Fetal Assessment in Pregnancy (Indication and Methodology for Fetal Monitoring in a low-risk Population). Guideline of the DGGG, DEGUM, OEGGG and SGGG (S3-Level, AWMF Registry No. 015/089, February 2023)

Abstract

Purpose The aim of this guideline was to find evidence on whether carrying out Doppler examinations and CTGs in low-risk cohorts of pregnant women improves outcomes.

Methods First, a systematic search for guidelines was carried out. Identified guidelines were evaluated using the DELPHI instrument of the AWMF. Three guidelines were found to be suitable to evaluate CTG. Two DEGUM best practice guidelines were judged suitable to describe the methods. All studies on this issue were additionally analyzed using 8 PICO questions. A structured consensus of the participating professional societies was achieved using a nominal group process and a structured consensus conference moderated by an independent moderator.

Recommendations No antepartum Doppler sonography examinations should be carried out in low-risk cohorts in the context of antenatal care. No antepartum CTG should be carried out in low-risk cohorts.

Note The guideline will be published simultaneously in the official journals of both professional societies (i. e., Geburtshilfe und Frauenheilkunde for the DGGG and Ultraschall in der Medizin/European Journal of Ultrasound for the DEGUM).

Key words

guideline - fetal assessment - prenatal care - check-up - pregnancy - Doppler sonography - ultrasound - CTG – cardiotocography

I Guideline Information

Guidelines program of the DGGG, OEGGG and SGGG

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

Citation format

Fetal Assessment in Pregnancy (Indication and Methodology for Fetal Condition Diagnostics in the Low-risk Collective). Guideline of the DGGG, DEGUM, OEGGG and SGGG (S3-Level, AWMF Registry No. 015/089, February 2023). Ultraschall in Med 2023. DOI: 10.1055/a-2113-7638

Guideline documents

The complete German-language long and short versions of this guideline together with a list of the conflicts of interest of all the authors are available on the homepage of the AWMF: http://www.awmf.org/leitlinien/detail/ll/015–089.html

Guideline authors

See [Table 1], [2].

Table 1 Lead and/or coordinating guideline authors.

Author	AWMF professional society
Prof. Dr. med. Sven Schiermeier	German Society for Gynecology and Obstetrics [Deutsche Gesellschaft für Gynäkologie und Geburtshilfe] (AGG in the DGGG)
Prof. Dr. med. Constantin von Kaisenberg	German Society for Ultrasound in Medicine [Deutsche Gesellschaft für Ultraschall in der Medizin] (DEGUM)

Table 2 Contributing guideline authors.

Author Mandate holder	DGGG working group (AG)/AWMF/non-AWMF professional society/organization/association
Prof. Dr. med. Sven Kehl	German Society for Ultrasound in Medicine
Prof. Dr. med. Frank Reister	German Society for Perinatal Medicine [Deutsche Gesellschaft für Perinatale Medizin]
PD. Dr. med. Beatrice Mosimann	Swiss Society for Gynecology and Obstetrics [Schweizer Gesellschaft für Gynäkologie und Geburtshilfe]
PD. Dr. med. Philipp Reif	Austrian Society for Gynecology and Obstetrics [Österreichische Gesellschaft für Gynäkologie und Geburtshilfe]
San.-Rat Dr. med. Werner Harlfinger	Federal Association of Gynecologists [Berufsverband der Frauenärzte]
Dr. med. Klaus König	Federal Association of Gynecologists
Prof. Dr. rer. medic. Christiane Schwarz	German Midwifery Society [Deutsche Gesellschaft für Hebammenwissenschaft]
Elke Mattern	German Midwifery Society
Prof. Dr. med. Maritta Kühnert	German Society for Prenatal and Obstetric Medicine [Deutsche Gesellschaft für Pränatal- und Geburtsmedizin]
Prof. Dr. med. Ralf Schmitz	Working Group for Ultrasound Diagnostics in Gynecology and Obstetrics [Arbeitsgemeinschaft für Ultraschalldiagnostik in der Gynäkologie und Geburtshilfe]
Prof. Dr. med Markus Hoopmann	Working Group for Ultrasound Diagnostics in Gynecology and Obstetrics
Andrea Ramsell	German Association of Midwives [Deutscher Hebammenverband]
Barbara Stocker Kalberer	Swiss Association of Midwives [Schweizer Hebammenverband]
Petra Graf Heule	Swiss Association of Midwives
Silke Heinzl	Austrian Midwives Association [Österreichisches Hebammengremium]
Beate Kayer	Austrian Midwives Association
Patricia Gruber	German Association of Midwives
Prof. Dr. med. Horst Steiner	Austrian Society for Ultrasound in Medicine [Österreichische Gesellschaft für Ultraschall in der Medizin]
Prof. Dr. med. Leonard Schäffer	Swiss Society for Ultrasound in Medicine [Schweizer Gesellschaft für Ultraschall in der Medizin]
Dr. med. Monika Nothacker[*]	AWMF

^* These persons played a significant role in the compilation of the guideline. They did not participate in the voting on recommendations and statements.

The guideline was moderated by Prof. Dr. med. Constantin von Kaisenberg (AWMF-certified guidelines adviser/moderator).

II Guideline Application

Purpose and objectives

This guideline is applicable for all professional groups who care for pregnant woman and who carry out diagnostic investigations into the condition of the fetus during pregnancy.

The aim of this guideline was to find evidence on whether carrying out Doppler examinations or CTGs in a low-risk cohort of pregnant women improves outcomes.

First, a definition of what constitutes low risk was required.

The necessary ultrasound procedures were outlined.

Finally, the indications for carrying out diagnostic investigations into the condition of the fetus during (low risk) pregnancy listed in official Maternity Guidelines and DEGUM best practice guidelines were reviewed.

The methods and procedures used to carry out Doppler sonography and CTG were then presented, as they had not previously been described in other AWMF guidelines.

The available evidence was then extensively prepared and summarized.

Targeted areas of care

Prenatal care

Target user groups/target audience

Gynecologists and midwives

Adoption and period of validity

The validity of this guideline was confirmed by the executive boards/heads of the participating professional societies/working groups/organizations/associations as well as by the boards of the DGGG, DEGUM, SGGG, OEGGG and the DGGG/OEGGG/SGGG guidelines commission and was thus approved in its entirety. This guideline is valid from 1 February 2023 through to 31 January 2028. Because of the contents of this guideline, this period of validity is only an estimate. The guideline can be reviewed and updated at an earlier point in time if urgently necessary. Likewise, the guideline’s period of validity can be extended if the guideline still reflects the current state of knowledge.

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 was classified as: S3

Assessment of evidence using the GRADE/SIGN frameworks

Evidence was assessed using the SIGN grading system. Details on this approach are available in the long German-language version and the associated guideline report.

Basically, all referenced sources were first assessed using the SIGN system (RCTs, meta-analyses, systematic reviews, and observational studies). Evidence tables were differentiated according to the type of study (LoE). The most important conclusions from the meta-analyses and systematic reviews were documented in the form of bullet-point summary statements.

Interventional publications on PICO questions (RCTs) were evaluated using the GRADE tool. The outcome incidence and sample strength of the different studies were pooled, the RR was calculated and the results were entered in a GRADE table of evidence. The level of evidence was determined after assessing the risk of bias.

Grading of recommendations

In this context, the term “grading” indicates the degree of certainty regarding the recommendation after its benefits and harms have been weighed up; it is not an indication of whether the recommendation itself is binding. Guidelines are recommendatory in nature, i. e., they cannot be binding. Individual statements and recommendations are differentiated by symbols and syntax ([Table 3]).

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

Symbols	Description of binding character	Expression
A	Strong recommendation with highly binding character	must/must not
B	Regular recommendation with moderately binding character	should/should not
0	Open recommendation with limited binding character	may/may not

The above-described classification of “recommendations” reflects both the assessment of the evidence and the clinical relevance of the studies on which the evidence is based as well as factors which are not included in the grading of evidence such as the choice of patient cohort, intention-to-treat and outcome analyses, medical actions and ethical behavior towards the patient, country-specific applicability, etc. In contrast, high, moderate, or low levels of evidence may result in a strong, simple, or open recommendation. A recommendation can only be upgraded or downgraded to a grade A or a grade 0 recommendation if the level of evidence is moderate. In exceptional cases, the highest level of evidence is only accorded a limited/open recommendation or vice versa, and this has to be explained in the background text.

• High level of evidence → grade A or grade B recommendation

• Moderate level of evidence → grade A or grade B or grade 0 recommendation

• Low level of evidence → grade B or grade 0 recommendation

Statements

Expositions or explanations of facts, circumstances, or problems with no direct recommendations for action in this guideline are referred to as “statements”. It is not possible to provide any information about the grading of evidence for these statements.

Achieving consensus and strength of consensus

At structured NIH-type consensus-based conferences (S2k/S3 level), authorized participants attending the session vote on draft statements and recommendations. The process is as follows. A recommendation is presented, its contents are discussed, proposed changes are put forward, and all proposed changes are voted on. If a consensus (> 75 % of votes) is not achieved, there is another round of discussions, followed by a repeat vote. 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

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 Grading of recommendations but without the use of symbols; it is only expressed semantically (“must”/“must not” or “should”/“should not” or “may”/“may not”).

IV Guideline

1 The most important recommendations at a glance

1.1 The evidence for Doppler sonography in low-risk populations

E15.1	Recommendation	Status 2022
Level of recommendation: A	Antepartum Doppler sonography should not be carried out in low-risk cohorts in the context of prenatal care.
Level of evidence 1 + 1 ++ 1 + 1− 1 + 1 +	Giles et al., BJOG 2003 Lees et al., Lancet 2 Newnham et al., 2004 Lancet Subtil et al., BJOG 2003 Williams et al., Am J Obstet Gynecol 2003 Alfirevic Z et al., Cochrane Database Syst Rev 2015
	Level of consensus: 93.3 %

1.2 The evidence for performing CTG in low-risk populations

E16.1	Recommendation	Status 2022
Level of recommendation: 1/↑↑	No CTG should be performed antepartum in low-risk cohorts.
Level of evidence: Adapted from guidelines/EC ⊕⊕⊕⊕ HIGH	NICE Guideline NG201 Antenatal Care [2] which has replaced CG 62, recommendation 1.10.8 Impey et la., 2003, Madaan et al., 2006, Mires et al., 2001, Siristatidis et al., 2012, Smith et al., 2019
	Level of consensus: 100 %

2 Definition of low-risk pregnancies

Low-risk pregnancies are pregnancies where no increased risks for mother and/or the unborn child have been identified and where there is no need for or no benefit from an intervention (modified from [1]).

3 Importance of ultrasound for fetal assessment

Before determining whether fetal Doppler sonography or CTG are indicated, careful ultrasound examination of the fetus must be carried out, ideally by starting with screening for chromosomal abnormalities (and genetic syndromes) in the first trimester, performing an ultrasound examination to screen for pre-eclampsia and detect malformations [3] [4], followed by an ultrasound scan for anomalies around week 20–23 of gestation [5] [6], fetal echocardiography [7] and, if necessary, a systematic search for ultrasound markers of fetal chromosomal disorders [8].

4 Doppler sonography

4.1 Indications for Doppler sonography

E12.1	Recommendation	Status 2022
EC	Maternal Doppler sonography of the uterine arteries may be carried out during prenatal screening to detect high-risk pregnancies.
Faber et al., 2019/2021 [9] [10]	Level of consensus: 100 % (strong consensus)

4.1.1 Indications for Doppler sonography in the official Maternity Guidelines

E12.2	Recommendation	Status 2022
EC	According to the official Maternity Guidelines, Doppler sonography is indicated in antenatal care under the following circumstances: suspected fetal growth restriction (FGR) gestational hypertension, pre-eclampsia status post FGR or IUFD status post pre-eclampsia/eclampsia fetal heart rate anomalies (CTG) suspected malformation/fetal disease multiple pregnancy with discordant fetal growth suspicion of cardiac defect or fetal cardiac arrhythmia
2022 German Maternity Guidelines (Appendix 1 d) [11]	Level of consensus: 100 % (strong consensus)

4.1.2 Indications for Doppler sonography according to the DEGUM

E12.3	Recommendation	Status 2022
EC	According to the recommendations of the DEGUM, Doppler sonography is also indicated as part of prenatal care for the following conditions: pre-existing maternal vascular disorders (hypertension, nephropathy, diabetes mellitus, autoimmune diseases) suspected fetal anemia suspected fetal infection fetal hydrops to monitor monochorionic multiple pregnancy (TTTS, TAPS/TOPS, TRAP, sFGR) to diagnose pathological umbilical cord insertion and vasa previa to diagnose disorders of placentation (e. g., placenta increta)
Faber et al., 2019, 2021 [9] [10]	Level of consensus: 100 % (strong consensus)

4.2 Doppler sonography methods

4.2.1 Techniques

4.2.1.1 CW Doppler

In CW (continuous wave) Doppler, a signal is continuously emitted and the reflected signal is registered.

4.2.1.2 PW Doppler

Pulsed wave (PW) Doppler has become the Doppler method of choice in prenatal medicine. With pulsed wave Doppler, a B-mode image is generated with activation of a crystal to emit and receive Doppler signals (Duplex scanning). Regular sound waves are emitted and received.

4.2.1.3 Color Doppler

Color Doppler allows the blood flow, direction of flow and velocity distribution to be visualized in a defined image section of the B-mode image (color window).

4.3.1 Patient safety

E12.4	Recommendation	Status 2022
EC	Strict diagnostic criteria should be used when recommending Doppler ultrasound in early pregnancy or of the brain.
Faber et al., 2019/2021 [9] [10]	Level of consensus: 100 % (strong consensus)

To date, no clinical studies have shown that Doppler sonography damages the fetus in vivo. In principle, however, fetal examination using Doppler sonography should only be carried out when indicated, and the exposure time and sound energy should be kept as low as reasonably achievable (ALARA principle).

4.4.1 Settings

Most current Doppler units have several pre-set settings which can be individually amended and stored. It is important to understand the impact of these parameters on the Doppler sonogram to obtain valid measurements and be able to react if problems occur.

4.4.1.1 Wall motion filter

The wall motion filter serves to suppress low-frequency vessel wall motion and interference signals. In prenatal medicine it should be set as low as possible (≤ 60 Hz).

4.4.1.2 Angle

The angle of insonation should be kept as small as possible for both planned qualitative (PI, RI) and quantitative analysis (absolute speed) as this minimizes measurement errors.

4.4.1.3 Doppler window

Generally, a large Doppler window (5–10 mm) is initially selected (covering the vessel) when carrying out fetomaternal Doppler diagnostics (with the exception of echocardiography).

4.4.1.4 Scaling

Scaling (pulse repetition frequency, PRF) changes the number of Doppler pulses emitted and therefore the frequency of blood flow measurements. It must be adapted to the blood flow velocities which will be measured and must therefore be frequently adjusted as blood flow velocities of fetal and uteroplacental vessels vary widely.

4.5.1 Choice of vessel

S12.1	Statement	Status 2022
EC	The choice of vessels depends on the indication for the Doppler examination ([Table 5])
Faber et al., 2019/2021 [9] [10]	Level of consensus: 100 % (strong consensus)

Table 5 Indications for Doppler sonography and relevant vessels.

Indication	Examined vessel(s)
Suspected early severe fetal growth restriction	UA, MCA, veins (DV, umbilical vein), Ut
Suspected late mild fetal growth restriction	UA, MCA, Ut
Gestational hypertension, pre-eclampsia (eclampsia)	UA, if MCA is pathological, poss. veins, Ut
Status post pre-eclampsia, eclampsia	Ut, poss. additional vessels
Status post SGA infant, intrauterine fetal death	Ut, UA, poss. additional vessels
Fetal heart rate abnormalities	UA, MCA and poss. veins
Well-founded suspicion of malformation, fetal disease	Umbilical artery, fetal arteries, veins, quantitative measurements if anemia suspected (MCA), poss. color Doppler/duplex Doppler ultrasound
Multiple pregnancy (discordant for growth)	UA, MCA, also quantitative, poss. veins
Clarification if cardiac defect is suspected, cardiac disease	Color Doppler, Doppler of pre-cardiac, intracardiac, post-cardiac vessels
Pre-existing relevant maternal vascular disease (hypertension, nephropathy, diabetes mellitus, autoimmune disease)	Ut, UA
Suspected fetal infection	MCA with Vmax, poss. additional vessels
Fetal hydrops	UA, MCA with Vmax, DV
Monitoring of monochorionic multiple pregnancy TTTS, TOPS, TAPS, TRAP and sFGR	UA, MCA with Vmax, DV, umbilical vein
Diagnostic assessment of pathological umbilical cord insertions and vasa previa	Color Doppler
Diagnostic assessment of disorders of placentation (e. g., placenta increta)	Color Doppler

4.6.1 Vessels

Doppler sonography can be used to examine fetal vessels (arteries and veins), fetal-placental (arteries) and placental-fetal (veins) vessels and maternal-placental vessels (uterine arteries).

4.6.1.1 Umbilical artery

E12.5	Recommendation	Status 2022
EC	To obtain a Doppler signal of the umbilical artery, a free-floating part of the umbilical cord in the amniotic fluid must be identified and the signal must be obtained using a small angle of insonation.
Faber et al., 2019/2021 [9] [10]	Level of consensus: 100 % (strong consensus)

4.6.1.2 Middle cerebral artery

S12.2	Statement	Status 2022
EC	A pulsatility index of < 5th percentile for the middle cerebral artery is pathological.
Faber et al., 2019/2021 [9] [10]	Level of consensus: 100 % (strong consensus)

Blood flow in the middle cerebral artery (MCA) is responsible for the major part of cerebral perfusion and is largely independent of fetal movement.

4.6.1.3 Ductus venosus

S12.3	Statement	Status 2022
EC	An increase in pulsatility above the 95th percentile for the ductus venosus with zero flow pressure and reverse flow of the A-wave is pathological.
Faber et al., 2019/2021 [9] [10]	Level of consensus: 100 % (strong consensus)

The ductus venosus is the most important venous vessel (apart from the umbilical vein). It plays an important role for the timing of delivery in high-risk pregnancies.

4.6.1.4 Uterine artery

S12.4	Statement	Status 2022
EC	Pulsatility indices > 95th percentile for the uterine artery and uterine artery notching after week 24 + 0 of gestation are pathological.
Faber et al., 2019/2021 [9] [10]	Level of consensus: 100 % (strong consensus)

The uterine artery depicts maternal-placental flow conditions.

4.7.1 Analysis

4.7.1.1 Indices and cycles of measurement

E12.6	Recommendation	Status 2022
EC	A representative number of cycles (usually 3–6) should be included when recording the Doppler curves of fetal and maternal vessels.
Faber et al., 2019/2021 [9] [10]	Level of consensus: 100 % (strong consensus)

The following indices are commonly used:

• Resistance index (RI); RI = (A−B)/A

  • Advantage: simple to calculate, with good reproducibility

  • Limitations: flow patterns with a very high pulsatility (e. g., diastolic zero-flow). Use of the pulsatility index is recommended in these cases

• Pulsatility index (PI): PI = (A−B)/V mean

• Pulsatility index for veins (PIV): PIV = (S−a)/D

• Peak velocity index for veins (PVIV): PVIV = (S−a)/T max

4.7.1.2 Envelope analysis

The envelope is defined by the maximum blood flow velocities at the respective times of the cardiac cycle.

4.8.1 Overall spectrum curve

In addition to the envelope, the Doppler sonogram also includes other measured flow data.

4.9 Documentation

E12.7	Recommendation	Status 2022
EC	The results of the Doppler ultrasound examination must be evaluated (normal, pathological, requires monitoring) and further consequences must be determined.
Faber et al., 2019/2021 [9] [10]	Level of consensus: 100 % (strong consensus)

5 CTG

5.1 Antepartum indications

There is no evidence-based indication that routine CTG monitoring should be carried out in low-risk populations. An antepartum CTG trace may be indicated for certain high-risk cohorts. They are listed in [Table 6], [7].

Table 6 Guidelines issued by or involving the DGGG on the use of CTG in high-risk pregnancies.

AWMF Reg. No.	Title of the guideline
015–081	Obesity and Pregnancy
057–023	Diabetes and Pregnancy
015–088	Induction of Labor
057–008	Gestational Diabetes Mellitus – Diagnostics, Therapy and Follow-up
015–018	Hypertensive Diseases of Pregnancy – Diagnostics and Therapy
015–080	Intrauterine Growth Restriction
015–087	Monitoring and Care of Twin Pregnancies

Table 7 Indications for antepartum cardiotocography as listed in the official Maternity Care Guidelines (Appendix 2).

First CTG

in the 26th and 27th week of gestation for threatened preterm birth

from week 28 of gestation for heart sound changes detected on auscultation suspected preterm labor

Indication to repeat the CTG

Changes in the CTG trace, such as persistent tachycardia (> 160/minute) bradycardia (< 100/minute) deceleration(s) (including repeated DIP 0) reduced variability, no variability unclear cardiotocography findings with suspected preterm labor multiple pregnancy intrauterine fetal death in a previous pregnancy suspected placental insufficiency based on clinical or biochemical findings suspicion of post-term pregnancy uterine bleeding

Tocolysis

In Austria, performing a CTG to assess the fetus is not required for the Maternal Health Passport (Mutter-Kind-Pass) but social security agencies will bear the costs of a CTG if specific diagnostic workups are required.

In Switzerland, Article13 of the Health Care Benefits Ordinance (Krankenpflege-Leistungsverordnung, KLV) states that funding agencies will bear the cost of prepartum CTG examinations if CTG examinations are indicated in high-risk pregnancies.

CTG registration may be carried out if maternal risk factors (e. g., cholestasis, lupus, higher-grade anemia) are present.

5.2 CTG registration methods

5.2.1 Obtaining the signal (external cardiotocography)

Fetal heart rate monitoring is carried out using a Doppler transducer. Maternal contractions are recorded with a pressure transducer. Pressure on the sensor results in voltage changes which are continuously recorded. In addition, some units offer the option of recording maternal heart rate using pulse oximetry.

E13.1	Recommendation	Status 2022
EC	Units which can register simultaneous recordings should be used to avoid confusing maternal and fetal heart rates. Alternatively, the maternal pulse should be taken manually and recorded.
NICE CG 190 2014 (updated 2017) [12], FIGO Consensus Guideline (2015) [13]	Level of consensus: 93.3 % (strong consensus)

5.2.2 Duration of registration, patient position, paper speed

E13.2	Recommendation	Status 2022
EC	Conventional CTGs should be recorded for a period of 20–30 minutes.
NICE CG 190 2014 (updated 2017) [12]	Level of consensus: 100 % (strong consensus)

E13.3	Recommendation	Status 2022
EC	The CTG should be recorded with the patient in a lateral position, either half-sitting or upright.
NICE CG 190 2014 (updated 2017) [12]	Level of consensus: 100 % (strong consensus)

E13.4	Recommendation	Status 2022
EC	The paper speed of the CTG should be at least 1 cm/min. If a vertical scale is used, the recommended speed is at least 20 bpm/cm.
NICE CG 190 2014 (updated 2017) [12]	Level of consensus: 100 % (strong consensus)

5.2.3 Additional diagnostic tests (stress test)

E13.5	Recommendation	Status 2022
EC	Additional testing in the form of stress tests (contraction stress test) should not be carried out.
Devoe et al., 2008 [14] Figueras et al., 2003 [15] Staisch et al., 1980 [16]	Level of consensus: 93.3 % (strong consensus)

5.2.4 Patient safety

To date there are no indications that the emitted ultrasound energy of Doppler transducers has a harmful effect on the fetus [17].

5.3 Documentation and storage obligations

The following information must be clearly attached to the CTG trace:

1. First and last name of the pregnant woman

2. Date of birth of the pregnant woman

3. Date and time when the recording began

4. The paper speed must be evident.

5. The scale used for the CTG must be unambiguous.

6. Every CTG must be recorded and assessed in a transparent manner; if necessary, it should be followed by instructions, therapy, or other measures.

7. CTG records must be kept for at least 10 years. The professional rules of individual countries must be complied with.

5.4 Analysis

The following parameters must be evaluated when analyzing the CTG: baseline, variability, accelerations, decelerations, and contractions. The recorded values form the basis for the overall assessment of the CTG. The FIGO score does not include accelerations in its assessment.

5.4.1 Assessment parameters

E13.6	Recommendation	Status 2022
Level of recommendation: EC	The FIGO score must be used to evaluate the CTG.
NICE CG 190 2014 (updated 2017) [12]	Level of consensus: 100 % (strong consensus)

5.5 FIGO classification

See [Table 8].

Table 8 CTG – evaluation based on the FIGO score (from the S3-guideline Vaginal Birth at Term [18]).

	Normal	Suspicious	Pathological
Baseline	110–160 bpm	Lacks at least one of the normal characteristics but no pathological characteristics	< 100 bpm
Oscillations	5–25 bpm		Limited or increased variability, sinusoidal pattern
Decelerations	No repetitive[*] decelerations		Repetitive late or prolonged decelerations > 30 min (with reduced variability > 20 min), prolonged decelerations > 5 min
Interpretation	No hypoxia/acidosis	Low probability of hypoxia/acidosis	High risk of hypoxia/acidosis
Clinical management	No intervention required	Conservative measures: correction of reversible causes, close monitoring, further diagnostics	Conservative and/or invasive measures: immediate correction of reversible causes, further diagnostics or (if this is not possible) rapid delivery of the infant

^* Decelerations are considered repetitive if they occur in > 50 % of contractions. It is not clear what a lack of accelerations during the birth signifies.

5.6 Fetal behavioral states

Periods of quiet fetal activity and sleep alternate with periods of active sleep and wakefulness.

5.7 Fetal movement – kineto-cardiotocography

Fetal movements can be registered and quantified using kineto-cardiotocography and can indicate the level of fetal well-being.

5.8 CTG training

E13.7	Recommendation	Status 2022
Level of recommendation: B	According to some studies, regular participation in CTG analysis training improves the quality of CTG assessments, and regular participation in such courses is recommended.
Level of evidence: ⊕⊕⊕⊕○ MODERATE	Level of consensus: 100 % (strong consensus)

5.9 New developments

Fetal ECG

Direct registration of the fetal ECG is possible both antepartum and during the birth.

Computerized CTG (short-term variation – STV)

The Dawes-Redman system is used to detect short-term variation of the fetal heart rate. STV is calculated by dividing each minute into 16 segments and recording the fetal heart rate every 3.75 seconds as a heart-beat interval in milliseconds (ms). The short-term variation is the difference between heart-beat intervals in ms.

6 Non-technological fetal monitoring methods

Instrument-based and non-instrument-based methods can be used to assess the condition and well-being of the unborn infant.

E14.1	Recommendation	Status 2022
Level of recommendation: EC	If no ultrasound is carried out to assess fetal growth, the symphysis-fundal height should be measured and recorded during every antenatal examination.
Level of evidence: Adapted from guidelines	NICE 2019 Guideline Antenatal Care. [1.10.1 Fetal growth and well-being] NICE 2021 (NG201) Antenatal care, Monitoring fetal growth and well-being 1.2.30
	Level of consensus: 84.6 % (strong consensus)

E14.2	Recommendation	Status 2022
Level of recommendation: EC	If ultrasound was not used to determine fetal position, fetal presentation should only be palpated from week 36+ 0 of gestation.
Level of evidence: Adapted from guidelines	NICE 2019 Guideline Antenatal Care. [1.10.6 Fetal growth and well-being]
	Level of consensus: 61.5 % (consensus)

E14.3	Recommendation	Status 2022
Level of recommendation: EC	An ultrasound examination must be carried out for confirmation if there is a suspicion of non-cephalic presentation.
Level of evidence: Adapted from guidelines	NICE 2019 guideline Antenatal Care. [1.10.5 Fetal growth and well-being]
	Level of consensus: 93.3 % (strong consensus)

E14.4	Recommendation	Status 2022
Level of recommendation: EC	Routine counting of fetal movements should not be recommended.
Level of evidence: Adapted from guidelines	NICE 2019 Guideline Antenatal Care. [1.10.6 Fetal growth and well-being] WHO 2018 Guideline Antenatal Care for a Positive Pregnancy Experience [B.2 maternal and fetal assessment]
	Level of consensus: 100 % (strong consensus)

E14.5	Recommendation	Status 2022
Level of recommendation: EC	Auscultation of fetal cardiac activity may confirm the fetus’ vitality but has no predictive value and should therefore not be routinely carried out. Auscultation may be carried out to reassure the mother if the mother requests it. Auscultation of fetal cardiac activity may be used to determine the vitality of the fetus.
Level of evidence: Adapted from guidelines	NICE 2019 Guideline Antenatal Care. [1.10.5 Fetal growth and well-being]
	Level of consensus: 100.0 % (strong consensus)

7 Doppler sonography and evidence

7.1 The evidence for using Doppler sonography in low-risk populations

E15.1	Recommendation	Status 2022
Level of recommendation: A	Doppler sonography should not be carried out antepartum for fetal or maternal assessment in low-risk cohorts.
Level of evidence: 1 + 1 ++ 1 + 1− 1 + 1 +	Giles et al., BJOG 2003 [19] Lees et al., Lancet [20] Newnham et al., 2004 Lancet [21] Subtil et al., BJOG 2003 [22] Williams et al., Am J Obstet Gynecol 2003 [23] Alfirevic Z, Stampalija T, Medley N. Fetal and umbilical Doppler ultrasound in normal pregnancy. Cochrane Database Syst Rev 2015; (4): CD001450 [24]
	Level of consensus: 93.3 % (strong consensus)

8 CTG and evidence

8.1 The evidence for using CTG in low-risk populations

E16.1	Empfehlung	Status 2022
Level of recommendation: 1/↑↑	CTG should not be performed antepartum in low-risk cohorts.
Level of evidence: Adapted from guidelines/EC ⊕⊕⊕⊕ HIGH	NICE Guideline NG201 Antenatal Care [2] which has replaced CG 62, recommendation 1.10.8 Impey et al., 2003 [25], Madaan et al., 2006 [26], Mires et al., 2001 [27], Siristatidis et al., 2012 [28], Smith et al., 2019 [29]
	Level of consensus: 100.0 % (strong consensus)

Note

This guideline is published simultaneously in the official journals of both professional societies (i. e., Geburtshilfe und Frauenheilkunde for the DGGG and Ultraschall in der Medizin/European Journal of Ultrasound for the DEGUM).

Conflict of Interest

The conflicts of interest of all the authors are listed in the German-language long version of the guideline.

• References

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Publikationsverlauf

Eingereicht: 13. Mai 2023

Angenommen: 16. Mai 2023

Artikel online veröffentlicht:
15. August 2023