Geburtshilfe Frauenheilkd 2021; 81(08): 870-895
DOI: 10.1055/a-1519-7713
GebFra Science
Guideline/Leitlinie

Induction of Labour. Guideline of the DGGG, OEGGG and SGGG (S2k, AWMF Registry No. 015-088, December 2020)

Article in several languages: English | deutsch
Sven Kehl
1   Frauenklinik, Universitätsklinikum Erlangen, Erlangen, Germany
,
Irene Hösli
2   Frauenklinik, Universitätsspital Basel, Basel, Switzerland
,
Ulrich Pecks
3   Klinik für Gynäkologie und Geburtshilfe, Universitätsklinikum Schleswig-Holstein, Campus Kiel, Kiel, Germany
,
Philipp Reif
4   Frauenheilkunde und Geburtshilfe, Universitätsklinikum Graz, Graz, Austria
,
Ralf L. Schild
5   Klinik für Geburtshilfe und Perinatalmedizin, Diakovere Krankenhaus gGmbH, Hannover, Germany
,
Markus Schmidt
6   Frauenheilkunde und Geburtshilfe, Sana Kliniken Duisburg, Duisburg, Germany
,
Dagmar Schmitz
7   Institut für Geschichte, Theorie und Ethik der Medizin, Uniklinik RWTH Aachen, Aachen, Germany
,
Christiane Schwarz
8   Fachbereich Hebammenwissenschaft, Institut für Gesundheitswissenschaften, Universität zu Lübeck, Lübeck, Germany
,
Daniel Surbek
9   Frauenklinik, Inselspital, Universitätsspital Bern, Bern, Switzerland
,
Michael Abou-Dakn
10   Klinik für Gynäkologie, St. Joseph Krankenhaus, Berlin Tempelhof, Berlin, Germany
› Author Affiliations
 

Abstract

Aim The aim of this official guideline published and coordinated by the German Society of Gynaecology and Obstetrics (DGGG) in cooperation with the Austrian Society of Gynaecology and Obstetrics (OEGGG) and the Swiss Society of Gynaecology and Obstetrics (SGGG) is to provide a consensus-based overview of the indications, methods and general management of induction of labour by evaluating the relevant literature.

Methods This S2k guideline was developed using a structured consensus process which included representative members from various professions; the guideline was commissioned by the guidelines commission of the DGGG, OEGGG and SGGG.

Recommendations The guideline provides recommendations on the indications, management, methods, monitoring and special situations occurring in the context of inducing labour.


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I  Guideline Information

Guidelines programme of the DGGG, OEGGG and SGGG

For information on the guidelines programme, please refer to the end of this guideline.


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Citation format

Induction of Labour. Guideline of the DGGG, OEGGG and SGGG (S2k, AWMF Registry No. 015-088, December 2020). Geburtsh Frauenheilk 2021; 81: 870–895


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Guideline documents

The complete long version in German and a slide version of these guidelines together with a list of the conflicts of interest of all of the authors are available on the homepage of the AWMF: http://www.awmf.org/leitlinien/detail/ll/015-088.html


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Guideline authors

See [Tables 1] and [2].

Table 1 Lead author and/or coordinating guideline authors.

Author

AWMF professional society

Prof. Dr. med. Sven Kehl

German Society of Gynaecology and Obstetrics [Deutsche Gesellschaft für Gynäkologie und Geburtshilfe e. V.] (DGGG)

Prof. Dr. med. Michael Abou-Dakn

German Society of Gynaecology and Obstetrics [Deutsche Gesellschaft für Gynäkologie und Geburtshilfe e. V.] (DGGG)

Table 2 Contributing guideline authors (listed alphabetically).

Author

Mandate holder

DGGG working group/AWMF/non-AWMF professional society/organisation/association

Prof. Dr. med. Michael Abou-Dakn

German Society of Gynaecology and Obstetrics [Deutsche Gesellschaft für Gynäkologie und Geburtshilfe e. V.] (DGGG)

Obstetrics and Prenatal Medicine Working Group in the DGGG [Arbeitsgemeinschaft für Geburtshilfe und Pränatalmedizin in der DGGG e. V.] (AGG)

Prof. Dr. med. Irene Hösli

Academy for Fetomaternal Medicine [Akademie für fetomaternale Medizin] (AFMM)

Prof. Dr. med. Sven Kehl

German Society of Gynaecology and Obstetrics [Deutsche Gesellschaft für Gynäkologie und Geburtshilfe e. V.] (DGGG)

Obstetrics and Prenatal Medicine Working Group in the DGGG [Arbeitsgemeinschaft für Geburtshilfe und Pränatalmedizin in der DGGG e. V.] (AGG)

PD Dr. med. Ulrich Pecks

German Society for Perinatal Medicine [Deutsche Gesellschaft für Perinatale Medizin e. V.] (DGPM)

PD Dr. med. Philipp Reif

Austrian Society of Gynaecology and Obstetrics [Österreichische Gesellschaft für Gynäkologie und Geburtshilfe] (ÖGGGG)

Prof. Dr. med. Ralf L. Schild

German Society of Ultrasound in Medicine [Deutsche Gesellschaft für Ultraschall in der Medizin e. V.] (DEGUM)

Prof. Dr. med. Markus Schmidt

German Society for Prenatal and Obstetric Medicine [Deutsche Gesellschaft für Pränatal- und Geburtsmedizin] (DGPGM)

PD Dr. med. Dagmar Schmitz

Academy for Ethics in Medicine [Akademie für Ethik in der Medizin e. V.] (AEM)

Prof. Dr. Christiane Schwarz

German Midwifery Society [Deutsche Gesellschaft für Hebammenwissenschaft] (DGHWi)

Prof. Dr. med. Daniel Surbek

Swiss Society of Gynaecology and Obstetrics [Schweizer Gesellschaft für Gynäkologie und Geburtshilfe] (SGGG)

The following professional societies/working groups/organisations/associations were interested in contributing to the guideline text and participating in the consensus conference and nominated representatives to contribute and to attend the conference:


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Abbreviations

CI: confidence interval
CTG: cardiotocography
g: grams
GDM: gestational diabetes mellitus
GW: week of gestation
ICSI: intracytoplasmic sperm injection
IUFD: intrauterine foetal death
IUGR: intrauterine growth restriction
LGA: large for gestational age
µg: microgrammes
mg: milligrammes
PROM: premature rupture of membranes
PPROM: preterm premature rupture of membranes
RCT: randomised controlled trial
RR: risk ratio
SDP: single deepest pocket
SGA: small for gestational age
s/p: status post
WHO: World Health Organisation


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II  Guideline Application

Purpose and objectives

The induction of labour is one of the most commonly performed procedures in routine obstetric care. Despite sufficient available evidence, there is considerable heterogeneity in the approaches used, which is why the indications to induce labour and the different methods used together with their advantages, disadvantages and risks are presented here.


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Targeted areas of patient care

  • Inpatient care

  • Day-patient care

  • Outpatient care


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Targeted patient group

This guideline is aimed at pregnant women.


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Target user groups/target audience

This guideline is aimed at the following groups of users:

  • gynaecologists and obstetricians

  • midwives


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Adoption and period of validity

The validity of this guideline was confirmed by the executive boards/heads of the participating medical professional societies, working groups, organisations and associations as well as by the boards of the DGGG, the SGGG and the OEGGG as well as the board of the DGGG/SGGG and OEGGG Guidelines Commission in July 2020 and was thus approved in its entirety. This guideline is valid from 1st December 2020 through to 1st December 2025. Because of the contents of this guideline, this period of validity is only an estimate. If changes are urgently required, the guideline may be updated earlier. Similarly, if the guideline continues to reflect the current state of knowledge, its period of validity may be extended.


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III  Methodology

Basic principles

The method used to prepare this guideline was determined by the class to which this guideline was assigned. The AWMF Guidance Manual (version 1.0) has set out the respective rules and requirements for different classes of guidelines. Guidelines are differentiated into lowest (S1), intermediate (S2), and highest (S3) class. The lowest class is defined as consisting of a set of recommendations for action compiled by a non-representative group of experts. In 2004, the S2 class was divided into two subclasses: a systematic evidence-based subclass (S2e) and a structural consensus-based subclass (S2k). The highest S3 class combines both approaches.

This guideline has been classified as: S2k


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Grading of recommendations

The grading of evidence based on the systematic search, selection, evaluation and synthesis of an evidence base which is then used to grade recommendations is not envisaged for S2k guidelines. The different individual statements and recommendations are only differentiated linguistically, not by the use of symbols ([Table 3]):

Table 3 Grading of recommendations (based on Lomotan et al., Qual Saf Health Care 2010).

Description of binding character

Expression

Strong recommendation with highly binding character

must/must not

Regular recommendation with moderately binding character

should/should not

Open recommendation with limited binding character

may/may not


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Statements

Expositions or explanations of specific facts, circumstances or problems without any direct recommendations for action included in this guideline are referred to as “statements”.


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Achieving consensus and strength of consensus

At structured NIH-type consensus-based conferences (S2k/S3 level), authorised participants attending the session vote on draft statements and recommendations. This can lead to significant changes in the wording, etc. Finally, the extent of consensus is determined based on the number of participants ([Table 4]).

Table 4 Level of consensus based on extent of agreement.

Symbol

Level of consensus

Extent of agreement in percent

+++

Strong consensus

> 95% of participants agree

++

Consensus

> 75 – 95% of participants agree

+

Majority agreement

> 50 – 75% of participants agree

No consensus

< 51% of participants agree


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Expert consensus

As the term already indicates, this refers to consensus decisions taken specifically with regard to recommendations/statements issued without a prior systematic search of the literature (S2k) or where evidence is lacking (S2e/S3). The term “expert consensus” (EC) used here is synonymous with terms used in other guidelines such as “good clinical practice” (GCP) or “clinical consensus point” (CCP). The strength of the recommendation is graded as previously described in the chapter on the grading of recommendations; it is only expressed semantically (“must”/“must not” or “should”/“should not” or “may”/“may not”) without the use of symbols.


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IV  Guideline

1  Purpose of inducing labour

The decision to induce labour must be considered very carefully, as inducing labour affects the natural course of the pregnancy. The assumed benefits must be weighed against the potential disadvantages. In general, the guiding principle must be that inducing labour will achieve a better perinatal outcome for mother and child than expectant management of the pregnancy.


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2  Indications for inducing labour

2.1  Exceeding the due date, post-term/prolonged pregnancy

Consensus-based Recommendation 2.E1

Expert consensus

Level of consensus +++

The presumed gestational age (which is based on information provided by the mother) must be checked by measuring the crown-rump length in early pregnancy and corrected if there is a discrepancy of 7 days or more. In Switzerland, according to the guidelines of the SGUM [the Swiss Society of Ultrasound in Medicine], the due date is amended if there is a discrepancy of 5 days or more.

Consensus-based Recommendation 2.E2

Expert consensus

Level of consensus +++

Mother and child must be supervised more closely from week 40 + 0 of gestation to detect risks early on.

Consensus-based Recommendation 2.E3

Expert consensus

Level of consensus +++

Induction of labour may be offered from week 41 + 0 of gestation.

Consensus-based Recommendation 2.E4

Expert consensus

Level of consensus +++

Induction of labour should be offered from week 41 + 3 of gestation.

Consensus-based Recommendation 2.E5

Expert consensus

Level of consensus +++

Induction of labour must be urgently recommended from week 42 + 0 of gestation.

As the gestational age increases, the risk of mortality and morbidity, which is very low in absolute numbers, steadily increases [1], [2], [3], and randomised studies on inducing labour carried out in recent years show that inducing labour from week 39 + 0 of gestation is associated with a lower rate of caesarean sections [4], [5], [6], [7], [8].

As part of antenatal care, information must be provided about individual risk situations (e.g., maternal age, nicotine abuse, parity, Bishop score, obesity, estimated foetal weight) and the respective individual advantages and disadvantages of terminating the pregnancy must be described and weighed up in consultation with the pregnant woman (cf. 3.1.). The low absolute risk of intrauterine foetal death may be higher in certain situations (e.g., a maternal age of more than 40 years) [9]. If the pregnancy is continued, the pregnancyʼs progress should be monitored more closely from week 40 + 0 (e.g., every 3 – 5 days). In German-speaking countries, monitoring to detect potential early-stage risks is usually done with CTG and sonography. However, there are no prospective data on monitoring pregnancies who have just passed their due date, which is why some countries do not monitor pregnant women between week 40 + 0 and week 41 + 0 of gestation [10].


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2.2  (Preterm) premature rupture of membranes

2.2.1  Preterm premature rupture of membranes (PPROM)

Consensus-based Recommendation 2.E6

Expert consensus

Level of consensus +++

Induction of labour should be recommended by week 37 + 0 of gestation at the latest following preterm premature rupture of membranes (PPROM) if there are no “Triple I” (amniotic fluid infection syndrome) signs.


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2.2.2  Premature rupture of membranes (PROM)

Consensus-based Recommendation 2.E7

Expert consensus

Level of consensus +++

Induction of labour must be recommended at the latest 24 hours after premature rupture of membranes.


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2.3  Gestational diabetes

Consensus-based Recommendation 2.E8

Expert consensus

Level of consensus +++

Given the morbidity associated with preterm birth, preterm induction of labour (before week 38 + 0 of gestation) must not be pursued because of poor control of blood sugar levels; instead, the aim must be to optimise prenatal blood sugar levels.

Consensus-based Recommendation 2.E9

Expert consensus

Level of consensus +++

Inducing labour before week 39 + 0 of gestation increases neonatal morbidity and the likelihood of the neonate needing to be transferred to a neonatal unit and must be avoided.

Consensus-based Recommendation 2.E10

Expert consensus

Level of consensus +++

Induction of labour must be offered from week 40 + 0 of gestation to mothers with insulin-dependent gestational diabetes.

Consensus-based Statement 2.S1

Expert consensus

Level of consensus +++

Well-managed gestational diabetes which is maintained by careful dietary control is not, per se, an indication to induce labour.

Detailed recommendations are given in the German-language AWMF S3 guideline no. 057-008 “Gestational Diabetes Mellitus (GDM): Diagnosis, Therapy and Follow-up Care” [11].


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2.4  Abnormal amniotic fluid volumes

2.4.1  Oligohydramnios

Consensus-based Recommendation 2.E11

Expert consensus

Level of consensus +++

The SDP (single deepest pocket) method must be used to evaluate the volume of amniotic fluid.

Consensus-based Recommendation 2.E12

Expert consensus

Level of consensus +++

Inducing labour before week 37 + 0 of gestation leads to higher rates of neonatal morbidity and should therefore not be carried out for oligohydramnios alone.

Consensus-based Recommendation 2.E13

Expert consensus

Level of consensus +++

Termination of the pregnancy from week 37 + 0 of gestation should not be routinely recommended for oligohydramnios alone.

However, from week 39 + 0 of gestation, the leeway to decide whether terminating the pregnancy is indicated in cases with isolated oligohydramnios and additional risk factors is greater – even though there is no clear evidence on this matter.


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2.4.2  Polyhydramnios

Consensus-based Recommendation 2.E14

Expert consensus

Level of consensus +++

Termination of the pregnancy should not be routinely recommended because of isolated polyhydramnios.


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2.5  SGA foetus or intrauterine growth restriction

Up to 70% of SGA (small for gestational age) foetuses are constitutionally small and have a normal perinatal outcome [12], [13]. In contrast, intrauterine growth restriction (IUGR) is associated with higher perinatal morbidity and mortality rates and may be identified when additional anomalies (pathological Doppler sonography, oligohydramnios, no interval growth, estimated weight < 3rd percentile) are present. The risk of intrauterine foetal death increases with increasing gestational age, which is why preterm termination of the pregnancy should be discussed with the patient.

As regards the rationale behind the recommendations on inducing labour, we refer interested parties to the S2k guideline no. 015-080 “Intrauterine Growth Restriction” [14].


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2.6  Intrahepatic cholestasis of pregnancy

Consensus-based Recommendation 2.E15

Expert consensus

Level of consensus +++

Induction of labour must be recommended from week 38 + 0 of gestation if the pregnant woman has intrahepatic cholestasis of pregnancy.

Consensus-based Recommendation 2.E16

Expert consensus

Level of consensus +++

Induction of labour should be recommended from week 37 + 0 of gestation if the pregnant woman has intrahepatic cholestasis of pregnancy.

Induction of labour may already be recommended between week 34 + 0 and week 36 + 6 of gestation if bile acid concentrations are > 100 µmol/l.

The level of bile acid concentrations at an undefined time point in pregnancy is a predictive marker for stillbirth and neonatal complications, and the cut-off value in different studies varies between > 40 µmol/L and > 100 µmol/L [15], [16], [17], [18], [19]. Based on the best available evidence, induction of labour may be recommended between week 34 + 0 and week 36 + 6 of gestation if bile acid concentrations are > 100 µmol/L [20].


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2.7  Hypertensive disorders of pregnancy

Consensus-based Recommendation 2.E17

Expert consensus

Level of consensus +++

Termination of the pregnancy after weighing up the maternal and neonatal risks must be recommended from week 34 + 0 of gestation in cases with preeclampsia.

When deciding whether or not to induce labour from week 34 + 0 of gestation because of preeclampsia, the increased neonatal morbidity associated with late preterm birth and the risks for the pregnant woman must be taken into account.

Consensus-based Recommendation 2.E18

Expert consensus

Level of consensus +++

In cases with preeclampsia, termination of pregnancy must be recommended from week 37 + 0 of gestation at the latest. The pregnancy may be terminated by inducing labour.

Consensus-based Recommendation 2.E19

Expert consensus

Level of consensus +++

Termination of pregnancy should be recommended from week 37 + 0 of gestation in cases with gestational diabetes. The pregnancy may be terminated by inducing labour.

Consensus-based Recommendation 2.E20

Expert consensus

Level of consensus +++

Termination of pregnancy should be recommended from week 38 + 0 of gestation in cases with chronic hypertension. The pregnancy may be terminated by inducing labour. The pregnancy should not be continued beyond the due date.

The definitions of hypertensive disorders of pregnancy are presented in detail in the S2k guideline no. 015/018 “Hypertensive Disorders of Pregnancy: Diagnosis and Therapy” [21]. The pregnancy may be terminated by inducing labour for hypertensive disorder of pregnancy after due consideration of additional foetal and obstetric factors.

In cases with HELLP syndrome, the foetus should be delivered from week 34 + 0 of gestation (at the latest); inducing labour may be an option once the overall situation has been carefully considered.


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2.8  Suspicion of (non-diabetogenic) macrosomia

Consensus-based Recommendation 2.E21

Expert consensus

Level of consensus +++

If there is a suspicion of a LGA foetus > 95th percentile, induction of labour should be offered from week 39 + 0 of gestation.

Foetal macrosomia is a risk factor for birth complications. Inducing labour must therefore reduce the risk of shoulder dystocia with the potential for a subsequent lesion of the brachial plexus and the risk of surgical intervention.


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2.9  Termination on request/no medical reason

Consensus-based Recommendation 2.E22

Expert consensus

Level of consensus +++

Inducing labour on request for no medical reason should not be done before week 39 + 0 of gestation.

Studies carried out in recent years have shown that inducing labour in women with no risk factors/no medical indications from week 39 + 0 of gestation was not associated with a higher risk of caesarean section compared to expectant management [4], [5], [22]. These findings have led to international guidelines presenting the option of inducing labour from week 39 + 0 of gestation to primipara with no risk factors [23]. Because of the potentially higher neonatal morbidity (hyperbilirubinemia, hypoglycaemia), labour should not be induced before week 39 + 0 of gestation.


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3  Measures taken before inducing labour

3.1  Information, consultation and documentation

Consensus-based Recommendation 3.E23

Expert consensus

Level of consensus +++

Medical information and advice must be provided to pregnant women with the aim of coming to a joint decision before initiating any induction of labour.

Consensus-based Recommendation 3.E24

Expert consensus

Level of consensus +++

If the pregnant woman has previously had a caesarean section, she must be given medical information and advice about the advantages and disadvantages (especially uterine rupture) of inducing labour and must give her consent in writing.

Inducing labour is a medical intervention, which is why providing information and advice/consultation with an individual risk-benefit analysis is necessary. The aim when consulting with the patient is to arrive at a joint decision which is supported by the pregnant woman. The indications for inducing labour must be reviewed, possible contraindications must be excluded, and the method used to induce labour must be chosen after all factors have been taken into consideration. The time frame, possible progress, and outcome as well as other options (e.g., deferring the decision and waiting) should be discussed with the pregnant woman. As some methods have only been approved for certain settings, the specifically approved indications and contraindications should be known. However, a procedure may be used if there is sufficient existing evidence, even if it has not been approved. But this requires appropriate information to be given to the patient and the patient to consent. The consent should be recorded in writing.

Inducing labour in a pregnant woman who has previously had a caesarean section requires high levels of information and advice/consultation. The decision that induction of labour is indicated must be based on very strict criteria, and possible alternatives (e.g. repeat caesarean section) must be pointed out. The patient must be informed about the risks (primarily uterine rupture and the corresponding consequences for mother and child) associated with inducing labour after a previous delivery by caesarean section and must be given extensive detailed advice. Moreover, as almost all procedures for inducing labour have not been approved in this setting and are contraindicated, the patient must give her consent in writing.


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3.2  Risk-benefit analysis, contraindications

In certain situations, the risks of inducing labour outweigh the intended benefit. Medication given to induce labour when the patient is already having regular contractions may lead to overstimulation and have a negative impact on the babyʼs condition. In addition, the standard contraindications for vaginal delivery (e.g., transverse presentation, total placenta praevia, presenting umbilical cord/umbilical cord prolapse, active herpes simplex, s/p uterine rupture and s/p caesarean section with a vertical uterotomy) must be taken into account.


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3.3  Predicting the success of induced labour

Consensus-based Recommendation 3.E25

Expert consensus

Level of consensus +++

Factors which have a favourable or unfavourable impact on the induction of labour must be considered when choosing the appropriate method to induce labour.

Consensus-based Recommendation 3.E26

Expert consensus

Level of consensus ++

The Bishop score must be ascertained and recorded.

Factors which have a positive impact on the induction of labour include a ripe cervix, a prior history of vaginal delivery, and premature rupture of membranes [24]. Cervical ripening is evaluated clinically and described using the Bishop score. The Bishop score is one of the most important predictors for successful induction of labour and should therefore be ascertained and recorded. Unfavourable factors for inducing labour include a low Bishop score, nulliparity, a high body mass index, previous caesarean section, and low gestational age.


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4  Methods for inducing labour

A number of mechanical procedures and medications are available to induce labour. The choice of method to induce labour is determined, first and foremost, by the cervical findings (Bishop score, cf. 3.3). Other factors which must be taken into account when selecting the appropriate method include whether (premature) rupture of membranes has occurred and whether the mother has a previous history of caesarean section.

4.1  Mechanical induction of labour

4.1.1  Membrane sweep

Consensus-based Recommendation 4.E27

Expert consensus

Level of consensus +++

The pregnant woman may be offered a membrane sweep at term.

A membrane sweep is a procedure during which one or two fingers are inserted into the uterine cervix to separate the lower part of the amniotic sac from the lower uterine segment using circular movements of the fingers.


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4.1.2  Amniotomy

Consensus-based Recommendation 4.E28

Expert consensus

Level of consensus +++

Amniotomy must not be used only for the purpose of inducing labour.

Amniotomy (also known as artificial rupture of membranes) is carried out when the cervix is ripe and the cervical os has begun to open. The aim of this intervention is to trigger the release of endogenous prostaglandins.


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4.1.3  Balloon catheter

Consensus-based Statement 4.S2

Expert consensus

Level of consensus +++

Balloon catheters (single and double balloon catheters) are an effective procedure for cervical ripening and inducing labour when the cervix is still unripe.

Consensus-based Statement 4.S3

Expert consensus

Level of consensus +++

The uterine overstimulation rates are lower with balloon catheters compared to the administration of prostaglandins.

Consensus-based Statement 4.S4

Expert consensus

Level of consensus +++

Sequential induction of labour starting with balloon catheters followed by prostaglandins is especially effective when treating primiparous women with an unripe cervix.

Consensus-based Statement 4.S5

Expert consensus

Level of consensus +++

Simultaneous induction of labour using balloon catheters and oxytocin or prostaglandins is effective and results in a shorter interval between induction and delivery compared to using only one method.

Balloon catheters are used for cervical ripening and to induce labour when the cervix is still unripe. Both single and double catheters with fill volumes ranging from 30 to 100 ml can be used. The pressure of the liquid-filled balloon(s) on the uterine cervix results in the endogenous release of prostaglandins, which may lead to cervical ripening and the onset of labour.


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4.1.4  Hygroscopic dilators

Consensus-based Recommendation 4.E29

Expert consensus

Level of consensus +++

Cervical dilators may be used to induce labour when the cervix is unripe.

Hygroscopic cervical dilators are placed in the uterine cervix and lead to dilation of the cervix through osmotic dehydration of cervical cells with endogenous release of prostaglandins. They are mostly used to induce abortion in the early weeks of pregnancy [25].


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4.2  Pharmaceutical induction of labour

4.2.1  Oxytocin

Consensus-based Recommendation 4.E30

Expert consensus

Level of consensus +++

Oxytocin must not be used to induce labour when the cervix is still unripe.

Consensus-based Recommendation 4.E31

Expert consensus

Level of consensus +++

Oxytocin may be used to induce labour when the cervix is ripe. Combining oxytocin with an amniotomy increases the probability of vaginal delivery.

Oxytocin is administered intravenously and acts by inducing contractions. The benefits of oxytocin are that it can be easily controlled as it floods the body very quickly (onset of effect occurs after around 3 – 10 minutes) and is also eliminated quickly from the bloodstream (its half-life is 3 – 6 minutes). It is approved to induce labour when the cervix is ripe.


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4.2.2  Prostaglandin E2 (dinoprostone)

Consensus-based Recommendation 4.E32

Expert consensus

Level of consensus +++

Vaginal application of prostaglandin E2 to induce labour when the cervix is unripe is appropriate and effective and vaginal application should be preferred to intracervical application.

In contrast to oxytocin, prostaglandins take effect through cervix-ripening and contraction-inducing mechanisms, which is why they may also be used in cases with unripe cervix.


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4.2.3  Prostaglandin E1 analogues (misoprostol)

Consensus-based Recommendation 4.E33

Expert consensus

Level of consensus +++

Until drugs have been approved to induce labour, patients must be informed about their off-label use.

March 2021 Addendum:

In September 2020 a misoprostol-containing drug, which was already on the market in a number of other European countries, was approved for use in Germany and Austria.

The drug is already available in Austria.

The drug is expected to be launched in Germany sometime this year.

An application for approval has been submitted in Switzerland (as at March 2021).

Consensus-based Statement 4.S6

Expert consensus

Level of consensus +++

Misoprostol is the most effective drug to induce labour when the cervix is unripe.

Consensus-based Recommendation 4.E34

Expert consensus

Level of consensus +++

Misoprostol should be administered orally.

Consensus-based Statement 4.S7

Expert consensus

Level of consensus +++

Misoprostol doses of 25 µg are considered safe even when applied vaginally.

Consensus-based Statement 4.S8

Expert consensus

Level of consensus +++

An oral 50 µg dosage of misoprostol corresponds to the safety profile of a vaginal application of 25 µg.

Consensus-based Statement 4.S9

Expert consensus

Level of consensus +++

A side effect such as uterine overstimulation does not inevitably result in a pathological CTG, require caesarean section and/or lead to a poorer foetal outcome.

Consensus-based Statement 4.S10

Expert consensus

Level of consensus +++

Although taking oral/vaginal misoprostol in a dosage of ≥ 50 µg per tablet results in more cases of overstimulation compared to placebo, there was no difference between the two approaches with regard to the rate of infants requiring transfer to a paediatric clinic.

Consensus-based Recommendation 4.E35

Expert consensus

Level of consensus +++

An initial dose of > 50 µg and individual doses of > 100 µg should be avoided.

Consensus-based Statement 4.S11

Expert consensus

Level of consensus +++

Cutting up tablets with higher doses by hand and/or dissolving tablets in liquid and administering them in the form of specified amounts of liquid to be drunk by to the patient must be avoided because of the imprecise stability of drug concentrations. Correct preparation by a pharmacy is indispensable.

Misoprostol may be administered orally or vaginally and may be administered both to women with an unripe cervix and to women with a ripe cervix. The use of misoprostol to induce labour is now well researched, and it appears to be the most effective pharmaceutical to induce labour when the cervix is unripe.


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4.3  Other methods to induce labour

4.3.1  Castor oil

Consensus-based Recommendation 4.E36

Expert consensus

Level of consensus +++

Castor oil must not be used to induce labour in an outpatient setting.

Consensus-based Recommendation 4.E37

Expert consensus

Level of consensus +++

Castor oil should only be used in the context of studies on inducing labour.

A “contractions cocktail” using castor oil was the first drug-based procedure used to induce labour in the first half of the last century [26], [27], [28]. Because of its side effects (especially diarrhoea), castor oil came to be used less and less over time and was finally replaced by oxytocin. The effect of castor oil is based on ricinoleic acid, the active ingredient of castor oil. Ricinoleic acid affects the prostaglandin receptors of the uterine and abdominal muscle cells, which is why it can lead to uterine contractions in addition to the typical symptoms associated with the use of laxatives. Although castor oil has been used to induce labour since almost one hundred years, evidence is insufficient.


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4.3.2  Other methods

Many other methods are also being used to induce labour. They include, among others, the insertion of a clove oil tampon, sexual intercourse [29], [30], acupuncture [31], nipple stimulation, and homeopathic methods such as the administration of caulophyllum. As these alternative methods have not been sufficiently studied, they are not recommended as a means of inducing labour and should only be used in the context of scientific trials.


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5  Monitoring the induction of labour

Consensus-based Statement 5.S12

Expert consensus

Level of consensus +++

There are no evidence-based recommendations on how precisely the induction of labour must be monitored.

Consensus-based Recommendation 5.E38

Expert consensus

Level of consensus +++

A CTG examination must be carried out before starting medication to induce labour.

Consensus-based Recommendation 5.E39

Expert consensus

Level of consensus +++

A CTG examination must be carried out if relevant contractions and/or rupture of membranes occur following the administration of medication to induce labour.

Consensus-based Recommendation 5.E40

Expert consensus

Level of consensus +++

CTG examinations should be carried out to monitor progress after the administration of prostaglandins.

Consensus-based Recommendation 5.E41

Expert consensus

Level of consensus +++

Continuous CTG monitoring is necessary when oxytocin in used to induce labour.

There are no evidence-based recommendations on how precise the monitoring of induction of labour must be. The general consensus is that a CTG should be carried out at least 30 minutes before starting induction of labour.

Mechanical methods (cf. 4.1.) lead to cervical ripening through endogenous release of prostaglandins, which is why side effects such as uterine overstimulation are not anticipated [32] and CTG examinations are not mandatory during the course of labour. CTG examinations are recommended in cases of vaginal bleeding or other anomalies.


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6  Special situations when inducing labour

6.1  Obesity

Consensus-based Statement 6.S13

Expert consensus

Level of consensus +++

In cases of maternal obesity, induction of labour is associated with longer induction-to-delivery intervals and higher doses of oxytocin and prostaglandins.

Maternal obesity is not an indication per se for inducing labour if there are no other obstetric or medical indications [33]. However, obese pregnant women have an increased risk of needing labour to be induced because of existing co-morbidities or newly occurring complications of pregnancy. Moreover, maternal obesity is associated with a higher rate of antenatal, intrapartum and postpartum complications [34], [35].


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6.2  Breech presentation

Consensus-based Statement 6.S14

Expert consensus

Level of consensus +++

Inducing labour is also possible in cases with foetal breech presentation.

The data on inducing labour in cases with foetal breech presentation are based on a few non-randomised controlled studies. A few cases series have shown that when the patient is selected carefully, the risk for mother and infant is low [36], [37], [38], [39].


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6.3  Twin pregnancy

Consensus-based Recommendation 6.E42

Expert consensus

Level of consensus +++

When a dichorionic twin pregnancy is progressing normally, the pregnancy may be terminated from week 37 + 0 of gestation.

Consensus-based Recommendation 6.E43

Expert consensus

Level of consensus +++

When a dichorionic twin pregnancy is progressing normally, the pregnancy should be terminated from week 38 + 0 of gestation.

Consensus-based Recommendation 6.E44

Expert consensus

Level of consensus +++

When a monochorionic diamniotic twin pregnancy is progressing normally, the pregnancy may be terminated from week 36 + 0 of gestation.

Consensus-based Recommendation 6.E45

Expert consensus

Level of consensus +++

When a monochorionic diamniotic twin pregnancy is progressing normally, the pregnancy should be terminated from week 37 + 0 of gestation.

There are no evidence-based data about the right time to deliver dichorionic twin pregnancies. The studies which have been carried out to date are limited by different factors [40], [41], [42], [43], [44]. While the prospective risk of intrauterine foetal death (IUFD) between week 37 + 0 and week 37 + 6 of gestation appears to be equivalent to the risk of neonatal mortality, the IUFD risk exceeds the risk of neonatal mortality from week 38 + 0 of gestation [45]. The risk of neonatal morbidity (e.g., respiratory distress syndromes, admissions to a neonatal intensive care unit …) is lower in later weeks of gestation. But as these data are still controversially discussed because of the lack of information on ultrasound examinations, antepartum monitoring, the mode of delivery, and the quality of neonatal care, it is difficult to give a general recommendation to induce labour from week 37 + 0 of gestation in dichorionic twin pregnancies. For this reason, various professional societies recommend inducing labour from week 37 + 0 or 38 + 0 of gestation [46], [47].

There are no RCTs which have investigated the optimum time point to begin inducing labour for monochorionic diamniotic twin pregnancies. There appears to be a trend that after the 36th week of gestation the risk of IUFD is higher than the risk of neonatal mortality, but because of the above-mentioned criticisms, the data are limited [45]. Nevertheless, the potentially higher risk of intrauterine death should be discussed [47], [48], [49], [50], [51], even though there is no unambiguous evidence for inducing labour from week 36 + 0 of gestation for monochorionic diamniotic twin pregnancies [52], [53]. Because of this, some international professional societies recommend delivering twins by week 37 + 6 of gestation [46], [51].


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6.4  Previous caesarean section

6.4.1  Information and advice/consultation

Inducing labour after a previous caesarean section places high demands on the information and advice provided to patients (cf. 3.1.). In view of the high risks involved compared to spontaneous labour (e.g., a higher rate of caesarean sections (OR 1.52, 95% CI: 1.26 – 1.83 [54]), the decision whether induction of labour is indicated must be made very carefully. Nevertheless, the overwhelming majority of affected pregnant women meet the requirements for an attempt to delivery vaginally and must be informed about that (cf. 3.2.).

Consensus-based Statement 6.S15

Expert consensus

Level of consensus +++

The overall success rate for vaginal delivery after prior caesarean section is about 75% (60 – 85%).

Consensus-based Recommendation 6.E46

Expert consensus

Level of consensus +++

Pregnant women must be informed that a successful vaginal birth after prior delivery by caesarean section has a lower rate of complications.

Consensus-based Recommendation 6.E47

Expert consensus

Level of consensus +++

Pregnant women must be informed that after an unsuccessful attempt at vaginal delivery, some cases will require acute caesarean section/emergency caesarean section, which is associated with a higher rate of complications.

Consensus-based Recommendation 6.E48

Expert consensus

Level of consensus +++

Pregnant women must be informed that the risk of uterine rupture during vaginal birth after a previous delivery by caesarean section is around 0.5 – 1%.

If the previous caesarean section was not a horizontal incision, particularly if it consists of a fundal uterotomy or a classic C-section or an inverted T incision, no attempt at vaginal delivery should be made [55], [56], [57].

Consensus-based Recommendation 6.E49

Expert consensus

Level of consensus +++

Pregnant women must be informed that the risk of uterine rupture increases two to threefold (approx. 1 – 1.5%) and the probability of delivering by caesarean section increases 1.5-fold if labour is induced.

Consensus-based Recommendation 6.E50

Expert consensus

Level of consensus +++

Pregnant women must be informed that the overall risk of delivery-associated perinatal infant death is very low with vaginal delivery after a previous delivery by caesarean section.

Consensus-based Statement 6.S16

Expert consensus

Level of consensus +++

Maternal mortality is higher for elective repeat caesarean section than for a planned vaginal birth. The absolute risk remains very low for both methods of delivery.

Consensus-based Recommendation 6.E51

Expert consensus

Level of consensus +++

Pregnant women must be informed that every repeat caesarean section will lead to a further increase in the risk of disorders of placentation in subsequent pregnancies and may cause adhesions which may complicate future abdominal interventions.


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6.4.2  Methods of inducing labour after previous caesarean section

Consensus-based Statement 6.S17

Expert consensus

Level of consensus +++

If the cervix is ripe (Bishop score ≥ 6), inducing labour with oxytocin and amniotomy in a woman who has had a previous caesarean section is a low-risk method.

Consensus-based Statement 6.S18

Expert consensus

Level of consensus +++

If the cervix is unripe (Bishop score < 6), inducing labour with prostaglandin E2 (dinoprostone) in a woman who has had a previous caesarean section is a low-risk method, even if there is an increased risk of uterine rupture.

Consensus-based Statement 6.S19

Expert consensus

Level of consensus +++

Using mechanical methods (transcervical balloon catheter, amniotomy) to induce labour is associated with a lower risk of uterine rupture than the use of prostaglandins.

Consensus-based Recommendation 6.E52

Expert consensus

Level of consensus +++

Misoprostol must not be used to induce labour or for cervical ripening in the third trimester of pregnancy in a woman who has had a previous caesarean section or an operation which involved opening of the uterine cavity.


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6.4.3  Induction of labour after previous caesarean section

Consensus-based Statement 6.S20

Expert consensus

Level of consensus +++

Continuous foetal monitoring (CTG) up until the birth must be carried out when regular contractions have started and the pregnant woman has had a previous caesarean section.


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7  Setting for inducing labour

Consensus-based Statement 7.S21

Expert consensus

Level of consensus +++

Outpatient management of induced labour is possible under certain circumstances for pregnant women at low risk of complications.

Consensus-based Recommendation 7.E53

Expert consensus

Level of consensus +++

Only mechanical methods with a low risk of overstimulation should be used in outpatient induction of labour.

Consensus-based Recommendation 7.E54

Expert consensus

Level of consensus +++

The patient must be informed about the potential risks of outpatient induction of labour.


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8  Induction of abortion/induction of labour for intrauterine foetal death

8.1  Induction of abortion in the 1st trimester

It is important to differentiate between induction of abortion for disorders of pregnancy (e.g., missed abortion, anembryonic pregnancy, gestational trophoblastic disease) and termination of a viable pregnancy in accordance with the German legal requirement of compulsory ethical counselling (in Austria: legal provisions permitting abortion within the first 3 months of pregnancy as outlined in § 97 of the Austrian Penal Code; in Switzerland: non-punishable termination of pregnancy in accordance with Article 119, Para. 2 of the Swiss Penal Code) or for criminological or medical reasons. Before terminating the pregnancy, an ultrasound examination must be carried out to determine the duration of the pregnancy.

Consensus-based Recommendation 8.E55

Expert consensus

Level of consensus +++

Up until the 63rd day after the last menstruation, the procedure may be either a medication-based or a surgical approach.

The patient should be informed about the advantages and disadvantages of the respective methods (cf. [Table 5]) [58].

Table 5 Advantages and disadvantages of the different methods used to induce abortion in the 1st trimester of pregnancy [58].

Medication

Surgery

Invasive procedure

usually not

yes

Anaesthesia

not required

required

Timing can be predicted

timing uncertain

can be scheduled

Success rate

approx. 95%

approx. 99%

Bleeding

moderate

slight

Follow-up care

required to exclude incomplete abortion

often not required

Approach

more than one session

single session

Consensus-based Recommendation 8.E56

Expert consensus

Level of consensus +++

If the patient opts for a medication-based approach, then a sequential procedure should be used, consisting first of the administration of 200 mg mifepristone followed by vaginal application of 800 µg misoprostol.

Consensus-based Recommendation 8.E57

Expert consensus

Level of consensus +++

From week 9 + 0 of gestation, the procedure should consist of a surgical approach which may be either suction curettage or sharp curettage.

Consensus-based Recommendation 8.E58

Expert consensus

Level of consensus +++

If a surgical approach is planned, carrying out preoperative cervical ripening measures may reduce the rate of intraoperative cervical dilations.


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8.2  Induction of abortion/induction of labour for intrauterine foetal death in the second and third trimester of pregnancy

Consensus-based Recommendation 8.E59

Expert consensus

Level of consensus +++

Induction of abortion/induction of labour for intrauterine foetal death in the 2nd trimester should be carried out by sequential administration of mifepristone followed by misoprostol.

In German-speaking countries, medication is used to terminate a pregnancy from week 14 + 0 of gestation at the latest. The sequential administration of mifepristone and misoprostol has been reported to be superior to applying only misoprostol, even in the 2nd trimester. There are many variations of dosages and intervals between applications.

Below are examples of recommended regimens:

  • mifepristone 200 mg administered orally, followed after 24 – 48 hours by:

    • misoprostol 400 µg, buccal administration every 3 hours (maximum of 5 doses) [59], or

    • misoprostol 400 µg, (oral, vaginal or sublingual administration) every 3 hours (maximum of 5 doses) [60], or

    • misoprostol 800 µg, vaginal administration every 3 hours (maximum of 5 doses) [59], or

    • misoprostol 800 µg, vaginal administration, followed by 400 µg misoprostol every 3 hours, administered vaginally or sublingually (maximum of 5 doses) [60].

In the 3rd trimester, it is recommended that misoprostol doses given after the administration of mifepristone are lower:

  • misoprostol 200 µg, (vaginal, sublingual or buccal administration) every 4 – 6 hours [61]

  • misoprostol 100 µg, (vaginal, sublingual or buccal administration) every 4 – 6 hours [61]

If the foetus has not been aborted/delivered after 5 doses of misoprostol, most international guidelines recommend pausing further drug treatment for 12 hours; the current NICE recommendations do not stipulate a pause [62].

After abortion/delivery has occurred, the placenta should be carefully inspected and an ultrasound examination of the uterine cavity should be carried out; additional curettage is not required. But curettage should be carried out if there is a suspicion of retained placental fragments or postpartum haemorrhage.

Consensus-based Recommendation 8.E60

Expert consensus

Level of consensus +++

When inducing abortion or labour for intrauterine foetal death in women who have had a previous caesarean section, the patient must be informed about the risk of uterine rupture. The misoprostol doses should be reduced and the patient should be informed about its off-label use.

Consensus-based Recommendation 8.E61

Expert consensus

Level of consensus +++

In women who have had a previous caesarean section, the interval to abortion/delivery may be reduced by additional use of a balloon catheter coupled with a reduction of the overall misoprostol dosage.


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Conflict of Interest/Interessenkonflikt

The conflicts of interest of all of the authors are listed in the German-language long version of the guideline./Die Interessenkonflikte der Autoren sind in der Langfassung der Leitlinie aufgelistet.


Correspondence/Korrespondenzadresse

Prof. Dr. med. habil. Sven Kehl
Frauenklinik
Universitätsklinikum Erlangen
Universitätsstraße 21 – 23
91054 Erlangen
Germany   

Publication History

Received: 25 May 2021

Accepted after revision: 27 May 2021

Article published online:
09 August 2021

© 2021. Thieme. All rights reserved.

Georg Thieme Verlag KG
Rüdigerstraße 14, 70469 Stuttgart, Germany


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