Safe Deliveries Project Management of Indeterminate (Category
II) Intrapartum Fetal Heart Rate Tracings Kathleen Simpson, PhD,
RNC November 19, 2013 Presented at Washington State Hospital
Association Safe Table 11/19/2013 Slide 2 Slide 3 Assuring Fetal
Wellbeing Supporting a woman in giving birth vaginally within the
upper normal limits of labor duration must be in the context of a
well fetus Assessment of fetal status should be considered relative
to the likelihood and timing of vaginal birth Presented at
Washington State Hospital Association Safe Table 11/19/2013 Slide 4
Labor Progress: Nulliparous Women cmSpontaneous (Hours) (5th / 95th
percentiles) Induction (Hours) (5th / 95th percentiles) Augmented
(Hours) (5th / 95th percentiles) 3-104.2 (1.3, 13.1)6.9 (2.0,
24.9)6.6 (2.0, 23.6) 3-40.4 (0.1, 2.3)1.4 (0.2, 8.1)1.2 (0.2, 6.8)
4-50.5 (0.1, 2.7)1.3 (.02, 6.8)1.4 (.03, 7.6) 5-60.4 (0.06, 2.7)0.6
(0.1, 4.3)0.7 (0.1, 4.9) 6-70.3 (0.03, 2.1)0.4 (0.05, 2.8)0.5
(0.06, 3.9) 7-80.3 (0.04, 1.7)0.2 (0.03, 1.5)0.3 (0.05, 2.2) 8-90.2
(0.03, 1.3) 0.3 (0.03, 2.0) 9-100.3 (0.04, 1.8)0.3 (0.04, 1.9)0.3
(0.05, 2.4) Harper et al., 2012 Normal progress of induced labor.
Obstetrics and Gynecology 119(6),11138 Presented at Washington
State Hospital Association Safe Table 11/19/2013 Slide 5 Assuring
Fetal Wellbeing Birth of the fetus, when possible, prior to the
development of damaging degrees of hypoxia/ acidemia Presented at
Washington State Hospital Association Safe Table 11/19/2013 Slide 6
Slide 7 Fetal Status Fluctuations during Labor Most fetuses (84%)
will demonstrate FHR pattern characteristics that are both normal
(category I) and indeterminate (category II) over the course of
labor Abnormal (category III) FHR patterns are rare (0.1%) On
average, the duration of category I is about 78% of labor, category
II; 22% and category III; 0.004% Ideally, if the FHR pattern is
category II, there is moderate variability and/or accelerations to
support the presumption of a non-acidotic fetus Jackson et al.
(2011). Frequency of fetal heart rate categories and short-term
neonatal outcome. Obstet Gynecol. 118(4):803808. Presented at
Washington State Hospital Association Safe Table 11/19/2013 Slide 8
Frequency of FHR Categories/ Short-Term Neonatal Outcome Babies of
women whose last 2 hrs were exclusively normal (category I) did
well only 0.6% had 5-min Apgar scores less than 7 0.2% had low
Apgar scores with NICU admission When >75% of last 2 hrs was
indeterminate (category II) low 5-min Apgar score increased to 1.3%
of patients low 5-min Apgar score with NICU admission increased to
0.7% Jackson et al. (2011). Frequency of fetal heart rate
categories and short-term neonatal outcome. Obstet Gynecol.
118(4):803808. Presented at Washington State Hospital Association
Safe Table 11/19/2013 Slide 9 Indeterminate (Category II) Wide
range of clinical implications associated with various types of FHR
patterns within category II Imprecise nature of category II as it
relates to fetal wellbeing makes it challenging / not always useful
for clinical decisions during labor Presented at Washington State
Hospital Association Safe Table 11/19/2013 Slide 10 Indeterminate
(Category II) Presented at Washington State Hospital Association
Safe Table 11/19/2013 Slide 11 11 Presented at Washington State
Hospital Association Safe Table 11/19/2013 Slide 12
Assumptions/Clarifications Marked variability is considered same as
moderate variability Significant decelerations are defined as any
of the following: Variable decelerations lasting >60 sec and
>60 bpm below baseline. Variable decelerations lasting >60
sec andSlide 13 Assumptions/Clarifications Application of algorithm
may be initially delayed for up to 30 min while attempts are made
to alleviate category II pattern with conservative therapeutic
interventions (e.g., correction of hypotension, position change,
amnioinfusion, tocolysis, reduction or discontinuation of oxytocin)
Once a category II FHR pattern is identified, FHR is evaluated and
algorithm applied q 30 min Any significant change in FHR parameters
should result in reapplication of algorithm Clark et al., (2013).
Intrapartum management of category II fetal heart rate tracings:
Towards standardization of care. Am J Obstet Gynecol;209(2):8997.
Presented at Washington State Hospital Association Safe Table
11/19/2013 Slide 14 Assumptions/Clarifications For category II FHR
patterns in which algorithm suggests cesarean birth is indicated,
birth should ideally be initiated within 30 min of decision Clark
et al., (2013). Intrapartum management of category II fetal heart
rate tracings: Towards standardization of care. Am J Obstet
Gynecol;209(2):8997. Presented at Washington State Hospital
Association Safe Table 11/19/2013 Slide 15
Assumptions/Clarifications If at any time tracing reverts to
category I status, or deteriorates for even a short time to
category III status, the algorithm no longer applies Clark et al.,
(2013). Intrapartum management of category II fetal heart rate
tracings: Towards standardization of care. Am J Obstet
Gynecol;209(2):8997. Presented at Washington State Hospital
Association Safe Table 11/19/2013 Slide 16 Moderate variability and
accelerations, thus excluding clinically significant acidemia Per
algorithm, if labor is progressing normally in active phase or
second stage, careful observation would be appropriate If the fetus
is remote from birth, expediting birth would be appropriate
Presented at Washington State Hospital Association Safe Table
11/19/2013 Slide 17 Moderate variability and accelerations, thus
excluding clinically significant acidemia Significant variable
decelerations suggest umbilical cord compression during
contraction, which could, over time, lead to significant acidemia
Per algorithm, if labor is progressing normally in active phase or
second stage, careful observation would be appropriate; if the
fetus is remote from birth, expediting birth would be appropriate
Presented at Washington State Hospital Association Safe Table
11/19/2013 Slide 18 Minimal to absent variability without
decelerations, despite regular contractions Medication effect has
been excluded clinically as part of the initial period of
intrauterine resuscitation attempts While the fetus may have
experienced prelabor central nervous system injury, absence of late
decelerations excludes ongoing hypoxia in a neurologically intact
fetus However, since such fetuses may not tolerate labor without
sudden deterioration and demise, cesarean birth would be
appropriate, per algorithm, if pattern persists for 1 hour
Presented at Washington State Hospital Association Safe Table
11/19/2013 Slide 19 Minimal to absent variability/late
decelerations occurring with >50% of contractions Per algorithm,
expedited birth is indicated regardless of labor progress Presented
at Washington State Hospital Association Safe Table 11/19/2013
Slide 20 Summary It is reasonable to initiate management of a
category II FHR pattern with an assessment of variability and
accelerations, thus allowing the clinician to immediately rule out
the presence of clinically significant metabolic acidemia For
nonacidemic fetuses, the focus then shifts to assessing the
likelihood of developing significant acidemia prior to birth Clark
et al., (2013). Intrapartum management of category II fetal heart
rate tracings: Towards standardization of care. Am J Obstet
Gynecol;209(2):8997. Presented at Washington State Hospital
Association Safe Table 11/19/2013
