Intrapartum Fetal Monitoring, Postdates Pregnancy and Neonatal Resuscitation

Intra-partum Fetal Monitoring Can be Done

• Externally

  • Doppler (ultrasound transducers)

  • Tocodynamometer

• Internally: when indicated

  • Fetal scalp electrode

  • Intra-uterine pressure catheter

Intra-partum Monitoring: Baby

• Doppler

  • Noninvasive ultrasound device that uses sound waves to measure the fetal heart rate

• Fetal Scalp Electrode

  • Internal fetal monitoring device used during labor

  • Directly measures fetal heart rate

Intra-partum Monitoring: Mom

• Tocodynamometer

  • Pressure sensitive device that measures uterine contractions externally: measures contraction frequency and duration but not intensity

• Internal Uterine Pressure Catheter

  • Rests between uterine wall and the baby

  • Accurately measures uterine contraction intensity, frequency, and duration

  • Provides more precise data

Electronic Fetal Monitor/CTG

• Machine that simultaneously records fetal heart rate and uterine contractions

  • Fetal heart rate → via an ultrasound doppler transducer

  • Uterine contractions → via tocodynamometer

  • Top part is baby and bottom is mom

• From one red line to another red line is 1 minute

  • Each box is 10 seconds

Functions of Intrapartum Fetal Monitoring

• Assess fetal well being during labor

• Detects signs of fetal hypoxia or distress

• Monitor fetal heart rate patterns and variability

• Evaluate the fetal response to uterine contractions

• Identify early indications of acidemia

• Guide timely clinical interventions (position change)

• Reduce the risk of fetal injury or adverse neonatal outcomes

• Provide ongoing data to support labor management decisions

Continuous Fetal Monitoring

• Continues monitoring of fetal HR and contractions during labor and delivery using internal or external devices

• Indications

  • Use of Pitocin for induction of augmentation

  • Epidural or spinal anesthesia

  • Induced or augmented labor

  • Non-reassuring fetal HR patterns

  • Meconium stained amniotic fluid

  • Maternal HTN or pre-eclampsia

  • Maternal DM

  • Maternal fever or suspected infection

  • Preterm labor

  • Post-term pregnancy

  • IUGR

  • Multiple gestation

  • Vaginal bleeding during delivery

  • History of previous C-section or uterine surgery

  • PROM with risk of infection

  • Any medical or obstetric complication affecting fetal oxygenation

• Has led to an increase in

  • C-sections

  • Instrumental vaginal births

• Maternal negative impact

  • Restricts maternal movement

  • Reduced physical contact with her partner

Intermittent Fetal Monitoring

• Fetal HR is checked at scheduled intervals

• Recommended in low risk pregnancies

• Benefits

  • Allows more maternal mobility and comfort

  • Fewer restrictions and less equipment

• Endorsed by ACOG and WHO for appropriate candidates

• Lower rates of intervention

Baseline Fetal Heart Rate

• Average heart rate over a 10 minute window

  • Normal range: 110-160 bpm

• Baseline reflects the fetus’s overall:

  • Oxygenation

  • Neurological status

  • Autonomic nervous system

• Excludes accelerations and decelerations

Variability

• Beat to beat fluctuations in the fetal heart rate

• Reflects intact neurologic pathways and adequate oxygenation

  • If the variability is good → fetus is generally coping well

• Types

  • Absent: no detectible variation (concerning)

  • Minimal: <=5 bpm (could be sleep, medications, hypoxia)

  • Moderate: 6-25 bpm (reassuring: oxygenated fetus)

  • Marked: > 25 bpm (may indicate stress: could be ok and need to assess further)

Accelerations

• Temporary increase in the fetal heart rate that is reassuring

  • >= 32 weeks: increase of >= 15 bpm that lasts >= 15 seconds (15 × 15)

  • < 32 weeks: 10 × 10

• Causes

  • Adequate oxygenation

  • Responsive autonomic nervous system

  • Fetal well being

  • Fetal movement/stimulation

• Absence is not abnormal but may require additional monitoring

Decelerations

• Periodic decreases in the fetal heart from the baseline

• Can indicate:

  • Normal physiologic responses

  • Potential fetal distress: depends on timing, shape, and duration

FHR Pattern, Cause, Management

Uterine Contractions

• Assess:

  • Frequency (peak to peak measurement)

  • Duration

  • Intensity

    • Measured by palpating the abdomen

      • Mild: nose

      • Moderate: chin

      • Strong: forehead

    • IUPC

      • Mild: < 40 mmHg

      • Moderate: 40-70 mmHg

      • Strong: > 70 mmHg

• Normal labor pattern

  • Every 2-5 minutes lasting 60-90 seconds

• Rate: number of contractions in 10 minute window

• Assessed independently and also in conjunction with fetal heart rate monitoring

• Uterine contractions reduce placental blood flow and can cause late decelerations

Category

• Overall interpretation and big picture conclusion

• Tracings are classified into categories based on their pattern

  • Category I: normal

  • Category II: indeterminate

  • Category III: abnormal

• Category II and III tracing interventions focus on:

  • Improving fetal oxygenation

  • Reducing uterine stress

  • Preparing for potential delivery

Category I Criteria

• Baseline FHR 110-160 bpm

• Variability: moderate (6-25 bpm fluctuations)

• No late or variable decelerations

• Early decelerations or accelerations may be present

Category II Criteria

• Everything’s that not I or III

• Requires continued surveillance and reassessment

• Intervene, reassess, and continue monitoring

• Goal

  • Improve fetal oxygenation

  • Correct reversible causes

• Interventions

  • Reposition patient

  • IV fluids

  • Stop Pitocin

  • Give oxygen

  • Treat maternal hypotension

  • Amnioinfusion

  • Fetal scalp stimulation

  • Close monitoring

Category III Criteria

• Absent variability plus

  • Recurrent late decelerations

  • Recurrent variable decelerations

  • Bradycardia

• Immediate intervention needed

• Goal

  • Immediate correction or expedited delivery

• Interventions

  • Stop Pitocin immediately

  • Reposition patient

  • IV fluids

  • Administer oxygen

  • Correct maternal hypotension

  • Tocolysis if tachysystole present

  • Amnioinfusion

• No improvement → prepare for operative delivery

Fetal Scalp Blood Sampling

• Used to directly assess fetal oxygenation and acid base status during labor when there are concerns about fetal distress

• Process

  • Small incision on fetal scalp and tiny blood sample collected

  • Requires ruptured membranes, cervical dilation, and cephalic presentation

• Normal pH → continue monitoring

• Low pH → acidemia and expedite immediately

• Invasive and used less often today

• Contraindications

  • Infection

  • Prematurity

  • Bleeding disorders

Non-stress Test

• Non-invasive test to assess fetal well being by monitoring the FHR in response to fetal movement

  • No uterine contractions are induced and fetus is not stressed during test

• Process

  • Uses electronic fetal monitoring: FHR and contraction measurement

• Indicated adequate oxygenation and intact neurologic function

• Used outpatient in high risk pregnancies or for reduced fetal movement

Reactive NST

• 2 or more accelerations in 20 minutes

• Reassuring

Non-reactive NST

• Fewer than 2 qualifying accelerations in 40 minutes

• Non-reassuring but does not automatically mean fetal distress

• May indicate

  • Fetal sleep

  • Medications

  • Need for further testing

• Can try to give cold water or juice to mom

Contraction Stress Test

• Measures the fetal HR after the mother’s uterus is stimulated to contract

• Potentially used in rare cases where NSTs are repeatedly nonreactive

• Test is done to make sure the fetus can handle contractions during labor and get the oxygen needed from the placenta

  • Identifies fetal distress before labor begins

• Not routinely done

Biophysical Profile

• Pre-natal test that combines U/S assessment and FHR monitoring to evaluate fetal well being and oxygenation

• Components

  • NST (non-U/S)

  • Fetal breathing movements → watch fetal diaphragm or chest wall move

  • Fetal tone → 1 episode of extension with return to flexion

  • Gross body movements → minimum of 3 times

  • Amniotic fluid index

  • Each component scored 0 or 2 with maximum of 10

• Scores

  • 8-10: reassuring

  • 6: equivocal (repeat testing or further evaluation)

  • 4 or less: non-reassuring (consider delivery)

  • Amniotic fluid is low: score of 8 or 9 is abnormal

NST and BPP

• Used for high risk pregnancies for structured monitoring of the fetus at specific intervals

Induction

• Intentional initiation of labor using mechanical or medical methods during labor begins on its own, with the goal of achieving a vaginal delivery → ripens the cervix and stimulates uterine contractions

• Indications

  • Postdates pregnancy

  • PPROM

  • Maternal conditions (HTN/DM)

  • Fetal concerns (IUGR)

  • Elective induction at term

• Methods

  • Pharmacologic

  • Mechanical

  • Membrane sweeping (stripping)

  • Amniotomy (AROM)

  • Nipple stimulation

Augmentation

• Labor has started but needs strengthening

Methods of Induction: Pharmacologic

• Prostaglandins:

  • Soften and dilate the cervix

  • May stimulate contractions

  • Used when the cervix is unfavorable (low Bishop score)

• Pitocin

  • Has to be primed and ready with favorable cervix

  • IV medication

  • Requires continuous fetal monitoring

Bishop Score (don’t memorize)

• Cervical assessment used to predict the likelihood of a successful labor initiation

• 5 factors

  • Cervical dilation

  • Cervical effacement

  • Cervical consistency

  • Cervical position

  • Fetal station

• Score >= 8: cervical favorable and induction likely to succeed

• Score < 6: cervix unfavorable and ripening needed first

• In between score: gray zone

Methods of Induction: Mechanical

• Foley balloon

  • Balloon inserted into cervix and inflated → applies pressure to promote dilation

  • Lower risk of tachysystole than medications

  • Used for cervical ripening

Methods of Induction: Membrane sweeping

• Provider manually separates membranes from cervix during vaginal exam → releases natural prostaglandins

• Can initiate labor

• Not formal induction: just mechanical/natural

• Do not use with:

  • Placenta previa

  • High risk of bleeding

  • Vaginal exams are contraindicated

Methods of Induction: Amniotomy

• Intentional breaking of amniotic sac

• Releases prostaglandins and increases contraction strength

• Requires fetal head to be well engaged

• Increases risk for: infection and cord prolapse

Big Picture

• Unfavorable cervix → prostaglandins or balloon first

• Favorable cervix → Pitocin +/- amniotomy

• More intervention → more monitoring

Newborn Assessment Immediate Goals

• Assess cardiorespiratory status

• Establish and maintain ABCs

• Identify need for resuscitation

• Evaluate adaptation to extra-uterine life

Initial Newborn Assessment

• Immediately after birth

• Key observations

  • Respiratory effort (crying, breathing, apnea)

  • HR

  • Muscle tone

  • Color

  • Gestational age assessment

  • Presence of anomalies

APGAR

• Performed at 1 minute and 5 minutes after birth

• Interpretations

  • 7-10 → normal adaptation

  • 4-6 → moderate difficulty and may need assistance

  • 0-3 → severe distress and need immediate resuscitation

• Does not predict long term outcomes and is not used to decide whether to resuscitate → reflects response to resuscitation

Ongoing Newborn Assessment

• Vital signs (HR/RR/temperature)

• Physical exam

  • Skin color and perfusion

  • Gross malformations, molding, caput, spina bifida

• Heart and lung sounds

• Abdomen and umbilical cord

• Genitalia and anus

• Reflexes (Moro, grasp, suck)

Neonatal Resuscitation

• Initial questions

  • Is the infant term

  • Is the infant breathing or crying

  • Does the infant have good muscle tone

• Yes to all → routine care

• No to any → begin resuscitation steps

Initial Resuscitation Steps

• Provide warmth

• Position airway

• Clear secretions if needed

• Dry and stimulate

• Evaluate breathing and HR

• PPV if apnea, gasping, HR < 100 bpm

• Chest compressions if

  • HR < 60 bpm after 30 seconds of effective PPV

• Medications

  • Epinephrine if HR < 60 bpm after ventilation and compressions

  • Volume expansion if hypovolemia suspected

• Pearls

  • HR is the most important indicator in neonatal resuscitation

  • Ventilation is the single most effective intervention

  • APGAR scores assess response, not the need for resuscitation