From the Editor
Transfer to the hospital for women planning a home birth: A high-risk obstetrics problem
Do you have a written clinical guideline for pregnant women planning a home birth who are transferred to your hospital?
CASE 2 Continued
Over the next 2 hours, recurrent variable decelerations develop, and then sudden, prolonged fetal bradycardia leads to urgent cesarean delivery. At delivery, a uterine rupture is diagnosed and a fetal hand is observed protruding through a lower-uterine segment defect into the maternal abdomen.
TIP #7: Always consider the entire clinical scenario
In this case, the team caring for the patient was not aware that her previous pregnancy had ended with a low transverse cesarean delivery. How does this information change your interpretation of the clinical scenario? The importance of understanding the entire clinical context when interpreting individual characteristics of cardiotocography cannot be overstated. For example, the sudden onset of recurrent, significant variable decelerations is more concerning in the context of a prior cesarean delivery, and late decelerations are more concerning in a patient with placental abruption, fetal growth restriction, or poorly controlled maternal diabetes.
An estimated 70% of fetuses will have an indeterminate FHR pattern (category II) at some time during labor.9 To appropriately interpret the FHR tracing, it is crucial to know the a priori risk for fetal hypoxia and metabolic acidosis (the precursor of fetal injury) due to such identified clinical risk factors as placental insufficiency, medical comorbidities (hypertension, diabetes), or postdates gestational age.
It is well established that cardiotocography has a good negative predictive value for the absence of fetal metabolic acidosis when there is moderate variability and spontaneous or induced accelerations. When attempting to risk stratify the fetus with a category II (indeterminate) FHR tracing, consider these 3 important questions:
- What are the risk factors for this particular patient and her fetus?
- What is the state of the fetus right now, and when was the last time metabolic acidosis could be excluded reasonably (by the presence of moderate variability and accelerations)?
- What is the risk that the fetus will develop acidemia prior to delivery?
The presence of decelerations indicates interruption of oxygen delivery to the fetus, and recurrent decelerations may indicate an evolving process of accumulated oxygen deprivation, hypoxia, and eventually, metabolic acidosis. Most authorities agree that, for the fetus with a previously normal FHR tracing, the onset of significant, recurrent decelerations with slowly cumulative oxygen deficit can lead to fetal acidemia over the course of approximately 1 hour.10 Of course, acidosis also can occur much more quickly with acute events, such as placental abruption or uterine rupture. In deciding whether or not to intervene based on an FHR tracing, the clinician must take into account the clinical context to determine if delivery is likely to occur before significant acidemia develops.
Challenge: Lack of situational awareness, failure to address nursing concerns, reluctance to initiate the chain of command
CASE 3 Spontaneous labor in a second pregnancy
A 28-year-old woman (G2P1) at 40 weeks' gestation presents in spontaneous labor. She has a history of a previous uncomplicated vaginal delivery. After 6 hours she reaches complete dilation with the fetus at −1 station and begins pushing. After 60 minutes, the patient has only progressed to +1 station. She is contracting every 1 to 2 minutes with recurrent variable decelerations (FIGURE 4).
| FIGURE 4 FHR tracing shows time points for initiation and continuation of pushing | ||
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This tracing, from the patient described in Case 3, documents contraction frequency every 1-2 minutes for more than 60 minutes while the patient continues to push. The fetal heart rate demonstrates repetitive moderate variable decelerations with every push. | ||
TIP #6: Maintain situational awareness
A state of situational awareness exists when caregivers have a clear understanding of all of the factors at play in a clinical situation.11 This can be lost when caregivers focus too intensely on one aspect of care. It often happens when the patient is pushing in the second stage and the provider, focused on the progress of fetal descent, loses track of the amount of time that has passed without reassuring features (such as variability and induced or spontaneous accelerations) in the FHR tracing. The nurse, seeing the physician at the bedside, presumes he or she is aware of the tracing and is thus reluctant to point out the concerning features for fear of appearing insubordinate.
Situational awareness also may be lost at the time of patient hand off between providers wherein critical information, such as a history of previous cesarean delivery, is not communicated to the next care team. When receiving an intrapartum patient hand off, providers must have heightened vigilance to ensure they quickly reach situational awareness and are cognizant of the entire clinical context. Maintaining an environment in which all members of the care team, regardless of their training level, are encouraged to voice their concerns is another way to promote ongoing situational awareness.
