Obstetric examination and fetal heart rate monitoring

• Obstetric examination is the hands-on assessment of a pregnant woman's abdomen and, when appropriate, cervix; it establishes fetal lie, presentation, position, engagement, size and the mother's pelvic progress.
• Fetal heart rate monitoring is observation of the unborn baby's heart rate and its pattern in relation to uterine contractions; intermittent auscultation suits low-risk labour, continuous cardiotocography suits women with risk factors.
• The standard intrapartum pattern language comes from the NICHD workshop definitions adopted by ACOG, the RCOG and other bodies; a normal tracing has baseline 110 to 160 beats per minute, moderate variability, and no late or variable decelerations.
• Categories I, II and III stratify tracing concern; Category II (indeterminate) is common and should be managed by correcting reversible causes and reassessing.
• Thresholds and actions differ between guidelines; NICE uses normal, suspicious and pathological categories, while ACOG uses the NICHD three-tier system. Guidelines agree that the trace is one part of the whole clinical picture. ^[9]

By the end of this page you should be able to:

1. Perform and describe a systematic obstetric abdominal examination, including Leopold maneuvers, fundal height measurement and fetal heart rate auscultation.
2. Assess cervical favourability with the Bishop score and explain what each component measures.
3. Explain the definitions, mechanisms and categories of baseline, variability, accelerations and decelerations.
4. Choose and justify intermittent auscultation versus continuous cardiotocography using guideline criteria.
5. Manage a Category II tracing with appropriate conservative measures and escalation.
6. Recognise red flags, complications and the documentation standards that follow an obstetric examination and fetal monitoring.

An obstetric examination answers three questions: where is the baby, how is the baby and how is the labour progressing. It is repeated at antenatal visits, at admission in labour and any time the clinical picture changes. It ranges from abdominal palpation to, when indicated, vaginal examination and fetal heart rate assessment. No single finding stands alone; each is interpreted alongside the woman's history, maternal observations and labour progress ^{[1] [2]}.

Fetal heart rate monitoring developed as a screen for fetal hypoxia and acidosis during labour. It is the most commonly performed intrapartum procedure in many health systems, yet its positive predictive value for acidosis is poor and its widespread use has been associated with higher operative and caesarean delivery rates without improved neonatal outcomes ^[3]. This is why structured intermittent auscultation is preferred for low-risk labour in several guidelines, and why the trace is only one component of care.

The examination makes sense once the landmarks are clear.

• Pubic symphysis. The joint at the front of the pelvis; the lower end of the measuring tape for fundal height and the reference for fetal station.
• Uterine fundus. The rounded top of the uterus; its height above the symphysis tracks gestational age in mid-pregnancy.
• Fetal lie, presentation and position. The fetal spine relative to the mother's (longitudinal, transverse, oblique); the part closest to the pelvic inlet (cephalic, breech, shoulder); and the orientation of the occiput (anterior, transverse, posterior).
• Ischial spines. The pelvic landmarks used to define fetal station in centimetres: negative numbers are above the spines, positive numbers below.
• Cervix. Assessed digitally for dilation (0 to 10 cm), effacement (0 to 100%), position, consistency and station of the presenting part.

• Clean gloves, lubricating gel and a light or torch for vaginal examination.
• A flexible tape measure for symphysis-fundal height.
• A handheld Doppler or Pinard stethoscope for fetal heart rate auscultation and a watch or clock.
• A cardiotocograph monitor with transducers (external ultrasound and tocodynamometer) for continuous monitoring; a fetal scalp electrode and intrauterine pressure catheter are available when external signals are inadequate, kept in reserve because they require ruptured membranes and introduce infection risk.
• Support measures: pillows, left-lateral tilt wedge, blood pressure cuff, oxygen (for maternal indications), intravenous access equipment.

• Routine antenatal visits to confirm gestational age, fetal growth and presentation.
• From 36 weeks' gestation to assess fetal presentation; if a non-cephalic presentation is suspected, confirm with ultrasonography ^[5].
• Assessment of labour progress: cervical dilation, effacement, station, position and caput.
• Reassessment whenever there is discrepancy between uterine size and dates, reduced fetal movements, suspected malpresentation or maternal symptoms.

• Intermittent auscultation: offered to women with a low risk of complications during established labour ^[8].
• Continuous cardiotocography: offered when antenatal risk factors for fetal compromise are present (for example prior caesarean birth or full-thickness uterine scar, hypertensive disorder needing medication, ruptured membranes prolonged, vaginal bleeding other than show, suspected chorioamnionitis or sepsis, pre-existing or gestational diabetes needing medication), when fetal risk factors are present (non-cephalic presentation including while mode of birth is decided, fetal growth restriction or small-for-gestational-age with additional risk features, gestational age beyond 42 weeks, anhydramnios or polyhydramnios, reduced fetal movements in the 24 hours before regular contractions), and when intrapartum risk factors develop (for example contractions longer than 2 minutes or 5 or more in 10 minutes, meconium, maternal pyrexia, fresh vaginal bleeding, maternal pulse over 120 beats per minute on two occasions 30 minutes apart, severe hypertension, confirmed delay in labour, epidural analgesia, or use of oxytocin) ^[8]. ^[2]

• Vaginal examination should not be undertaken when there is unexplained vaginal bleeding or suspected placenta previa until ultrasonography has excluded it; repeated unnecessary examinations add infection risk.
• External palpation is less reliable with obesity, polyhydramnios, an anterior placenta or an inexperienced examiner; ultrasonography should support clinical findings where doubt exists ^[4].
• Avoid over-reliance on the trace. Cardiotocography is a poor standalone screening test with a high false-positive rate for acidosis, so a woman should not be taken to operative delivery on the trace alone without a full risk assessment ^[3].
• Bishopscore and induction thresholds are guides to ripening, not absolute indications; fetal safety and maternal preference also govern timing ^{[6] [7]}.

1. Explain and gain consent. State what you will do, why it helps, and the expected discomfort; offer a chaperone and a full explanation of findings afterwards. Shared decision making is expected at every step ^[8].
2. Privacy and infection control. Hand hygiene, gloves, clean equipment, good lighting; dispose of or sterilise instruments according to unit protocol.
3. Positioning. The woman lies supine with a slight left lateral tilt to avoid aortocaval compression, with the abdomen exposed and comfortable, the bladder emptied and a drape for privacy. For haemodynamic comfort she should avoid lying flat on her back.
4. Baseline observations. Record maternal pulse, blood pressure, temperature and the stage of labour, and ensure the notes, time and date clocks are correct for any monitoring that follows ^[8].
5. Communication. Keep the woman and her birth companion(s) informed of any concerns and of the reason for moving from intermittent auscultation to continuous monitoring.

1. Stand at the woman's right side and expose the abdomen from xiphisternum to pubic symphysis.
2. Inspect for scars, distension, visible fetal movements and the shape of the abdomen.
3. Palpate the uterine fundus to decide what presents: a hard, smooth, rounded head or a softer, irregular breech. Count the fetal parts and lie.
4. Palpate the sides of the uterus to find the fetal back (a firm, continuous resistance) and the small parts (knobbly irregularities), and note where the limbs lie.

Leopold maneuvers are four systematic palpation grips used from the third trimester to assess fetal position, presentation and engagement; they are low cost, easy and non-invasive, and four classical maneuvers are used ^[4]:

• First maneuver (fundal grip). Use both hands to cup the fundus and feel whether the fetal head or breech lies uppermost, establishing the lie.
• Second maneuver (umbilical or lateral grip). Move the hands to the sides of the uterus to locate the fetal back and distinguish it from small parts, guiding where to place a Doppler or Pinard.
• Third maneuver (Pawlik grip). Grasp the lower uterus just above the pubic symphysis to confirm the presenting part and whether it is engaged in the pelvis.
• Fourth maneuver (pelvic grip). Face the woman's feet, place hands on the lower abdomen and press toward the inlet to assess descent, engagement and, in a cephalic presentation, the degree of flexion of the head. ^[4]

Leopold maneuvers can be used to assess fetal presentation beginning at 36 weeks' gestation; they are less accurate when the woman is obese or there is polyhydramnios or an anterior placenta, so a non-cephalic presentation suggested on examination should be confirmed with ultrasonography ^{[5] [4]}. They overestimate fetal weight in 58.2% and underestimate in 41.2% of patients in one study, so clinical weight estimates should be corroborated where the result affects management ^[4].

Measure the symphysis-fundal height from the upper border of the pubic symphysis to the top of the fundus with a tape measure, keeping it in contact with the skin along the abdominal midline. The assessment is recommended at each prenatal visit beginning at 20 weeks and should be plotted on a chart to detect deviation from the expected trajectory ^[5]. A tape measurement supports screening for growth restriction but does not replace ultrasonography where growth is suspected to be abnormal.

1. Wash and warm the probe or stethoscope. Use Leopold maneuvers to find the fetal back and place the device over it.
2. Differentiate the fetal heart rate from the maternal pulse: palpate the mother's wrist or abdomen while listening, because the two can be confused, especially in the second stage of labour ^[8].
3. Count the heart rate after a contraction in established labour for at least one minute and record it as a single rate; note accelerations or decelerations if heard.
4. Palpate and record the maternal pulse, every hour or more often if there are concerns ^[8].
5. If no heartbeat is detected, offer urgent real-time ultrasonography to check viability ^[8].

Intermittent auscultation does not record beat-to-beat variability, so a reassuring finding is the absence of a sustained rise or fall against baseline, not proof of normal intrapartum physiology ^[3].

A mnemonic commonly used for the pattern is VEAL CHOP: Variable decelerations suggest cord compression; Early decelerations suggest head compression; Accelerations are reassuring (OK); Late decelerations suggest uteroplacental insufficiency. This is a prompt, not a diagnosis, and every pattern must be read in the whole clinical context ^[1].

A sterile vaginal examination is justified to assess suspected labour, to judge induction ripening or to assess progress, not as a routine.

1. Consent and privacy: explain the procedure, warn of mild bleeding, ensure a chaperone if required and maintain sterile technique.
2. Evaluate five features: dilation in centimetres from 0 (closed) to 10 (fully dilated); effacement in percent; position (posterior, mid, anterior); consistency (firm, medium, soft); and station of the presenting part in relation to the ischial spines.
3. Calculate a Bishop score (range 0 to 13) to judge cervical favourability before induction: a full score greater than 8 is favourable and carries the same probability of vaginal birth as spontaneous labour, while a score of 5 or less is unfavourable and cervical ripening is likely to be needed ^{[6] [7]}. Modified versions using cervical length instead of effacement have a ceiling of 12 and take a threshold of 5 or more as favourable, particularly in multiparous women ^[7].
4. Document and limit repeats: each examination should be necessary, gentle, and recorded with date and time; unnecessary repeats increase infection risk.

1. Explain and place. Obtain maternal consent, apply two transducers (ultrasound for the fetal heart rate and a tocodynamometer for contractions) to the maternal abdomen, optimise the signal by adjusting position or pressure, and keep the woman mobile where wireless telemetry is available ^[8].
2. Differentiate maternal from fetal heart rate at least hourly (every five minutes in the second stage): palpate the pulse, use continuous maternal heart rate monitoring, or use a fetal scalp electrode if doubt persists ^[8].
3. Assess systematically every hour, including a "fresh eyes" review by a second clinician for women on continuous monitoring, and correct poor trace quality by repositioning the transducers or replacing them ^[8].
4. Keep it dry. Do not use continuously for women without risk factors; studies show that starting continuous monitoring on admission raises the chance it continues all labour and may increase caesarean delivery without neonatal benefit ^[3].

The baseline is the average fetal heart rate rounded to the nearest 5 beats per minute over a 10-minute segment in which the rate is stable, excluding accelerations and decelerations and periods of marked variability; at least 2 minutes (not necessarily continuous) of stable baseline must exist in any 10-minute window ^{[1] [2]}. A normal baseline is 110 to 160 beats per minute; less than 110 is bradycardia and more than 160 is tachycardia ^{[1] [2]}. Bradycardia under 100 beats per minute or tachycardia above 160 beats per minute are "red" features in the NICE scheme; lower baselines can be normal in post-term pregnancies, and higher baselines are expected in preterm pregnancies ^[8].

Variability is visually assessed beat-to-beat fluctuation around the baseline, excluding sinusoidal patterns ^{[1] [2]}. Its amplitude is classified as absent (undetectable), minimal (undetectable to 5 beats per minute), moderate (6 to 25 beats per minute) or marked (more than 25 beats per minute) ^{[1] [2]}. Moderate variability is reassuring: it is strongly associated with an umbilical cord pH above 7.15 (in 98% of cases) ^[1]. Absent or minimal variability below 5 beats per minute for more than 50 minutes, or marked variability above 25 beats per minute for more than 10 minutes, is a red feature in the NICE system, and a sinusoidal smooth wave appearing for at least 20 minutes is also red ^{[2] [8]}.

An acceleration is an abrupt increase from baseline, peaking in less than 30 seconds, of at least 15 beats per minute for at least 15 seconds but less than 2 minutes; before 32 weeks' gestation the thresholds fall to 10 beats per minute for 10 seconds ^{[1] [2]}. Prolonged accelerations last between 2 and 10 minutes and beyond 10 minutes count as a new baseline. The presence of spontaneous or stimulated accelerations reliably predicts that no acidemia is present ^[1].

• Early decelerations. A gradual symmetrical fall and return to baseline with each contraction, the nadir coinciding with the peak of the contraction. They are usually caused by fetal head compression and are benign ^[3].
• Variable decelerations. An abrupt fall of at least 15 beats per minute lasting between 15 seconds and 2 minutes, with variable relation to contractions; they are usually caused by umbilical cord compression. They are concerning when recurrent (with more than half of contractions in a 20-minute period) or when they display prolonged duration over 60 seconds, reduced variability within the fall, failure or slow return to baseline, or loss of shouldering ^{[1] [3]}. ^[2][8]
• Late decelerations. A gradual fall with onset after the start of the contraction and recovery after it ends, caused by uteroplacental insufficiency. Recurrent late decelerations are a red feature in NICE and Category III when combined with absent variability ^{[1] [2] [3] [8]}.
• Prolonged decelerations. A fall of at least 15 beats per minute lasting 2 minutes but less than 10 minutes, possibly representing rapid descent, maternal hypotension, abruption, cord prolapse or uterine rupture; beyond 10 minutes it counts as a new baseline ^{[1] [3]}.

Recurrent decelerations are those seen with at least 50% of uterine contractions in any 20-minute segment ^[1]. ^[2]

A reassuring tracing contains all of: a baseline between 110 and 160 beats per minute, moderate variability, accelerations when expected and no late or variable decelerations ^[1]. Either accelerations or moderate variability strongly predict an umbilical pH above 7.15, and the false-positive rate of a "non-reassuring" label for acidosis exceeds 90% ^{[1] [3]} . Acidemia may be present in up to one quarter of fetuses with minimal or absent variability combined with late or variable decelerations ^[1]. ^[2]

Full score range 0 to 13; greater than 8 favourable, 5 or less unfavourable. A simplified score (dilation, effacement, position) ranges 0 to 9 and greater than 5 predicts successful vaginal birth after induction. A modified version using cervical length instead of effacement has a ceiling of 12 and takes 5 or more as favourable, particularly in multiparous women. Station is measured in centimetres relative to the ischial spines. ^[6]

Concerning variable features: duration over 60 seconds, reduced variability within the deceleration, failure or slow return to baseline, or loss of shouldering.

• Document objectively: date, time, findings, who assessed, and the level of the monitoring recommended; retain cardiotocograph traces for 25 years and store them electronically where possible, with tracer systems that allow retrieval ^[8]. In cases of suspected brain injury, keep them indefinitely.
• Escalation records: when monitoring moves to continuous CTG, document the reasons, the woman's agreement, the time of the decision and of any senior review ^[8].
• Post-examination care: allow the woman to sit up comfortably, change pads if needed, provide privacy, and answer questions about the findings; the observations often cause anxiety even when normal.
• Return to intermittent auscultation if continuous CTG was started because of intermittent auscultation concerns but the trace is normal after 20 minutes, unless the woman prefers to continue continuous monitoring ^[8].
• Infection prevention: perform hand hygiene before and after, and clean equipment according to protocol.
• Psychological care: after an emergency delivery prompted by a trace, debrief the woman and her family and route them to follow-up.
• Postnatal check: confirm that any suspected malpresentation was excluded with ultrasonography and that growth concerns are referred for review ^{[5] [4]}.

• False-positive assessment leading to over-intervention. Continuous monitoring carries a false-positive rate for acidosis above 99% in some estimates and contributes to higher operative and caesarean delivery rates without neonatal benefit; this is the principal harm of routine monitoring ^[3].
• Infection. Repeated vaginal examinations and invasive devices can introduce intrauterine infection; strict asepsis and the fewest necessary examinations reduce it.
• Errors in pattern interpretation. Inter-observer agreement is modest; a structured reporting mnemonic such as DR C BRAVADO (Determine risk, Contractions, Baseline rate, Variability, Accelerations, Decelerations, Overall assessment) standardises communication ^[3].
• Misidentification of the maternal pulse as fetal. Particularly common in the second stage of labour; verify with a finger on the pulse or maternal heart rate monitoring ^[8].
• Fetal scalp electrode complications. Infection, haematoma and viral transmission are possible, and insertion requires ruptured membranes; use it when external signals are poor ^[3].
• Tachysystole and uterine overactivity. More than 5 contractions in 10 minutes averaged over 30 minutes increases acidosis risk and is corrected by stopping or reducing the uterotonic, or by adding a tocolytic such as terbutaline ^{[2] [3] [8]}.
• Cord prolapse, abruption and uterine rupture may present as an abrupt prolonged deceleration or bradycardia; act immediately ^[3].
• Postpartum risks include haematoma, infection and the psychological impact of an unexpected operative delivery.

Red flags requiring immediate action and senior review: absent or minimal variability with recurrent late or variable decelerations; a prolonged deceleration of 3 minutes or more; acute bradycardia of 3 minutes or more; a sinusoidal trace; meconium or fresh bleeding; maternal collapse or hypotension. Where acute bradycardia persists beyond 9 minutes, birth should be expedited (earlier if there are significant risk factors), with reassessment if the heart rate recovers ^[8].

NICE guideline NG229 (fetal monitoring in labour) uses intermittent auscultation for low-risk women, with at least one minute after each contraction immediately after it, repeated at least every 15 minutes in the first stage and every 5 minutes in the second stage, and maternal pulse assessment each hour ^[8]. It provides white/amber/red (normal/suspicious/pathological) categorisation rather than the NICHD tiers, and in the second stage lowers the threshold for a 20 bpm or greater rise in the baseline to a red feature. NICE lists clear antenatal and intrapartum indications for continuous cardiotocography and recommends hourly risk assessment, a second-clift "fresh eyes" review and conservative measures including maternal positioning, reduced or stopped oxytocin, and a tocolytic, while advising against maternal facial oxygen therapy and against amnioinfusion for resuscitation ^[8]. NICE guideline NG235 covers intrapartum care more broadly.

ACOG's current document is Clinical Practice Guideline No. 10 (October 2025, Intrapartum Fetal Heart Rate Monitoring: Interpretation and Management), which replaces Practice Bulletin 106 (2009) and Practice Bulletin 116 (2010) ^[9]. ACOG uses the NICHD three-tier categories (I/II/III) with the same baseline, variability and deceleration language described above, and emphasises intrauterine resuscitation before expediting delivery where reversible causes exist ^[9].

The Royal College of Obstetricians and Gynaecologists (RCOG) endorsed the NICHD workshop definitions alongside ACOG, AWHONN, and the Society of Obstetricians and Gynaecologists of Canada ^[2]. Current UK intrapartum practice follows NICE, while RCOG guidance in related areas (for example intrapartum care of specific conditions) continues to advise continuous electronic fetal monitoring in specified high-risk situations.

The WHO guideline WHO recommendations: intrapartum care for a positive childbirth experience (2018) emphasises woman-centred, respectful care delivered as an evidence-based package, irrespective of setting or level of health care, and encourages a holistic, human-rights-based approach to labour and childbirth ^[10]. It supports shared decision making, mobility and continuity of care, and reserves continuous technology for women who need it. Where staffing or equipment limits continuous monitoring, high-quality intermittent auscultation and a well-trained birth attendant remain acceptable and safe options ^[3].

NICE and ACOG use different category labels and thresholds, so a trace labelled suspicious in the UK system may be a Category II trace in the US system; NICE uses a 20 bpm rise as a red feature in active second stage, whereas ACOG's published thresholds lean on the 2008 NICHD definitions. Neither scheme has superior outcome evidence, and both insist on the whole clinical picture ^{[8] [9]}. Low-resource settings should adopt the simplest system the team can use consistently and train well in it.

• Clinical skill is the main monitor. Accurate Leopold maneuvers, fundal height plotting and structured intermittent auscultation with a Pinard or Doppler can be delivered without a cardiotocograph ^{[4] [5] [3]}.
• Use ultrasound to confirm presentation, growth or liquor concerns where there is doubt ^[5].
• Document clearly and have a clear pathway for transfer or expedited birth where intervention is not locally available.
• Train the whole team in one agreed system and run drills for tachysystole and bradycardia.

• Obstetric examination establishes lie, presentation, position, engagement, size, cervical state and, when used, fetal heart rate; it does not replace the woman's history and observations.
• Leopold maneuvers are four systematic abdominal grips (fundal, umbilical or lateral, Pawlik, pelvic); assess from 36 weeks and confirm non-cephalic presentation with ultrasonography.
• Fundal height is measured from pubic symphysis to fundus at each visit from 20 weeks and plotted to detect deviation.
• Intermittent auscultation is the appropriate first-line method for low-risk labour; continuous CTG is reserved for pregnancies or intrapartum developments with risk factors for fetal compromise.
• NICHD definitions set the standard language: baseline 110 to 160 bpm, moderate variability 6 to 25 bpm (absent, minimal and marked otherwise), accelerations at least 15 bpm for 15 seconds, early/variable/late and prolonged decelerations, recurrent decelerations with 50% or more of contractions, and tachysystole over 5 contractions in 10 minutes.
• VEAL CHOP: Variable = cord compression, Early = head compression, Accelerations = OK, Late = uteroplacental insufficiency.
• Categories I (normal), II (indeterminate, common) and III (abnormal) and the NICE normal/suspicious/pathological scheme both require whole-picture assessment.
• Either accelerations or moderate variability offers strong reassurance; absent or minimal variability with recurrent late or variable decelerations increases the chance of acidemia up to about one quarter.
• Bishop score (range 0 to 13): greater than 8 favourable for induction, 5 or less unfavourable; modified version ceiling 12 with 5 or more favourable.
• Invasive monitoring has infection and transmission risks and should be used when external signals are poor, not by default.
• Cardiotocograph traces are kept for 25 years, and NICE requires a full hourly risk assessment with a second clinician's fresh eyes review for women on continuous monitoring. ^[8]
• Red flags: acute bradycardia or prolonged deceleration of 3 minutes or more, absent variability with recurrent decelerations, a sinusoidal trace, and new-onset severe tachysystole.

Obstetric examination; antenatal care; fetal presentation and malpresentation; induction of labour; intrapartum care; pre-eclampsia and hypertensive disorders; decreased fetal movements; preterm labour; normal labour and delivery; maternal and neonatal resuscitation; perinatal infection.