freiburg, Germany
Ruben-J. Kuon

¹⁵Frauenklinik, Universitätsklinikum Heidelberg, Heidelberg, Germany
Ioannis Kyvernitakis

¹⁶Frauenklinik, Asklepios Kliniken Hamburg, Hamburg, Germany
Wolf Lütje

¹⁷Frauenklinik, Evangelisches Amalie Sieveking-Krankenhaus Hamburg, Hamburg, Germany
Silke Mader

¹⁸European Foundation for the Care of Newborn Infants, München, Germany
Holger Maul

¹⁶Frauenklinik, Asklepios Kliniken Hamburg, Hamburg, Germany
Werner Mendling

¹⁹Frauenklinik, Helios Universitätsklinikum Wuppertal, Wuppertal, Germany
Barbara Mitschdörfer

²⁰Bundesverband das frühgeborene Kind, Frankfurt am Main, Germany
Monika Nothacker

²¹Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften, Berlin, Germany
Dirk Olbertz

²²Klinik für Neonatologie, Klinikum Südstadt Rostock, Rostock, Germany
Andrea Ramsell

⁹Deutscher Hebammenverband, Karlsruhe, Germany
Werner Rath

²³Emeritus, Universitätsklinikum Aachen, Aachen, Germany
Claudia Roll

²⁴Vestische Kinder- und Jugendklinik Datteln, Universität Witten/Herdecke, Datteln, Germany
Dietmar Schlembach

²⁵Klinik für Geburtsmedizin, Klinikum Neukölln/Berlin Vivantes Netzwerk für Gesundheit, Berlin, Germany
Ekkehard Schleußner

²⁶Klinik für Geburtsmedizin, Universitätsklinikum Jena, Jena, Germany
Florian Schütz

²⁷Frauenklinik, Diakonissen-Stiftungs-Krankenhaus Speyer, Speyer, Germany
Vanadin Seifert-Klauss

²⁸Frauenklinik, Universitätsklinikum rechts der Isar München, München, Germany
Johannes Stubert

²⁹Frauenklinik, Universitätsklinikum Rostock, Rostock, Germany
Daniel Surbek

³⁰Universitätsklinik für Frauenheilkunde, Inselspital Bern, Universität Bern, Bern, Switzerland

Abstract

Aim This revised guideline was coordinated by the German Society for Gynecology and Obstetrics (DGGG), the Austrian Society for Gynecology and Obstetrics (OEGGG) and the Swiss Society for Gynecology and Obstetrics (SGGG). It aims to improve the prediction, prevention, and management of preterm birth, based on evidence from the current literature, the experience of members of the guidelines commission, and the viewpoint of self-help organizations.

Methods The members of the contributing professional societies and organizations developed recommendations and statements based on international literature. The recommendations and statements were presented and adopted using a formal process (structured consensus conferences with neutral moderation, written Delphi vote).

Recommendations Part 1 of this short version of the guideline presents statements and recommendations on the epidemiology, etiology, prediction, and primary and secondary prevention of preterm birth.

Key words

guideline - preterm birth - preterm labor - cervical insufficiency - preterm premature rupture of membranes

Full Text

References

References
1 Swiss-Paediatrics. Accessed April 28, 2019 at: http://www.swiss-paediatrics.org/sites/default/files/paediatrica/vol23/n1/pdf/10-12_0.pdf
2 Murray CJ, Vos T, Lozano R. et al. Disability-adjusted life years (DALYs) for 291 diseases and injuries in 21 regions, 1990–2010: a systematic analysis for the Global Burden of Disease Study 2010. Lancet 2012; 380: 2197-2223
3 Bundesauswertung zum Erfassungsjahr 2020 Geburtshilfe. Accessed November 13, 2021 at: https://iqtig.org/downloads/auswertung/2020/16n1gebh/QSKH_16n1-GEBH_2020_BUAW_V01_2021-08-10.pdf
4 Geburtenregister Österreich. Accessed May 26, 2022 at: https://www.iet.at/data.cfm?vpath=publikationen210/groe/groe-jahresbericht-2020
5 Schweizerische Eidgenossenschaft – Bundesamt für Statistik. Accessed November 13, 2021 at: https://www.bfs.admin.ch/bfs/de/home/statistiken/gesundheit/gesundheitszustand/gesundheit-neugeborenen.html
6 European Perinatal Health Report. Accessed July 20, 2021 at: https://www.europeristat.com/images/EPHR2015_web_hyperlinked_Euro-Peristat.pdf
7 Romero R, Dey SK, Fisher SJ. Preterm labor: one syndrome, many causes. Science 2014; 345: 760-765
8 Frühgeburt: Was Sie als werdende Eltern wissen sollten. Accessed February 03, 2022 at: https://register.awmf.org/assets/guidelines/015-025p_S2k_Praevention-Therapie_Fruehgeburt_2022-08.pdf
9 Hillier SL, Nugent RP, Eschenbach DA. et al. Association between bacterial vaginosis and preterm delivery of a low-birth-weight infant. The Vaginal Infections and Prematurity Study Group. N Engl J Med 1995; 333: 1737-1742
10 Meis PJ, Michielutte R, Peters TJ. et al. Factors associated with preterm birth in Cardiff, Wales. I. Univariable and multivariable analysis. Am J Obstet Gynecol 1995; 173: 590-596
11 Murphy DJ. Epidemiology and environmental factors in preterm labour. Best Pract Res Clin Obstet Gynaecol 2007; 21: 773-789
12 Yi SW, Han YJ, Ohrr H. Anemia before pregnancy and risk of preterm birth, low birth weight and small-for-gestational-age birth in Korean women. Eur J Clin Nutr 2013; 67: 337-342
13 Schummers L, Hutcheon JA, Hernandez-Diaz S. et al. Association of Short Interpregnancy Interval With Pregnancy Outcomes According to Maternal Age. JAMA Intern Med 2018; 178: 1661-1670
14 Korevaar TIM, Derakhshan A, Taylor PN. et al. Association of Thyroid Function Test Abnormalities and Thyroid Autoimmunity With Preterm Birth: A Systematic Review and Meta-analysis. JAMA 2019; 322: 632-641
15 Wetzka S, Gallwas J, Hasbargen U. et al. Einfluss von Konisation auf die Frühgeburtenrate und das perinatale Outcome: Eine retrospektive Analyse der Daten zur externen stationären Qualitätssicherung für die Erfassungsjahre 2009–2014. Geburtshilfe Frauenheilkd 2018; 78: 236-237
16 Cronos Registerstudie. Accessed January 06, 2022 at: https://www.dgpm-online.org/gesellschaft/covid-19/cronos-registerstudie/
17 Allotey J, Stallings E, Bonet M. et al. Clinical manifestations, risk factors, and maternal and perinatal outcomes of coronavirus disease 2019 in pregnancy: living systematic review and meta-analysis. BMJ 2020; 370: m3320
18 Norman M, Navér L, Söderling J. et al. Association of Maternal SARS-CoV-2 Infection in Pregnancy With Neonatal Outcomes. JAMA 2021; 325: 2076-2086
19 Gurol-Urganci I, Jardine JE, Carroll F. et al. Maternal and perinatal outcomes of pregnant women with SARS-CoV-2 infection at the time of birth in England: national cohort study. Am J Obstet Gynecol 2021; 225: 522.e1-522.e11
20 Wei SQ, Bilodeau-Bertrand M, Liu S. et al. The impact of COVID-19 on pregnancy outcomes: a systematic review and meta-analysis. CMAJ 2021; 193: E540-E548
21 Lipkind HS, Vazquez-Benitez G, DeSilva M. et al. Receipt of COVID-19 Vaccine During Pregnancy and Preterm or Small-for-Gestational-Age at Birth – Eight Integrated Health Care Organizations, United States, December 15, 2020-July 22, 2021. MMWR Morb Mortal Wkly Rep 2022; 71: 26-30
22 Kagan KO, Sonek J. How to measure cervical length. Ultrasound Obstet Gynecol 2015; 45: 358-362
23 Salomon LJ, Diaz-Garcia C, Bernard JP. et al. Reference range for cervical length throughout pregnancy: non-parametric LMS-based model applied to a large sample. Ultrasound Obstet Gynecol 2009; 33: 459-464
24 Iams JD, Goldenberg RL, Meis PJ. 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: 567-572
25 Son M, Grobman WA, Ayala NK. et al. A universal mid-trimester transvaginal cervical length screening program and its associated reduced preterm birth rate. Am J Obstet Gynecol 2016; 214: 365.e1-365.e5
26 Berghella V, Baxter JK, Hendrix NW. Cervical assessment by ultrasound for preventing preterm delivery. Cochrane Database Syst Rev 2013; (2013): CD007235
27 Berghella V, Talucci M, Desai A. Does transvaginal sonographic measurement of cervical length before 14 weeks predict preterm delivery in high-risk pregnancies?. Ultrasound Obstet Gynecol 2003; 21: 140-144
28 Owen J, Yost N, Berghella V. et al. Can shortened midtrimester cervical length predict very early spontaneous preterm birth?. Am J Obstet Gynecol 2004; 191: 298-303
29 Fox NS, Jean-Pierre C, Predanic M. et al. Short cervix: is a follow-up measurement useful?. Ultrasound Obstet Gynecol 2007; 29: 44-46
30 Dilek TU, Yazici G, Gurbuz A. et al. Progressive cervical length changes versus single cervical length measurement by transvaginal ultrasound for prediction of preterm delivery. Gynecol Obstet Invest 2007; 64: 175-179
31 Crane JM, Hutchens D. Follow-up cervical length in asymptomatic high-risk women and the risk of spontaneous preterm birth. J Perinatol 2011; 31: 318-323
32 Owen J, Yost N, Berghella V. et al. Mid-trimester endovaginal sonography in women at high risk for spontaneous preterm birth. JAMA 2001; 286: 1340-1348
33 Owen J, Hankins G, Iams JD. et al. Multicenter randomized trial of cerclage for preterm birth prevention in high-risk women with shortened midtrimester cervical length. Am J Obstet Gynecol 2009; 201: 375.e1-375.e8
34 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: 128.e1-128.e12
35 Lim AC, Hegeman MA, Huis In ʼT Veld MA. 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: 10-17
36 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: 303-314
37 van ʼt Hooft J, van der Lee JH, Opmeer BC. et al. Pessary for prevention of preterm birth in twin pregnancy with short cervix: 3-year follow-up study. Ultrasound Obstet Gynecol 2018; 51: 621-628
38 Berghella V, Palacio M, Ness A. et al. 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: 322-329
39 Ness A, Visintine J, Ricci E. et al. Does knowledge of cervical length and fetal fibronectin affect management of women with threatened preterm labor? A randomized trial. Am J Obstet Gynecol 2007; 197: 426.e1-426.e7
40 Palacio M, Caradeux J, Sánchez M. et al. Uterine Cervical Length Measurement to Reduce Length of Stay in Patients Admitted for Threatened Preterm Labor: A Randomized Trial. Fetal Diagn Ther 2018; 43: 184-190
41 Alfirevic Z, Allen-Coward H, Molina F. et al. Targeted therapy for threatened preterm labor based on sonographic measurement of the cervical length: a randomized controlled trial. Ultrasound Obstet Gynecol 2007; 29: 47-50
42 Conde-Agudelo A, Papageorghiou AT, Kennedy SH. et al. Novel biomarkers for the prediction of the spontaneous preterm birth phenotype: a systematic review and meta-analysis. BJOG 2011; 118: 1042-1054
43 Hezelgrave NL, Abbott DS, Radford SK. et al. Quantitative Fetal Fibronectin at 18 Weeks of Gestation to Predict Preterm Birth in Asymptomatic High-Risk Women. Obstet Gynecol 2016; 127: 255-263
44 Esplin MS, Elovitz MA, Iams JD. 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: 1047-1056
45 Melchor JC, Khalil A, Wing D. et al. Prediction of preterm delivery in symptomatic women using PAMG-1, fetal fibronectin and phIGFBP-1 tests: systematic review and meta-analysis. Ultrasound Obstet Gynecol 2018; 52: 442-451
46 Deshpande SN, van Asselt AD, Tomini F. et al. Rapid fetal fibronectin testing to predict preterm birth in women with symptoms of premature labour: a systematic review and cost analysis. Health Technol Assess 2013; 17: 1-138
47 Abbott DS, Radford SK, Seed PT. et al. Evaluation of a quantitative fetal fibronectin test for spontaneous preterm birth in symptomatic women. Am J Obstet Gynecol 2013; 208: 122.e1-122.e6
48 Kuhrt K, Unwin C, Hezelgrave N. et al. Endocervical and high vaginal quantitative fetal fibronectin in predicting preterm birth. J Matern Fetal Neonatal Med 2014; 27: 1576-1579
49 Kuhrt K, Hezelgrave N, Foster C. et al. Development and validation of a tool incorporating quantitative fetal fibronectin to predict spontaneous preterm birth in symptomatic women. Ultrasound Obstet Gynecol 2016; 47: 210-216
50 Bruijn MM, Kamphuis EI, Hoesli IM. et al. The predictive value of quantitative fibronectin testing in combination with cervical length measurement in symptomatic women. Am J Obstet Gynecol 2016; 215: 793.e1-793.e8
51 Meis PJ, Klebanoff M, Thom E. et al. Prevention of recurrent preterm delivery by 17 alpha-hydroxyprogesterone caproate. N Engl J Med 2003; 348: 2379-2385
52 Norman JE, Marlow N, Messow CM. et al. Vaginal progesterone prophylaxis for preterm birth (the OPPTIMUM study): a multicentre, randomised, double-blind trial. Lancet 2016; 387: 2106-2116
53 Ashoush S, ElKady O, AlHawwary G. et al. The value of oral micronized progesterone in the prevention of recurrent spontaneous preterm birth: a randomized controlled trial. Acta Obstet Gynecol Scand 2017; 96: 1460-1466
54 Dodd JM, Grivell RM, OBrien CM. et al. Prenatal administration of progestogens for preventing spontaneous preterm birth in women with a multiple pregnancy. Cochrane Database Syst Rev 2017; (10) CD012024
55 Crowther CA, Ashwood P, McPhee AJ. et al. Vaginal progesterone pessaries for pregnant women with a previous preterm birth to prevent neonatal respiratory distress syndrome (the PROGRESS Study): A multicentre, randomised, placebo-controlled trial. PLoS Med 2017; 14: e1002390
56 OʼBrien JM, Adair CD, Lewis DF. et al. Progesterone vaginal gel for the reduction of recurrent preterm birth: primary results from a randomized, double-blind, placebo-controlled trial. Ultrasound Obstet Gynecol 2007; 30: 687-696
57 Rai P, Rajaram S, Goel N. et al. Oral micronized progesterone for prevention of preterm birth. Int J Gynaecol Obstet 2009; 104: 40-43
58 da Fonseca EB, Bittar RE, Carvalho MHB. et al. Prophylactic administration of progesterone by vaginal suppository to reduce the incidence of spontaneous preterm birth in women at increased risk: a randomized placebo-controlled double-blind study. Am J Obstet Gynecol 2003; 188: 419-424
59 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: 148-155
60 Saling E, Schumacher E. Total surgical cervical occlusion. Conclusions from data of several clinica, which use total surgical cervical occlusion. Z Geburtshilfe Neonatol 1996; 200: 82-87
61 Shennan A, Chandiramani M, Bennett P. et al. MAVRIC: a multicenter randomized controlled trial of transabdominal vs. transvaginal cervical cerclage. Am J Obstet Gynecol 2020; 222: 261.e1-261.e9
62 Shennan A, Story L, Jacobsson B. et al. FIGO good practice recommendations on cervical cerclage for prevention of preterm birth. Int J Gynaecol Obstet 2021; 155: 19-22
63 Marchand G, Taher Masoud A, Azadi A. et al. Efficacy of laparoscopic and trans-abdominal cerclage (TAC) in patients with cervical insufficiency: A systematic review and meta-analysis. Eur J Obstet Gynecol Reprod Biol 2022; 270: 111-125
64 Ades A, Dobromilsky KC, Cheung KT. et al. Transabdominal Cervical Cerclage: Laparoscopy Versus Laparotomy. J Minim Invasive Gynecol 2015; 22: 968-973
65 Leitich H, Bodner-Adler B, Brunbauer M. et al. Bacterial vaginosis as a risk factor for preterm delivery: a meta-analysis. Am J Obstet Gynecol 2003; 189: 139-147
66 Flynn CA, Helwig AL, Meurer LN. Bacterial vaginosis in pregnancy and the risk of prematurity: a meta-analysis. J Fam Pract 1999; 48: 885-892
67 Lamont RF. Advances in the Prevention of Infection-Related Preterm Birth. Front Immunol 2015; 6: 566
68 Kiss H, Petricevic L, Husslein P. Prospective randomised controlled trial of an infection screening programme to reduce the rate of preterm delivery. BMJ 2004; 329: 371
69 Sangkomkamhang US, Lumbiganon P, Prasertcharoensuk W. et al. Antenatal lower genital tract infection screening and treatment programs for preventing preterm delivery. Cochrane Database Syst Rev 2015; (2015): CD006178
70 Subtil D, Brabant G, Tilloy E. et al. Early clindamycin for bacterial vaginosis in pregnancy (PREMEVA): a multicentre, double-blind, randomised controlled trial. Lancet 2018; 392: 2171-2179
71 Hoyme UB, Hesse M. Reduced Incidence of Early Preterm Birth in the State of Thuringia Following Initiation of a Screening Program by the Government in 2016 for Genital Infection Based on Intravaginal (i.vag.) pH-Self-Monitoring. Am J Obstet Gynecol Res 2021; 1: 1006
72 Hoyme UB, Saling E. Efficient prematurity prevention is possible by pH-self measurement and immediate therapy of threatening ascending infection. Eur J Obstet Gynecol Reprod Biol 2004; 115: 148-153
73 Bitzer EM, Schneider A, Wenzlaff P. et al. Self-testing of vaginal pH to prevent preterm delivery: a controlled trial. Dtsch Arztebl Int 2011; 108: 81-86
74 Hollowell J, Oakley L, Kurinczuk JJ. et al. The effectiveness of antenatal care programmes to reduce infant mortality and preterm birth in socially disadvantaged and vulnerable women in high-income countries: a systematic review. BMC Pregnancy Childbirth 2011; 11: 13
75 Moore E, Blatt K, Chen A. et al. Relationship of trimester-specific smoking patterns and risk of preterm birth. Am J Obstet Gynecol 2016; 215: 109.e1-109.e6
76 Polakowski LL, Akinbami LJ, Mendola P. Prenatal smoking cessation and the risk of delivering preterm and small-for-gestational-age newborns. Obstet Gynecol 2009; 114: 318-325
77 IQWIG. IQWIG 2015: Abschlussbericht S13-02 Bakteriuriescreening bei Schwangeren. Accessed April 28, 2019 at: https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=2ahUKEwj08cDHp6HfAhVKaBoKHfVACFwQFjAAegQIBxAC&url=https%253A%252F%252Fwww.iqwig.de%252Fdownload%252FS13-02_Abschlussbericht_Bakteriuriescreening-bei-Schwangeren.pdf&usg=AOvVaw37Fv32kK5I7_Zma_9FO6n0
78 Serra R, Peñailillo R, Monteiro LJ. et al. Supplementation of Omega 3 during Pregnancy and the Risk of Preterm Birth: A Systematic Review and Meta-Analysis. Nutrients 2021; 13: 1704
79 Romero R, Nicolaides KH, Conde-Agudelo A. et al. Vaginal progesterone decreases preterm birth </= 34 weeks of gestation in women with a singleton pregnancy and a short cervix: an updated meta-analysis including data from the OPPTIMUM study. Ultrasound Obstet Gynecol 2016; 48: 308-317
80 EPPPIC-Collaborative. Evaluating Progestogens for Preventing Preterm birth International Collaborative (EPPPIC): meta-analysis of individual participant data from randomised controlled trials. Lancet 2021; 397: 1183-1194
81 Berghella V, Odibo AO, To MS. et al. Cerclage for short cervix on ultrasonography: Meta-analysis of trials using individual patient-level data. Obstet Gynecol 2005; 106: 181-189
82 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: 100430
83 Perez-Lopez FR, Chedraui P, Perez-Roncero GR. et al. Effectiveness of the cervical pessary for the prevention of preterm birth in singleton pregnancies with a short cervix: a meta-analysis of randomized trials. Arch Gynecol Obstet 2019; 299: 1215-1231
84 Jarde A, Lutsiv O, Beyene J. et al. Vaginal progesterone, oral 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: 556-567
85 Dugoff L, Berghella V, Sehdev H. et al. Prevention of preterm birth with pessary in singletons (PoPPS): randomized controlled trial. Ultrasound Obstet Gynecol 2018; 51: 573-579
86 Nicolaides KH, Syngelaki A, Poon LC. et al. A Randomized Trial of a Cervical Pessary to Prevent Preterm Singleton Birth. N Engl J Med 2016; 374: 1044-1052
87 Palmer KT, Bonzini M, Bonde JP. et al. Pregnancy: occupational aspects of management: concise guidance. Clin Med 2013; 13: 75-79
88 Gesetz zum Schutz von Müttern bei der Arbeit, in der Ausbildung und im Studium. Accessed March 30, 2023 at: https://www.gesetze-im-internet.de/muschg_2018/