Cardiotocgram, in

1. Introduction
• Lack of technology, methods, protocols and
support systems
• Whelping a "stand back, cross your fingers and
hope every thing comes out OK“
• Depends on subjective symptoms such as
panting or nesting rather than accurate
objective information on uterine contractions
and fetal heart rates
“Breeder and veterinarian in a passive rather
than active role in the whelping process”

2. DYSTOCIA?????

3. Purpose of Fetal Monitoring
• To assess the influence of the intrauterine
environment for fetal well-being
– Identify the fetus at risk
– Assess fetal well being
• To assess progress of labor through
measurement of uterine activity

4. Methods of Monitoring
• Two methods of uterine activity monitoring
– Palpation only
– Electronic Monitoring
• External with tocodynamometer
• Internal with Intrauterine Pressure Catheter (IUPC)

5. Review
• The presence of uterine contractions in an organized
fashion in the canine was first documented by Vander et
al., (1989) by surgically implanting electrodes in the
canine myometrium.
• Tocodynamometry is a novel approach to monitor
parturition and obstetrical manipulations with the plan
of reducing neonatal death (Davidson, 1998).
• External monitoring devices using tocodynomometry
and a hand held doppler to detect and record uterine
activity and foetal heart rates is a novel approach to
veterinary obstetrical monitoring (Davidson, 2001;
Davidson, 2003).

6. Contd..
• The use of uterine and foetal monitors allows
the veterinary clinician to observe and monitor
labour, as well as manage labour medically or
surgically with insight instead of guess work
(Davidson et al., 2003).
• Davidson et al., (2003) reported the overall
still birth rate in female dogs declined from 9.2
per cent to 2.5 per cent with incorporation of
uterine and foetal monitoring into the whelping
process.

7. External tocodynamometer

8. External Tocodynamometer
• External tocography is currently the most
extensively used technique to monitor the
uterus during pregnancy and delivery.
• A tocodynamometer, consists of a strain gauge
transducer placed around the external surface
of the abdomen.
• The major benefit of a tocodynamometer is its
noninvasiveness.

9. Instrumentation
• Monitoring equipment
– Graph paper
– Display panel
• External Monitoring
– Tocodynamometer
– Doppler

10. Graph Paper
• Paper is heat sensitive
• Two distinct sections or channels
– FHR channel (on top)
• Vertical – monitors the FHR on a 30-240 bpm per cm scale
• Horizontal – each small box represents 20 sec, each dark line
marks 1 minute
– Uterine Activity “UA” (on bottom)
• Vertical – measures the intensity of the contractions on a 0-
100 mmHg scale
• Horizontal – each small box represents 20 sec, each dark line
marks 1 minute

11. Structure of TOCO

12. • The toco contains a flexible disk that responds
to pressure.
• When the uterus contracts, the fundus tightens
and the change in pressure against the toco is
amplified and conveyed to the electronic fetal
monitor.
• The monitor displays the uterine contraction as
a pattern on graph paper.

13. • The lateral abdomen of the animal has to be clipped,
and the animal has to be placed on animal examination
table in the lateral recumbancy.
• The uterine sensor should be placed and kept pressed
on the abdominal skin and has secured with abdominal
belts.
• During the course of uterine monitoring, the bitches
have to be kept quite avoiding any movements as far as
possible.
• The frequency, duration, amplitude and baseline shifts
in uterine contraction have to be recorded for a
minimum of thirty minutes.

14. • External monitoring provides a permanent
recording of the frequency and duration of uterine
contractions. However, it does not exactly record
the intensity of the uterine contraction.
• The signal provided by external tocography can
be affected by many variables, such as the sensor
position and the thickness of the subcutaneous fat
tissue, body movements, gastric activity, and
other nonlabor-induced stresses on the
tocodynamometer can be erroneously interpreted
for labor contractions.

15. • As a result, external recordings have an accuracy
that is highly reliant on the examiner’s skills and
are described by a low sensitivity.
• Therefore, the use of external tocodynamometry
can only provide information related to the
frequency of the contractions while it does not
measure the contraction amplitude and duration
(Garfield et al., 1998).

16. WhelpwiseTM Veterinary Perinatal
Specialties®

17. WhelpwiseTM Veterinary Perinatal
Specialties®
• This system consists of a tocodynamometer (uterine
sensor), a recorder, a modem, and a hand-held ecodoppler
unit.
• Tocodynamometry procedures can be used either in the
home setting or at the veterinary clinic.
• From the last week of pregnancy and throughout whelping
and delivery, bitches will be monitored by
tocodynamometry.
• The uterine sensor has to be placed and to be kept pressed
under the lightly clipped abdominal area, with the bitch in
lateral recumbency. During uterine monitoring bitches have
to be kept quiet, avoiding any movements throughout 20–30
min each session.

18. Contd..
• The recorder is worn in a small backpack
placed over the caudal shoulder area.
• During the monitoring sessions, bitches are at
rest in the whelping box or in a crate or cage.
• Following to each recording session, data is
transferred from the recorder via a modem
using standard telephones.

19. Fetal Doppler
• Fetal doppler monitoring is performed
bilaterally with a hand held unit with bitches in
lateral recumbancy.
• Directing the doppler perpendicularly over a
fetus results in a distinctive amplification of
the fetal heart sounds, distinct from maternal
arterial or cardiac sounds, which enables
determination of fetal heart rates (Davidson,
2003).

20. Procedure
• WhelpWise begins 4-5 days before the expected
due date and continues until whelping is
complete.
• Information on uterine contractions is gathered
twice daily for one hour, and fetal heart rates are
checked at least once daily.
• Early detection of distressed pups allows the
breeder to make informed decisions about
interventions.
• The fetal heart rate Doppler can also be used
around 6-7 weeks to confirm pregnancy.

21. Contd..
• Recordings are made twice daily, then intermittently on
bitches at home.
• During active labor shorter periods of time, when
patients are being evaluated for suspected dystocia
minimally 20 minutes (Davidson, 2001 and 2003).
• Pre-labour: 2–8 mm Hg above the baseline uterine
pressure and frequency of 0 –3 contractions per hour,
lasting 2–5 min in duration.
• Labour: 10 mm Hg in strength or more and frequency
ranged from 4 to 12 contractions per hour, each one of
2–5 min duration.

22. Benefits
• Providing the breeder with accurate
information on presence or absence of labor,
and assessments of fetal well being as detected
by the monitoring equipment
• Uterine contraction and fetal heart rate
monitoring will allow to know when labor has
begun, and directly monitor the heart rates of
the puppies.

23. • Common problems such as inertia can be
identified and treated
• All medication doses are determined by the
uterine contraction pattern
• Instances such as a stuck pup where strong
contractions exist and medication should not
be given can also be identified, helping to
prevent problems such as uterine rupture.

24. Active labor
• 0–3 mild (2–8 mmHg) contractions per 30 min
in pre-labour bitches, monitored every 12 h.
• 3–7 strength (10 mm of Hg) contractions per
30 min in bitches delivering puppies in a
interval comprised between 30 min and 3h.
Groppetti et al., (2010)

25. Inertia
• After the onset of labour, the intra-partum
detection of 0–3 mild contractions per 30 min
without parturition, constituted recommendation
for medical management of uterine inertia as long
as no fetal distress was noted.
• Bitches showing 3 strong intra-partum
contractions not followed by parturition within 3h
were submitted to emergency C-section for
dystocia.
Groppetti et al., (2010)

26. Spontaneous whelping (Jayakumar, 2015)
• Escalating and regular type of active labor pattern of
uterine contractions followed and coupled with
abdominal pressure spikes.
• Frequent and regular uterine contractions with duration
of 2 to 5 minutes
• Uterine contractile tone of 30 to 40% followed and
coupled with abdominal pressure increase in the form
of spikes of 80 to 99 % at expulsive phase.
• The number of spikes representing abdominal activity
along with uterine contractions at physiological births
varied between 2 to 4 in a period of thirty minutes.

27. Complete primary uterine inertia
• Baseline contraction strength of only 10%
without augmentation from the baseline.
(Jayakumar, 2015)

28. Partial primary uterine inertia
• Baseline contraction strength of only 10% with
marginal augmentation from the baseline.
• No consistent pattern either in frequency or the
duration of uterine contraction and abdominal
pressure spikes increased throughout the
monitoring period.
(Jayakumar, 2015)

29. Successful medical management in
primary uterine inertia (Jayakumar, 2015)
• Response to medical management evinced as increase in
strength and overall frequency as well as duration of
contraction.
• Augmentation of uterine contraction strength to 30% to
50% followed and coupled with abdominal pressure
increase spikes upto 70 to 95% during the expulsion phase.
• Frequency of 2 to 5 close coupled uterine contractions per
30 minutes, each with duration of 2 to 3 minutes followed
and coupled with abdominal pressure increase spikes of 3 to
4 noticed.

30. Unsuccessful medical management in primary
uterine inertia
• In unresponsive dogs to medical management,
no improvement in the contractility pattern
was noticed even after treatment.
• In few dogs, close coupled tetanic contractions
without fetal expulsion was noticed.
(Jayakumar, 2015)

31. Dystocia from obstructive cause
• Uterine hyperstimulation indicated by
abnormally high uterine resting tone (>20 to
30%) for an extended period.
• Increase in abdominal pressure spikes of
prolonged duration without fetal expulsion.
(Jayakumar, 2015)

32. Interpretation (Copley, 2002)
• The occurrence of 1-3 contractions an hour a normal
“baseline” uterine contraction pattern after 53 days post
LH surge.
• Further it was reported that uterine contractions
occurring before day 53, especially with the presence of
irritability (contractions that are less than a minute in
length) have a high incidence of premature delivery
and/or premature placental separation.
• Studies in bitches after uterine and fetal monitoring
have shown significantly lower stillbirth rates (2.5% to
3.7%) than previously reported.

33. Conclusion
• Medical therapy for dystocia, based on the
administration of oxytocin and calcium gluconate,
can be customized based on the results of
monitoring.
• Cesarean section can be indicated if aberrant
contractile patterns are noticed during uterine
monitoring.
• The overall stillbirth rate declined from 9.2 per
cent to 2.5 per cent with incorporation of uterine
and fetal monitoring into the whelping process
(Davidson, 2010).

34. Cardiotocography
• Uterine contractions can affect the fetal heart rate
(FHR) by subjecting the fetus to an intermittent
hyperbaric state.
• They also compress the myometrial vessels, may
influence the cerebral blood flow and depending on the
umbilical cord location, they may cause occlusion of
the umbilical cord with a resultant decrease in fetal
oxygenation.
• These situations are usually reflected in a deceleration
of the FHR.
• Scrutinizing the FHR in combination with the uterine
activity is referred to as cardiotocography (CTG).

35. Features of a CTG
• Baseline Heart Rate
• Short term variability
• Accelerations
• Decelerations
• Response to stimuli
– Contractions
– Fetal movements
– Others eg drugs

36. Baseline Fetal Heart Rate
• Normal rate 110 to 150 bpm at term
• Faster in early pregnancy
• Below 100 = baseline bradycardia
• Below 80 = severe bradycardia
• Tachycardia > 160 bpm
• Tachycardia if mother has fever

37. Hypoxia Chorioamnionitis
Maternal fever Drugs
Fetal anaemia,sepsis,heart failure, arrhythmias
37
TACHYCARDIA

38. Short Term Variability or
Beat to Beat Variability
• Should be 10 to 25 beats
• The most important feature of any CTG
• Reflection of competing acceleratory and decelerating
CNS influences on the fetal heart
• Represents the best measure of CNS oxygenation
• Will be affected by drugs
• Will be reduced in the pre term fetus

40. 40
Hypoxia Drugs Extreme prematurity
Sleep CNS abnormality
REDUCED VARIABILITY

41. 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.
• Associated with -
Severe chronic fetal anaemia
Severe hypoxia & acidosis 41

42. Accelerations
• Must be >15 bpm and >15 sec above baseline
• Should be >2 per 15 min period
• Always reassuring when present
• May not occur when fetus is “sleeping”
• Should occur in response to fetal movements or fetal
stimulation
• Non reactive periods usually do not exceed 45 min
– >90 min and no accelerations is worrying

43. DECCELERATIONS
• EARLY : Head compression
• LATE : Utero placental insufficiency
• VARIABLE : Cord compression
Primary CNS dysfunction
43

44. Early decelerations
• Begin with head compression.
• This reduction of cerebral blood flow leads to hypoxia
and hypercapnia
• Hypercapnia leads to hypertension with triggering of
baroreceptors
• Results in bradycardia mediated by parasympathetic
nervous system (via the vagal nerve)
• Fall in FHR is matched to rise in contraction strength
• Not indicative of fetal compromise

45. Late Decelerations
• Repetitive from one contraction to the next (3 or more)
• Recovery to baseline is late, well after the end of the
contraction
• More ominous when associated with minimal variability
&  baseline
• Reflects a change in placental ability to adequately meet
fetal needs
• May indicate the presence of fetal hypoxia and acidosis
• Often signifies fetal decompensation.

46. Variable Decelerations
• Repetitive or intermittent.
• Often mimic letters of the alphabet
U V W M
• Rapid sudden fall in FHR.
• Often rapid recovery.
• Reflect some degree of umbilical cord impingement
• Often seen when liquor volume is .