Cardiotocography

fetal monitoring during labour

1. Cardiotocography 1 Presented By Nirsuba Gurung MN,Women Health and Development 24-Apr-16

2. 24-Apr-16 2

3. Cardiocotography Cardiotocography (CTG) is a continuous electronic record of the fetal’s heart rate obtained via an ultrasound transducer placed on the mother’s abdomen It is sometimes referred to as ‘electronic fetal monitoring’ (EFM) 24-Apr-16 3

4. CTG Contd ….. The machine used to perform the monitoring is called a cardiotocograph , more commonly known as an electronic fetal monitor ( EFM ) 24-Apr-16 4

5. Invention The invasive fetal monitoring was invented by Doctors Alan Bradfield,  Orvan Hess and Edward Hon. A refined ( antepartal , non-invasive, beat-to-beat) version ( cardiotocograph ) was later developed for Hewlett Packard by Dr.  Konrad Hammacher . 24-Apr-16 5

6. Purpose To record FHS continuously To check uterine activity To detect any fetal distress To gain information about rate, rhythm of the fetal heart rate and fetal movement

7. Indications for the use of continuous EFM 9 24-Apr-16

8. Indication Continuous EFM should be offered and recommended for high-risk pregnancies where there is an increased risk of perinatal death, cerebral palsy or neonatal encephalopathy. Continuous EFM should be used where oxytocin is being used for induction or augmentation of labour . 10 24-Apr-16

9. ADMISSION CTG Current evidence does not support the use of the admission CTG in low-risk pregnancy and it is therefore not recommended 11 24-Apr-16

10. High-Risk Indications Maternal medical illness Gestational diabetes Hypertension Asthma Obstetric complications Multiple gestation Post-date gestation Previous cesarean section Intrauterine growth restriction Oligohydramnios Premature rupture of the membranes Congenital malformations Third-trimester bleeding Oxytocin induction/augmentation of labor Preeclampsia Meconium stained liquor 12 24-Apr-16

11. A Continuous EFM should be offered and recommended in pregnancies previously monitored with intermittent auscultation: if there is evidence on auscultation of a baseline less than 110 bpm or greater 160 bpm • if there is evidence on auscultation of any decelerations • if any intrapartum risk factors develop. 13 24-Apr-16

12. Methods External Cardiotocography - For continuous or intermittent monitoring of The fetal heart rate and The activity of the uterine muscle Placed two transducers on the mother's abdomen(one above the fetal heart and the other at the fundus).

13. External(Indirect) Monitoring The tocodynamometer (“ toco ”) is placed over the uterine fundus. The toco provides information that can be used to monitor uterine contractions . The ultrasound device is placed over the area of the fetal back. This device transmits information about the FHR .

14. The pressure transducer transmits the pressure generated by uterine contractions in mm Hg. Each small vertical square is 5 mm Hg Each small horizontal square is 10 seconds . Each large horizontal square is 1 minute . Pressure Transducer Toco sensor

15. Ultrasound transducer The ultrasound probe transmits the fetal heart rate in beats per minute. Each small vertical square is 10 beats. Each small horizontal square is 10 seconds . Each large horizontal square is 1 minute . 24-Apr-16 17 Ultrasound Probe

16. Information from both the toco and the ultrasound device is transmitted to the electronic fetal monitor. The FHR is displayed in a digital display (as a blinking light), on the special monitor paper, and audibly (by adjusting a button on the monitor). The uterine contractions are displayed on the special monitor paper as well. 18

17. Internal Cardiotocography - Uses an electronic transducer connected directly to the fetal scalp through the cervical opening and is connected to the monitor. Internal monitoring provides a more accurate. Internal monitoring may be used when external monitoring of the fetal heart rate is inadequate. It need some degree of cervical dilatation.

18. Internal Monitoring Criteria for Internal Monitoring: Amniotic membranes must be ruptured Cervix dilated 2 cm . Presentation must be cephalic Presenting part down against the cervix

19. Spiral Electrode is placed on the fetal occiput which allows for more accurate continuous data than external monitoring. Also is not affected by mom or fetal movement as with external monitoring. 24-Apr-16 21

20. Internal Monitoring The spiral electrode is attached to the fetal scalp Wires that extend from attached spiral electrode are attached to a leg plate and then attached to electronic fetal monitor.

21. Procedure Equipments Cardiotocograph Transducer(2): Toco and cardio Conduction gel or paste Abdominal binder (two belts) Monitor paper Tissue paper 24-Apr-16 23

22. Preparation for CTG Determine the indication for fetal monitoring Explain the purpose, time required for test Instruct the women for empty the bladder Place the women in supine position Uncover the abdomen

23. Procedure Place the tocosensor on the fundus of utreus and fix it with abdominal binder Identify the presentation and position of the fetus Localize the FHS and fix it with abdominal binder

24. Procedure Assure the recording of FHS and uterine contraction Explain the mother to push the bottom when she feel any movements Labeled the women’s name, I.P. number, date and time in CATAG graph 24-Apr-16 27

25. Procedure Turn off the monitor and replace Read the CTG and immediately notify the doctor ,if any abnormality seen 24-Apr-16 28

26. Interpretation Uterine activity (contractions) Baseline fetal heart rate (FHR) Baseline FHR variability Presence of accelerations Periodic or episodic decelerations Changes or trends of FHR patterns over time.

27. Uterine activity (contraction) Frequency - the amount of time between the start of one contraction to the start of the next contraction. Duration :The amount of time from the start of a contraction to the end of the same contraction Intensity ( strongeness ): a measure of how strong a contraction is. In early labour the contractions are weak, with amplitude of about 20 mm Hg and at the end of the first stage 60 mm Hg

28. Uterine activity (contraction) Resting Tone- a measure of how relaxed the uterus is between contraction(between 4-10 mm Hg) Interva l- the amount of time between the end of one contraction to the beginning of the next contraction.

29. Record the number of contractions present in a 10 minute period - e.g. 3 in 10 Each big square is equal to 1 minute, so look how many contractions occurred in 10 squares Individual contractions are seen as peaks on the part of the CTG monitoring uterine activity assess contractions for duration and intensity

30. Baseline fetal heart rate The mean level of the FHR when this is stable, excluding accelerations and decelerations. It is determined over a time period of 5 or 10 minutes and expressed in bpm . 33 24-Apr-16

31. – Normal Baseline FHR 110–160 bpm – Moderate bradycardia 100–109 bpm – Moderate tachycardia 161–180 bpm – Abnormal bradycardia < 100 bpm – Abnormal tachycardia > 180 bpm 34 24-Apr-16

32. Baseline Fetal Heart rate Normal Pattern Baseline FHR = 110 – 160 bpm

33. Baseline variability Variability refers to the normal beat to beat changes in FHR. Normal variability is between 5-15 bpm . Variability can be measured by analysing a one-minute portion of the CTG by estimating the difference in beats per minute between the highest peak and lowest trough of fluctuation in a one-minute segment of the trace 37

34. Baseline variability The fluctuations are visually quantities as the amplitude of the peak-to-trough in bpm . Using this definition, the baseline FHR variability is categorized by the quantitated amplitude as: Absent-  undetectable Minimal-  greater than undetectable, but less than or equal to 5 bpm Moderate-  6-25 bpm Marked-  greater than 25 bpm 24-Apr-16 38

35. 39 24-Apr-16

36. FHR Variability Absent variability = Amplitude range undetectable Minimal = < 5 BPM Moderate = 6 to 25 BPM Marked = > 25 BPM

37. Accelerations To be called an acceleration, the peak must be greater than or equal to 15 bpm , and the acceleration must last greater than or equal to 15 seconds from the onset to return to baseline. Prolonged acceleration : is greater than or equal to 2 minutes but less than 10 minutes in duration. Before 32 weeks of gestation, accelerations are defined as having a peak greater than or equal to 10 bpm and a duration of greater than or equal to 10 seconds.

38. ACCELERATIONS 45 24-Apr-16

39. Deceleration Decreases in fetal heart rate from the base line by at least 15b/m, lasting for at least 15 seconds.

40. DECCELERATIONS EARLY : Head compression LATE : U-P Insufficiency VARIABLE : Cord compression Primary CNS dysfn 48 24-Apr-16

41. Early Deceleration Early Deceleration: Early begin at start of uterine contraction and end with conclusion of contraction. Early decelerations are not a sign of fetal problems . In most cases the onset, nadir(lowest point), and recovery of the deceleration are coincident with the beginning, peak, and ending of the contraction, respectively

42. EARLY 50 24-Apr-16

43. Early Decelerations Related to Head Compression Intervention No intervention necessary. Just continue to watch for any changes.

44. Early decelerations contd … Early decelerations are a benign( kind/ gentle) finding caused by a vasovagal response as a result of fetal head compression by the contraction. Pressure on the fetal skull alters the cerebral blood flow and this in turn stimulates the vagus nerve

45. Early Decelerations

46. Variable Deceleration

47. Variable Deceleration Variable decelerations are variable in duration, intensity, and timing

48. Variable decelerations Abrupt(sudden)  decrease in FHR of  >  15 beats per minute measured from the most recently determined baseline rate.   The onset of deceleration to nadir is less than 30 seconds.   The deceleration lasts    >  15 seconds and less than 2 minutes.

49. VARIABLE 59 24-Apr-16

50. Variable Decelerations Related to cord compression Intervention Reposition Amnioinfusion

51. variable deceleration contd … The umbilical vein is often occluded first causing an acceleration in response Then the umbilical artery is occluded causing a subsequent rapid deceleration When pressure on the cord is reduced another acceleration occurs & then the baseline rate returns Accelerations before & after a variable deceleration are known as the “shoulders of deceleration” There presence indicates the foetus is not yet hypoxic & is adapting to the reduced blood flow.

52. Late Deceleration

53. Late Deceleration Gradual decrease in FHR  with onset of deceleration to nadir  > 30 seconds. Onset of the decleration occurs after the beginning of the contraction, and the nadir of the deceleration occurs after the peak of the contraction .

54. Late Decelerations Related to decreased uteroplacental perfusion

55. LATE 68 24-Apr-16

56. Late Deceleration The fetal heart tones return to the baseline AFTER end of contraction

57. Two varieties of late decelerations reflex and nonreflex . Reflex late decelerations: are those which occur in the presence of normal FHR variability Non-reflex late decelerations occur in association with diminished or absent FHR variability.   

58. Reflex late decelerations are thought to be due to vagal stimulation by chemoreceptors in the head in response to low oxygen tension. The hypoxemia -----increased sympathetic stimulation ------- increased systemic vascular resistance. The response to this increased pressure is a vagally mediated decrease in heart rate. This dual reflexive response may explain the delay in the heart rate following a contraction. Reflex late decelerations are associated with normal FHR variability because CNS system is intact.

59. Nonreflex late decelerations are associated with a greater degree of relative hypoxemia and result in hypoxic depression of the myocardium coupled with the previously described vagal response. In reflex late decelerations, variability was maintained because the fetus was able to compensate, shifting oxygenated blood to vital organs (e.g., the heart),

60. But in nonreflex late decelerations, the fetus is unable to compensate. It is these late decelerations which are more typically associated with fetal acidosis, and they are more commonly associated with placental dysfunction rather than uterine hypoperfusion or hyperactivity. 24-Apr-16 74

61. Late Decelerations Management Place patient on side Administer O2 by tight face mask Discontinue oxytocin. Correct any hypotension IV hydration. If hyperstimulation is present consider terbutaline 0.25 mg SC If late decelerations persist for more than 30 minutes despite the above maneuvers, fetal scalp pH is indicated. Scalp pH > 7.25 is reassuring, pH 7.2-7.25 may be repeated in 30 minutes. Deliver for pH < 7.2 or minimal baseline variability with late or prolonged decelerations and inability to obtain fetal scalp pH These maneuvers are primarily intended to alleviate "reflex" lates.

62. Prolonged Deceleration A prolonged deceleration is present when there is a visually apparent decrease in FHR from the baseline that is greater than or equal to 15 bpm , lasting greater than or equal to 2 minutes, but less than 10 minutes. If it lasts between 2-3 minutes it is classed as Non- Reasurring If it lasts longer than 3 minutes it is immediately classed as Abnormal Action must be taken quickly – e.g. Foetal blood sampling / emergency C-section

63. Prolonged Deceleration: A deceleration that lasts greater than or equal to 10 minutes is a baseline change.

64. 80 24-Apr-16

65. Categorisation of fetal heart rate traces Category Definition Normal All four reassuring Suspicious 1 non-reassuring Rest reassuring Pathological 2 or more non-reassuring 1 or more abnormal 81 24-Apr-16

66. SPECIAL PATTERNS 82 24-Apr-16

67. Sinusoidal pattern A regular oscillation of the baseline long-term variability resembling a sine wave. This smooth, undulating pattern, lasting at least 10 minutes, has a relatively fixed period of 3–5 cycles per minute and an amplitude of 5–15 bpm above and below the baseline. Baseline variability is absent Associated with - Severe chronic fetal anaemia Severe hypoxia & acidosis 83 24-Apr-16

68. SINUSOIDAL 84 24-Apr-16

69. PSEUDOSINUSOIDAL 85 24-Apr-16

70. SOME INTERESTING CASES 86 24-Apr-16

71. ACCELERATION OR DECCELERATION ??? 87 24-Apr-16

72. BASELINE BRADYCARDIA WITH ACCELERATIONS 88 24-Apr-16

73. HALVING PHENOMENON 89 24-Apr-16

74. EXCESSIVE VARIABILITY??? 90 24-Apr-16

75. GESTATIONAL DM ; NST ; 8:30am 91 24-Apr-16

76. GDM ; CST ; 12 noon 92 24-Apr-16

77. 24-Apr-16 93

78. References Dutta , D.C. (2004).Text book of Obstetrics. Sixth edition, New Central book agency Arias, F. Daftary , S.N. & Bhide , A. G.(2013). Practical guide to high risk pregnancy and delivery. Third edition, Elsiever 24-Apr-16 94 Nirsuba Gurung MN 1st year

79. The Royal Australian and New Zealand College of Obstetricians and Gynaecologists (2006) Intrapartum Fetal Surveillance Clinical Guidelines. Baker L, Beaves M, Trickey D and Wallace E. 2009. Fetal Surveillance: A Practical Guide. Southern Health and RANZCOG 24-Apr-16 95

80. Thank you 96 24-Apr-16